{"id":332,"date":"2023-04-18T02:16:13","date_gmt":"2023-04-18T09:16:13","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/?p=332"},"modified":"2023-05-10T13:40:02","modified_gmt":"2023-05-10T20:40:02","slug":"async-await%e5%9c%a8-c%e8%af%ad%e8%a8%80%e4%b8%ad%e6%98%af%e5%a6%82%e4%bd%95%e5%b7%a5%e4%bd%9c%e7%9a%84","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/async-await%e5%9c%a8-c%e8%af%ad%e8%a8%80%e4%b8%ad%e6%98%af%e5%a6%82%e4%bd%95%e5%b7%a5%e4%bd%9c%e7%9a%84\/","title":{"rendered":"Async\/Await\u5728 C#\u8bed\u8a00\u4e2d\u662f\u5982\u4f55\u5de5\u4f5c\u7684"},"content":{"rendered":"

\u672c\u6587\u7ffb\u8bd1\u4e8eStephen Toub<\/strong><\/i><\/span>\u7684\u8fd9\u7bc7\u82f1\u6587\u6587\u7ae0\uff1aHow Async\/Await Really Works in C# – .NET Blog (microsoft.com)<\/a><\/strong><\/i><\/span><\/p>\n

\u51e0\u5468\u524d\uff0c.NET Blog<\/a>\u520a\u767b\u4e86\u4e00\u7bc7\u6587\u7ae0\u00a0\u4ec0\u4e48\u662f .NET\uff0c\u4e3a\u4ec0\u4e48\u8981\u9009\u62e9\u5b83\uff1f<\/a>\u3002\u5b83\u63d0\u4f9b\u4e86\u5bf9\u5e73\u53f0\u7684\u9ad8\u5c42\u6b21\u6982\u8ff0\uff0c\u603b\u7ed3\u4e86\u5404\u79cd\u7ec4\u4ef6\u548c\u8bbe\u8ba1\u51b3\u7b56\uff0c\u5e76\u627f\u8bfa\u5bf9\u6240\u6d89\u53ca\u7684\u9886\u57df\u53d1\u8868\u66f4\u6df1\u5165\u7684\u6587\u7ae0\u3002\u8fd9\u662f\u7b2c\u4e00\u7bc7\u8fd9\u6837\u7684\u540e\u7eed\u6587\u7ae0\uff0c\u6df1\u5165\u63a2\u8ba8\u4e86C#\u548c.NET\u4e2dasync\/await\u7684\u5386\u53f2\u3001\u80cc\u540e\u7684\u8bbe\u8ba1\u51b3\u7b56\u548c\u5b9e\u73b0\u7ec6\u8282\u3002<\/p>\n

\u5bf9async\/await\u7684\u652f\u6301\u5df2\u7ecf\u5b58\u5728\u4e86\u5341\u5e74\u4e4b\u4e45\u3002\u5728\u8fd9\u6bb5\u65f6\u95f4\u91cc\uff0c\u5b83\u6539\u53d8\u4e86\u4e3a.NET\u7f16\u5199\u53ef\u6269\u5c55\u4ee3\u7801\u7684\u65b9\u5f0f\uff0c\u800c\u5728\u4e0d\u4e86\u89e3\u5176\u5e95\u5c42\u903b\u8f91\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u8be5\u529f\u80fd\u662f\u53ef\u884c\u7684\uff0c\u4e5f\u662f\u975e\u5e38\u5e38\u89c1\u7684\u3002\u4f60\u53ef\u4ee5\u4ece\u4e00\u4e2a\u50cf\u4e0b\u9762\u8fd9\u6837\u7684\u540c\u6b65\u65b9\u6cd5\u5f00\u59cb\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f\u201c\u540c\u6b65\u7684\u201d\uff0c\u56e0\u4e3a\u8c03\u7528\u8005\u5c06\u65e0\u6cd5\u505a\u5176\u4ed6\u4efb\u4f55\u4e8b\u60c5\uff0c\u76f4\u5230\u6574\u4e2a\u64cd\u4f5c\u5b8c\u6210\u5e76\u5c06\u63a7\u5236\u6743\u8fd4\u56de\u7ed9\u8c03\u7528\u8005):<\/p>\n

\/\/ Synchronously copy all data from source to destination.\r\npublic void CopyStreamToStream(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = source.Read(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        destination.Write(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
\u7136\u540e\u6dfb\u52a0\u51e0\u4e2a\u5173\u952e\u5b57\uff0c\u66f4\u6539\u51e0\u4e2a\u65b9\u6cd5\u540d\u79f0\uff0c\u6700\u7ec8\u5f97\u5230\u4ee5\u4e0b\u5f02\u6b65\u65b9\u6cd5\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f “\u5f02\u6b65 “\u7684\uff0c\u56e0\u4e3a\u63a7\u5236\u6743\u4f1a\u5f88\u5feb\u8fd4\u56de\u7ed9\u5b83\u7684\u8c03\u7528\u8005\uff0c\u800c\u4e14\u53ef\u80fd\u5728\u4e0e\u6574\u4e2a\u64cd\u4f5c\u76f8\u5173\u7684\u5de5\u4f5c\u5b8c\u6210\u4e4b\u524d\uff09\uff1a<\/p>\n
\/\/ Asynchronously copy all data from source to destination.\r\npublic async Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = await source.ReadAsync(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        await destination.WriteAsync(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
\u8bed\u6cd5\u4e0a\u51e0\u4e4e\u76f8\u540c\uff0c\u4ecd\u7136\u80fd\u591f\u5229\u7528\u6240\u6709\u76f8\u540c\u7684\u63a7\u5236\u6d41\u7ed3\u6784\uff0c\u4f46\u73b0\u5728\u662f\u975e\u963b\u585e\u6027\u7684\uff0c\u5177\u6709\u660e\u663e\u4e0d\u540c\u7684\u5e95\u5c42\u6267\u884c\u6a21\u578b\uff0c\u800c\u4e14\u6240\u6709\u7e41\u91cd\u7684\u5de5\u4f5c\u90fd\u7531C#\u7f16\u8bd1\u5668\u548c\u6838\u5fc3\u5e93\u4e3a\u4f60\u5b8c\u6210\u3002<\/p>\n
 <\/p>\n
\u867d\u7136\u5728\u4e0d\u77e5\u9053\u5e95\u5c42\u903b\u8f91\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u8fd9\u79cd\u652f\u6301\u662f\u5f88\u5e38\u89c1\u7684\uff0c\u4f46\u6211\u575a\u4fe1\uff0c\u4e86\u89e3\u67d0\u4e9b\u4e1c\u897f\u7684\u5b9e\u9645\u5de5\u4f5c\u539f\u7406\u6709\u52a9\u4e8e\u4f60\u66f4\u597d\u5730\u4f7f\u7528\u5b83\u3002\u7279\u522b\u662f\u5bf9\u4e8easync\/await\u6765\u8bf4\uff0c\u5f53\u4f60\u60f3\u770b\u6e05\u8868\u9762\u4e4b\u4e0b\u7684\u4e1c\u897f\u65f6\uff0c\u4e86\u89e3\u5176\u4e2d\u7684\u673a\u5236\u7279\u522b\u6709\u5e2e\u52a9\uff0c\u6bd4\u5982\u5f53\u4f60\u8bd5\u56fe\u8c03\u8bd5\u51fa\u9519\u7684\u4e1c\u897f\u6216\u63d0\u9ad8\u6b63\u5e38\u8fd0\u884c\u7684\u4ee3\u7801\u7684\u6027\u80fd\u65f6\u3002\u90a3\u4e48\uff0c\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u4eec\u5c06\u6df1\u5165\u63a2\u8ba8await\u5728\u8bed\u8a00\u3001\u7f16\u8bd1\u5668\u548c\u5e93\u7ea7\u522b\u7684\u5de5\u4f5c\u539f\u7406\uff0c\u4ee5\u4fbf\u4f60\u53ef\u4ee5\u5145\u5206\u5229\u7528\u8fd9\u4e9b\u6709\u4ef7\u503c\u7684\u529f\u80fd\u3002<\/p>\n
\u4e0d\u8fc7\uff0c\u8981\u505a\u5230\u8fd9\u4e00\u70b9\uff0c\u6211\u4eec\u9700\u8981\u8ffd\u6eaf\u5230async\/await\u4e4b\u524d\uff0c\u4ee5\u4e86\u89e3\u5728\u6ca1\u6709\u5b83\u7684\u60c5\u51b5\u4e0b\u6700\u5148\u8fdb\u7684\u5f02\u6b65\u4ee3\u7801\u662f\u4ec0\u4e48\u6837\u5b50\u7684\u3002\u53cb\u60c5\u63d0\u793a\uff0c\u5b83\u5e76\u4e0d\u6f02\u4eae\u3002<\/p>\n
\u4e00\u5f00\u59cb<\/strong>…<\/strong><\/p>\n
\u65e9\u5728.NET Framework 1.0\u4e2d\uff0c\u5c31\u6709\u5f02\u6b65\u7f16\u7a0b\u6a21\u578b\u6a21\u5f0f\uff0c\u53c8\u79f0APM\u6a21\u5f0f\u3001Begin\/End\u6a21\u5f0f\u3001IAsyncResult\u6a21\u5f0f\u3002\u5728\u9ad8\u5c42\u6b21\u4e0a\uff0c\u8be5\u6a21\u5f0f\u5f88\u7b80\u5355\u3002\u5bf9\u4e8e\u540c\u6b65\u64cd\u4f5cDoStuff\uff1a<\/p>\n
class Handler\r\n{\r\n    public int DoStuff(string arg);\r\n}<\/code><\/pre>\n
\u4f5c\u4e3a\u6a21\u5f0f\u7684\u4e00\u90e8\u5206\uff0c\u5c06\u6709\u4e24\u4e2a\u76f8\u5e94\u7684\u65b9\u6cd5\uff1aBeginDoStuff \u65b9\u6cd5\u548c EndDoStuff \u65b9\u6cd5\uff1a<\/p>\n
class Handler\r\n{\r\n    public int DoStuff(string arg);\r\n\r\n    public IAsyncResult BeginDoStuff(string arg, AsyncCallback? callback, object? state);\r\n    public int EndDoStuff(IAsyncResult asyncResult);\r\n}<\/code><\/pre>\n
BeginDoStuff\u4f1a\u50cfDoStuff\u4e00\u6837\u63a5\u53d7\u6240\u6709\u76f8\u540c\u7684\u53c2\u6570\uff0c\u4f46\u9664\u6b64\u4e4b\u5916\uff0c\u5b83\u8fd8\u4f1a\u63a5\u53d7AsyncCallback<\/a>\u59d4\u6258\u548c\u4e00\u4e2a\u4e0d\u900f\u660e\u7684\u72b6\u6001\u5bf9\u8c61\uff0c\u5176\u4e2d\u4e00\u4e2a\u6216\u4e24\u4e2a\u90fd\u53ef\u4ee5\u4e3anull\u3002Begin\u65b9\u6cd5\u8d1f\u8d23\u521d\u59cb\u5316\u5f02\u6b65\u64cd\u4f5c\uff0c\u5982\u679c\u63d0\u4f9b\u4e86\u56de\u8c03(\u901a\u5e38\u79f0\u4e3a\u521d\u59cb\u64cd\u4f5c\u7684\u201c\u5ef6\u7eed\u201d)\uff0c\u5b83\u8fd8\u8d1f\u8d23\u786e\u4fdd\u5728\u5f02\u6b65\u64cd\u4f5c\u5b8c\u6210\u65f6\u8c03\u7528\u56de\u8c03\u3002Begin\u65b9\u6cd5\u8fd8\u5c06\u6784\u9020\u4e00\u4e2a\u5b9e\u73b0\u4e86IAsyncResult<\/a>\u7684\u7c7b\u578b\u5b9e\u4f8b\uff0c\u4f7f\u7528\u53ef\u9009\u72b6\u6001\u586b\u5145IAsyncResult\u7684AsyncState\u5c5e\u6027:<\/p>\n
namespace System\r\n{\r\n    public interface IAsyncResult\r\n    {\r\n        object? AsyncState { get; }\r\n        WaitHandle AsyncWaitHandle { get; }\r\n        bool IsCompleted { get; }\r\n        bool CompletedSynchronously { get; }\r\n    }\r\n\r\n    public delegate void AsyncCallback(IAsyncResult ar);\r\n}<\/code><\/pre>\n
\u7136\u540e\uff0c\u8fd9\u4e2aIAsyncResult\u5b9e\u4f8b\u5c06\u4eceBegin\u65b9\u6cd5\u8fd4\u56de\uff0c\u5e76\u5728\u6700\u7ec8\u8c03\u7528AsyncCallback\u65f6\u4f20\u9012\u7ed9\u5b83\u3002\u5f53\u51c6\u5907\u4f7f\u7528\u64cd\u4f5c\u7684\u7ed3\u679c\u65f6\uff0c\u8c03\u7528\u8005\u5c06\u628aIAsyncResult\u5b9e\u4f8b\u4f20\u9012\u7ed9End\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u8d1f\u8d23\u786e\u4fdd\u64cd\u4f5c\u5df2\u5b8c\u6210(\u5982\u679c\u6ca1\u6709\u5b8c\u6210\uff0c\u5219\u901a\u8fc7\u963b\u585e\u540c\u6b65\u7b49\u5f85\u64cd\u4f5c\u5b8c\u6210)\uff0c\u7136\u540e\u8fd4\u56de\u64cd\u4f5c\u7684\u4efb\u4f55\u7ed3\u679c\uff0c\u5305\u62ec\u4f20\u64ad\u53ef\u80fd\u53d1\u751f\u7684\u4efb\u4f55\u9519\u8bef\/\u5f02\u5e38\u3002\u56e0\u6b64\uff0c\u4e0d\u7528\u50cf\u4e0b\u9762\u8fd9\u6837\u5199\u4ee3\u7801\u6765\u540c\u6b65\u6267\u884c\u64cd\u4f5c:<\/p>\n
try\r\n{\r\n    int i = handler.DoStuff(arg); \r\n    Use(i);\r\n}\r\ncatch (Exception e)\r\n{\r\n    ... \/\/ handle exceptions from DoStuff and Use\r\n}\r\n<\/code><\/pre>\n
\u53ef\u4ee5\u6309\u4ee5\u4e0b\u65b9\u5f0f\u4f7f\u7528 Begin\/End \u65b9\u6cd5\u5f02\u6b65\u6267\u884c\u76f8\u540c\u7684\u64cd\u4f5c\uff1a<\/p>\n
try\r\n{\r\n    handler.BeginDoStuff(arg, iar =>\r\n    {\r\n        try\r\n        {\r\n            Handler handler = (Handler)iar.AsyncState!;\r\n            int i = handler.EndDoStuff(iar);\r\n            Use(i);\r\n        }\r\n        catch (Exception e2)\r\n        {\r\n            ... \/\/ handle exceptions from EndDoStuff and Use\r\n        }\r\n    }, handler);\r\n}\r\ncatch (Exception e)\r\n{\r\n    ... \/\/ handle exceptions thrown from the synchronous call to BeginDoStuff\r\n}<\/code><\/pre>\n
\u5bf9\u4e8e\u5728\u4efb\u4f55\u8bed\u8a00\u4e2d\u5904\u7406\u8fc7\u57fa\u4e8e\u56de\u8c03\u7684API\u7684\u4eba\u6765\u8bf4\uff0c\u8fd9\u5e94\u8be5\u611f\u89c9\u5f88\u719f\u6089\u3002<\/p>\n
\u7136\u800c\uff0c\u4e8b\u60c5\u4ece\u6b64\u53d8\u5f97\u66f4\u52a0\u590d\u6742\u3002\u4f8b\u5982\uff0c\u6709\u4e00\u4e2a “stack dives”\u7684\u95ee\u9898\u3002stack dives\u662f\u6307\u4ee3\u7801\u53cd\u590d\u8c03\u7528\uff0c\u5728\u5806\u6808\u4e2d\u8d8a\u9677\u8d8a\u6df1\uff0c\u4ee5\u81f3\u4e8e\u53ef\u80fd\u51fa\u73b0\u5806\u6808\u6ea2\u51fa\u3002\u5982\u679c\u64cd\u4f5c\u540c\u6b65\u5b8c\u6210\uff0cBegin\u65b9\u6cd5\u88ab\u5141\u8bb8\u540c\u6b65\u8c03\u7528\u56de\u8c03\uff0c\u8fd9\u610f\u5473\u7740\u5bf9Begin\u7684\u8c03\u7528\u672c\u8eab\u53ef\u80fd\u76f4\u63a5\u8c03\u7528\u56de\u8c03\u3002\u540c\u6b65\u5b8c\u6210\u7684 “\u5f02\u6b65 “\u64cd\u4f5c\u5b9e\u9645\u4e0a\u662f\u5f88\u5e38\u89c1\u7684\uff1b\u5b83\u4eec\u4e0d\u662f “\u5f02\u6b65”\uff0c\u56e0\u4e3a\u5b83\u4eec\u88ab\u4fdd\u8bc1\u5f02\u6b65\u5b8c\u6210\uff0c\u800c\u53ea\u662f\u88ab\u5141\u8bb8\u8fd9\u6837\u505a\u3002\u4f8b\u5982\uff0c\u8003\u8651\u4ece\u4e00\u4e9b\u7f51\u7edc\u5316\u7684\u64cd\u4f5c\u4e2d\u8fdb\u884c\u5f02\u6b65\u8bfb\u53d6\uff0c\u6bd4\u5982\u4ece\u5957\u63a5\u5b57\u4e2d\u63a5\u6536\u3002\u5982\u679c\u4f60\u5bf9\u6bcf\u4e2a\u5355\u72ec\u7684\u64cd\u4f5c\u53ea\u9700\u8981\u5c11\u91cf\u7684\u6570\u636e\uff0c\u6bd4\u5982\u4ece\u4e00\u4e2a\u54cd\u5e94\u4e2d\u8bfb\u53d6\u4e00\u4e9b\u6807\u5934\u6570\u636e\uff0c\u5219\u53ef\u4ee5\u5728\u9002\u5f53\u7684\u4f4d\u7f6e\u8bbe\u7f6e\u7f13\u51b2\u533a\uff0c\u4ee5\u907f\u514d\u5927\u91cf\u7cfb\u7edf\u8c03\u7528\u7684\u5f00\u9500\u3002\u4e0d\u662f\u7acb\u5373\u5bf9\u9700\u8981\u7684\u6570\u636e\u91cf\u8fdb\u884c\u5c0f\u7684\u8bfb\u53d6\uff0c\u800c\u662f\u5bf9\u7f13\u51b2\u533a\u6267\u884c\u66f4\u5927\u7684\u8bfb\u53d6\uff0c\u7136\u540e\u4ece\u7f13\u51b2\u533a\u4e2d\u4f7f\u7528\u6570\u636e\uff0c\u76f4\u5230\u7f13\u51b2\u533a\u8017\u5c3d\uff1b\u4e0d\u662f\u7acb\u5373\u5bf9\u9700\u8981\u7684\u6570\u636e\u91cf\u8fdb\u884c\u5c0f\u7684\u8bfb\u53d6\uff0c\u800c\u662f\u5bf9\u7f13\u51b2\u533a\u6267\u884c\u66f4\u5927\u7684\u8bfb\u53d6\uff0c\u7136\u540e\u4ece\u7f13\u51b2\u533a\u4e2d\u4f7f\u7528\u6570\u636e\uff0c\u76f4\u5230\u7f13\u51b2\u533a\u8017\u5c3d\uff1b<\/p>\n
\u8fd9\u662f\u4e00\u79cd\u771f\u5b9e\u7684\u53ef\u80fd\u6027\uff0c\u5f88\u5bb9\u6613\u518d\u73b0\u3002\u5728.NET Core\u4e0a\u8bd5\u8bd5\u8fd9\u4e2a\u7a0b\u5e8f\uff1a<\/p>\n
using System.Net;\r\nusing System.Net.Sockets;\r\n\r\nusing Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);\r\nlistener.Bind(new IPEndPoint(IPAddress.Loopback, 0));\r\nlistener.Listen();\r\n\r\nusing Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);\r\nclient.Connect(listener.LocalEndPoint!);\r\n\r\nusing Socket server = listener.Accept();\r\n_ = server.SendAsync(new byte[100_000]);\r\n\r\nvar mres = new ManualResetEventSlim();\r\nbyte[] buffer = new byte[1];\r\n\r\nvar stream = new NetworkStream(client);\r\n\r\nvoid ReadAgain()\r\n{\r\n    stream.BeginRead(buffer, 0, 1, iar =>\r\n    {\r\n        if (stream.EndRead(iar) != 0)\r\n        {\r\n            ReadAgain(); \/\/ uh oh!\r\n        }\r\n        else\r\n        {\r\n            mres.Set();\r\n        }\r\n    }, null);\r\n};\r\nReadAgain();\r\n\r\nmres.Wait();<\/code><\/pre>\n
\u5728\u8fd9\u91cc\uff0c\u6211\u8bbe\u7f6e\u4e86\u4e00\u4e2a\u76f8\u4e92\u8fde\u63a5\u7684\u7b80\u5355\u5ba2\u6237\u7aef\u5957\u63a5\u5b57\u548c\u670d\u52a1\u5668\u5957\u63a5\u5b57\u3002\u670d\u52a1\u5668\u5411\u5ba2\u6237\u7aef\u53d1\u9001100,000\u5b57\u8282\uff0c\u7136\u540e\u5ba2\u6237\u7aef\u7ee7\u7eed\u4f7f\u7528BeginRead\/EndRead\u6765\u201c\u5f02\u6b65\u201d\u5730\u6bcf\u6b21\u8bfb\u53d6\u4e00\u4e2a\u5b57\u8282(\u8fd9\u662f\u975e\u5e38\u4f4e\u6548\u7684\uff0c\u800c\u4e14\u53ea\u662f\u4ee5\u6559\u5b66\u7684\u540d\u4e49\u8fd9\u4e48\u505a)\u3002\u4f20\u7ed9BeginRead\u7684\u56de\u8c03\u51fd\u6570\u901a\u8fc7\u8c03\u7528EndRead\u6765\u5b8c\u6210\u8bfb\u53d6\uff0c\u7136\u540e\u5982\u679c\u5b83\u6210\u529f\u8bfb\u53d6\u4e86\u6240\u9700\u7684\u5b57\u8282(\u8fd9\u79cd\u60c5\u51b5\u4e0b\u8fd8\u6ca1\u6709\u5230\u8fbe\u6d41\u7684\u7ed3\u5c3e)\uff0c\u5b83\u4f1a\u901a\u8fc7\u9012\u5f52\u8c03\u7528ReadAgain\u5c40\u90e8\u51fd\u6570\u6765\u53d1\u51fa\u53e6\u4e00\u4e2aBeginRead\u3002\u7136\u800c\uff0c\u5728 .net Core\u4e2d\uff0c\u5957\u63a5\u5b57\u64cd\u4f5c\u6bd4\u5728 .net Framework\u4e0a\u5feb\u5f97\u591a\uff0c\u5e76\u4e14\u5982\u679c\u64cd\u4f5c\u7cfb\u7edf\u80fd\u591f\u6ee1\u8db3\u540c\u6b65\u64cd\u4f5c\uff0c\u5b83\u5c06\u540c\u6b65\u5b8c\u6210(\u6ce8\u610f\u5185\u6838\u672c\u8eab\u6709\u4e00\u4e2a\u7f13\u51b2\u533a\u7528\u4e8e\u6ee1\u8db3\u5957\u63a5\u5b57\u63a5\u6536\u64cd\u4f5c)\u3002\u56e0\u6b64\uff0c\u8fd9\u4e2a\u5806\u6808\u4f1a\u6ea2\u51fa\uff1a\"Image<\/a><\/p>\n
\u56e0\u6b64\uff0cAPM\u6a21\u578b\u4e2d\u5185\u7f6e\u4e86\u8865\u507f\u673a\u5236\u3002\u6709\u4e24\u79cd\u53ef\u80fd\u7684\u65b9\u6cd5\u53ef\u4ee5\u5f25\u8865\u8fd9\u4e00\u70b9:<\/p>\n
    \n
  1. \u4e0d\u8981\u5141\u8bb8AsyncCallback\u88ab\u540c\u6b65\u8c03\u7528\u3002\u5982\u679c\u4e00\u76f4\u5f02\u6b65\u8c03\u7528\u5b83\uff0c\u5373\u4f7f\u64cd\u4f5c\u4ee5\u540c\u6b65\u65b9\u5f0f\u5b8c\u6210\uff0c\u90a3\u4e48stack dives\u7684\u98ce\u9669\u4e5f\u4f1a\u6d88\u5931\u3002\u4f46\u662f\u6027\u80fd\u4e5f\u662f\u5982\u6b64\uff0c\u56e0\u4e3a\u540c\u6b65\u5b8c\u6210\u7684\u64cd\u4f5c(\u6216\u8005\u5feb\u5230\u65e0\u6cd5\u89c2\u5bdf\u5230\u5b83\u4eec\u7684\u533a\u522b)\u662f\u975e\u5e38\u5e38\u89c1\u7684\uff0c\u5f3a\u8feb\u6bcf\u4e2a\u64cd\u4f5c\u6392\u961f\u56de\u8c03\u4f1a\u589e\u52a0\u53ef\u6d4b\u91cf\u7684\u5f00\u9500\u3002<\/li>\n
  2. \u4f7f\u7528\u4e00\u79cd\u673a\u5236\uff0c\u5141\u8bb8\u8c03\u7528\u65b9\u800c\u4e0d\u662f\u56de\u8c03\u65b9\u5728\u64cd\u4f5c\u540c\u6b65\u5b8c\u6210\u65f6\u6267\u884c\u5ef6\u7eed\u5de5\u4f5c\u3002\u8fd9\u6837\uff0c\u60a8\u5c31\u53ef\u4ee5\u907f\u5f00\u989d\u5916\u7684\u65b9\u6cd5\u6846\u67b6\uff0c\u7ee7\u7eed\u6267\u884c\u540e\u7eed\u5de5\u4f5c\uff0c\u800c\u4e0d\u6df1\u5165\u5806\u6808\u3002<\/li>\n<\/ol>\n
    APM\u6a21\u5f0f\u4e0eoption(2)\u4e00\u8d77\u4f7f\u7528\u3002\u4e3a\u6b64\uff0cIAsyncResult\u63a5\u53e3\u516c\u5f00\u4e86\u4e24\u4e2a\u76f8\u5173\u4f46\u4e0d\u540c\u7684\u6210\u5458:IsCompleted\u548cCompletedSynchronously\u3002IsCompleted\u544a\u8bc9\u4f60\u64cd\u4f5c\u662f\u5426\u5df2\u7ecf\u5b8c\u6210:\u4f60\u53ef\u4ee5\u591a\u6b21\u68c0\u67e5\u5b83\uff0c\u6700\u7ec8\u5b83\u4f1a\u4ecefalse\u8f6c\u6362\u4e3atrue\uff0c\u7136\u540e\u4fdd\u6301\u4e0d\u53d8\u3002\u76f8\u6bd4\u4e4b\u4e0b\uff0cCompletedSynchronously\u6c38\u8fdc\u4e0d\u4f1a\u6539\u53d8(\u5982\u679c\u6539\u53d8\u4e86\uff0c\u90a3\u5c31\u662f\u4e00\u4e2a\u4ee4\u4eba\u8ba8\u538c\u7684bug);\u5b83\u7528\u4e8eBegin\u65b9\u6cd5\u7684\u8c03\u7528\u8005\u548cAsyncCallback\u4e4b\u95f4\u7684\u901a\u4fe1\uff0c\u4ed6\u4eec\u4e2d\u7684\u4e00\u4e2a\u8d1f\u8d23\u6267\u884c\u4efb\u4f55\u5ef6\u7eed\u5de5\u4f5c\u3002\u5982\u679cCompletedSynchronously\u4e3afalse\uff0c\u5219\u64cd\u4f5c\u662f\u5f02\u6b65\u5b8c\u6210\u7684\uff0c\u54cd\u5e94\u64cd\u4f5c\u5b8c\u6210\u7684\u4efb\u4f55\u540e\u7eed\u5de5\u4f5c\u90fd\u5e94\u8be5\u7559\u7ed9\u56de\u8c03;\u6bd5\u7adf\uff0c\u5982\u679c\u5de5\u4f5c\u6ca1\u6709\u540c\u6b65\u5b8c\u6210\uff0cBegin\u7684\u8c03\u7528\u65b9\u65e0\u6cd5\u771f\u6b63\u5904\u7406\u5b83\uff0c\u56e0\u4e3a\u8fd8\u4e0d\u77e5\u9053\u64cd\u4f5c\u5df2\u7ecf\u5b8c\u6210(\u5982\u679c\u8c03\u7528\u65b9\u53ea\u662f\u8c03\u7528End\uff0c\u5b83\u5c06\u963b\u585e\u76f4\u5230\u64cd\u4f5c\u5b8c\u6210)\u3002\u7136\u800c\uff0c\u5982\u679cCompletedSynchronously\u4e3a\u771f\uff0c\u5982\u679c\u56de\u8c03\u8981\u5904\u7406\u5ef6\u7eed\u5de5\u4f5c\uff0c\u90a3\u4e48\u5b83\u5c31\u6709stack dives\u7684\u98ce\u9669\uff0c\u56e0\u4e3a\u5b83\u5c06\u5728\u5806\u6808\u4e0a\u6267\u884c\u6bd4\u5f00\u59cb\u65f6\u66f4\u6df1\u7684\u5ef6\u7eed\u5de5\u4f5c\u3002\u56e0\u6b64\uff0c\u4efb\u4f55\u6d89\u53ca\u5230\u8fd9\u79cd\u5806\u6808\u6f5c\u6c34\u7684\u5b9e\u73b0\u90fd\u9700\u8981\u68c0\u67e5CompletedSynchronously\uff0c\u5e76\u8ba9Begin\u65b9\u6cd5\u7684\u8c03\u7528\u8005\u6267\u884c\u5ef6\u7eed\u5de5\u4f5c(\u5982\u679c\u5b83\u4e3a\u771f)\uff0c\u8fd9\u610f\u5473\u7740\u56de\u8c03\u4e0d\u9700\u8981\u6267\u884c\u5ef6\u7eed\u5de5\u4f5c\u3002\u8fd9\u4e5f\u662fCompletedSynchronously\u6c38\u8fdc\u4e0d\u80fd\u66f4\u6539\u7684\u539f\u56e0:\u8c03\u7528\u65b9\u548c\u56de\u8c03\u65b9\u9700\u8981\u770b\u5230\u76f8\u540c\u7684\u503c\uff0c\u4ee5\u786e\u4fdd\u4e0d\u7ba1\u7ade\u4e89\u6761\u4ef6\u5982\u4f55\uff0c\u5ef6\u7eed\u5de5\u4f5c\u53ea\u6267\u884c\u4e00\u6b21\u3002<\/p>\n
    \u5728\u6211\u4eec\u4e4b\u524d\u7684DoStuff\u793a\u4f8b\u4e2d\uff0c\u5c31\u4f1a\u5bfc\u81f4\u4ee3\u7801\u50cf\u8fd9\u6837:<\/p>\n
    try\r\n{\r\n    IAsyncResult ar = handler.BeginDoStuff(arg, iar =>\r\n    {\r\n        if (!iar.CompletedSynchronously)\r\n        {\r\n            try\r\n            {\r\n                Handler handler = (Handler)iar.AsyncState!;\r\n                int i = handler.EndDoStuff(iar);\r\n                Use(i);\r\n            }\r\n            catch (Exception e2)\r\n            {\r\n                ... \/\/ handle exceptions from EndDoStuff and Use\r\n            }\r\n        }\r\n    }, handler);\r\n    if (ar.CompletedSynchronously)\r\n    {\r\n        int i = handler.EndDoStuff(ar);\r\n        Use(i);\r\n    }\r\n}\r\ncatch (Exception e)\r\n{\r\n    ... \/\/ handle exceptions that emerge synchronously from BeginDoStuff and possibly EndDoStuff\/Use<\/code><\/pre>\n
    \u592a\u62d7\u53e3\u4e86\u3002\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u6211\u4eec\u53ea\u7814\u7a76\u4e86\u5982\u4f55\u4f7f\u7528\u8be5\u6a21\u5f0f\u2026\u2026\u8fd8\u6ca1\u6709\u7814\u7a76\u5982\u4f55\u5b9e\u73b0\u8be5\u6a21\u5f0f\u3002\u867d\u7136\u5927\u591a\u6570\u5f00\u53d1\u4eba\u5458\u4e0d\u9700\u8981\u5173\u5fc3\u53f6\u5b50\u64cd\u4f5c(\u4f8b\u5982\uff0c\u5b9e\u73b0\u4e0e\u64cd\u4f5c\u7cfb\u7edf\u4ea4\u4e92\u7684\u5b9e\u9645Socket.BeginReceive\/EndReceive\u65b9\u6cd5)\uff0c\u4f46\u5f88\u591a\u5f88\u591a\u5f00\u53d1\u4eba\u5458\u9700\u8981\u5173\u5fc3\u8fd9\u4e9b\u64cd\u4f5c\u7684\u7ec4\u5408(\u6267\u884c\u591a\u4e2a\u5f02\u6b65\u64cd\u4f5c\uff0c\u5f62\u6210\u4e00\u4e2a\u66f4\u5927\u7684\u64cd\u4f5c)\uff0c\u8fd9\u610f\u5473\u7740\u4e0d\u4ec5\u8981\u4f7f\u7528\u5176\u4ed6Begin\/End\u65b9\u6cd5\uff0c\u8fd8\u9700\u8981\u81ea\u5df1\u53bb\u5b9e\u73b0\u5b83\u4eec\uff0c\u4ee5\u4fbf\u4f60\u7684\u7ec4\u5408\u672c\u8eab\u53ef\u4ee5\u5728\u5176\u4ed6\u5730\u65b9\u4f7f\u7528\u3002\u4f60\u4f1a\u6ce8\u610f\u5230\uff0c\u5728\u6211\u4e4b\u524d\u7684DoStuff\u793a\u4f8b\u4e2d\u6ca1\u6709\u63a7\u5236\u6d41\u3002\u5982\u679c\u5f15\u5165\u591a\u79cd\u64cd\u4f5c\uff0c\u5c24\u5176\u662f\u50cf\u5faa\u73af\u8fd9\u6837\u7b80\u5355\u7684\u63a7\u5236\u6d41\uff0c\u7a81\u7136\u4e4b\u95f4\uff0c\u8fd9\u5c31\u50cf\u8fdb\u5165\u5230\u4e86\u90a3\u4e9b\u4eab\u53d7\u75db\u82e6\u7684\u4e13\u5bb6\u6216\u535a\u5ba2\u4f5c\u8005\u7684\u9886\u57df\u3002<\/p>\n
    \u4e3a\u4e86\u6df1\u5165\u7406\u89e3\u8fd9\u4e00\u70b9\uff0c\u6211\u4eec\u6765\u5b9e\u73b0\u4e00\u4e2a\u5b8c\u6574\u7684\u4f8b\u5b50\u3002\u5728\u8fd9\u7bc7\u6587\u7ae0\u7684\u5f00\u59cb\uff0c\u6211\u5c55\u793a\u4e86\u4e00\u4e2aCopyStreamToStream\u65b9\u6cd5\uff0c\u5b83\u5c06\u6240\u6709\u6570\u636e\u4ece\u4e00\u4e2a\u6d41\u590d\u5236\u5230\u53e6\u4e00\u4e2a\u6d41(\u4ee5Stream.CopyTo\u7684\u65b9\u5f0f\uff0c\u4f46\u662f\u4e3a\u4e86\u89e3\u91ca\uff0c\u5047\u8bbe\u5b83\u4e0d\u5b58\u5728):<\/p>\n
    public void CopyStreamToStream(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = source.Read(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        destination.Write(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
    \u7b80\u5355\u6765\u8bf4\uff1a\u6211\u4eec\u53cd\u590d\u7684\u4ece\u4e00\u4e2a\u6d41\u4e2d\u8bfb\u53d6\u6570\u636e\uff0c\u7136\u540e\u5c06\u4ea7\u751f\u7684\u6570\u636e\u5199\u5230\u53e6\u4e00\u4e2a\u6d41\u4e2d\uff0c\u4ece\u4e00\u4e2a\u6d41\u4e2d\u8bfb\u53d6\u5e76\u5199\u5230\u53e6\u4e00\u4e2a\u6d41\u4e2d\uff0c\u5982\u6b64\u53cd\u590d\uff0c\u76f4\u5230\u6211\u4eec\u6ca1\u6709\u66f4\u591a\u7684\u6570\u636e\u53ef\u4ee5\u8bfb\u53d6\u3002\u73b0\u5728\uff0c\u6211\u4eec\u5982\u4f55\u4f7f\u7528APM\u6a21\u5f0f\u5f02\u6b65\u5b9e\u73b0\u8fd9\u4e2a\u529f\u80fd\u5462\uff1f\u50cf\u8fd9\u6837\uff1a<\/p>\n
    public IAsyncResult BeginCopyStreamToStream(\r\n    Stream source, Stream destination,\r\n    AsyncCallback callback, object state)\r\n{\r\n    var ar = new MyAsyncResult(state);\r\n    var buffer = new byte[0x1000];\r\n\r\n    Action<IAsyncResult?> readWriteLoop = null!;\r\n    readWriteLoop = iar =>\r\n    {\r\n        try\r\n        {\r\n            for (bool isRead = iar == null; ; isRead = !isRead)\r\n            {\r\n                if (isRead)\r\n                {\r\n                    iar = source.BeginRead(buffer, 0, buffer.Length, static readResult =>\r\n                    {\r\n                        if (!readResult.CompletedSynchronously)\r\n                        {\r\n                            ((Action<IAsyncResult?>)readResult.AsyncState!)(readResult);\r\n                        }\r\n                    }, readWriteLoop);\r\n\r\n                    if (!iar.CompletedSynchronously)\r\n                    {\r\n                        return;\r\n                    }\r\n                }\r\n                else\r\n                {\r\n                    int numRead = source.EndRead(iar!);\r\n                    if (numRead == 0)\r\n                    {\r\n                        ar.Complete(null);\r\n                        callback?.Invoke(ar);\r\n                        return;\r\n                    }\r\n\r\n                    iar = destination.BeginWrite(buffer, 0, numRead, writeResult =>\r\n                    {\r\n                        if (!writeResult.CompletedSynchronously)\r\n                        {\r\n                            try\r\n                            {\r\n                                destination.EndWrite(writeResult);\r\n                                readWriteLoop(null);\r\n                            }\r\n                            catch (Exception e2)\r\n                            {\r\n                                ar.Complete(e);\r\n                                callback?.Invoke(ar);\r\n                            }\r\n                        }\r\n                    }, null);\r\n\r\n                    if (!iar.CompletedSynchronously)\r\n                    {\r\n                        return;\r\n                    }\r\n\r\n                    destination.EndWrite(iar);\r\n                }\r\n            }\r\n        }\r\n        catch (Exception e)\r\n        {\r\n            ar.Complete(e);\r\n            callback?.Invoke(ar);\r\n        }\r\n    };\r\n\r\n    readWriteLoop(null);\r\n\r\n    return ar;\r\n}\r\n\r\npublic void EndCopyStreamToStream(IAsyncResult asyncResult)\r\n{\r\n    if (asyncResult is not MyAsyncResult ar)\r\n    {\r\n        throw new ArgumentException(null, nameof(asyncResult));\r\n    }\r\n\r\n    ar.Wait();\r\n}\r\n\r\nprivate sealed class MyAsyncResult : IAsyncResult\r\n{\r\n    private bool _completed;\r\n    private int _completedSynchronously;\r\n    private ManualResetEvent? _event;\r\n    private Exception? _error;\r\n\r\n    public MyAsyncResult(object? state) => AsyncState = state;\r\n\r\n    public object? AsyncState { get; }\r\n\r\n    public void Complete(Exception? error)\r\n    {\r\n        lock (this)\r\n        {\r\n            _completed = true;\r\n            _error = error;\r\n            _event?.Set();\r\n        }\r\n    }\r\n\r\n    public void Wait()\r\n    {\r\n        WaitHandle? h = null;\r\n        lock (this)\r\n        {\r\n            if (_completed)\r\n            {\r\n                if (_error is not null)\r\n                {\r\n                    throw _error;\r\n                }\r\n                return;\r\n            }\r\n\r\n            h = _event ??= new ManualResetEvent(false);\r\n        }\r\n\r\n        h.WaitOne();\r\n        if (_error is not null)\r\n        {\r\n            throw _error;\r\n        }\r\n    }\r\n\r\n    public WaitHandle AsyncWaitHandle\r\n    {\r\n        get\r\n        {\r\n            lock (this)\r\n            {\r\n                return _event ??= new ManualResetEvent(_completed);\r\n            }\r\n        }\r\n    }\r\n\r\n    public bool CompletedSynchronously\r\n    {\r\n        get\r\n        {\r\n            lock (this)\r\n            {\r\n                if (_completedSynchronously == 0)\r\n                {\r\n                    _completedSynchronously = _completed ? 1 : -1;\r\n                }\r\n\r\n                return _completedSynchronously == 1;\r\n            }\r\n        }\r\n    }\r\n\r\n    public bool IsCompleted\r\n    {\r\n        get\r\n        {\r\n            lock (this)\r\n            {\r\n                return _completed;\r\n            }\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
    \u51fa\u4eba\u610f\u6599\u3002\u800c\u4e14\uff0c\u5373\u4f7f\u6709\u90a3\u4e48\u591a\u5b98\u6837\u6587\u7ae0\uff0c\u5b83\u4ecd\u7136\u4e0d\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u5b9e\u73b0\u3002\u4f8b\u5982\uff0cIAsyncResult\u5b9e\u73b0\u662f\u9501\u5b9a\u6bcf\u4e2a\u64cd\u4f5c\uff0c\u800c\u4e0d\u662f\u5728\u53ef\u80fd\u7684\u60c5\u51b5\u4e0b\u4ee5\u66f4\u65e0\u9501\u7684\u65b9\u5f0f\u8fdb\u884c\u64cd\u4f5c\uff0c\u5f02\u5e38\u88ab\u539f\u59cb\u5b58\u50a8\uff0c\u800c\u4e0d\u662f\u4f5c\u4e3aExceptionDispatchInfo<\/a>\uff0c\u53ef\u4ee5\u5728\u4f20\u64ad\u65f6\u589e\u52a0\u5176\u8c03\u7528\u5806\u6808\uff0c\u6bcf\u4e2a\u5355\u72ec\u7684\u64cd\u4f5c\u6d89\u53ca\u5927\u91cf\u7684\u5206\u914d(\u4f8b\u5982\uff0c\u4e3a\u6bcf\u4e2aBeginWrite\u8c03\u7528\u5206\u914d\u4e00\u4e2a\u59d4\u6258)\uff0c\u7b49\u7b49\u3002\u73b0\u5728\uff0c\u60f3\u8c61\u4e00\u4e0b\uff0c\u4f60\u5fc5\u987b\u4e3a\u4f60\u60f3\u8981\u7f16\u5199\u7684\u6bcf\u4e2a\u65b9\u6cd5\u6267\u884c\u6240\u6709\u8fd9\u4e9b\u64cd\u4f5c\u3002\u6bcf\u6b21\u4f60\u60f3\u7f16\u5199\u4e00\u4e2a\u53ef\u590d\u7528\u7684\u65b9\u6cd5\u6765\u5904\u7406\u53e6\u4e00\u4e2a\u5f02\u6b65\u64cd\u4f5c\u65f6\uff0c\u90fd\u9700\u8981\u5b8c\u6210\u6240\u6709\u8fd9\u4e9b\u5de5\u4f5c\u3002\u5982\u679c\u4f60\u60f3\u7f16\u5199\u53ef\u590d\u7528\u7684\u7ec4\u5408\u5668\uff0c\u5e76\u4e14\u80fd\u591f\u9ad8\u6548\u5730\u5bf9\u591a\u4e2a\u79bb\u6563\u7684IAsyncResults\u8fdb\u884c\u64cd\u4f5c(\u60f3\u60f3Task.WhenAll)\uff0c\u8fd9\u53c8\u662f\u53e6\u4e00\u4e2a\u96be\u5ea6\u7ea7\u522b;\u6bcf\u4e2a\u64cd\u4f5c\u90fd\u5b9e\u73b0\u5e76\u516c\u5f00\u4e86\u5b83\u81ea\u5df1\u7684\u7279\u5b9a\u4e8e\u8be5\u64cd\u4f5c\u7684 API\uff0c\u8fd9\u610f\u5473\u7740\u6ca1\u6709\u4e00\u79cd\u901a\u7528\u8bed\u8a00\u53ef\u4ee5\u7c7b\u4f3c\u5730\u8ba8\u8bba\u5b83\u4eec(\u5c3d\u7ba1\u4e00\u4e9b\u5f00\u53d1\u4eba\u5458\u7f16\u5199\u4e86\u5e93\uff0c\u8bd5\u56fe\u51cf\u8f7b\u8d1f\u62c5\uff0c\u901a\u5e38\u901a\u8fc7\u53e6\u4e00\u5c42\u56de\u8c03\uff0c\u4f7fAPI\u80fd\u591f\u4e3aBegin\u65b9\u6cd5\u63d0\u4f9b\u9002\u5f53\u7684AsyncCallback)\u3002<\/p>\n
    \u6240\u6709\u8fd9\u4e9b\u590d\u6742\u60c5\u51b5\u610f\u5473\u7740\u5f88\u5c11\u6709\u4eba\u4f1a\u5c1d\u8bd5\u8fd9\u6837\u505a\uff0c\u800c\u5bf9\u4e8e\u90a3\u4e9b\u5c1d\u8bd5\u7684\u4eba\u6765\u8bf4\uff0cbug\u5f88\u7316\u7357\u3002\u516c\u5e73\u5730\u8bf4\uff0c\u8fd9\u5e76\u4e0d\u662f\u5bf9APM\u6a21\u5f0f\u7684\u6279\u8bc4\u3002\u76f8\u53cd\uff0c\u5b83\u4e00\u822c\u662f\u5bf9\u57fa\u4e8e\u56de\u8c03\u7684\u5f02\u6b65\u7684\u6279\u8bc4\u3002\u6211\u4eec\u90fd\u4e60\u60ef\u4e86\u73b0\u4ee3\u8bed\u8a00\u4e2d\u7684\u63a7\u5236\u6d41\u7ed3\u6784\u4e3a\u6211\u4eec\u63d0\u4f9b\u7684\u5f3a\u5927\u548c\u7b80\u5355\u6027\uff0c\u4e00\u65e6\u5f15\u5165\u4e86\u4efb\u4f55\u5408\u7406\u7684\u590d\u6742\u6027\uff0c\u800c\u57fa\u4e8e\u56de\u8c03\u7684\u65b9\u6cd5\u901a\u5e38\u4f1a\u4e0e\u8fd9\u79cd\u7ed3\u6784\u76f8\u51b2\u7a81\u3002\u5176\u4ed6\u4e3b\u6d41\u8bed\u8a00\u4e5f\u6ca1\u6709\u66f4\u597d\u7684\u66ff\u4ee3\u65b9\u6848\u3002<\/p>\n
    \u6211\u4eec\u9700\u8981\u4e00\u79cd\u66f4\u597d\u7684\u65b9\u6cd5\uff0c\u4e00\u79cd\u4eceAPM\u6a21\u5f0f\u4e2d\u5b66\u4e60\u7684\u65b9\u6cd5\uff0c\u878d\u5408\u5b83\u6b63\u786e\u7684\u4e1c\u897f\uff0c\u540c\u65f6\u907f\u514d\u5b83\u7684\u9677\u9631\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662f\uff0cAPM\u6a21\u5f0f\u53ea\u662f\u4e00\u79cd\u6a21\u5f0f; \u8fd0\u884c\u65f6\u95f4\u3001\u6838\u5fc3\u5e93\u548c\u7f16\u8bd1\u5668\u5728\u4f7f\u7528\u6216\u5b9e\u73b0\u8be5\u6a21\u5f0f\u65f6\u5e76\u6ca1\u6709\u63d0\u4f9b\u4efb\u4f55\u5e2e\u52a9\u3002<\/p>\n
    \u57fa\u4e8e\u4e8b\u4ef6\u7684\u5f02\u6b65\u6a21\u5f0f<\/strong><\/p>\n
    . net Framework 2.0\u5f15\u5165\u4e86\u4e00\u4e9bapi\uff0c\u5b9e\u73b0\u4e86\u5904\u7406\u5f02\u6b65\u64cd\u4f5c\u7684\u4e0d\u540c\u6a21\u5f0f\uff0c\u8fd9\u79cd\u6a21\u5f0f\u4e3b\u8981\u7528\u4e8e\u5728\u5ba2\u6237\u7aef\u5e94\u7528\u7a0b\u5e8f\u4e0a\u4e0b\u6587\u4e2d\u5904\u7406\u5f02\u6b65\u64cd\u4f5c\u3002\u8fd9\u79cd\u57fa\u4e8e\u4e8b\u4ef6\u7684\u5f02\u6b65\u6a21\u5f0f\u6216 EAP \u4e5f\u4f5c\u4e3a\u4e00\u5bf9\u6210\u5458\u51fa\u73b0(\u81f3\u5c11\uff0c\u53ef\u80fd\u66f4\u591a)\uff0c\u8fd9\u6b21\u662f\u4e00\u4e2a\u7528\u4e8e\u521d\u59cb\u5316\u5f02\u6b65\u64cd\u4f5c\u7684\u65b9\u6cd5\u548c\u4e00\u4e2a\u7528\u4e8e\u4fa6\u542c\u5176\u5b8c\u6210\u7684\u4e8b\u4ef6\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u4e4b\u524d\u7684DoStuff\u793a\u4f8b\u53ef\u80fd\u88ab\u516c\u5f00\u4e3a\u4e00\u7ec4\u6210\u5458\uff0c\u5982\u4e0b\u6240\u793a:<\/p>\n
    class Handler\r\n{\r\n    public int DoStuff(string arg);\r\n\r\n    public void DoStuffAsync(string arg, object? userToken);\r\n    public event DoStuffEventHandler? DoStuffCompleted;\r\n}\r\n\r\npublic delegate void DoStuffEventHandler(object sender, DoStuffEventArgs e);\r\n\r\npublic class DoStuffEventArgs : AsyncCompletedEventArgs\r\n{\r\n    public DoStuffEventArgs(int result, Exception? error, bool canceled, object? userToken) :\r\n        base(error, canceled, usertoken) => Result = result;\r\n\r\n    public int Result { get; }\r\n}<\/code><\/pre>\n
    \u4f60\u9700\u8981\u7528DoStuffCompleted\u4e8b\u4ef6\u6ce8\u518c\u4f60\u7684\u7ee7\u7eed\u5de5\u4f5c\uff0c\u7136\u540e\u8c03\u7528DoStuffAsync\u65b9\u6cd5;\u5b83\u5c06\u542f\u52a8\u8be5\u64cd\u4f5c\uff0c\u5e76\u4e14\u5728\u8be5\u64cd\u4f5c\u5b8c\u6210\u65f6\uff0c\u8c03\u7528\u8005\u5c06\u5f02\u6b65\u5730\u5f15\u53d1DoStuffCompleted\u4e8b\u4ef6\u3002\u7136\u540e\uff0c\u5904\u7406\u7a0b\u5e8f\u53ef\u4ee5\u7ee7\u7eed\u6267\u884c\u540e\u7eed\u5de5\u4f5c\uff0c\u53ef\u80fd\u4f1a\u9a8c\u8bc1\u6240\u63d0\u4f9b\u7684userToken\u4e0e\u5b83\u6240\u671f\u671b\u7684\u8fdb\u884c\u5339\u914d\uff0c\u4ece\u800c\u5141\u8bb8\u591a\u4e2a\u5904\u7406\u7a0b\u5e8f\u540c\u65f6\u8fde\u63a5\u5230\u4e8b\u4ef6\u3002<\/p>\n
    \u8fd9\u79cd\u6a21\u5f0f\u4f7f\u4e00\u4e9b\u7528\u4f8b\u53d8\u5f97\u66f4\u7b80\u5355\uff0c\u540c\u65f6\u4f7f\u5176\u4ed6\u7528\u4f8b\u53d8\u5f97\u66f4\u52a0\u56f0\u96be(\u8003\u8651\u5230\u524d\u9762\u7684APM CopyStreamToStream\u793a\u4f8b\uff0c\u8fd9\u8bf4\u660e\u4e86\u4e00\u4e9b\u95ee\u9898)\u3002\u5b83\u6ca1\u6709\u4ee5\u5e7f\u6cdb\u7684\u65b9\u5f0f\u63a8\u51fa\uff0c\u53ea\u662f\u5728\u4e00\u4e2a\u5355\u72ec\u7684 .NET Framework\u7248\u672c\u4e2d\u5306\u5306\u7684\u51fa\u73b0\u53c8\u6d88\u5931\u4e86\uff0c\u5c3d\u7ba1\u7559\u4e0b\u4e86\u5b83\u4f7f\u7528\u671f\u95f4\u6dfb\u52a0\u7684api\uff0c\u5982Ping.SendAsync\/Ping.PingCompleted:<\/p>\n
    public class Ping : Component\r\n{\r\n    public void SendAsync(string hostNameOrAddress, object? userToken);\r\n    public event PingCompletedEventHandler? PingCompleted;\r\n    ...\r\n}<\/code><\/pre>\n
    \u7136\u800c\uff0c\u5b83\u786e\u5b9e\u53d6\u5f97\u4e86\u4e00\u4e2aAPM\u6a21\u5f0f\u5b8c\u5168\u6ca1\u6709\u8003\u8651\u5230\u7684\u663e\u8457\u8fdb\u6b65\uff0c\u5e76\u4e14\u8fd9\u4e00\u70b9\u4e00\u76f4\u5ef6\u7eed\u5230\u6211\u4eec\u4eca\u5929\u6240\u63a5\u53d7\u7684\u6a21\u578b\u4e2d: SynchronizationContext<\/a>\u3002<\/p>\n
    \u5728. net Framework 2.0\u4e2d\u8fd8\u5f15\u5165\u4e86SynchronizationContext\uff0c\u4f5c\u4e3a\u901a\u7528\u8c03\u5ea6\u5668\u7684\u62bd\u8c61\u6982\u5ff5\u3002\u7279\u522b\u662f\uff0cSynchronizationContext\u6700\u5e38\u7528\u7684\u65b9\u6cd5\u662fPost\uff0c\u5b83\u5c06\u4e00\u4e2a\u5de5\u4f5c\u9879\u6392\u5230\u8be5\u4e0a\u4e0b\u6587\u6240\u4ee3\u8868\u7684\u4efb\u4f55\u8c03\u5ea6\u5668\u4e2d\u3002\u4f8b\u5982\uff0cSynchronizationContext\u7684\u57fa\u672c\u5b9e\u73b0\u53ea\u4ee3\u8868ThreadPool\uff0c\u56e0\u6b64\u00a0base implementation of\u00a0SynchronizationContext.Post<\/a>\u53ea\u662f\u59d4\u6258\u7ed9ThreadPool.QueueUserWorkItem<\/a>\uff0c\u7528\u4e8e\u8981\u6c42\u7ebf\u7a0b\u6c60\u8c03\u7528\u6240\u63d0\u4f9b\u7684\u56de\u8c03\uff0c\u5e76\u5728\u6c60\u4e2d\u7684\u4e00\u4e2a\u7ebf\u7a0b\u4e0a\u4f7f\u7528\u5173\u8054\u72b6\u6001\u3002\u7136\u800cSynchronizationContext\u7684\u57fa\u672c\u529f\u80fd\u4e0d\u4ec5\u4ec5\u662f\u652f\u6301\u4efb\u610f\u7684\u8c03\u5ea6\u5668\uff0c\u800c\u662f\u652f\u6301\u4ee5\u6839\u636e\u5404\u79cd\u5e94\u7528\u7a0b\u5e8f\u6a21\u578b\u7684\u9700\u8981\u5de5\u4f5c\u7684\u65b9\u5f0f\u8fdb\u884c\u8c03\u5ea6\u3002<\/p>\n
    \u8003\u8651\u5230\u50cfWindows Forms\u8fd9\u6837\u7684UI\u6846\u67b6\u3002\u4e0eWindows\u4e0a\u7684\u5927\u591a\u6570UI\u6846\u67b6\u4e00\u6837\uff0c\u63a7\u4ef6\u4e0e\u7279\u5b9a\u7684\u7ebf\u7a0b\u76f8\u5173\u8054\uff0c\u8be5\u7ebf\u7a0b\u8fd0\u884c\u4e00\u4e2a\u6d88\u606f\u6cf5\uff0c\u8be5\u6d88\u606f\u6cf5\u8fd0\u884c\u80fd\u591f\u4e0e\u8fd9\u4e9b\u63a7\u4ef6\u4ea4\u4e92\u7684\u5de5\u4f5c: \u53ea\u6709\u8be5\u7ebf\u7a0b\u5e94\u8be5\u5c1d\u8bd5\u64cd\u4f5c\u8fd9\u4e9b\u63a7\u4ef6\uff0c\u800c\u4efb\u4f55\u5176\u4ed6\u60f3\u8981\u4e0e\u63a7\u4ef6\u4ea4\u4e92\u7684\u7ebf\u7a0b\u90fd\u5e94\u8be5\u901a\u8fc7\u53d1\u9001\u6d88\u606f\u7531UI\u7ebf\u7a0b\u7684\u6cf5\u6d88\u8017\u6765\u5b8c\u6210\u64cd\u4f5c\u3002Windows\u7a97\u4f53\u4f7f\u7528ControlBeginInvoke\u7b49\u65b9\u6cd5\u4f7f\u8fd9\u53d8\u5f97\u5f88\u5bb9\u6613\uff0c\u5b83\u5c06\u63d0\u4f9b\u7684\u59d4\u6258\u548c\u53c2\u6570\u6392\u961f\uff0c\u7531\u4e0e\u8be5\u63a7\u4ef6\u76f8\u5173\u8054\u7684\u4efb\u4f55\u7ebf\u7a0b\u8fd0\u884c\u3002\u56e0\u6b64\uff0c\u4f60\u53ef\u4ee5\u8fd9\u6837\u7f16\u5199\u4ee3\u7801:<\/p>\n
    private void button1_Click(object sender, EventArgs e)\r\n{\r\n    ThreadPool.QueueUserWorkItem(_ =>\r\n    {\r\n        string message = ComputeMessage();\r\n        button1.BeginInvoke(() =>\r\n        {\r\n            button1.Text = message;\r\n        });\r\n    });\r\n}<\/code><\/pre>\n
    \u8fd9\u5c06\u5378\u8f7d\u5728ThreadPool\u7ebf\u7a0b\u4e0a\u5b8c\u6210\u7684ComputeMessage()\u5de5\u4f5c(\u4ee5\u4fbf\u5728\u5904\u7406UI\u7684\u8fc7\u7a0b\u4e2d\u4fdd\u6301UI\u7684\u54cd\u5e94\u6027)\uff0c\u7136\u540e\u5728\u5de5\u4f5c\u5b8c\u6210\u65f6\uff0c\u5c06\u59d4\u6258\u961f\u5217\u8fd4\u56de\u5230\u4e0ebutton1\u76f8\u5173\u7684\u7ebf\u7a0b\uff0c\u4ee5\u66f4\u65b0button1\u7684\u6807\u7b7e\u3002\u8fd9\u5f88\u7b80\u5355\uff0cWPF\u4e5f\u6709\u7c7b\u4f3c\u7684\u4e1c\u897f\uff0c\u53ea\u662f\u7528\u5b83\u7684Dispatcher\u7c7b\u578b:<\/p>\n
    private void button1_Click(object sender, RoutedEventArgs e)\r\n{\r\n    ThreadPool.QueueUserWorkItem(_ =>\r\n    {\r\n        string message = ComputeMessage();\r\n        button1.Dispatcher.InvokeAsync(() =>\r\n        {\r\n            button1.Content = message;\r\n        });\r\n    });\r\n}<\/code><\/pre>\n
    . net MAUI\u4e5f\u6709\u7c7b\u4f3c\u7684\u529f\u80fd\u3002\u4f46\u5982\u679c\u6211\u60f3\u628a\u8fd9\u4e2a\u903b\u8f91\u653e\u5230\u8f85\u52a9\u65b9\u6cd5\u4e2d\u5462?<\/p>\n
    \/\/ Call ComputeMessage and then invoke the update action to update controls.\r\ninternal static void ComputeMessageAndInvokeUpdate(Action<string> update) { ... }<\/code><\/pre>\n
    \u7136\u540e\u6211\u53ef\u4ee5\u8fd9\u6837\u4f7f\u7528\u5b83:<\/p>\n
    private void button1_Click(object sender, EventArgs e)\r\n{\r\n    ComputeMessageAndInvokeUpdate(message => button1.Text = message);\r\n}<\/code><\/pre>\n
    \u4f46\u662f\u5982\u4f55\u5b9e\u73b0ComputeMessageAndInvokeUpdate\uff0c\u4f7f\u5176\u80fd\u591f\u5728\u8fd9\u4e9b\u5e94\u7528\u7a0b\u5e8f\u4e2d\u5de5\u4f5c\u5462?\u662f\u5426\u9700\u8981\u786c\u7f16\u7801\u624d\u80fd\u4e86\u89e3\u6bcf\u4e2a\u53ef\u80fd\u7684UI\u6846\u67b6?\u8fd9\u5c31\u662fSynchronizationContext\u7684\u9b45\u529b\u6240\u5728\u3002\u6211\u4eec\u53ef\u4ee5\u8fd9\u6837\u5b9e\u73b0\u8fd9\u4e2a\u65b9\u6cd5\uff1a<\/p>\n
    internal static void ComputeMessageAndInvokeUpdate(Action<string> update)\r\n{\r\n    SynchronizationContext? sc = SynchronizationContext.Current;\r\n    ThreadPool.QueueUserWorkItem(_ =>\r\n    {\r\n        string message = ComputeMessage();\r\n        if (sc is not null)\r\n        {\r\n            sc.Post(_ => update(message), null);\r\n        }\r\n        else\r\n        {\r\n            update(message);\r\n        }\r\n    });\r\n}<\/code><\/pre>\n
    \u5b83\u4f7f\u7528SynchronizationContext\u4f5c\u4e3a\u4e00\u4e2a\u62bd\u8c61\uff0c\u76ee\u6807\u662f\u4efb\u4f55\u201c\u8c03\u5ea6\u5668\u201d\uff0c\u5e94\u8be5\u7528\u4e8e\u56de\u5230\u4e0eUI\u4ea4\u4e92\u7684\u5fc5\u8981\u73af\u5883\u3002\u7136\u540e\uff0c\u6bcf\u4e2a\u5e94\u7528\u7a0b\u5e8f\u6a21\u578b\u786e\u4fdd\u5b83\u4f5c\u4e3aSynchronizationContext.Current\u53d1\u5e03\u4e00\u4e2aSynchronizationContext-derived\u00a0\u7c7b\u578b\uff0c\u53bb\u505a “\u6b63\u786e\u7684\u4e8b\u60c5”\u3002\u4f8b\u5982\uff0cWindows Forms\u6709\u8fd9\u4e2a<\/a>\uff1a<\/p>\n
    public sealed class WindowsFormsSynchronizationContext : SynchronizationContext, IDisposable\r\n{\r\n    public override void Post(SendOrPostCallback d, object? state) =>\r\n        _controlToSendTo?.BeginInvoke(d, new object?[] { state });\r\n    ...\r\n}<\/code><\/pre>\n
    WPF\u6709\u8fd9\u4e2a<\/a>:<\/p>\n
    public sealed class DispatcherSynchronizationContext : SynchronizationContext\r\n{\r\n    public override void Post(SendOrPostCallback d, Object state) =>\r\n        _dispatcher.BeginInvoke(_priority, d, state);\r\n    ...\r\n}<\/code><\/pre>\n
    ASP.NET\u66fe\u7ecf\u6709\u4e00\u4e2a<\/a>\uff0c\u5b83\u5b9e\u9645\u4e0a\u5e76\u4e0d\u5173\u5fc3\u5de5\u4f5c\u5728\u4ec0\u4e48\u7ebf\u7a0b\u4e0a\u8fd0\u884c\uff0c\u800c\u662f\u5173\u5fc3\u7ed9\u5b9a\u7684\u8bf7\u6c42\u76f8\u5173\u7684\u5de5\u4f5c\u88ab\u5e8f\u5217\u5316\uff0c\u8fd9\u6837\u591a\u4e2a\u7ebf\u7a0b\u5c31\u4e0d\u4f1a\u5e76\u53d1\u5730\u8bbf\u95ee\u7ed9\u5b9a\u7684HttpContext\uff1a<\/p>\n
    internal sealed class AspNetSynchronizationContext : AspNetSynchronizationContextBase\r\n{\r\n    public override void Post(SendOrPostCallback callback, Object state) =>\r\n        _state.Helper.QueueAsynchronous(() => callback(state));\r\n    ...\r\n}<\/code><\/pre>\n
    \u8fd9\u4e5f\u4e0d\u9650\u4e8e\u8fd9\u4e9b\u4e3b\u8981\u7684\u5e94\u7528\u7a0b\u5e8f\u6a21\u578b\u3002\u4f8b\u5982\uff0cxunit<\/a>\u662f\u4e00\u4e2a\u6d41\u884c\u7684\u5355\u5143\u6d4b\u8bd5\u6846\u67b6\uff0c\u662f.NET\u6838\u5fc3\u5b58\u50a8\u5e93\u7528\u4e8e\u5355\u5143\u6d4b\u8bd5\u7684\u6846\u67b6\uff0c\u5b83\u4e5f\u91c7\u7528\u4e86\u591a\u4e2a\u81ea\u5b9a\u4e49\u7684SynchronizationContext\u3002\u4f8b\u5982\uff0c\u4f60\u53ef\u4ee5\u5141\u8bb8\u5e76\u884c\u8fd0\u884c\u6d4b\u8bd5\uff0c\u4f46\u9650\u5236\u5141\u8bb8\u5e76\u53d1\u8fd0\u884c\u7684\u6d4b\u8bd5\u6570\u91cf\u3002\u8fd9\u662f\u5982\u4f55\u5b9e\u73b0\u7684\u5462\uff1f\u901a\u8fc7SynchronizationContext\uff1a<\/p>\n
    public class MaxConcurrencySyncContext : SynchronizationContext, IDisposable\r\n{\r\n    public override void Post(SendOrPostCallback d, object? state)\r\n    {\r\n        var context = ExecutionContext.Capture();\r\n        workQueue.Enqueue((d, state, context));\r\n        workReady.Set();\r\n    }\r\n}<\/code><\/pre>\n
    MaxConcurrencySyncContext<\/a>\u7684Post\u65b9\u6cd5\u53ea\u662f\u5c06\u5de5\u4f5c\u6392\u5230\u81ea\u5df1\u7684\u5185\u90e8\u5de5\u4f5c\u961f\u5217\u4e2d\uff0c\u7136\u540e\u5728\u5b83\u81ea\u5df1\u7684\u5de5\u4f5c\u7ebf\u7a0b\u4e0a\u5904\u7406\u5b83\uff0c\u5b83\u6839\u636e\u6240\u9700\u7684\u6700\u5927\u5e76\u53d1\u6570\u6765\u63a7\u5236\u6709\u591a\u5c11\u5de5\u4f5c\u7ebf\u7a0b\u3002\u4f60\u4f1a\u660e\u767d\u7684\u3002<\/p>\n
    \u8fd9\u4e0e\u57fa\u4e8e\u4e8b\u4ef6\u7684\u5f02\u6b65\u6a21\u5f0f\u6709\u4ec0\u4e48\u8054\u7cfb\uff1fEAP\u548cSynchronizationContext\u662f\u540c\u65f6\u5f15\u5165\u7684\uff0c\u5f53\u5f02\u6b65\u64cd\u4f5c\u88ab\u542f\u52a8\u65f6\uff0cEAP\u89c4\u5b9a\u5b8c\u6210\u4e8b\u4ef6\u5e94\u8be5\u6392\u961f\u5230\u5f53\u524d\u4efb\u4f55SynchronizationContext\u4e2d\u3002\u4e3a\u4e86\u7a0d\u5fae\u7b80\u5316\u4e00\u4e0b(\u53ef\u80fd\u4e0d\u8db3\u4ee5\u4fdd\u8bc1\u989d\u5916\u7684\u590d\u6742\u6027)\uff0cSystem.ComponentModel\u4e2d\u4e5f\u5f15\u5165\u4e86\u4e00\u4e9b\u8f85\u52a9\u7c7b\u578b\uff0c\u5c24\u5176\u662fAsyncOperation\u548cAsyncOperationManager\u3002\u524d\u8005\u53ea\u662f\u4e00\u4e2a\u5143\u7ec4\uff0c\u5c01\u88c5\u4e86\u7528\u6237\u63d0\u4f9b\u7684\u72b6\u6001\u5bf9\u8c61\u548c\u6355\u83b7\u7684SynchronizationContext\uff0c\u800c\u540e\u8005\u53ea\u662f\u4f5c\u4e3a\u4e00\u4e2a\u7b80\u5355\u7684\u5de5\u5382\u6765\u6355\u83b7\u5e76\u521b\u5efaAsyncOperation\u5b9e\u4f8b\u3002\u7136\u540eEAP\u5b9e\u73b0\u5c06\u4f7f\u7528\u8fd9\u4e9b\uff0c\u4f8b\u5982Ping.SendAsync\u8c03\u7528AsyncOperationManager.CreateOperation<\/a>\u6765\u6355\u83b7SynchronizationContext\u3002\u5f53\u64cd\u4f5c\u5b8c\u6210\u65f6\uff0cAsyncOperation\u7684PostOperationCompleted<\/a>\u65b9\u6cd5\u5c06\u88ab\u8c03\u7528\uff0c\u4ee5\u8c03\u7528\u5b58\u50a8\u7684SynchronizationContext\u7684Post\u65b9\u6cd5\u3002<\/p>\n
     <\/p>\n
    SynchronizationContext\u8fd8\u63d0\u4f9b\u4e86\u4e00\u4e9b\u503c\u5f97\u4e00\u63d0\u7684\u5c0f\u529f\u80fd\uff0c\u56e0\u4e3a\u5b83\u4eec\u7a0d\u540e\u4f1a\u518d\u6b21\u51fa\u73b0\u3002\u7279\u522b\u662f\uff0c\u5b83\u516c\u5f00\u4e86OperationStarted\u548cOperationCompleted\u65b9\u6cd5\u3002\u8fd9\u4e9b\u865a\u51fd\u6570\u7684\u57fa\u672c\u5b9e\u73b0\u662f\u7a7a\u7684\uff0c\u4ec0\u4e48\u90fd\u4e0d\u505a\uff0c\u4f46\u6d3e\u751f\u5b9e\u73b0\u53ef\u80fd\u4f1a\u8986\u76d6\u5b83\u4eec\uff0c\u4ee5\u4e86\u89e3\u8fd0\u884c\u4e2d\u7684\u64cd\u4f5c\u3002\u8fd9\u610f\u5473\u7740EAP\u5b9e\u73b0\u4e5f\u4f1a\u5728\u6bcf\u4e2a\u64cd\u4f5c\u7684\u5f00\u59cb\u548c\u7ed3\u675f\u65f6\u8c03\u7528OperationStarted\/OperationCompleted\uff0c\u4ee5\u4fbf\u901a\u77e5\u4efb\u4f55\u5b58\u5728\u7684SynchronizationContext\uff0c\u5e76\u5141\u8bb8\u5b83\u8ddf\u8e2a\u5de5\u4f5c\u3002\u8fd9\u4e0eEAP\u6a21\u5f0f\u7279\u522b\u76f8\u5173\uff0c\u56e0\u4e3a\u53d1\u8d77\u5f02\u6b65\u64cd\u4f5c\u7684\u65b9\u6cd5\u662fvoid\u8fd4\u56de\u7684:\u60a8\u6ca1\u6709\u5f97\u5230\u4efb\u4f55\u8fd4\u56de\uff0c\u56e0\u6b64\u5141\u8bb8\u4f60\u5355\u72ec\u8ddf\u8e2a\u5de5\u4f5c\u3002\u6211\u4eec\u4f1a\u56de\u5230\u8fd9\u4e2a\u95ee\u9898\u4e0a\u3002<\/p>\n
     <\/p>\n
    \u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u6bd4APM\u6a21\u5f0f\u66f4\u597d\u7684\u4e1c\u897f\uff0c\u63a5\u4e0b\u6765\u51fa\u73b0\u7684EAP\u5f15\u5165\u4e86\u4e00\u4e9b\u65b0\u7684\u4e8b\u52a1\uff0c\u4f46\u5e76\u6ca1\u6709\u771f\u6b63\u89e3\u51b3\u6211\u4eec\u9762\u4e34\u7684\u6838\u5fc3\u95ee\u9898\u3002\u6211\u4eec\u4ecd\u7136\u9700\u8981\u66f4\u597d\u7684\u4e1c\u897f\u3002<\/p>\n
    \u8f93\u5165\u4efb\u52a1<\/strong><\/p>\n
    . net Framework 4.0\u5f15\u5165\u4e86System.Threading.Tasks.Task\u7c7b\u578b\u3002\u4ece\u672c\u8d28\u4e0a\u8bb2\uff0cTask\u53ea\u662f\u4e00\u4e2a\u6570\u636e\u7ed3\u6784\uff0c\u8868\u793a\u67d0\u4e9b\u5f02\u6b65\u64cd\u4f5c\u7684\u6700\u7ec8\u5b8c\u6210(\u5176\u4ed6\u6846\u67b6\u5c06\u7c7b\u4f3c\u7684\u7c7b\u578b\u79f0\u4e3a\u201cpromise\u201d\u6216\u201cfuture\u201d)\u3002\u521b\u5efaTask\u662f\u4e3a\u4e86\u8868\u793a\u67d0\u4e9b\u64cd\u4f5c\uff0c\u7136\u540e\u5f53\u5b83\u8868\u793a\u7684\u64cd\u4f5c\u903b\u8f91\u4e0a\u5b8c\u6210\u65f6\uff0c\u7ed3\u679c\u5b58\u50a8\u5230\u8be5Task\u4e2d\u3002\u5f88\u7b80\u5355\u3002\u4f46\u662fTask\u63d0\u4f9b\u7684\u5173\u952e\u7279\u6027\u4f7f\u5b83\u6bd4IAsyncResult\u66f4\u6709\u7528\uff0c\u5b83\u5728\u81ea\u5df1\u5185\u90e8\u5185\u7f6e\u4e86continuation\u7684\u6982\u5ff5\u3002\u8fd9\u4e00\u7279\u6027\u610f\u5473\u7740\u60a8\u53ef\u4ee5\u8bbf\u95ee\u4efb\u4f55Task\uff0c\u5e76\u5728\u5176\u5b8c\u6210\u65f6\u8bf7\u6c42\u5f02\u6b65\u901a\u77e5\uff0c\u7531\u4efb\u52a1\u672c\u8eab\u5904\u7406\u540c\u6b65\uff0c\u4ee5\u786e\u4fdd\u7ee7\u7eed\u88ab\u8c03\u7528\uff0c\u65e0\u8bba\u4efb\u52a1\u662f\u5426\u5df2\u7ecf\u5b8c\u6210\u3001\u5c1a\u672a\u5b8c\u6210\u3001\u8fd8\u662f\u4e0e\u901a\u77e5\u8bf7\u6c42\u540c\u65f6\u5b8c\u6210\u3002\u4e3a\u4ec0\u4e48\u4f1a\u6709\u5982\u6b64\u5927\u7684\u5f71\u54cd?\u5982\u679c\u4f60\u8fd8\u8bb0\u5f97\u6211\u4eec\u5bf9\u65e7APM\u6a21\u5f0f\u7684\u8ba8\u8bba\uff0c\u6709\u4e24\u4e2a\u4e3b\u8981\u95ee\u9898\u3002<\/p>\n
      \n
    1. \u4f60\u5fc5\u987b\u4e3a\u6bcf\u4e2a\u64cd\u4f5c\u5b9e\u73b0\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684IAsyncResult\u5b9e\u73b0:\u6ca1\u6709\u5185\u7f6e\u7684IAsyncResult\u5b9e\u73b0\uff0c\u4efb\u4f55\u4eba\u90fd\u53ef\u4ee5\u6839\u636e\u9700\u8981\u4f7f\u7528\u3002<\/li>\n
    2. \u5728Begin\u65b9\u6cd5\u88ab\u8c03\u7528\u4e4b\u524d\uff0c\u4f60\u5fc5\u987b\u77e5\u9053\u5f53\u5b83\u5b8c\u6210\u65f6\u8981\u505a\u4ec0\u4e48\u3002\u8fd9\u4f7f\u5f97\u5b9e\u73b0\u7ec4\u5408\u5668\u548c\u5176\u4ed6\u7528\u4e8e\u6d88\u8017\u548c\u7ec4\u5408\u4efb\u610f\u5f02\u6b65\u5b9e\u73b0\u7684\u901a\u7528\u4f8b\u7a0b\u6210\u4e3a\u4e00\u4e2a\u91cd\u5927\u6311\u6218\u3002<\/li>\n<\/ol>\n
      \u76f8\u6bd4\u4e4b\u4e0b\uff0c\u5728Task\u4e2d\uff0c\u8fd9\u79cd\u5171\u4eab\u8868\u793a\u65b9\u5f0f\u8ba9\u4f60\u5728\u542f\u52a8\u64cd\u4f5c\u540e\u7ee7\u7eed\u6267\u884c\u5f02\u6b65\u64cd\u4f5c\uff0c\u5e76\u5728\u542f\u52a8\u64cd\u4f5c\u540e\u63d0\u4f9bcontinuation\u2026\u2026\u4f60\u4e0d\u9700\u8981\u4e3a\u542f\u52a8\u64cd\u4f5c\u7684\u65b9\u6cd5\u63d0\u4f9bcontinuation\u3002\u6bcf\u4e2a\u8fdb\u884c\u5f02\u6b65\u64cd\u4f5c\u7684\u4eba\u90fd\u53ef\u4ee5\u751f\u6210\u4e00\u4e2aTask\uff0c\u6bcf\u4e2a\u4f7f\u7528\u5f02\u6b65\u64cd\u4f5c\u7684\u4eba\u90fd\u53ef\u4ee5\u4f7f\u7528\u4e00\u4e2aTask\uff0c\u5e76\u4e14\u4e0d\u9700\u8981\u4efb\u4f55\u81ea\u5b9a\u4e49\u64cd\u4f5c\u5c06\u4e24\u8005\u8fde\u63a5\u8d77\u6765:Task\u6210\u4e3a\u4f7f\u5f02\u6b65\u64cd\u4f5c\u7684\u751f\u4ea7\u8005\u548c\u6d88\u8d39\u8005\u4ea4\u8c08\u7684\u901a\u7528\u8bed\u8a00\u3002\u8fd9\u6539\u53d8\u4e86.net\u7684\u9762\u8c8c\u3002\u7a0d\u540e\u4f1a\u8be6\u7ec6\u4ecb\u7ecd\u2026\u2026<\/p>\n
       <\/p>\n
      \u73b0\u5728\uff0c\u8ba9\u6211\u4eec\u66f4\u597d\u5730\u7406\u89e3\u5b83\u7684\u5b9e\u9645\u542b\u4e49\u3002\u6211\u4eec\u5c06\u505a\u4e00\u4e9b\u6559\u5b66\u4e0a\u7684\u4e8b\u60c5\uff0c\u5e76\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u7248\u672c\uff0c\u800c\u4e0d\u662f\u6df1\u5165\u5230Task\u590d\u6742\u7684\u4ee3\u7801\u4e2d\u3002\u8fd9\u5e76\u4e0d\u662f\u4e00\u4e2a\u5f88\u597d\u7684\u5b9e\u73b0\uff0c\u53ea\u662f\u5728\u529f\u80fd\u4e0a\u8db3\u591f\u5b8c\u6574\uff0c\u8db3\u4ee5\u5e2e\u52a9\u7406\u89e3\u4ec0\u4e48\u662fTask\uff0c\u6700\u7ec8\uff0c\u5b83\u5b9e\u9645\u4e0a\u53ea\u662f\u4e00\u4e2a\u5904\u7406\u534f\u8c03\u8bbe\u7f6e\u548c\u63a5\u6536\u5b8c\u6210\u4fe1\u53f7\u7684\u6570\u636e\u7ed3\u6784\u3002\u6211\u4eec\u5148\u4ece\u51e0\u4e2a\u5b57\u6bb5\u5f00\u59cb:<\/p>\n
      class MyTask\r\n{\r\n    private bool _completed;\r\n    private Exception? _error;\r\n    private Action<MyTask>? _continuation;\r\n    private ExecutionContext? _ec;\r\n    ...\r\n}<\/code><\/pre>\n
      \u6211\u4eec\u9700\u8981\u4e00\u4e2a\u5b57\u6bb5\u6765\u77e5\u9053\u4efb\u52a1\u662f\u5426\u5b8c\u6210(_completed)\uff0c\u8fd8\u9700\u8981\u4e00\u4e2a\u5b57\u6bb5\u6765\u5b58\u50a8\u5bfc\u81f4\u4efb\u52a1\u5931\u8d25\u7684\u4efb\u4f55\u9519\u8bef(_error);\u5982\u679c\u6211\u4eec\u8fd8\u8981\u5b9e\u73b0\u4e00\u4e2a\u901a\u7528\u7684MyTask<TResult>\uff0c\u90a3\u4e48\u4e5f\u4f1a\u6709\u4e00\u4e2a\u79c1\u6709\u7684TResult _result\u5b57\u6bb5\uff0c\u7528\u4e8e\u5b58\u50a8\u64cd\u4f5c\u7684\u6210\u529f\u7ed3\u679c\u3002\u5230\u76ee\u524d\u4e3a\u6b62\uff0c\u8fd9\u770b\u8d77\u6765\u5f88\u50cf\u6211\u4eec\u4e4b\u524d\u81ea\u5b9a\u4e49\u7684IAsyncResult\u5b9e\u73b0(\u5f53\u7136\uff0c\u8fd9\u4e0d\u662f\u5de7\u5408)\u3002\u4f46\u662f\u73b0\u5728\u6700\u91cd\u8981\u7684\u90e8\u5206\uff0c\u662f _continuation\u5b57\u6bb5\u3002\u5728\u8fd9\u4e2a\u7b80\u5355\u7684\u5b9e\u73b0\u4e2d\uff0c\u6211\u4eec\u53ea\u652f\u6301\u4e00\u4e2acontinuation\uff0c\u4f46\u5bf9\u4e8e\u89e3\u91ca\u76ee\u7684\u6765\u8bf4\u8fd9\u5df2\u7ecf\u8db3\u591f\u4e86(\u771f\u6b63\u7684\u4efb\u52a1\u4f7f\u7528\u4e86\u4e00\u4e2a\u5bf9\u8c61<\/u>\u5b57\u6bb5<\/a>\uff0c\u8be5\u5b57\u6bb5\u53ef\u4ee5\u662f\u5355\u4e2acontinuation\u5bf9\u8c61\uff0c\u4e5f\u53ef\u4ee5\u662fcontinuation\u5bf9\u8c61\u7684List<>)\u3002\u8fd9\u662f\u4e00\u4e2a\u59d4\u6258\uff0c\u5c06\u5728\u4efb\u52a1\u5b8c\u6210\u65f6\u8c03\u7528\u3002<\/p>\n
      \u73b0\u5728\uff0c\u6709\u4e00\u4e9b\u8868\u9762\u7684\u4e1c\u897f\u3002\u5982\u524d\u6240\u8ff0\uff0c\u4e0e\u4ee5\u524d\u7684\u6a21\u578b\u76f8\u6bd4\uff0cTask\u7684\u4e00\u4e2a\u57fa\u672c\u8fdb\u6b65\u662f\u80fd\u591f\u5728\u64cd\u4f5c\u5f00\u59cb\u540e\u63d0\u4f9b\u5ef6\u7eed\u5de5\u4f5c\uff08\u56de\u8c03\uff09\u3002\u6211\u4eec\u9700\u8981\u4e00\u4e2a\u65b9\u6cd5\u6765\u505a\u5230\u8fd9\u4e00\u70b9\uff0c\u6240\u4ee5\u8ba9\u6211\u4eec\u6dfb\u52a0ContinueWith\uff1a<\/p>\n
      public void ContinueWith(Action<MyTask> action)\r\n{\r\n    lock (this)\r\n    {\r\n        if (_completed)\r\n        {\r\n            ThreadPool.QueueUserWorkItem(_ => action(this));\r\n        }\r\n        else if (_continuation is not null)\r\n        {\r\n            throw new InvalidOperationException(\"Unlike Task, this implementation only supports a single continuation.\");\r\n        }\r\n        else\r\n        {\r\n            _continuation = action;\r\n            _ec = ExecutionContext.Capture();\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
      \u5982\u679c\u4efb\u52a1\u5728ContinueWith\u88ab\u8c03\u7528\u65f6\u5df2\u7ecf\u88ab\u6807\u8bb0\u4e3a\u5b8c\u6210\uff0cContinueWith\u53ea\u662f\u6392\u961f\u6267\u884c\u59d4\u6258\u3002\u5426\u5219\uff0c\u8be5\u65b9\u6cd5\u5c06\u5b58\u50a8\u8be5\u59d4\u6258\uff0c\u4ee5\u4fbf\u5728\u4efb\u52a1\u5b8c\u6210\u65f6\u53ef\u4ee5\u6392\u961f\u7ee7\u7eed\u6267\u884c\uff08\u5b83\u8fd8\u5b58\u50a8\u4e86\u4e00\u4e2a\u53eb\u505aExecutionContext\u7684\u4e1c\u897f\uff0c\u7136\u540e\u5728\u4ee5\u540e\u8c03\u7528\u8be5\u59d4\u6258\u65f6\u4f7f\u7528\u5b83\uff0c\u4f46\u73b0\u5728\u4e0d\u8981\u62c5\u5fc3\u8fd9\u90e8\u5206……\u6211\u4eec\u4f1a\u8ba8\u8bba\u5b83\uff09\u3002\u5f88\u7b80\u5355\u3002<\/p>\n
       <\/p>\n
      \u7136\u540e\uff0c\u6211\u4eec\u9700\u8981\u80fd\u591f\u5c06MyTask\u6807\u8bb0\u4e3a\u5b8c\u6210\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u6240\u4ee3\u8868\u7684\u5f02\u6b65\u64cd\u4f5c\u5df2\u7ecf\u5b8c\u6210\u3002\u4e3a\u6b64\uff0c\u6211\u4eec\u5c06\u63d0\u4f9b\u4e24\u4e2a\u65b9\u6cd5\uff0c\u4e00\u4e2a\u7528\u4e8e\u6807\u8bb0\u5b8c\u6210(” SetResult “)\uff0c\u53e6\u4e00\u4e2a\u7528\u4e8e\u6807\u8bb0\u5b8c\u6210\u5e76\u8fd4\u56de\u9519\u8bef(” SetException “):<\/p>\n
      public void SetResult() => Complete(null);\r\n\r\npublic void SetException(Exception error) => Complete(error);\r\n\r\nprivate void Complete(Exception? error)\r\n{\r\n    lock (this)\r\n    {\r\n        if (_completed)\r\n        {\r\n            throw new InvalidOperationException(\"Already completed\");\r\n        }\r\n\r\n        _error = error;\r\n        _completed = true;\r\n\r\n        if (_continuation is not null)\r\n        {\r\n            ThreadPool.QueueUserWorkItem(_ =>\r\n            {\r\n                if (_ec is not null)\r\n                {\r\n                    ExecutionContext.Run(_ec, _ => _continuation(this), null);\r\n                }\r\n                else\r\n                {\r\n                    _continuation(this);\r\n                }\r\n            });\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
      \u6211\u4eec\u5b58\u50a8\u4efb\u4f55\u9519\u8bef\uff0c\u5c06\u4efb\u52a1\u6807\u8bb0\u4e3a\u5df2\u5b8c\u6210\uff0c\u7136\u540e\u5982\u679c\u4e4b\u524d\u5df2\u7ecf\u6ce8\u518c\u4e86continuation\uff0c\u5219\u5c06\u5176\u6392\u961f\u7b49\u5f85\u8c03\u7528\u3002<\/p>\n
       <\/p>\n
      \u6700\u540e\uff0c\u6211\u4eec\u9700\u8981\u4e00\u79cd\u65b9\u6cd5\u6765\u4f20\u64ad\u4efb\u52a1\u4e2d\u53ef\u80fd\u53d1\u751f\u7684\u4efb\u4f55\u5f02\u5e38(\u5e76\u4e14\uff0c\u5982\u679c\u8fd9\u662f\u4e00\u4e2a\u6cdb\u578bMyTask<T>\uff0c\u5219\u8fd4\u56de\u5176_result);\u4e3a\u4e86\u65b9\u4fbf\u67d0\u4e9b\u60c5\u51b5\uff0c\u6211\u4eec\u8fd8\u5141\u8bb8\u6b64\u65b9\u6cd5\u963b\u585e\u7b49\u5f85\u4efb\u52a1\u5b8c\u6210\uff0c\u8fd9\u53ef\u4ee5\u901a\u8fc7ContinueWith\u5b9e\u73b0(continuation\u00a0\u53ea\u662f\u53d1\u51faManualResetEventSlim\u4fe1\u53f7\uff0c\u7136\u540e\u8c03\u7528\u8005\u963b\u585e\u7b49\u5f85\u5b8c\u6210)\u3002<\/p>\n
      public void Wait()\r\n{\r\n    ManualResetEventSlim? mres = null;\r\n    lock (this)\r\n    {\r\n        if (!_completed)\r\n        {\r\n            mres = new ManualResetEventSlim();\r\n            ContinueWith(_ => mres.Set());\r\n        }\r\n    }\r\n\r\n    mres?.Wait();\r\n    if (_error is not null)\r\n    {\r\n        ExceptionDispatchInfo.Throw(_error);\r\n    }\r\n}<\/code><\/pre>\n
      \u57fa\u672c\u4e0a\u5c31\u662f\u8fd9\u6837\u3002\u73b0\u5728\u53ef\u4ee5\u80af\u5b9a\u7684\u662f\uff0c\u771f\u6b63\u7684Task\u8981\u590d\u6742\u5f97\u591a\uff0c\u6709\u66f4\u9ad8\u6548\u7684\u5b9e\u73b0\uff0c\u652f\u6301\u4efb\u610f\u6570\u91cf\u7684continuation\uff0c\u6709\u5927\u91cf\u5173\u4e8e\u5b83\u5e94\u8be5\u5982\u4f55\u8868\u73b0\u7684\u6309\u94ae(\u4f8b\u5982\uff0ccontinuation\u5e94\u8be5\u50cf\u8fd9\u91cc\u6240\u505a\u7684\u90a3\u6837\u6392\u961f\uff0c\u8fd8\u662f\u5e94\u8be5\u4f5c\u4e3a\u4efb\u52a1\u5b8c\u6210\u7684\u4e00\u90e8\u5206\u540c\u6b65\u8c03\u7528)\uff0c\u80fd\u591f\u5b58\u50a8\u591a\u4e2a\u5f02\u5e38\u800c\u4e0d\u662f\u4e00\u4e2a\u5f02\u5e38\uff0c\u5177\u6709\u53d6\u6d88\u7684\u7279\u6b8a\u77e5\u8bc6\uff0c\u6709\u5927\u91cf\u7684\u8f85\u52a9\u65b9\u6cd5\u7528\u4e8e\u6267\u884c\u5e38\u89c1\u64cd\u4f5c(\u4f8b\u5982Task.Run\uff0c\u5b83\u521b\u5efa\u4e00\u4e2aTask\u6765\u8868\u793a\u7ebf\u7a0b\u6c60\u4e0a\u8c03\u7528\u7684\u59d4\u6258\u961f\u5217)\uff0c\u7b49\u7b49\u3002\u4f46\u8fd9\u4e9b\u90fd\u6ca1\u6709\u4ec0\u4e48\u795e\u5947\u4e4b\u5904\uff1b\u5176\u6838\u5fc3\u5c31\u662f\u6211\u4eec\u5728\u8fd9\u91cc\u770b\u5230\u7684\u4e1c\u897f\u3002<\/p>\n
      \u4f60\u53ef\u80fd\u8fd8\u6ce8\u610f\u5230\uff0c\u6211\u7b80\u5355\u7684MyTask\u76f4\u63a5\u6709\u516c\u5171\u7684SetResult\/SetException\u65b9\u6cd5\uff0c\u800cTask\u6ca1\u6709\u3002\u5b9e\u9645\u4e0a\uff0cTask\u786e\u5b9e\u6709\u8fd9\u6837\u7684\u65b9\u6cd5\uff0c\u5b83\u4eec\u53ea\u662f\u5185\u90e8\u7684<\/a>\uff0cSystem.Threading.Tasks.TaskCompletionSource\u7c7b\u578b\u4f5c\u4e3a\u4efb\u52a1\u53ca\u5176\u5b8c\u6210\u7684\u72ec\u7acb\u201c\u751f\u4ea7\u8005\u201d;\u8fd9\u6837\u505a\u4e0d\u662f\u51fa\u4e8e\u6280\u672f\u4e0a\u7684\u9700\u8981\uff0c\u800c\u662f\u4e3a\u4e86\u8ba9\u5b8c\u6210\u65b9\u6cd5\u8fdc\u79bb\u53ea\u7528\u4e8e\u6d88\u8d39\u7684\u4e1c\u897f\u3002\u7136\u540e\uff0c\u4f60\u5c31\u53ef\u4ee5\u628aTask\u5206\u53d1\u51fa\u53bb\uff0c\u800c\u4e0d\u5fc5\u62c5\u5fc3\u5b83\u4f1a\u5728\u4f60\u4e0b\u9762\u5b8c\u6210;\u5b8c\u6210\u4fe1\u53f7\u662f\u521b\u5efa\u4efb\u52a1\u7684\u5b9e\u73b0\u7ec6\u8282\uff0c\u5e76\u4e14\u901a\u8fc7\u4fdd\u7559TaskCompletionSource\u672c\u8eab\u6765\u4fdd\u7559\u5b8c\u6210\u5b83\u7684\u6743\u5229\u3002(CancellationToken\u548cCancellationTokenSource\u9075\u5faa\u7c7b\u4f3c\u7684\u6a21\u5f0f:CancellationToken\u53ea\u662fCancellationTokenSource\u7684\u4e00\u4e2a\u7ed3\u6784\u5c01\u88c5\u5668\uff0c\u53ea\u63d0\u4f9b\u4e0e\u6d88\u8d39\u53d6\u6d88\u4fe1\u53f7\u76f8\u5173\u7684\u516c\u5171\u533a\u57df\uff0c\u4f46\u6ca1\u6709\u4ea7\u751f\u53d6\u6d88\u4fe1\u53f7\u7684\u80fd\u529b\uff0c\u800c\u4ea7\u751f\u53d6\u6d88\u4fe1\u53f7\u7684\u80fd\u529b\u4ec5\u9650\u4e8e\u80fd\u591f\u8bbf\u95eeCancellationTokenSource\u7684\u4eba\u3002)<\/p>\n
      \u5f53\u7136\uff0c\u6211\u4eec\u53ef\u4ee5\u4e3a\u8fd9\u4e2aMyTask\u5b9e\u73b0\u7ec4\u5408\u5668\u548c\u8f85\u52a9\u5668\uff0c\u5c31\u50cfTask\u63d0\u4f9b\u7684\u90a3\u6837\u3002\u60f3\u8981\u4e00\u4e2a\u7b80\u5355\u7684MyTask.WhenAll\uff1f\u7ed9\u4f60\uff1a<\/p>\n
      public static MyTask WhenAll(MyTask t1, MyTask t2)\r\n{\r\n    var t = new MyTask();\r\n\r\n    int remaining = 2;\r\n    Exception? e = null;\r\n\r\n    Action<MyTask> continuation = completed =>\r\n    {\r\n        e ??= completed._error; \/\/ just store a single exception for simplicity\r\n        if (Interlocked.Decrement(ref remaining) == 0)\r\n        {\r\n            if (e is not null) t.SetException(e);\r\n            else t.SetResult();\r\n        }\r\n    };\r\n\r\n    t1.ContinueWith(continuation);\r\n    t2.ContinueWith(continuation);\r\n\r\n    return t;\r\n}<\/code><\/pre>\n
      \u60f3\u8981\u4e00\u4e2aMyTask.Run\uff1f\u4f60\u5f97\u5230\u4e86\u5b83\uff1a<\/p>\n
      public static MyTask Run(Action action)\r\n{\r\n    var t = new MyTask();\r\n\r\n    ThreadPool.QueueUserWorkItem(_ =>\r\n    {\r\n        try\r\n        {\r\n            action();\r\n            t.SetResult();\r\n        }\r\n        catch (Exception e)\r\n        {\r\n            t.SetException(e);\r\n        }\r\n    });\r\n\r\n    return t;\r\n}<\/code><\/pre>\n
      \u4e00\u4e2aMyTask.Delay\u600e\u4e48\u6837\uff1f\u5f53\u7136\u53ef\u4ee5\uff1a<\/p>\n
      public static MyTask Delay(TimeSpan delay)\r\n{\r\n    var t = new MyTask();\r\n\r\n    var timer = new Timer(_ => t.SetResult());\r\n    timer.Change(delay, Timeout.InfiniteTimeSpan);\r\n\r\n    return t;\r\n}<\/code><\/pre>\n
      \u4f60\u61c2\u7684\u3002<\/p>\n
      \u6709\u4e86Task\uff0c . net\u4e2d\u4e4b\u524d\u7684\u6240\u6709\u5f02\u6b65\u6a21\u5f0f\u90fd\u5c06\u6210\u4e3a\u8fc7\u53bb\u3002\u5728\u4ee5\u524d\u4f7f\u7528APM\u6a21\u5f0f\u6216EAP\u6a21\u5f0f\u5b9e\u73b0\u5f02\u6b65\u5b9e\u73b0\u7684\u5730\u65b9\uff0c\u90fd\u4f1a\u516c\u5f00\u65b0\u7684Task\u8fd4\u56de\u65b9\u6cd5\u3002<\/p>\n
       <\/p>\n
      ValueTasks<\/strong><\/p>\n
      \u65f6\u81f3\u4eca\u65e5\uff0cTask\u4ecd\u7136\u662f. net\u4e2d\u5f02\u6b65\u7684\u4e3b\u52a8\u529b\uff0c\u6bcf\u4e2a\u7248\u672c\u90fd\u516c\u5f00\u4e86\u65b0\u7684\u65b9\u6cd5\uff0c\u5e76\u4e14\u5728\u6574\u4e2a\u751f\u6001\u7cfb\u7edf\u4e2d\u5b9a\u671f\u8fd4\u56deTask\u548cTask<TResult>\u3002\u7136\u800c\uff0cTask\u662f\u4e00\u4e2a\u7c7b\uff0c\u8fd9\u610f\u5473\u7740\u521b\u5efa\u4e00\u4e2a\u7c7b\u9700\u8981\u5206\u914d\u5185\u5b58\u3002\u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u4e3a\u4e00\u4e2a\u957f\u671f\u5f02\u6b65\u64cd\u4f5c\u989d\u5916\u5206\u914d\u5185\u5b58\u662f\u5fae\u4e0d\u8db3\u9053\u7684\uff0c\u9664\u4e86\u5bf9\u6027\u80fd\u6700\u654f\u611f\u7684\u64cd\u4f5c\u4e4b\u5916\uff0c\u4e0d\u4f1a\u5bf9\u4ea7\u751f\u6709\u610f\u4e49\u7684\u5f71\u54cd\u3002\u4e0d\u8fc7\uff0c\u5982\u524d\u6240\u8ff0\uff0c\u5f02\u6b65\u64cd\u4f5c\u7684\u540c\u6b65\u5b8c\u6210\u662f\u76f8\u5f53\u5e38\u89c1\u7684\u3002<\/p>\n
      \u65f6\u81f3\u4eca\u65e5\uff0cTask\u4ecd\u7136\u662f. net\u4e2d\u5f02\u6b65\u5904\u7406\u7684\u4e3b\u529b\uff0c\u6bcf\u6b21\u53d1\u5e03\u90fd\u6709\u65b0\u65b9\u6cd5\u516c\u5f00\uff0c\u5e76\u4e14\u5728\u6574\u4e2a\u751f\u6001\u7cfb\u7edf\u4e2d\u90fd\u4f8b\u884c\u5730\u8fd4\u56deTask\u548cTask\u3002\u7136\u800c\uff0cTask\u662f\u4e00\u4e2a\u7c7b\uff0c\u8fd9\u610f\u5473\u7740\u521b\u5efa\u4e00\u4e2a\u7c7b\u9700\u8981\u5206\u914d\u5185\u5b58\u3002\u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u4e3a\u4e00\u4e2a\u957f\u671f\u5f02\u6b65\u64cd\u4f5c\u989d\u5916\u5206\u914d\u5185\u5b58\u662f\u5fae\u4e0d\u8db3\u9053\u7684\uff0c\u9664\u4e86\u5bf9\u6027\u80fd\u6700\u654f\u611f\u7684\u64cd\u4f5c\u4e4b\u5916\uff0c\u4e0d\u4f1a\u5bf9\u6240\u6709\u64cd\u4f5c\u7684\u6027\u80fd\u4ea7\u751f\u6709\u610f\u4e49\u7684\u5f71\u54cd\u3002\u4e0d\u8fc7\uff0c\u5982\u524d\u6240\u8ff0\uff0c\u5f02\u6b65\u64cd\u4f5c\u7684\u540c\u6b65\u5b8c\u6210\u662f\u76f8\u5f53\u5e38\u89c1\u7684\u3002\u5f15\u5165Stream.ReadAsync\u662f\u4e3a\u4e86\u8fd4\u56de\u4e00\u4e2a\u00a0Task<int>\uff0c\u4f46\u5982\u679c\u4f60\u4ece\u4e00\u4e2aBufferedStream\u4e2d\u8bfb\u53d6\u6570\u636e\uff0c\u5f88\u6709\u53ef\u80fd\u5f88\u591a\u8bfb\u53d6\u90fd\u662f\u540c\u6b65\u5b8c\u6210\u7684\uff0c\u56e0\u4e3a\u53ea\u9700\u8981\u4ece\u5185\u5b58\u4e2d\u7684\u7f13\u51b2\u533a\u4e2d\u8bfb\u53d6\u6570\u636e\uff0c\u800c\u4e0d\u662f\u6267\u884c\u7cfb\u7edf\u8c03\u7528\u548c\u771f\u6b63\u7684I\/O\u64cd\u4f5c\u3002\u4e0d\u5f97\u4e0d\u5206\u914d\u4e00\u4e2a\u989d\u5916\u7684\u5bf9\u8c61\u6765\u8fd4\u56de\u8fd9\u6837\u7684\u6570\u636e\u662f\u4e0d\u5e78\u7684(\u6ce8\u610f\uff0cAPM\u4e5f\u662f\u8fd9\u6837\u7684\u60c5\u51b5)\u3002\u5bf9\u4e8e\u8fd4\u56deTask\u7684\u975e\u6cdb\u578b\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u53ef\u4ee5\u53ea\u8fd4\u56de\u4e00\u4e2a\u5df2\u7ecf\u5b8c\u6210\u7684\u5355\u4f8b\u4efb\u52a1\uff0c\u800c\u5b9e\u9645\u4e0aTask.CompletedTask\u63d0\u4f9b\u4e86\u4e00\u4e2a\u8fd9\u6837\u7684\u5355\u4f8bTask\u3002\u4f46\u5bf9\u4e8eTask<TResult>\u6765\u8bf4\uff0c\u4e0d\u53ef\u80fd\u4e3a\u6bcf\u4e2a\u53ef\u80fd\u7684\u7ed3\u679c\u7f13\u5b58\u4e00\u4e2aTask\u3002\u6211\u4eec\u53ef\u4ee5\u505a\u4e9b\u4ec0\u4e48\u6765\u8ba9\u8fd9\u79cd\u540c\u6b65\u5b8c\u6210\u66f4\u5feb\u5462?<\/p>\n
       <\/p>\n
      \u7f13\u5b58\u4e00\u4e9bTask<TResult>\u662f\u53ef\u80fd\u7684\u3002\u4f8b\u5982\uff0cTask<bool>\u975e\u5e38\u5e38\u89c1\uff0c\u800c\u4e14\u53ea\u6709\u4e24\u4e2a\u6709\u610f\u4e49\u7684\u4e1c\u897f\u9700\u8981\u7f13\u5b58\uff1a\u5f53\u7ed3\u679c\u4e3atrue\u65f6\uff0c\u4e00\u4e2aTask<bool>\uff0c\u5f53\u7ed3\u679c\u4e3afalse\u65f6\uff0c\u4e00\u4e2aTask<bool>\u3002\u6216\u8005\uff0c\u867d\u7136\u6211\u4eec\u4e0d\u60f3\u7f13\u5b5840\u4ebf\u4e2aTask<int>\u6765\u5bb9\u7eb3\u6240\u6709\u53ef\u80fd\u7684Int32\u7ed3\u679c\uff0c\u4f46\u5c0f\u7684Int32\u503c\u662f\u975e\u5e38\u5e38\u89c1\u7684\uff0c\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u7f13\u5b58\u4e00\u4e9b\u503c\uff0c\u6bd4\u5982-1\u52308\u3002\u6216\u8005\u5bf9\u4e8e\u4efb\u610f\u7c7b\u578b\uff0cdefault\u662f\u4e00\u4e2a\u5408\u7406\u7684\u901a\u7528\u503c\uff0c\u56e0\u6b64\u6211\u4eec\u53ef\u4ee5\u7f13\u5b58\u6bcf\u4e2a\u76f8\u5173\u7c7b\u578b\u7684Task<TResult>\uff0c\u5176\u4e2dResult\u4e3adefault(TResult)\u3002\u4e8b\u5b9e\u4e0a\uff0cTask.FromResult\u4eca\u5929\u4e5f\u662f\u8fd9\u6837\u505a\u7684\u00a0<\/a>\uff08\u4ece\u6700\u8fd1\u7684.NET\u7248\u672c\u5f00\u59cb\uff09\uff0c\u4f7f\u7528\u4e00\u4e2a\u5c0f\u578b\u7684\u53ef\u590d\u7528\u7684Task<TResult>\u5355\u4f8b\u7f13\u5b58\uff0c\u5e76\u5728\u9002\u5f53\u65f6\u8fd4\u56de\u5176\u4e2d\u4e00\u4e2a\uff0c\u6216\u8005\u4e3a\u51c6\u786e\u63d0\u4f9b\u7684\u7ed3\u679c\u503c\u5206\u914d\u4e00\u4e2a\u65b0\u7684Task<TResult>\u3002\u53ef\u4ee5\u521b\u5efa\u5176\u4ed6\u65b9\u6848\u6765\u5904\u7406\u5176\u4ed6\u5408\u7406\u7684\u5e38\u89c1\u60c5\u51b5\u3002\u4f8b\u5982\uff0c\u5f53\u4f7f\u7528Stream.ReadAsync\u65f6\uff0c\u5728\u540c\u4e00\u4e2a\u6d41\u4e0a\u591a\u6b21\u8c03\u7528\u5b83\u662f\u5408\u7406\u7684\uff0c\u800c\u4e14\u6bcf\u6b21\u8c03\u7528\u65f6\u5141\u8bb8\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u90fd\u662f\u76f8\u540c\u7684\u3002\u5b9e\u73b0\u80fd\u591f\u5b8c\u5168\u6ee1\u8db3count\u8bf7\u6c42\u662f\u5408\u7406\u7684\u3002\u8fd9\u610f\u5473\u7740Stream.ReadAsync\u91cd\u590d\u8fd4\u56de\u76f8\u540c\u7684int\u503c\u662f\u5f88\u5e38\u89c1\u7684\u3002\u4e3a\u4e86\u907f\u514d\u8fd9\u79cd\u60c5\u51b5\u4e0b\u7684\u591a\u6b21\u5206\u914d\uff0c\u591a\u4e2aStream\u7c7b\u578b\uff08\u5982MemoryStream\uff09\u4f1a\u7f13\u5b58\u5b83\u4eec\u6700\u540e\u6210\u529f\u8fd4\u56de\u7684Task<int>\uff0c\u5982\u679c\u4e0b\u4e00\u6b21\u8bfb\u53d6\u4e5f\u540c\u6b65\u5b8c\u6210\u5e76\u6210\u529f\u83b7\u5f97\u76f8\u540c\u7684\u7ed3\u679c\uff0c\u5b83\u53ef\u4ee5\u53ea\u662f\u518d\u6b21\u8fd4\u56de\u76f8\u540c\u7684Task<int>\uff0c\u800c\u4e0d\u662f\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u3002\u4f46\u5176\u4ed6\u60c5\u51b5\u5462\uff1f\u5728\u6027\u80fd\u5f00\u9500\u975e\u5e38\u91cd\u8981\u7684\u60c5\u51b5\u4e0b\uff0c\u5982\u4f55\u66f4\u666e\u904d\u5730\u907f\u514d\u5bf9\u540c\u6b65\u5b8c\u6210\u7684\u8fd9\u79cd\u5206\u914d\uff1f<\/p>\n
       <\/p>\n
      \u8fd9\u5c31\u662fValueTask<TResult>\u7684\u4f5c\u7528(\u8fd8\u6709\u5173\u4e8eValueTask<TResult> \u7684\u66f4\u8be6\u7ec6\u7684\u7814\u7a76<\/a>\u4e5f\u53ef\u4ee5\u627e\u5230)\u3002ValueTask<TResult>\u6700\u521d\u662f\u4f5c\u4e3aTResult\u548cTask<TResult>\u4e4b\u95f4\u7684\u4e00\u4e2a\u533a\u5206\u5e76\u96c6\u3002\u8bf4\u5230\u5e95\uff0c\u629b\u5f00\u90a3\u4e9b\u82b1\u54e8\u7684\u4e1c\u897f\uff0c\u8fd9\u5c31\u662f\u5b83\u7684\u5168\u90e8<\/a> (\u6216\u8005\uff0c\u66f4\u786e\u5207\u5730\u8bf4\uff0c\u66fe\u7ecf\u662f)\uff0c\u662f\u4e00\u4e2a\u5373\u65f6\u7684\u7ed3\u679c\uff0c\u6216\u8005\u662f\u5bf9\u672a\u6765\u67d0\u4e2a\u65f6\u523b\u7684\u4e00\u4e2a\u7ed3\u679c\u7684\u627f\u8bfa:<\/p>\n
      public readonly struct ValueTask<TResult>\r\n{\r\n   private readonly Task<TResult>? _task;\r\n   private readonly TResult _result;\r\n   ...\r\n}<\/code><\/pre>\n
      \u7136\u540e\uff0c\u4e00\u4e2a\u65b9\u6cd5\u53ef\u4ee5\u8fd4\u56de\u8fd9\u6837\u4e00\u4e2aValueTask<TResult>\uff0c\u800c\u4e0d\u662f\u4e00\u4e2aTask<TResult>\uff0c\u5982\u679cTResult\u5728\u9700\u8981\u8fd4\u56de\u7684\u65f6\u5019\u5df2\u7ecf\u77e5\u9053\u4e86\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u907f\u514dTask<TResult>\u7684\u5206\u914d\uff0c\u4ee3\u4ef7\u662f\u4e00\u4e2a\u66f4\u5927\u7684\u8fd4\u56de\u7c7b\u578b\u548c\u7a0d\u5fae\u591a\u4e00\u70b9\u95f4\u63a5\u6027\u3002<\/p>\n
      \u7136\u800c\uff0c\u5728\u4e00\u4e9b\u8d85\u7ea7\u8d85\u7ea7\u6781\u7aef\u7684\u9ad8\u6027\u80fd\u573a\u666f\u4e2d\uff0c\u5373\u4f7f\u5728\u5f02\u6b65\u5b8c\u6210\u7684\u60c5\u51b5\u4e0b\uff0c\u60a8\u4e5f\u5e0c\u671b\u80fd\u591f\u907f\u514dTask<TResult>\u5206\u914d\u3002\u4f8b\u5982\uff0cSocket\u4f4d\u4e8e\u7f51\u7edc\u5806\u6808\u7684\u5e95\u90e8\uff0cSocket\u4e0a\u7684SendAsync\u548cReceiveAsync\u5bf9\u4e8e\u8bb8\u591a\u670d\u52a1\u6765\u8bf4\u662f\u975e\u5e38\u70ed\u95e8\u7684\u8def\u5f84\uff0c\u540c\u6b65\u548c\u5f02\u6b65\u5b8c\u6210\u90fd\u975e\u5e38\u5e38\u89c1(\u5927\u591a\u6570\u540c\u6b65\u53d1\u9001\u5b8c\u6210\uff0c\u8bb8\u591a\u540c\u6b65\u63a5\u6536\u5b8c\u6210\uff0c\u56e0\u4e3a\u6570\u636e\u5df2\u7ecf\u5728\u5185\u6838\u4e2d\u7f13\u51b2\u4e86)\u3002\u5982\u679c\u5728\u4e00\u4e2a\u7ed9\u5b9a\u7684Socket\u4e0a\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u8fd9\u6837\u7684\u53d1\u9001\u548c\u63a5\u6536\u4e0d\u53d7\u5206\u914d\u9650\u5236\uff0c\u800c\u4e0d\u7ba1\u64cd\u4f5c\u662f\u540c\u6b65\u5b8c\u6210\u8fd8\u662f\u5f02\u6b65\u5b8c\u6210\uff0c\u8fd9\u4e0d\u662f\u5f88\u597d\u5417?<\/p>\n
       <\/p>\n
      \u8fd9\u5c31\u662fSystem.Threading.Tasks.Sources.IValueTaskSource<TResult>\u8fdb\u5165\u7684\u5730\u65b9\uff1a<\/p>\n
      public interface IValueTaskSource<out TResult>\r\n{\r\n    ValueTaskSourceStatus GetStatus(short token);\r\n    void OnCompleted(Action<object?> continuation, object? state, short token, ValueTaskSourceOnCompletedFlags flags);\r\n    TResult GetResult(short token);\r\n}<\/code><\/pre>\n
      IValueTaskSource<TResult>\u63a5\u53e3\u5141\u8bb8\u4e00\u4e2a\u5b9e\u73b0\u4e3aValueTask<TResult>\u63d0\u4f9b\u81ea\u5df1\u7684\u652f\u6301\u5bf9\u8c61\uff0c\u4f7f\u8be5\u5bf9\u8c61\u80fd\u591f\u5b9e\u73b0\u50cfGetResult\u8fd9\u6837\u7684\u65b9\u6cd5\u6765\u68c0\u7d22\u64cd\u4f5c\u7684\u7ed3\u679c\uff0c\u4ee5\u53caOnCompleted\u6765\u8fde\u63a5\u64cd\u4f5c\u7684\u5ef6\u7eed\u3002\u5c31\u8fd9\u6837\uff0cValueTask<TResult>\u5bf9\u5176\u5b9a\u4e49\u8fdb\u884c\u4e86\u4e00\u4e2a\u5c0f\u5c0f\u7684\u66f4\u6539<\/a>\uff0c\u5176Task<TResult>? _task\u5b57\u6bb5\u66ff\u6362\u4e3aobject? _obj\u5b57\u6bb5\uff1a<\/p>\n
      public readonly struct ValueTask<TResult>\r\n{\r\n   private readonly object? _obj;\r\n   private readonly TResult _result;\r\n   ...\r\n}<\/code><\/pre>\n
      \u4ee5\u524d_task\u5b57\u6bb5\u8981\u4e48\u662fTask<TResult>\u8981\u4e48\u662fnull\uff0c\u73b0\u5728_obj\u5b57\u6bb5\u4e5f\u53ef\u4ee5\u662fIValueTaskSource<TResult>\u3002\u4e00\u65e6Task<TResult>\u88ab\u6807\u8bb0\u4e3a\u5df2\u5b8c\u6210\uff0c\u5b83\u5c06\u4fdd\u6301\u5b8c\u6210\u72b6\u6001\uff0c\u5e76\u4e14\u6c38\u8fdc\u4e0d\u4f1a\u8f6c\u6362\u56de\u672a\u5b8c\u6210\u7684\u72b6\u6001\u3002\u76f8\u6bd4\u4e4b\u4e0b\uff0c\u5b9e\u73b0 IValueTaskSource<TResult> \u7684\u5bf9\u8c61\u5bf9\u5b9e\u73b0\u6709\u5b8c\u5168\u7684\u63a7\u5236\u6743\uff0c\u53ef\u4ee5\u81ea\u7531\u5730\u5728\u5b8c\u6210\u72b6\u6001\u548c\u4e0d\u5b8c\u6210\u72b6\u6001\u4e4b\u95f4\u53cc\u5411\u8f6c\u6362\uff0c\u56e0\u4e3a ValueTask<TResult> \u7684\u5951\u7ea6\u662f\u4e00\u4e2a\u7ed9\u5b9a\u7684\u5b9e\u4f8b\u53ea\u80fd\u88ab\u6d88\u8017\u4e00\u6b21\uff0c\u56e0\u6b64\u4ece\u7ed3\u6784\u4e0a\u770b\uff0c\u5b83\u4e0d\u5e94\u8be5\u89c2\u5bdf\u5230\u5e95\u5c42\u5b9e\u4f8b\u7684\u6d88\u8017\u540e\u53d8\u5316\uff08\u8fd9\u5c31\u662f CA2012<\/a>\u7b49\u5206\u6790\u89c4\u5219\u5b58\u5728\u7684\u539f\u56e0\uff09\u3002\u8fd9\u5c31\u4f7f\u5f97\u50cfSocket\u8fd9\u6837\u7684\u7c7b\u578b\u80fd\u591f\u5c06IValueTaskSource<TResult>\u7684\u5b9e\u4f8b\u96c6\u4e2d\u8d77\u6765\uff0c\u7528\u4e8e\u91cd\u590d\u8c03\u7528\u3002Socket\u6700\u591a\u53ef\u4ee5\u7f13\u5b58\u4e24\u4e2a\u8fd9\u6837\u7684\u5b9e\u4f8b\uff0c\u4e00\u4e2a\u7528\u4e8e\u8bfb\uff0c\u4e00\u4e2a\u7528\u4e8e\u5199\uff0c\u56e0\u4e3a99.999%\u7684\u60c5\u51b5\u662f\u5728\u540c\u4e00\u65f6\u95f4\u6700\u591a\u53ea\u6709\u4e00\u4e2a\u63a5\u6536\u548c\u4e00\u4e2a\u53d1\u9001\u3002<\/p>\n
      \u6211\u63d0\u5230\u4e86ValueTask<TResult>\uff0c\u4f46\u6ca1\u6709\u63d0\u5230ValueTask\u3002\u5f53\u53ea\u5904\u7406\u907f\u514d\u540c\u6b65\u5b8c\u6210\u7684\u5206\u914d\u65f6\uff0c\u4f7f\u7528\u975e\u6cdb\u578bValueTask\uff08\u4ee3\u8868\u65e0\u7ed3\u679c\u7684\u65e0\u6548\u64cd\u4f5c\uff09\u5728\u6027\u80fd\u4e0a\u6ca1\u6709\u4ec0\u4e48\u597d\u5904\uff0c\u56e0\u4e3a\u540c\u6837\u7684\u6761\u4ef6\u53ef\u4ee5\u7528Task.CompletedTask\u6765\u8868\u793a\u3002\u4f46\u662f\uff0c\u4e00\u65e6\u6211\u4eec\u5173\u5fc3\u5728\u5f02\u6b65\u5b8c\u6210\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u53ef\u6c60\u5316\u7684\u5e95\u5c42\u5bf9\u8c61\u6765\u907f\u514d\u5206\u914d\u7684\u80fd\u529b\uff0c\u90a3\u4e48\u8fd9\u5bf9\u975e\u6cdb\u578b\u4e5f\u5f88\u91cd\u8981\u3002\u56e0\u6b64\uff0c\u5f53IValueTaskSource<TResult>\u88ab\u5f15\u5165\u65f6\uff0cIValueTaskSource\u548cValueTask\u4e5f\u88ab\u5f15\u5165\u3002<\/p>\n
      \u56e0\u6b64\uff0c\u6211\u4eec\u6709Task\u3001Task<TResult>\u3001ValueTask\u548cValueTask<TResult>\u3002\u6211\u4eec\u80fd\u591f\u4ee5\u5404\u79cd\u65b9\u5f0f\u4e0e\u5b83\u4eec\u4ea4\u4e92\uff0c\u8868\u793a\u4efb\u610f\u7684\u5f02\u6b65\u64cd\u4f5c\uff0c\u5e76\u8fde\u63a5continuation\u6765\u5904\u7406\u8fd9\u4e9b\u5f02\u6b65\u64cd\u4f5c\u7684\u5b8c\u6210\u3002\u6ca1\u9519\uff0c\u6211\u4eec\u53ef\u4ee5\u5728\u64cd\u4f5c\u5b8c\u6210\u4e4b\u524d\u6216\u4e4b\u540e\u6267\u884c\u8fd9\u4e9b\u64cd\u4f5c\u3002<\/p>\n
      \u4f46\u662f……\u8fd9\u4e9b\u5ef6\u7eed\u4ecd\u7136\u662f\u56de\u8c03!<\/p>\n
      \u6211\u4eec\u4ecd\u7136\u88ab\u8feb\u91c7\u7528\u5ef6\u7eed\u4f20\u9012\u7684\u65b9\u5f0f\u6765\u7f16\u7801\u6211\u4eec\u7684\u5f02\u6b65\u63a7\u5236\u6d41\uff01\uff01\uff01<\/p>\n
      \u8fd9\u4ecd\u7136\u5f88\u96be\u505a\u5230!!<\/p>\n
      \u6211\u4eec\u5982\u4f55\u624d\u80fd\u89e3\u51b3\u8fd9\u4e2a\u95ee\u9898????<\/p>\n
       <\/p>\n
      C# Iterators to the Rescue<\/strong><\/p>\n
      \u8fd9\u4e2a\u89e3\u51b3\u65b9\u6848\u7684\u4e00\u7ebf\u5e0c\u671b\u5b9e\u9645\u4e0a\u662f\u5728Task\u51fa\u73b0\u7684\u51e0\u5e74\u524d\uff0c\u5373C# 2.0\uff0c\u5f53\u65f6\u5b83\u589e\u52a0\u4e86\u5bf9\u8fed\u4ee3\u5668\u7684\u652f\u6301\u3002<\/p>\n
      \u201c\u8fed\u4ee3\u5668?\u201c\u4f60\u4f1a\u95ee?\u201c\u4f60\u662f\u8bf4IEnumerable<T>?\u201d\u5c31\u662f\u8fd9\u4e2a\u3002\u8fed\u4ee3\u5668\u5141\u8bb8\u4f60\u7f16\u5199\u4e00\u4e2a\u65b9\u6cd5\uff0c\u7136\u540e\u7531\u7f16\u8bd1\u5668\u7528\u6765\u5b9e\u73b0IEnumerable<T>\u548c\/\u6216IEnumerator<T>\u3002\u4f8b\u5982\uff0c\u5982\u679c\u6211\u60f3\u521b\u5efa\u4e00\u4e2a\u4ea7\u751f\u6590\u6ce2\u90a3\u5951\u6570\u5217\u7684\u679a\u4e3e\u6570\uff0c\u6211\u53ef\u4ee5\u8fd9\u6837\u5199:<\/p>\n
      public static IEnumerable<int> Fib()\r\n{\r\n    int prev = 0, next = 1;\r\n    yield return prev;\r\n    yield return next;\r\n\r\n    while (true)\r\n    {\r\n        int sum = prev + next;\r\n        yield return sum;\r\n        prev = next;\r\n        next = sum;\r\n    }\r\n}<\/code><\/pre>\n
      \u7136\u540e\u6211\u53ef\u4ee5\u7528foreach\u679a\u4e3e\u5b83:<\/p>\n
      foreach (int i in Fib())\r\n{\r\n    if (i > 100) break;\r\n    Console.Write($\"{i} \");\r\n}<\/code><\/pre>\n
      \u6211\u53ef\u4ee5\u901a\u8fc7\u50cfSystem.Linq.Enumerable\u4e0a\u7684\u7ec4\u5408\u5668\u5c06\u5b83\u4e0e\u5176\u4ed6IEnumerable<T>\u8fdb\u884c\u7ec4\u5408\uff1a<\/p>\n
      foreach (int i in Fib().Take(12))\r\n{\r\n    Console.Write($\"{i} \");\r\n}<\/code><\/pre>\n
      \u6216\u8005\u6211\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7IEnumerator<T>\u6765\u624b\u52a8\u679a\u4e3e\u5b83\uff1a<\/p>\n
      using IEnumerator<int> e = Fib().GetEnumerator();\r\nwhile (e.MoveNext())\r\n{\r\n    int i = e.Current;\r\n    if (i > 100) break;\r\n    Console.Write($\"{i} \");\r\n}<\/code><\/pre>\n
      \u4ee5\u4e0a\u6240\u6709\u7684\u7ed3\u679c\u662f\u8fd9\u6837\u7684\u8f93\u51fa:<\/p>\n
      0 1 1 2 3 5 8 13 21 34 55 89<\/code><\/pre>\n
      \u771f\u6b63\u6709\u8da3\u7684\u662f\uff0c\u4e3a\u4e86\u5b9e\u73b0\u4e0a\u8ff0\u76ee\u6807\uff0c\u6211\u4eec\u9700\u8981\u80fd\u591f\u591a\u6b21\u8fdb\u5165\u548c\u9000\u51faFib\u65b9\u6cd5\u3002\u6211\u4eec\u8c03\u7528MoveNext\uff0c\u5b83\u8fdb\u5165\u65b9\u6cd5\uff0c\u7136\u540e\u8be5\u65b9\u6cd5\u6267\u884c\uff0c\u76f4\u5230\u5b83\u9047\u5230yield return\uff0c\u6b64\u65f6\u5bf9MoveNext\u7684\u8c03\u7528\u9700\u8981\u8fd4\u56detrue\uff0c\u968f\u540e\u5bf9Current\u7684\u8bbf\u95ee\u9700\u8981\u8fd4\u56deyield value\u3002\u7136\u540e\u6211\u4eec\u518d\u6b21\u8c03\u7528MoveNext\uff0c\u6211\u4eec\u9700\u8981\u80fd\u591f\u5728Fib\u4e2d\u4ece\u6211\u4eec\u4e0a\u6b21\u505c\u6b62\u7684\u5730\u65b9\u5f00\u59cb\uff0c\u5e76\u4e14\u4fdd\u6301\u4e0a\u6b21\u8c03\u7528\u7684\u6240\u6709\u72b6\u6001\u4e0d\u53d8\u3002\u8fed\u4ee3\u5668\u5b9e\u9645\u4e0a\u662f\u7531c#\u8bed\u8a00\/\u7f16\u8bd1\u5668\u63d0\u4f9b\u7684\u534f\u7a0b\uff0c\u7f16\u8bd1\u5668\u5c06Fib\u8fed\u4ee3\u5668\u6269\u5c55\u4e3a\u4e00\u4e2a\u6210\u719f\u7684\u72b6\u6001\u673a:<\/p>\n
      public static IEnumerable<int> Fib() => new <Fib>d__0(-2);\r\n\r\n[CompilerGenerated]\r\nprivate sealed class <Fib>d__0 : IEnumerable<int>, IEnumerable, IEnumerator<int>, IEnumerator, IDisposable\r\n{\r\n    private int <>1__state;\r\n    private int <>2__current;\r\n    private int <>l__initialThreadId;\r\n    private int <prev>5__2;\r\n    private int <next>5__3;\r\n    private int <sum>5__4;\r\n\r\n    int IEnumerator<int>.Current => <>2__current;\r\n    object IEnumerator.Current => <>2__current;\r\n\r\n    public <Fib>d__0(int <>1__state)\r\n    {\r\n        this.<>1__state = <>1__state;\r\n        <>l__initialThreadId = Environment.CurrentManagedThreadId;\r\n    }\r\n\r\n    private bool MoveNext()\r\n    {\r\n        switch (<>1__state)\r\n        {\r\n            default:\r\n                return false;\r\n            case 0:\r\n                <>1__state = -1;\r\n                <prev>5__2 = 0;\r\n                <next>5__3 = 1;\r\n                <>2__current = <prev>5__2;\r\n                <>1__state = 1;\r\n                return true;\r\n            case 1:\r\n                <>1__state = -1;\r\n                <>2__current = <next>5__3;\r\n                <>1__state = 2;\r\n                return true;\r\n            case 2:\r\n                <>1__state = -1;\r\n                break;\r\n            case 3:\r\n                <>1__state = -1;\r\n                <prev>5__2 = <next>5__3;\r\n                <next>5__3 = <sum>5__4;\r\n                break;\r\n        }\r\n        <sum>5__4 = <prev>5__2 + <next>5__3;\r\n        <>2__current = <sum>5__4;\r\n        <>1__state = 3;\r\n        return true;\r\n    }\r\n\r\n    IEnumerator<int> IEnumerable<int>.GetEnumerator()\r\n    {\r\n        if (<>1__state == -2 &&\r\n            <>l__initialThreadId == Environment.CurrentManagedThreadId)\r\n        {\r\n            <>1__state = 0;\r\n            return this;\r\n        }\r\n        return new <Fib>d__0(0);\r\n    }\r\n\r\n    IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable<int>)this).GetEnumerator();\r\n    void IEnumerator.Reset() => throw new NotSupportedException();\r\n    void IDisposable.Dispose() { }\r\n}<\/code><\/pre>\n
      \u6240\u6709\u5173\u4e8eFib\u7684\u903b\u8f91\u73b0\u5728\u90fd\u5728MoveNext\u65b9\u6cd5\u4e2d\uff0c\u4f46\u662f\u4f5c\u4e3a\u8df3\u8f6c\u8868\u7684\u4e00\u90e8\u5206\uff0c\u5b83\u5141\u8bb8\u5b9e\u73b0\u5206\u652f\u5230\u5b83\u4e0a\u6b21\u79bb\u5f00\u7684\u4f4d\u7f6e\uff0c\u8fd9\u5728\u679a\u4e3e\u5668\u7c7b\u578b\u4e0a\u751f\u6210\u7684\u72b6\u6001\u5b57\u6bb5\u4e2d\u88ab\u8ddf\u8e2a\u3002\u800c\u6211\u5199\u7684\u5c40\u90e8\u53d8\u91cf\uff0c\u5982prev\u3001next\u548csum\uff0c\u5df2\u7ecf\u88ab “\u63d0\u5347 “\u4e3a\u679a\u4e3e\u5668\u4e0a\u7684\u5b57\u6bb5\uff0c\u8fd9\u6837\u5b83\u4eec\u5c31\u53ef\u4ee5\u5728\u8c03\u7528MoveNext\u65f6\u6301\u7eed\u5b58\u5728\u3002<\/p>\n
       <\/p>\n
      (\u6ce8\u610f\uff0c\u524d\u9762\u7684\u4ee3\u7801\u7247\u6bb5\u663e\u793a\u4e86C#\u7f16\u8bd1\u5668\u662f\u5982\u4f55\u53d1\u51fa\u5b9e\u73b0\u7684\uff0c\u5b83\u4e0d\u4f1a\u6309\u539f\u6837\u7f16\u8bd1\u3002C#\u7f16\u8bd1\u5668\u5408\u6210\u4e86 “\u4e0d\u53ef\u8bf4 “\u7684\u540d\u5b57\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u4ee5\u4e00\u79cd\u6709\u6548\u7684IL\u4f46\u65e0\u6548\u7684C#\u65b9\u5f0f\u547d\u540d\u5b83\u6240\u521b\u5efa\u7684\u7c7b\u578b\u548c\u6210\u5458\uff0c\u8fd9\u6837\u5c31\u4e0d\u4f1a\u4e0e\u4efb\u4f55\u7528\u6237\u547d\u540d\u7684\u7c7b\u578b\u548c\u6210\u5458\u51b2\u7a81\u3002\u6211\u4fdd\u7559\u4e86\u7f16\u8bd1\u5668\u7684\u6240\u6709\u540d\u79f0\uff0c\u4f46\u5982\u679c\u4f60\u60f3\u5c1d\u8bd5\u7f16\u8bd1\u5b83\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u6709\u6548\u7684c#\u540d\u79f0\u91cd\u547d\u540d\u3002)<\/p>\n
       <\/p>\n
      \u5728\u6211\u4e4b\u524d\u7684\u4f8b\u5b50\u4e2d\uff0c\u6211\u5c55\u793a\u7684\u6700\u540e\u4e00\u79cd\u679a\u4e3e\u5f62\u5f0f\u6d89\u53ca\u624b\u52a8\u4f7f\u7528IEnumerator<T>\u3002\u5728\u90a3\u4e2a\u5c42\u9762\u4e0a\uff0c\u6211\u4eec\u624b\u52a8\u8c03\u7528MoveNext()\uff0c\u51b3\u5b9a\u4f55\u65f6\u662f\u91cd\u65b0\u8fdb\u5165\u5faa\u73af\u7a0b\u5e8f\u7684\u9002\u5f53\u65f6\u673a\u3002\u4f46\u662f……\u5982\u679c\u4e0d\u8fd9\u6837\u8c03\u7528\u5b83\uff0c\u800c\u662f\u8ba9MoveNext\u7684\u4e0b\u4e00\u6b21\u8c03\u7528\u5b9e\u9645\u6210\u4e3a\u5f02\u6b65\u64cd\u4f5c\u5b8c\u6210\u65f6\u6267\u884c\u7684\u5ef6\u7eed\u5de5\u4f5c\u7684\u4e00\u90e8\u5206\u5462\uff1f\u5982\u679c\u6211\u53ef\u4ee5yield\u8fd4\u56de\u4e00\u4e9b\u4ee3\u8868\u5f02\u6b65\u64cd\u4f5c\u7684\u4e1c\u897f\uff0c\u5e76\u8ba9\u6d88\u8017\u4ee3\u7801\u5c06continuation\u8fde\u63a5\u5230\u8be5yield\u5bf9\u8c61\uff0c\u7136\u540e\u5728\u8be5continuation\u6267\u884cMoveNext\u65f6\u4f1a\u600e\u4e48\u6837?\u4f7f\u7528\u8fd9\u79cd\u65b9\u6cd5\uff0c\u6211\u53ef\u4ee5\u7f16\u5199\u4e00\u4e2a\u8f85\u52a9\u65b9\u6cd5:<\/p>\n
      static Task IterateAsync(IEnumerable<Task> tasks)\r\n{\r\n    var tcs = new TaskCompletionSource();\r\n\r\n    IEnumerator<Task> e = tasks.GetEnumerator();\r\n\r\n    void Process()\r\n    {\r\n        try\r\n        {\r\n            if (e.MoveNext())\r\n            {\r\n                e.Current.ContinueWith(t => Process());\r\n                return;\r\n            }\r\n        }\r\n        catch (Exception e)\r\n        {\r\n            tcs.SetException(e);\r\n            return;\r\n        }\r\n        tcs.SetResult();\r\n    };\r\n    Process();\r\n\r\n    return tcs.Task;\r\n}<\/code><\/pre>\n
       <\/p>\n
      \u73b0\u5728\u53d8\u5f97\u6709\u8da3\u4e86\u3002\u6211\u4eec\u5f97\u5230\u4e86\u4e00\u4e2a\u53ef\u8fed\u4ee3\u7684\u4efb\u52a1\u5217\u8868\u3002\u6bcf\u6b21\u6211\u4eecMoveNext\u00a0\u5230\u4e0b\u4e00\u4e2aTask\u00a0\u5e76\u83b7\u5f97\u4e00\u4e2a\u65f6\uff0c\u6211\u4eec\u5c06\u8be5\u4efb\u52a1\u7684continuation\u8fde\u63a5\u8d77\u6765;\u5f53\u8fd9\u4e2aTask\u00a0\u5b8c\u6210\u65f6\uff0c\u5b83\u53ea\u4f1a\u56de\u8fc7\u5934\u6765\u8c03\u7528\u6267\u884cMoveNext\u3001\u83b7\u53d6\u4e0b\u4e00\u4e2aTask\u00a0\u7684\u76f8\u540c\u903b\u8f91\uff0c\u4ee5\u6b64\u7c7b\u63a8\u3002\u8fd9\u662f\u5efa\u7acb\u5728\u5c06Task\u00a0\u4f5c\u4e3a\u4efb\u4f55\u5f02\u6b65\u64cd\u4f5c\u7684\u5355\u4e00\u8868\u793a\u7684\u601d\u60f3\u4e4b\u4e0a\u7684\uff0c\u6240\u4ee5\u6211\u4eec\u8f93\u5165\u7684\u679a\u4e3e\u8868\u53ef\u4ee5\u662f\u4e00\u4e2a\u4efb\u4f55\u5f02\u6b65\u64cd\u4f5c\u7684\u5e8f\u5217\u3002\u8fd9\u6837\u7684\u5e8f\u5217\u662f\u4ece\u54ea\u91cc\u6765\u7684\u5462?\u5f53\u7136\u662f\u901a\u8fc7\u8fed\u4ee3\u5668\u3002\u8fd8\u8bb0\u5f97\u6211\u4eec\u4e4b\u524d\u7684CopyStreamToStream\u4f8b\u5b50\u5417\uff0c\u4ee5\u53ca\u57fa\u4e8eAPM\u7684\u5b9e\u73b0\u662f\u591a\u4e48\u7684\u5149\u8363\u800c\u53ef\u6015\uff1f\u8003\u8651\u4e00\u4e0b\u8fd9\u4e2a\uff1a<\/p>\n
      static Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    return IterateAsync(Impl(source, destination));\r\n\r\n    static IEnumerable<Task> Impl(Stream source, Stream destination)\r\n    {\r\n        var buffer = new byte[0x1000];\r\n        while (true)\r\n        {\r\n            Task<int> read = source.ReadAsync(buffer, 0, buffer.Length);\r\n            yield return read;\r\n            int numRead = read.Result;\r\n            if (numRead <= 0)\r\n            {\r\n                break;\r\n            }\r\n\r\n            Task write = destination.WriteAsync(buffer, 0, numRead);\r\n            yield return write;\r\n            write.Wait();\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
      \u54c7\uff0c\u8fd9\u51e0\u4e4e\u53ef\u4ee5\u8fa8\u8ba4\u4e86\u3002\u6211\u4eec\u6b63\u5728\u8c03\u7528\u90a3\u4e2aIterateAsync\u52a9\u624b\uff0c\u800c\u6211\u4eec\u63d0\u4f9b\u7ed9\u5b83\u7684\u679a\u4e3e\u8868\u662f\u7531\u4e00\u4e2a\u5904\u7406\u6240\u6709\u63a7\u5236\u6d41\u7684\u8fed\u4ee3\u5668\u4ea7\u751f\u7684\u3002\u5b83\u8c03\u7528Stream.ReadAsync\u7136\u540eyield\u8fd4\u56deTask;yield task\u5728\u8c03\u7528MoveNext\u4e4b\u540e\u4f1a\u88ab\u4f20\u9012\u7ed9IterateAsync\uff0c\u800cIterateAsync\u4f1a\u5c06\u4e00\u4e2acontinuation\u6302\u63a5\u5230\u90a3\u4e2atask\u4e0a\uff0c\u5f53\u5b83\u5b8c\u6210\u65f6\uff0c\u5b83\u4f1a\u56de\u8c03MoveNext\u5e76\u5728yield\u4e4b\u540e\u56de\u5230\u8fd9\u4e2a\u8fed\u4ee3\u5668\u3002\u6b64\u65f6\uff0cImpl\u903b\u8f91\u83b7\u5f97\u65b9\u6cd5\u7684\u7ed3\u679c\uff0c\u8c03\u7528WriteAsync\uff0c\u5e76\u518d\u6b21\u751f\u6210\u5b83\u751f\u6210\u7684Task\u3002\u4ee5\u6b64\u7c7b\u63a8\u3002<\/p>\n
       <\/p>\n
      \u6211\u7684\u670b\u53cb\uff0c\u8fd9\u5c31\u662fC#\u548c.NET\u4e2dasync\/await\u7684\u5f00\u59cb\u3002\u5728C#\u7f16\u8bd1\u5668\u4e2d\u652f\u6301\u8fed\u4ee3\u5668\u548casync\/await\u7684\u903b\u8f91\u4e2d\uff0c\u5927\u7ea6\u670995%\u5de6\u53f3\u7684\u903b\u8f91\u662f\u5171\u4eab\u7684\u3002\u4e0d\u540c\u7684\u8bed\u6cd5\uff0c\u4e0d\u540c\u7684\u7c7b\u578b\uff0c\u4f46\u672c\u8d28\u4e0a\u662f\u76f8\u540c\u7684\u8f6c\u6362\u3002\u77a5\u4e00\u773cyield returns, \u4f60\u51e0\u4e4e\u53ef\u4ee5\u770b\u5230\u7b49\u5f85\u4ed6\u4eec\u7684\u662f\u4ec0\u4e48\u3002<\/p>\n
       <\/p>\n
      \u4e8b\u5b9e\u4e0a\uff0c\u5728async\/await\u51fa\u73b0\u4e4b\u524d\uff0c\u4e00\u4e9b\u6709\u8fdb\u53d6\u5fc3\u7684\u5f00\u53d1\u4eba\u5458\u5c31\u4ee5\u8fd9\u79cd\u65b9\u5f0f\u4f7f\u7528\u8fed\u4ee3\u5668\u8fdb\u884c\u5f02\u6b65\u7f16\u7a0b<\/a>\u3002\u5728\u5b9e\u9a8c\u6027\u7684Axum<\/a><\/u>\u7f16\u7a0b\u8bed\u8a00\u4e2d\u4e5f\u6709\u7c7b\u4f3c\u7684\u8f6c\u6362\u539f\u578b\uff0c\u8fd9\u662fc#\u652f\u6301\u5f02\u6b65\u7684\u5173\u952e\u7075\u611f\u6765\u6e90\u3002Axum\u63d0\u4f9b\u4e86\u4e00\u4e2a\u53ef\u4ee5\u653e\u5728\u65b9\u6cd5\u4e0a\u7684async\u5173\u952e\u5b57\uff0c\u5c31\u50cfc#\u4e2d\u7684async\u4e00\u6837\u3002<\/p>\n
      Task\u8fd8\u4e0d\u666e\u904d\uff0c\u6240\u4ee5\u5728\u5f02\u6b65\u65b9\u6cd5\u4e2d\uff0cAxum\u7f16\u8bd1\u5668\u542f\u53d1\u5f0f\u5730\u5c06\u540c\u6b65\u65b9\u6cd5\u8c03\u7528\u4e0eAPM\u5bf9\u5e94\u7684\u65b9\u6cd5\u76f8\u5339\u914d\uff0c\u4f8b\u5982\uff0c\u5982\u679c\u5b83\u770b\u5230\u4f60\u8c03\u7528stream.Read\uff0c\u5b83\u4f1a\u627e\u5230\u5e76\u5229\u7528\u76f8\u5e94\u7684stream.BeginRead\u548cstream.EndRead\u65b9\u6cd5\uff0c\u5408\u6210\u9002\u5f53\u7684\u59d4\u6258\u4f20\u9012\u7ed9Begin\u65b9\u6cd5\uff0c\u540c\u65f6\u8fd8\u4e3a\u5b9a\u4e49\u4e3a\u53ef\u7ec4\u5408\u7684async\u65b9\u6cd5\u751f\u6210\u5b8c\u6574\u7684APM\u5b9e\u73b0\u3002\u5b83\u751a\u81f3\u8fd8\u96c6\u6210\u4e86SynchronizationContext! \u867d\u7136Axum\u6700\u7ec8\u88ab\u6401\u7f6e\uff0c\u4f46\u5b83\u4e3ac#\u4e2d\u7684async\/await\u63d0\u4f9b\u4e86\u4e00\u4e2a\u5f88\u68d2\u7684\u539f\u578b\u3002<\/p>\n
       <\/p>\n
      async\/await under the covers<\/h2>\n
      \u73b0\u5728\u6211\u4eec\u77e5\u9053\u4e86\u6211\u4eec\u662f\u5982\u4f55\u505a\u5230\u8fd9\u4e00\u70b9\u7684\uff0c\u8ba9\u6211\u4eec\u6df1\u5165\u7814\u7a76\u5b83\u5b9e\u9645\u4e0a\u662f\u5982\u4f55\u5de5\u4f5c\u7684\u3002\u4f5c\u4e3a\u53c2\u8003\uff0c\u4e0b\u9762\u662f\u6211\u4eec\u7684\u540c\u6b65\u65b9\u6cd5\u793a\u4f8b:<\/p>\n
      public void CopyStreamToStream(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = source.Read(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        destination.Write(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
      \u4e0b\u9762\u662fasync\/await\u5bf9\u5e94\u7684\u65b9\u6cd5:<\/p>\n
      public async Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = await source.ReadAsync(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        await destination.WriteAsync(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
      \u4e0e\u6211\u4eec\u8fc4\u4eca\u4e3a\u6b62\u6240\u89c1\u7684\u4e00\u5207\u76f8\u6bd4\uff0c\u8fd9\u91cc\u7a7a\u6c14\u6e05\u65b0\u3002\u7b7e\u540d\u4ecevoid\u53d8\u6210\u4e86async Task\uff0c\u6211\u4eec\u5206\u522b\u8c03\u7528\u4e86ReadAsync\u548cWriteAsync\uff0c\u800c\u4e0d\u662fRead\u548cWrite\uff0c\u8fd9\u4e24\u4e2a\u64cd\u4f5c\u90fd\u5e26await\u524d\u7f00\u3002\u5c31\u662f\u8fd9\u6837\u3002\u7f16\u8bd1\u5668\u548c\u6838\u5fc3\u5e93\u63a5\u7ba1\u4e86\u5176\u4f59\u90e8\u5206\uff0c\u4ece\u6839\u672c\u4e0a\u6539\u53d8\u4e86\u4ee3\u7801\u5b9e\u9645\u6267\u884c\u7684\u65b9\u5f0f\u3002\u8ba9\u6211\u4eec\u6df1\u5165\u4e86\u89e3\u4e00\u4e0b\u662f\u5982\u4f55\u505a\u5230\u7684\u3002<\/p>\n
       <\/p>\n
      \u7f16\u8bd1\u5668\u8f6c\u6362<\/strong><\/p>\n
      \u6211\u4eec\u5df2\u7ecf\u770b\u5230\uff0c\u548c\u8fed\u4ee3\u5668\u4e00\u6837\uff0c\u7f16\u8bd1\u5668\u57fa\u4e8e\u72b6\u6001\u673a\u91cd\u5199\u4e86async\u65b9\u6cd5\u3002\u6211\u4eec\u4ecd\u7136\u6709\u4e00\u4e2a\u4e0e\u5f00\u53d1\u4eba\u5458\u5199\u7684\u7b7e\u540d\u76f8\u540c\u7684\u65b9\u6cd5(public Task CopyStreamToStreamAsync(Stream source, Stream destination))\uff0c\u4f46\u8be5\u65b9\u6cd5\u7684\u4e3b\u4f53\u5b8c\u5168\u4e0d\u540c:<\/p>\n
      [AsyncStateMachine(typeof(<CopyStreamToStreamAsync>d__0))]\r\npublic Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    <CopyStreamToStreamAsync>d__0 stateMachine = default;\r\n    stateMachine.<>t__builder = AsyncTaskMethodBuilder.Create();\r\n    stateMachine.source = source;\r\n    stateMachine.destination = destination;\r\n    stateMachine.<>1__state = -1;\r\n    stateMachine.<>t__builder.Start(ref stateMachine);\r\n    return stateMachine.<>t__builder.Task;\r\n}\r\n\r\nprivate struct <CopyStreamToStreamAsync>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    public Stream source;\r\n    public Stream destination;\r\n    private byte[] <buffer>5__2;\r\n    private TaskAwaiter <>u__1;\r\n    private TaskAwaiter<int> <>u__2;\r\n\r\n    ...\r\n}<\/code><\/pre>\n
      \u6ce8\u610f\uff0c\u4e0e\u5f00\u53d1\u4eba\u5458\u6240\u5199\u7684\u7b7e\u540d\u7684\u552f\u4e00\u533a\u522b\u662f\u7f3a\u5c11async\u5173\u952e\u5b57\u672c\u8eab\u3002Async\u5b9e\u9645\u4e0a\u4e0d\u662f\u65b9\u6cd5\u7b7e\u540d\u7684\u4e00\u90e8\u5206;\u5c31\u50cfunsafe\u4e00\u6837\uff0c\u5f53\u4f60\u628a\u5b83\u653e\u5728\u65b9\u6cd5\u7b7e\u540d\u4e2d\uff0c\u4f60\u662f\u5728\u8868\u8fbe\u65b9\u6cd5\u7684\u5b9e\u73b0\u7ec6\u8282\uff0c\u800c\u4e0d\u662f\u4f5c\u4e3a\u5951\u7ea6\u7684\u4e00\u90e8\u5206\u5b9e\u9645\u516c\u5f00\u51fa\u6765\u7684\u4e1c\u897f\u3002\u4f7f\u7528async\/await\u5b9e\u73b0task -return\u65b9\u6cd5\u662f\u5b9e\u73b0\u7ec6\u8282\u3002<\/p>\n
       <\/p>\n
      \u7f16\u8bd1\u5668\u5df2\u7ecf\u751f\u6210\u4e86\u4e00\u4e2a\u540d\u4e3a<CopyStreamToStreamAsync>d__0\u7684\u7ed3\u6784\u4f53\uff0c\u5e76\u4e14\u5b83\u5728\u5806\u6808\u4e0a\u5bf9\u8be5\u7ed3\u6784\u4f53\u7684\u5b9e\u4f8b\u8fdb\u884c\u4e86\u96f6\u521d\u59cb\u5316\u3002\u91cd\u8981\u7684\u662f\uff0c\u5982\u679c\u5f02\u6b65\u65b9\u6cd5\u540c\u6b65\u5b8c\u6210\uff0c\u8be5\u72b6\u6001\u673a\u5c06\u6c38\u8fdc\u4e0d\u4f1a\u79bb\u5f00\u5806\u6808\u3002\u8fd9\u610f\u5473\u7740\u6ca1\u6709\u4e0e\u72b6\u6001\u673a\u76f8\u5173\u7684\u5206\u914d\uff0c\u9664\u975e\u8be5\u65b9\u6cd5\u9700\u8981\u5f02\u6b65\u5b8c\u6210\uff0c\u4e5f\u5c31\u662f\u8bf4\u5b83\u9700\u8981\u7b49\u5f85\u4e00\u4e9b\u5c1a\u672a\u5b8c\u6210\u7684\u4efb\u52a1\u3002\u7a0d\u540e\u4f1a\u6709\u66f4\u591a\u5173\u4e8e\u8fd9\u65b9\u9762\u7684\u5185\u5bb9\u3002<\/p>\n
       <\/p>\n
      \u8be5\u7ed3\u6784\u4f53\u662f\u65b9\u6cd5\u7684\u72b6\u6001\u673a\uff0c\u4e0d\u4ec5\u5305\u542b\u5f00\u53d1\u4eba\u5458\u7f16\u5199\u7684\u6240\u6709\u8f6c\u6362\u903b\u8f91\uff0c\u8fd8\u5305\u542b\u7528\u4e8e\u8ddf\u8e2a\u8be5\u65b9\u6cd5\u4e2d\u5f53\u524d\u4f4d\u7f6e\u7684\u5b57\u6bb5\uff0c\u4ee5\u53ca\u7f16\u8bd1\u5668\u4ece\u65b9\u6cd5\u4e2d\u63d0\u53d6\u7684\u6240\u6709\u201c\u672c\u5730\u201d\u72b6\u6001\uff0c\u8fd9\u4e9b\u72b6\u6001\u9700\u8981\u5728MoveNext\u8c03\u7528\u4e4b\u95f4\u751f\u5b58\u3002\u5b83\u5728\u903b\u8f91\u4e0a\u7b49\u4ef7\u4e8e\u8fed\u4ee3\u5668\u4e2d\u7684IEnumerable<T>\/IEnumerator<T>\u5b9e\u73b0\u3002(\u8bf7\u6ce8\u610f\uff0c\u6211\u5c55\u793a\u7684\u4ee3\u7801\u6765\u81ea\u53d1\u5e03\u7248\u672c;\u5728\u8c03\u8bd5\u6784\u5efa\u4e2d\uff0cc#\u7f16\u8bd1\u5668\u5c06\u5b9e\u9645\u751f\u6210\u8fd9\u4e9b\u72b6\u6001\u673a\u7c7b\u578b\u4f5c\u4e3a\u7c7b\uff0c\u56e0\u4e3a\u8fd9\u6837\u505a\u53ef\u4ee5\u5e2e\u52a9\u67d0\u4e9b\u8c03\u8bd5\u5de5\u4f5c)\u3002<\/p>\n
       <\/p>\n
      \u5728\u521d\u59cb\u5316\u72b6\u6001\u673a\u4e4b\u540e\uff0c\u6211\u4eec\u770b\u5230\u5bf9AsyncTaskMethodBuilder.Create()<\/a>\u7684\u8c03\u7528\u3002\u867d\u7136\u6211\u4eec\u76ee\u524d\u5173\u6ce8\u7684\u662fTasks\uff0c\u4f46c#\u8bed\u8a00\u548c\u7f16\u8bd1\u5668\u5141\u8bb8\u4ece\u5f02\u6b65\u65b9\u6cd5\u8fd4\u56de\u4efb\u610f\u7c7b\u578b(\u201ctask-like<\/a>\u201d\u7c7b\u578b)\uff0c\u4f8b\u5982\uff0c\u6211\u53ef\u4ee5\u7f16\u5199\u4e00\u4e2a\u65b9\u6cd5public async MyTask CopyStreamToStreamAsync\uff0c\u53ea\u8981\u6211\u4eec\u4ee5\u9002\u5f53\u7684\u65b9\u5f0f\u6269\u5c55\u6211\u4eec\u524d\u9762\u5b9a\u4e49\u7684MyTask\uff0c\u5b83\u5c31\u80fd\u987a\u5229\u7f16\u8bd1\u3002\u8fd9\u79cd\u9002\u5f53\u6027\u5305\u62ec\u58f0\u660e\u4e00\u4e2a\u76f8\u5173\u7684\u201cbuilder\u201d\u7c7b\u578b\uff0c\u5e76\u901a\u8fc7AsyncMethodBuilder\u5c5e\u6027\u5c06\u5176\u4e0e\u8be5\u7c7b\u578b\u5173\u8054\u8d77\u6765:<\/p>\n
      [AsyncMethodBuilder(typeof(MyTaskMethodBuilder))]\r\npublic class MyTask\r\n{\r\n    ...\r\n}\r\n\r\npublic struct MyTaskMethodBuilder\r\n{\r\n    public static MyTaskMethodBuilder Create() { ... }\r\n\r\n    public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine { ... }\r\n    public void SetStateMachine(IAsyncStateMachine stateMachine) { ... }\r\n\r\n    public void SetResult() { ... }\r\n    public void SetException(Exception exception) { ... }\r\n\r\n    public void AwaitOnCompleted<TAwaiter, TStateMachine>(\r\n        ref TAwaiter awaiter, ref TStateMachine stateMachine)\r\n        where TAwaiter : INotifyCompletion\r\n        where TStateMachine : IAsyncStateMachine { ... }\r\n    public void AwaitUnsafeOnCompleted<TAwaiter, TStateMachine>(\r\n        ref TAwaiter awaiter, ref TStateMachine stateMachine)\r\n        where TAwaiter : ICriticalNotifyCompletion\r\n        where TStateMachine : IAsyncStateMachine { ... }\r\n\r\n    public MyTask Task { get { ... } }\r\n}<\/code><\/pre>\n
      \u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u8fd9\u6837\u7684\u201cbuilder\u201d\u77e5\u9053\u5982\u4f55\u521b\u5efa\u8be5\u7c7b\u578b\u7684\u5b9e\u4f8b(Task\u5c5e\u6027)\uff0c\u5982\u4f55\u6210\u529f\u5b8c\u6210\u5e76\u5728\u9002\u5f53\u7684\u60c5\u51b5\u4e0b\u6709\u7ed3\u679c(SetResult)\u6216\u6709\u5f02\u5e38(SetException)\uff0c\u4ee5\u53ca\u5982\u4f55\u5904\u7406\u8fde\u63a5\u7b49\u5f85\u5c1a\u672a\u5b8c\u6210\u7684\u4e8b\u52a1\u7684\u5ef6\u7eed(AwaitOnCompleted\/AwaitUnsafeOnCompleted)\u3002\u5728System.Threading.Tasks.Task\u7684\u60c5\u51b5\u4e0b\uff0c\u5b83\u9ed8\u8ba4\u4e0eAsyncTaskMethodBuilder\u76f8\u5173\u8054\u3002\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u8fd9\u79cd\u5173\u8054\u662f\u901a\u8fc7\u5e94\u7528\u5728\u7c7b\u578b\u4e0a\u7684[AsyncMethodBuilder(\u2026)]\u5c5e\u6027\u63d0\u4f9b\u7684\uff0c\u4f46\u5728c#\u4e2d\uff0cTask\u662f\u5df2\u77e5\u7684\uff0c\u56e0\u6b64\u5b9e\u9645\u4e0a\u6ca1\u6709\u8be5\u5c5e\u6027\u3002\u56e0\u6b64\uff0c\u7f16\u8bd1\u5668\u5df2\u7ecf\u8ba9\u6784\u5efa\u5668\u4f7f\u7528\u8fd9\u4e2a\u5f02\u6b65\u65b9\u6cd5\uff0c\u5e76\u4f7f\u7528\u6a21\u5f0f\u4e2d\u7684Create\u65b9\u6cd5\u6784\u5efa\u5b83\u7684\u5b9e\u4f8b\u3002\u8bf7\u6ce8\u610f\uff0c\u4e0e\u72b6\u6001\u673a\u4e00\u6837\uff0cAsyncTaskMethodBuilder\u4e5f\u662f\u4e00\u4e2a\u7ed3\u6784\u4f53\uff0c\u56e0\u6b64\u8fd9\u91cc\u4e5f\u6ca1\u6709\u5185\u5b58\u5206\u914d\u3002<\/p>\n
       <\/p>\n
      \u7136\u540e\u7528\u8fd9\u4e2a\u5165\u53e3\u70b9\u65b9\u6cd5\u7684\u53c2\u6570\u586b\u5145\u72b6\u6001\u673a\u3002\u8fd9\u4e9b\u53c2\u6570\u9700\u8981\u80fd\u591f\u88ab\u79fb\u52a8\u5230MoveNext\u4e2d\u7684\u65b9\u6cd5\u4f53\u8bbf\u95ee\uff0c\u56e0\u6b64\u8fd9\u4e9b\u53c2\u6570\u9700\u8981\u5b58\u50a8\u5728\u72b6\u6001\u673a\u4e2d\uff0c\u4ee5\u4fbf\u540e\u7eed\u8c03\u7528MoveNext\u65f6\u4ee3\u7801\u53ef\u4ee5\u5f15\u7528\u5b83\u4eec\u3002\u8be5\u72b6\u6001\u673a\u4e5f\u88ab\u521d\u59cb\u5316\u4e3a\u521d\u59cb-1\u72b6\u6001\u3002\u5982\u679cMoveNext\u88ab\u8c03\u7528\u4e14\u72b6\u6001\u4e3a-1\uff0c\u90a3\u4e48\u903b\u8f91\u4e0a\u6211\u4eec\u5c06\u4ece\u65b9\u6cd5\u7684\u5f00\u59cb\u5904\u5f00\u59cb\u3002<\/p>\n
       <\/p>\n
      \u73b0\u5728\u662f\u6700\u4e0d\u663e\u773c\u4f46\u6700\u91cd\u8981\u7684\u4e00\u884c:\u8c03\u7528\u6784\u5efa\u5668\u7684Start<\/a>\u65b9\u6cd5\u3002\u8fd9\u662f\u6a21\u5f0f\u7684\u53e6\u4e00\u90e8\u5206\uff0c\u5fc5\u987b\u5728async\u65b9\u6cd5\u7684\u8fd4\u56de\u4f4d\u7f6e\u6240\u4f7f\u7528\u7684\u7c7b\u578b\u4e0a\u516c\u5f00\uff0c\u5b83\u7528\u4e8e\u5728\u72b6\u6001\u673a\u4e0a\u6267\u884c\u521d\u59cb\u7684MoveNext\u3002\u6784\u5efa\u5668\u7684Start\u65b9\u6cd5\u5b9e\u9645\u4e0a\u662f\u8fd9\u6837\u7684:<\/p>\n
      public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine\r\n{\r\n    stateMachine.MoveNext();\r\n}<\/code><\/pre>\n
      \u4f8b\u5982\uff0c\u8c03\u7528stateMachine.<>t__builder.Start(ref stateMachine); \u5b9e\u9645\u4e0a\u53ea\u662f\u8c03\u7528stateMachine.MoveNext()\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u4e3a\u4ec0\u4e48\u7f16\u8bd1\u5668\u4e0d\u76f4\u63a5\u53d1\u51fa\u8fd9\u4e2a\u4fe1\u53f7\u5462\uff1f\u4e3a\u4ec0\u4e48\u8fd8\u8981\u6709Start\u5462\uff1f\u7b54\u6848\u662f\uff0cStart\u7684\u5185\u5bb9\u6bd4\u6211\u6240\u8bf4\u7684\u8981\u591a\u4e00\u70b9\u3002\u4f46\u4e3a\u6b64\uff0c\u6211\u4eec\u9700\u8981\u7b80\u5355\u5730\u4e86\u89e3\u4e00\u4e0bExecutionContext\u3002<\/p>\n
       <\/p>\n
      ExecutionContext<\/strong><\/p>\n
      \u6211\u4eec\u90fd\u719f\u6089\u5728\u65b9\u6cd5\u4e4b\u95f4\u4f20\u9012\u72b6\u6001\u3002\u8c03\u7528\u4e00\u4e2a\u65b9\u6cd5\uff0c\u5982\u679c\u8be5\u65b9\u6cd5\u6307\u5b9a\u4e86\u5f62\u53c2\uff0c\u5c31\u4f7f\u7528\u5b9e\u53c2\u8c03\u7528\u8be5\u65b9\u6cd5\uff0c\u4ee5\u4fbf\u5c06\u8be5\u6570\u636e\u4f20\u9012\u7ed9\u88ab\u8c03\u7528\u65b9\u3002\u8fd9\u662f\u663e\u5f0f\u4f20\u9012\u6570\u636e\u3002\u4f46\u8fd8\u6709\u5176\u4ed6\u66f4\u9690\u853d\u7684\u65b9\u6cd5\u3002\u4f8b\u5982\uff0c\u65b9\u6cd5\u53ef\u4ee5\u662f\u65e0\u53c2\u6570\u7684\uff0c\u4f46\u53ef\u4ee5\u6307\u5b9a\u5728\u8c03\u7528\u65b9\u6cd5\u4e4b\u524d\u586b\u5145\u67d0\u4e9b\u7279\u5b9a\u7684\u9759\u6001\u5b57\u6bb5\uff0c\u7136\u540e\u4ece\u90a3\u91cc\u83b7\u53d6\u72b6\u6001\u3002\u8fd9\u4e2a\u65b9\u6cd5\u7684\u7b7e\u540d\u4e2d\u6ca1\u6709\u4efb\u4f55\u4e1c\u897f\u8868\u660e\u5b83\u63a5\u6536\u53c2\u6570\uff0c\u56e0\u4e3a\u5b83\u786e\u5b9e\u6ca1\u6709:\u53ea\u662f\u8c03\u7528\u8005\u548c\u88ab\u8c03\u7528\u8005\u4e4b\u95f4\u6709\u4e00\u4e2a\u9690\u542b\u7684\u7ea6\u5b9a\uff0c\u5373\u8c03\u7528\u8005\u53ef\u80fd\u586b\u5145\u67d0\u4e9b\u5185\u5b58\u4f4d\u7f6e\uff0c\u800c\u88ab\u8c03\u7528\u8005\u53ef\u80fd\u8bfb\u53d6\u8fd9\u4e9b\u5185\u5b58\u4f4d\u7f6e\u3002\u88ab\u8c03\u7528\u8005\u548c\u8c03\u7528\u8005\u751a\u81f3\u53ef\u80fd\u6ca1\u6709\u610f\u8bc6\u5230\u5b83\u7684\u53d1\u751f\uff0c\u5982\u679c\u4ed6\u4eec\u662f\u4e2d\u4ecb\uff0c\u65b9\u6cd5A\u53ef\u80fd\u586b\u5145\u9759\u6001\u4fe1\u606f\uff0c\u7136\u540e\u8c03\u7528B, B\u8c03\u7528C, C\u8c03\u7528D\uff0c\u6700\u7ec8\u8c03\u7528E\uff0c\u8bfb\u53d6\u8fd9\u4e9b\u9759\u6001\u4fe1\u606f\u7684\u503c\u3002\u8fd9\u901a\u5e38\u88ab\u79f0\u4e3a\u201c\u73af\u5883\u201d\u6570\u636e:\u5b83\u4e0d\u662f\u901a\u8fc7\u53c2\u6570\u4f20\u9012\u7ed9\u4f60\u7684\uff0c\u800c\u662f\u6302\u5728\u90a3\u91cc\uff0c\u5982\u679c\u9700\u8981\u7684\u8bdd\uff0c\u4f60\u53ef\u4ee5\u4f7f\u7528\u3002<\/p>\n
       <\/p>\n
      \u6211\u4eec\u53ef\u4ee5\u66f4\u8fdb\u4e00\u6b65\uff0c\u4f7f\u7528\u7ebf\u7a0b\u5c40\u90e8\u72b6\u6001\u3002\u7ebf\u7a0b\u5c40\u90e8\u72b6\u6001\uff0c\u5728.net\u4e2d\u662f\u901a\u8fc7\u5c5e\u6027\u4e3a[ThreadStatic]\u7684\u9759\u6001\u5b57\u6bb5\u6216\u901a\u8fc7ThreadLocal<T>\u7c7b\u578b\u5b9e\u73b0\u7684\uff0c\u53ef\u4ee5\u4ee5\u76f8\u540c\u7684\u65b9\u5f0f\u4f7f\u7528\uff0c\u4f46\u6570\u636e\u4ec5\u9650\u4e8e\u5f53\u524d\u6267\u884c\u7684\u7ebf\u7a0b\uff0c\u6bcf\u4e2a\u7ebf\u7a0b\u90fd\u80fd\u591f\u62e5\u6709\u8fd9\u4e9b\u5b57\u6bb5\u7684\u81ea\u5df1\u7684\u9694\u79bb\u526f\u672c\u3002\u8fd9\u6837\uff0c\u60a8\u5c31\u53ef\u4ee5\u586b\u5145\u7ebf\u7a0b\u9759\u6001\uff0c\u8fdb\u884c\u65b9\u6cd5\u8c03\u7528\uff0c\u7136\u540e\u5728\u65b9\u6cd5\u5b8c\u6210\u540e\u5c06\u66f4\u6539\u8fd8\u539f\u5230\u7ebf\u7a0b\u9759\u6001\uff0c\u4ece\u800c\u542f\u7528\u8fd9\u79cd\u9690\u5f0f\u4f20\u9012\u6570\u636e\u7684\u5b8c\u5168\u9694\u79bb\u5f62\u5f0f\u3002<\/p>\n
       <\/p>\n
      \u4f46\u662f\uff0c\u5f02\u6b65\u5462?\u5982\u679c\u6211\u4eec\u8fdb\u884c\u5f02\u6b65\u65b9\u6cd5\u8c03\u7528\uff0c\u800c\u5f02\u6b65\u65b9\u6cd5\u4e2d\u7684\u903b\u8f91\u60f3\u8981\u8bbf\u95ee\u73af\u5883\u6570\u636e\uff0c\u5b83\u4f1a\u600e\u4e48\u505a?\u5982\u679c\u6570\u636e\u5b58\u50a8\u5728\u5e38\u89c4\u9759\u6001\u4e2d\uff0c\u5f02\u6b65\u65b9\u6cd5\u5c06\u80fd\u591f\u8bbf\u95ee\u5b83\uff0c\u4f46\u4e00\u6b21\u53ea\u80fd\u6709\u4e00\u4e2a\u8fd9\u6837\u7684\u65b9\u6cd5\u5728\u8fd0\u884c\uff0c\u56e0\u4e3a\u591a\u4e2a\u8c03\u7528\u8005\u5728\u5199\u5165\u8fd9\u4e9b\u5171\u4eab\u9759\u6001\u5b57\u6bb5\u65f6\u53ef\u80fd\u4f1a\u8986\u76d6\u5f7c\u6b64\u7684\u72b6\u6001\u3002\u5982\u679c\u6570\u636e\u5b58\u50a8\u5728\u7ebf\u7a0b\u9759\u6001\u4fe1\u606f\u4e2d\uff0c\u5f02\u6b65\u65b9\u6cd5\u5c06\u80fd\u591f\u8bbf\u95ee\u5b83\uff0c\u4f46\u53ea\u6709\u5728\u8c03\u7528\u7ebf\u7a0b\u505c\u6b62\u540c\u6b65\u8fd0\u884c\u4e4b\u524d;\u5982\u679c\u5b83\u5c06continuation\u8fde\u63a5\u5230\u5b83\u53d1\u8d77\u7684\u67d0\u4e2a\u64cd\u4f5c\uff0c\u5e76\u4e14\u8be5continuation\u6700\u7ec8\u5728\u67d0\u4e2a\u5176\u4ed6\u7ebf\u7a0b\u4e0a\u8fd0\u884c\uff0c\u90a3\u4e48\u5b83\u5c06\u4e0d\u518d\u80fd\u591f\u8bbf\u95ee\u7ebf\u7a0b\u9759\u6001\u4fe1\u606f\u3002\u5373\u4f7f\u5b83\u78b0\u5de7\u8fd0\u884c\u5728\u540c\u4e00\u4e2a\u7ebf\u7a0b\u4e0a\uff0c\u65e0\u8bba\u662f\u5076\u7136\u7684\u8fd8\u662f\u7531\u4e8e\u8c03\u5ea6\u5668\u7684\u5f3a\u5236\uff0c\u5728\u5b83\u8fd9\u6837\u505a\u7684\u65f6\u5019\uff0c\u6570\u636e\u53ef\u80fd\u5df2\u7ecf\u88ab\u8be5\u7ebf\u7a0b\u53d1\u8d77\u7684\u5176\u4ed6\u64cd\u4f5c\u5220\u9664\u548c\/\u6216\u8986\u76d6\u3002\u5bf9\u4e8e\u5f02\u6b65\uff0c\u6211\u4eec\u9700\u8981\u4e00\u79cd\u673a\u5236\uff0c\u5141\u8bb8\u4efb\u610f\u73af\u5883\u6570\u636e\u5728\u8fd9\u4e9b\u5f02\u6b65\u70b9\u4e0a\u6d41\u52a8\uff0c\u8fd9\u6837\u5728async\u65b9\u6cd5\u7684\u6574\u4e2a\u903b\u8f91\u4e2d\uff0c\u65e0\u8bba\u4f55\u65f6\u4f55\u5730\u8fd0\u884c\uff0c\u5b83\u90fd\u53ef\u4ee5\u8bbf\u95ee\u76f8\u540c\u7684\u6570\u636e\u3002<\/p>\n
       <\/p>\n
      \u8f93\u5165ExecutionContext\u3002ExecutionContext\u7c7b\u578b\u662f\u5f02\u6b65\u64cd\u4f5c\u548c\u5f02\u6b65\u64cd\u4f5c\u4e4b\u95f4\u4f20\u9012\u73af\u5883\u6570\u636e\u7684\u5a92\u4ecb\u3002\u5b83\u5b58\u5728\u4e8e\u4e00\u4e2a[ThreadStatic]\u4e2d\uff0c\u4f46\u662f\u5f53\u67d0\u4e9b\u5f02\u6b65\u64cd\u4f5c\u542f\u52a8\u65f6\uff0c\u5b83\u88ab\u201c\u6355\u83b7\u201d(\u4ece\u8be5\u7ebf\u7a0b\u9759\u6001\u4e2d\u8bfb\u53d6\u526f\u672c\u7684\u4e00\u79cd\u5947\u7279\u7684\u65b9\u5f0f)\uff0c\u5b58\u50a8\uff0c\u7136\u540e\u5f53\u8be5\u5f02\u6b65\u64cd\u4f5c\u7684\u5ef6\u7eed\u88ab\u8fd0\u884c\u65f6\uff0cExecutionContext\u9996\u5148\u88ab\u6062\u590d\u5230\u5373\u5c06\u8fd0\u884c\u8be5\u64cd\u4f5c\u7684\u7ebf\u7a0b\u4e2d\u7684[ThreadStatic]\u4e2d\u3002ExecutionContext\u662f\u5b9e\u73b0AsyncLocal<T>\u7684\u673a\u5236(\u4e8b\u5b9e\u4e0a\uff0c\u5728.net Core\u4e2d\uff0cExecutionContext\u5b8c\u5168\u662f\u5173\u4e8eAsyncLocal<T>\u7684\uff0c\u4ec5\u6b64\u800c\u5df2)\uff0c\u4f8b\u5982\uff0c\u5982\u679c\u4f60\u5c06\u4e00\u4e2a\u503c\u5b58\u50a8\u5230AsyncLocal<T>\u4e2d\uff0c\u7136\u540e\u4f8b\u5982\u961f\u5217\u4e00\u4e2a\u5de5\u4f5c\u9879\u5728ThreadPool\u4e0a\u8fd0\u884c\uff0c\u8be5\u503c\u5c06\u5728\u8be5AsyncLocal<T>\u4e2d\u53ef\u89c1\uff0c\u5728\u8be5\u5de5\u4f5c\u9879\u4e0a\u8fd0\u884c\uff1a<\/p>\n
      var number = new AsyncLocal<int>();\r\n\r\nnumber.Value = 42;\r\nThreadPool.QueueUserWorkItem(_ => Console.WriteLine(number.Value));\r\nnumber.Value = 0;\r\n\r\nConsole.ReadLine();<\/code><\/pre>\n
      \u8fd9\u6bb5\u4ee3\u7801\u6bcf\u6b21\u8fd0\u884c\u65f6\u90fd\u4f1a\u6253\u537042\u3002\u5728\u6211\u4eec\u5bf9\u59d4\u6258\u8fdb\u884c\u6392\u961f\u4e4b\u540e\uff0c\u6211\u4eec\u5c06AsyncLocal<int>\u7684\u503c\u91cd\u7f6e\u4e3a0\uff0c\u8fd9\u65e0\u5173\u7d27\u8981\uff0c\u56e0\u4e3aExecutionContext\u662f\u4f5c\u4e3aQueueUserWorkItem\u8c03\u7528\u7684\u4e00\u90e8\u5206\u88ab\u6355\u83b7\u7684\uff0c\u800c\u8be5\u6355\u83b7\u5305\u542b\u4e86\u5f53\u65f6AsyncLocal<int>\u7684\u72b6\u6001\u3002\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u5b9e\u73b0\u6211\u4eec\u81ea\u5df1\u7684\u7b80\u5355\u7ebf\u7a0b\u6c60\u6765\u66f4\u8be6\u7ec6\u5730\u4e86\u89e3\u8fd9\u4e00\u70b9\uff1a<\/p>\n
      using System.Collections.Concurrent;\r\n\r\nvar number = new AsyncLocal<int>();\r\n\r\nnumber.Value = 42;\r\nMyThreadPool.QueueUserWorkItem(() => Console.WriteLine(number.Value));\r\nnumber.Value = 0;\r\n\r\nConsole.ReadLine();\r\n\r\nclass MyThreadPool\r\n{\r\n    private static readonly BlockingCollection<(Action, ExecutionContext?)> s_workItems = new();\r\n\r\n    public static void QueueUserWorkItem(Action workItem)\r\n    {\r\n        s_workItems.Add((workItem, ExecutionContext.Capture()));\r\n    }\r\n\r\n    static MyThreadPool()\r\n    {\r\n        for (int i = 0; i < Environment.ProcessorCount; i++)\r\n        {\r\n            new Thread(() =>\r\n            {\r\n                while (true)\r\n                {\r\n                    (Action action, ExecutionContext? ec) = s_workItems.Take();\r\n                    if (ec is null)\r\n                    {\r\n                        action();\r\n                    }\r\n                    else\r\n                    {\r\n                        ExecutionContext.Run(ec, s => ((Action)s!)(), action);\r\n                    }\r\n                }\r\n            })\r\n            { IsBackground = true }.UnsafeStart();\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
      \u8fd9\u91cc\uff0cMyThreadPool\u6709\u4e00\u4e2aBlockingCollection<(Action, ExecutionContext?)>\u8868\u793a\u5b83\u7684\u5de5\u4f5c\u9879\u961f\u5217\uff0c\u6bcf\u4e2a\u5de5\u4f5c\u9879\u90fd\u662f\u8981\u8c03\u7528\u7684\u5de5\u4f5c\u7684\u59d4\u6258\uff0c\u4ee5\u53ca\u4e0e\u8be5\u5de5\u4f5c\u76f8\u5173\u8054\u7684ExecutionContext\u3002\u6c60\u7684\u9759\u6001\u6784\u9020\u51fd\u6570\u542f\u52a8\u4e00\u5806\u7ebf\u7a0b\uff0c\u6bcf\u4e2a\u7ebf\u7a0b\u90fd\u5904\u4e8e\u65e0\u9650\u5faa\u73af\u4e2d\uff0c\u83b7\u53d6\u4e0b\u4e00\u4e2a\u5de5\u4f5c\u9879\u5e76\u8fd0\u884c\u5b83\u3002\u5982\u679c\u6ca1\u6709\u4e3a\u7ed9\u5b9a\u59d4\u6258\u6355\u83b7ExecutionContext\uff0c\u8be5\u59d4\u6258\u5c31\u4f1a\u88ab\u76f4\u63a5\u8c03\u7528\u3002\u4f46\u5982\u679c\u6355\u83b7\u4e86\u4e00\u4e2aExecutionContext\uff0c\u6211\u4eec\u4e0d\u662f\u76f4\u63a5\u8c03\u7528\u59d4\u6258\uff0c\u800c\u662f\u8c03\u7528ExecutionContext.Run\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u4f1a\u5728\u8fd0\u884c\u59d4\u6258\u4e4b\u524d\u5c06\u63d0\u4f9b\u7684ExecutionContext\u6062\u590d\u4e3a\u5f53\u524d\u4e0a\u4e0b\u6587\uff0c\u7136\u540e\u518d\u91cd\u7f6e\u4e0a\u4e0b\u6587\u3002\u8fd9\u4e2a\u4f8b\u5b50\u5305\u542b\u4e86\u4e0e\u4e4b\u524d\u5b8c\u5168\u76f8\u540c\u7684AsyncLocal<int>\u7684\u4ee3\u7801\uff0c\u9664\u4e86\u8fd9\u6b21\u4f7f\u7528\u4e86MyThreadPool\u800c\u4e0d\u662fThreadPool\uff0c\u4f46\u5b83\u4ecd\u7136\u6bcf\u6b21\u8f93\u51fa42\uff0c\u56e0\u4e3a\u6c60\u5b50\u91cc\u7684ExecutionContext\u662f\u6b63\u786e\u6d41\u52a8\u7684\u3002<\/p>\n
       <\/p>\n
      \u987a\u4fbf\u8bf4\u4e00\u53e5\uff0c\u4f60\u4f1a\u6ce8\u610f\u5230\u6211\u5728MyThreadPool\u7684\u9759\u6001\u6784\u9020\u51fd\u6570\u4e2d\u8c03\u7528\u4e86UnsafeStart\u3002\u542f\u52a8\u4e00\u4e2a\u65b0\u7684\u7ebf\u7a0b\u6b63\u662f\u90a3\u79cd\u5e94\u8be5\u6d41\u5411ExecutionContext\u7684\u5f02\u6b65\u70b9\uff0c\u4e8b\u5b9e\u4e0a\uff0cThread\u7684Start\u65b9\u6cd5\u4f7f\u7528ExecutionContext.Capture\u6765\u6355\u83b7\u5f53\u524d\u7684\u4e0a\u4e0b\u6587\uff0c\u5c06\u5176\u5b58\u50a8\u5728Thread\u4e0a\uff0c\u7136\u540e\u5728\u6700\u7ec8\u8c03\u7528Thread\u7684ThreadStart\u59d4\u6258\u65f6\u4f7f\u7528\u6355\u83b7\u7684\u4e0a\u4e0b\u6587\u3002\u4f46\u6211\u4e0d\u60f3\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\u8fd9\u6837\u505a\uff0c\u56e0\u4e3a\u6211\u4e0d\u60f3\u8ba9Threads\u5728\u9759\u6001\u6784\u9020\u51fd\u6570\u8fd0\u884c\u65f6\u6355\u83b7\u78b0\u5de7\u5b58\u5728\u7684\u4efb\u4f55ExecutionContext\uff08\u8fd9\u6837\u505a\u4f1a\u4f7f\u5173\u4e8eExecutionContext\u7684\u6f14\u793a\u66f4\u52a0\u590d\u6742\uff09\uff0c\u6240\u4ee5\u6211\u7528UnsafeStart\u65b9\u6cd5\u4ee3\u66ff\u3002\u4ee5Unsafe\u5f00\u5934\u7684\u7ebf\u7a0b\u76f8\u5173\u65b9\u6cd5\u4e0e\u7f3a\u5c11Unsafe\u524d\u7f00\u7684\u76f8\u5e94\u65b9\u6cd5\u7684\u884c\u4e3a\u5b8c\u5168\u76f8\u540c\uff0c\u53ea\u662f\u5b83\u4eec\u4e0d\u6355\u83b7ExecutionContext\uff0c\u4f8b\u5982\uff0cThread.Start\u548cThread.UnsafeStart\u7684\u5de5\u4f5c\u76f8\u540c\uff0c\u4f46Start\u6355\u83b7ExecutionContext\uff0cUnsafeStart\u4e0d\u6355\u83b7\u3002<\/p>\n
      Back To Start<\/strong><\/p>\n
      \u5f53\u6211\u5728\u5199AsyncTaskMethodBuilder.Start\u7684\u5b9e\u73b0\u65f6\uff0c\u6211\u4eec\u7ed5\u9053\u8ba8\u8bba\u4e86ExecutionContext\uff0c\u6211\u8bf4\u8fd9\u662f\u6709\u6548\u7684\uff1a<\/p>\n
      public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine\r\n{\r\n    stateMachine.MoveNext();\r\n}<\/code><\/pre>\n
      \u7136\u540e\u5efa\u8bae\u6211\u7b80\u5316\u4e00\u4e0b\u3002\u8fd9\u79cd\u7b80\u5316\u5ffd\u7565\u4e86\u4e00\u4e2a\u4e8b\u5b9e\uff0c\u5373\u8be5\u65b9\u6cd5\u5b9e\u9645\u4e0a\u9700\u8981\u5c06ExecutionContext\u8003\u8651\u5728\u5185\uff0c\u56e0\u6b64\u66f4\u50cf\u662f\u8fd9\u6837:<\/p>\n
      public void Start<TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine\r\n{\r\n    ExecutionContext previous = Thread.CurrentThread._executionContext; \/\/ [ThreadStatic] field\r\n    try\r\n    {\r\n        stateMachine.MoveNext();\r\n    }\r\n    finally\r\n    {\r\n        ExecutionContext.Restore(previous); \/\/ internal helper\r\n    }\r\n}<\/code><\/pre>\n
      \u8fd9\u91cc\u4e0d\u50cf\u6211\u4e4b\u524d\u5efa\u8bae\u7684\u90a3\u6837\u53ea\u8c03\u7528statemmachine .MoveNext()\uff0c\u800c\u662f\u5728\u8fd9\u91cc\u505a\u4e86\u4e00\u4e2a\u52a8\u4f5c:\u83b7\u53d6\u5f53\u524d\u7684ExecutionContext\uff0c\u518d\u8c03\u7528MoveNext\uff0c\u7136\u540e\u5728\u5b83\u5b8c\u6210\u65f6\u5c06\u5f53\u524d\u4e0a\u4e0b\u6587\u91cd\u7f6e\u4e3a\u8c03\u7528MoveNext\u4e4b\u524d\u7684\u72b6\u6001\u3002<\/p>\n
       <\/p>\n
      \u8fd9\u6837\u505a\u7684\u539f\u56e0\u662f\u4e3a\u4e86\u9632\u6b62\u5f02\u6b65\u65b9\u6cd5\u5c06\u73af\u5883\u6570\u636e\u6cc4\u9732\u7ed9\u8c03\u7528\u8005\u3002\u4e00\u4e2a\u793a\u4f8b\u65b9\u6cd5\u8bf4\u660e\u4e86\u4e3a\u4ec0\u4e48\u8fd9\u5f88\u91cd\u8981:<\/p>\n
      async Task ElevateAsAdminAndRunAsync()\r\n{\r\n    using (WindowsIdentity identity = LoginAdmin())\r\n    {\r\n        using (WindowsImpersonationContext impersonatedUser = identity.Impersonate())\r\n        {\r\n            await DoSensitiveWorkAsync();\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
      \u201c\u5192\u5145\u201d\u662f\u5c06\u5f53\u524d\u7528\u6237\u7684\u73af\u5883\u4fe1\u606f\u6539\u4e3a\u5176\u4ed6\u4eba\u7684;\u8fd9\u8ba9\u4ee3\u7801\u53ef\u4ee5\u4ee3\u8868\u5176\u4ed6\u4eba\uff0c\u4f7f\u7528\u4ed6\u4eec\u7684\u7279\u6743\u548c\u8bbf\u95ee\u6743\u9650\u3002\u5728\u3002net\u4e2d\uff0c\u8fd9\u79cd\u6a21\u62df\u8de8\u5f02\u6b65\u64cd\u4f5c\u6d41\u52a8\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u662fExecutionContext\u7684\u4e00\u90e8\u5206\u3002\u73b0\u5728\u60f3\u8c61\u4e00\u4e0b\uff0c\u5982\u679cStart\u6ca1\u6709\u6062\u590d\u4e4b\u524d\u7684\u4e0a\u4e0b\u6587\uff0c\u8003\u8651\u4e0b\u9762\u7684\u4ee3\u7801:<\/p>\n
      Task t = ElevateAsAdminAndRunAsync();\r\nPrintUser();\r\nawait t;<\/code><\/pre>\n
      \u8fd9\u6bb5\u4ee3\u7801\u53ef\u4ee5\u53d1\u73b0\uff0cElevateAsAdminAndRunAsync\u4e2d\u4fee\u6539\u7684ExecutionContext\u5728ElevateAsAdminAndRunAsync\u8fd4\u56de\u5230\u5b83\u7684\u540c\u6b65\u8c03\u7528\u8005\u4e4b\u540e\u4ecd\u7136\u5b58\u5728(\u8fd9\u53d1\u751f\u5728\u8be5\u65b9\u6cd5\u7b2c\u4e00\u6b21\u7b49\u5f85\u5c1a\u672a\u5b8c\u6210\u7684\u5185\u5bb9\u65f6)\u3002\u8fd9\u662f\u56e0\u4e3a\u5728\u8c03\u7528Impersonate\u4e4b\u540e\uff0c\u6211\u4eec\u8c03\u7528\u4e86DoSensitiveWorkAsync\u5e76\u7b49\u5f85\u5b83\u8fd4\u56de\u7684\u4efb\u52a1\u3002\u5047\u8bbe\u4efb\u52a1\u6ca1\u6709\u5b8c\u6210\uff0c\u5b83\u5c06\u5bfc\u81f4\u5bf9ElevateAsAdminAndRunAsync\u7684\u8c03\u7528yield\u5e76\u8fd4\u56de\u5230\u8c03\u7528\u8005\uff0c\u6a21\u62df\u4ecd\u7136\u5728\u5f53\u524d\u7ebf\u7a0b\u4e0a\u6709\u6548\u3002\u8fd9\u4e0d\u662f\u6211\u4eec\u60f3\u8981\u7684\u3002\u56e0\u6b64\uff0cStart\u8bbe\u7f6e\u4e86\u8fd9\u4e2a\u4fdd\u62a4\u673a\u5236\uff0c\u4ee5\u786e\u4fdd\u5bf9ExecutionContext\u7684\u4efb\u4f55\u4fee\u6539\u90fd\u4e0d\u4f1a\u4ece\u540c\u6b65\u65b9\u6cd5\u8c03\u7528\u4e2d\u6d41\u51fa\uff0c\u800c\u53ea\u4f1a\u968f\u7740\u65b9\u6cd5\u6267\u884c\u7684\u4efb\u4f55\u540e\u7eed\u5de5\u4f5c\u4e00\u8d77\u6d41\u51fa\u3002<\/p>\n
       <\/p>\n
      MoveNext<\/strong><\/p>\n
      \u56e0\u6b64\uff0c\u8c03\u7528\u4e86\u5165\u53e3\u70b9\u65b9\u6cd5\uff0c\u521d\u59cb\u5316\u4e86\u72b6\u6001\u673a\u7ed3\u6784\u4f53\uff0c\u8c03\u7528\u4e86Start\uff0c\u7136\u540e\u8c03\u7528\u4e86MoveNext\u3002\u4ec0\u4e48\u662fMoveNext?\u8fd9\u4e2a\u65b9\u6cd5\u5305\u542b\u4e86\u5f00\u53d1\u8005\u65b9\u6cd5\u4e2d\u6240\u6709\u7684\u539f\u59cb\u903b\u8f91\uff0c\u4f46\u505a\u4e86\u4e00\u5927\u5806\u4fee\u6539\u3002\u8ba9\u6211\u4eec\u5148\u770b\u770b\u8fd9\u4e2a\u65b9\u6cd5\u7684\u811a\u624b\u67b6\u3002\u4e0b\u9762\u662f\u7f16\u8bd1\u5668\u4e3a\u6211\u4eec\u7684\u65b9\u6cd5\u751f\u6210\u7684\u53cd\u7f16\u8bd1\u7248\u672c\uff0c\u4f46\u5220\u9664\u4e86\u751f\u6210\u7684try\u5757\u4e2d\u7684\u6240\u6709\u5185\u5bb9:<\/p>\n
      private void MoveNext()\r\n{\r\n    try\r\n    {\r\n        ... \/\/ all of the code from the CopyStreamToStreamAsync method body, but not exactly as it was written\r\n    }\r\n    catch (Exception exception)\r\n    {\r\n        <>1__state = -2;\r\n        <buffer>5__2 = null;\r\n        <>t__builder.SetException(exception);\r\n        return;\r\n    }\r\n\r\n    <>1__state = -2;\r\n    <buffer>5__2 = null;\r\n    <>t__builder.SetResult();\r\n}<\/code><\/pre>\n
       <\/p>\n
      \u65e0\u8bbaMoveNext\u6267\u884c\u4ec0\u4e48\u5176\u4ed6\u5de5\u4f5c\uff0c\u5f53\u6240\u6709\u5de5\u4f5c\u5b8c\u6210\u540e\uff0c\u5b83\u90fd\u6709\u8d23\u4efb\u5b8c\u6210async Task\u65b9\u6cd5\u8fd4\u56de\u7684\u4efb\u52a1\u3002\u5982\u679ctry\u4ee3\u7801\u5757\u7684\u4e3b\u4f53\u629b\u51fa\u4e86\u672a\u5904\u7406\u7684\u5f02\u5e38\uff0c\u90a3\u4e48\u4efb\u52a1\u5c31\u4f1a\u629b\u51fa\u8be5\u5f02\u5e38\u3002\u5982\u679casync\u65b9\u6cd5\u6210\u529f\u5230\u8fbe\u5b83\u7684\u7ec8\u70b9(\u76f8\u5f53\u4e8e\u540c\u6b65\u65b9\u6cd5\u8fd4\u56de)\uff0c\u5b83\u5c06\u6210\u529f\u5b8c\u6210\u8fd4\u56de\u7684\u4efb\u52a1\u3002\u5728\u4efb\u4f55\u4e00\u79cd\u60c5\u51b5\u4e0b\uff0c\u5b83\u90fd\u5c06\u8bbe\u7f6e\u72b6\u6001\u673a\u7684\u72b6\u6001\u4ee5\u8868\u793a\u5b8c\u6210\u3002(\u6211\u6709\u65f6\u542c\u5230\u5f00\u53d1\u4eba\u5458\u4ece\u7406\u8bba\u4e0a\u8bf4\uff0c\u5f53\u6d89\u53ca\u5230\u5f02\u5e38\u65f6\uff0c\u5728\u7b2c\u4e00\u4e2aawait\u4e4b\u524d\u629b\u51fa\u7684\u5f02\u5e38\u548c\u5728\u7b2c\u4e00\u4e2aawait\u4e4b\u540e\u629b\u51fa\u7684\u5f02\u5e38\u662f\u6709\u533a\u522b\u7684\u2026\u2026\u57fa\u4e8e\u4e0a\u8ff0\uff0c\u5e94\u8be5\u6e05\u695a\u60c5\u51b5\u5e76\u975e\u5982\u6b64\u3002\u4efb\u4f55\u672a\u5728async\u65b9\u6cd5\u4e2d\u5904\u7406\u7684\u5f02\u5e38\uff0c\u4e0d\u7ba1\u5b83\u5728\u65b9\u6cd5\u7684\u4ec0\u4e48\u4f4d\u7f6e\uff0c\u4e5f\u4e0d\u7ba1\u65b9\u6cd5\u662f\u5426\u4ea7\u751f\u4e86\u7ed3\u679c\uff0c\u90fd\u4f1a\u5728\u4e0a\u9762\u7684catch\u5757\u4e2d\u7ed3\u675f\uff0c\u7136\u540e\u88ab\u6355\u83b7\u7684\u5f02\u5e38\u4f1a\u5b58\u50a8\u5728async\u65b9\u6cd5\u8fd4\u56de\u7684\u4efb\u52a1\u4e2d\u3002)<\/p>\n
       <\/p>\n
      \u8fd8\u8981\u6ce8\u610f\uff0c\u8fd9\u4e2a\u5b8c\u6210\u8fc7\u7a0b\u662f\u901a\u8fc7\u6784\u5efa\u5668\u5b8c\u6210\u7684\uff0c\u4f7f\u7528\u5b83\u7684SetException\u548cSetResult\u65b9\u6cd5\uff0c\u8fd9\u662f\u7f16\u8bd1\u5668\u9884\u671f\u7684\u6784\u5efa\u5668\u6a21\u5f0f\u7684\u4e00\u90e8\u5206\u3002\u5982\u679casync\u65b9\u6cd5\u4e4b\u524d\u5df2\u7ecf\u6302\u8d77\u4e86\uff0c\u90a3\u4e48\u6784\u5efa\u5668\u5c06\u4e0d\u5f97\u4e0d\u5728\u6302\u8d77\u5904\u7406\u4e2d\u521b\u5efa\u4e00\u4e2aTask (\u7a0d\u540e\u6211\u4eec\u4f1a\u770b\u5230\u5982\u4f55\u4ee5\u53ca\u5728\u54ea\u91cc\u6267\u884c)\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u8c03\u7528SetException\/SetResult\u5c06\u5b8c\u6210\u8be5\u4efb\u52a1\u3002\u7136\u800c\uff0c\u5982\u679casync\u65b9\u6cd5\u4e4b\u524d\u6ca1\u6709\u6302\u8d77\uff0c\u90a3\u4e48\u6211\u4eec\u8fd8\u6ca1\u6709\u521b\u5efa\u4efb\u52a1\u6216\u5411\u8c03\u7528\u8005\u8fd4\u56de\u4efb\u4f55\u4e1c\u897f\uff0c\u56e0\u6b64\u6784\u5efa\u5668\u5728\u751f\u6210\u4efb\u52a1\u65f6\u6709\u66f4\u5927\u7684\u7075\u6d3b\u6027\u3002\u5982\u679c\u4f60\u8fd8\u8bb0\u5f97\u4e4b\u524d\u5728\u5165\u53e3\u70b9\u65b9\u6cd5\u4e2d\uff0c\u5b83\u505a\u7684\u6700\u540e\u4e00\u4ef6\u4e8b\u662f\u5c06\u4efb\u52a1\u8fd4\u56de\u7ed9\u8c03\u7528\u8005\uff0c\u5b83\u901a\u8fc7\u8bbf\u95ee\u6784\u5efa\u5668\u7684Task\u5c5e\u6027(\u6211\u77e5\u9053\uff0c\u6709\u8fd9\u4e48\u591a\u4e1c\u897f\u88ab\u79f0\u4e3a “Task”)\u8fd4\u56de\u7ed3\u679c:<\/p>\n
      public Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    ...\r\n    return stateMachine.<>t__builder.Task;\r\n}<\/code><\/pre>\n
      \u6784\u5efa\u5668\u77e5\u9053\u8be5\u65b9\u6cd5\u662f\u5426\u6302\u8d77\u8fc7\uff0c\u5982\u679c\u6302\u8d77\u4e86\uff0c\u5b83\u5c31\u4f1a\u8fd4\u56de\u5df2\u7ecf\u521b\u5efa\u7684\u4efb\u52a1\u3002\u5982\u679c\u65b9\u6cd5\u4ece\u672a\u6302\u8d77\uff0c\u800c\u4e14\u6784\u5efa\u5668\u8fd8\u6ca1\u6709\u4efb\u52a1\uff0c\u90a3\u4e48\u5b83\u53ef\u4ee5\u5728\u8fd9\u91cc\u521b\u5efa\u4e00\u4e2a\u5b8c\u6210\u7684\u4efb\u52a1\u3002\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5728\u6210\u529f\u5b8c\u6210\u7684\u60c5\u51b5\u4e0b\uff0c\u5b83\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528Task.CompletedTask\u800c\u4e0d\u662f\u5206\u914d\u4e00\u4e2a\u65b0\u7684\u4efb\u52a1\uff0c\u907f\u514d\u4efb\u4f55\u5206\u914d\u3002\u5982\u679c\u662f\u4e00\u822c\u7684\u4efb\u52a1<TResult>\uff0c\u6784\u5efa\u8005\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528Task.FromResult<TResult>\uff08TResult result\uff09\u3002<\/p>\n
      \u6784\u5efa\u5668\u8fd8\u53ef\u4ee5\u5bf9\u5b83\u521b\u5efa\u7684\u5bf9\u8c61\u8fdb\u884c\u4efb\u4f55\u5b83\u8ba4\u4e3a\u5408\u9002\u7684\u8f6c\u6362\u3002\u4f8b\u5982\uff0cTask\u5b9e\u9645\u4e0a\u6709\u4e09\u79cd\u53ef\u80fd\u7684\u6700\u7ec8\u72b6\u6001:\u6210\u529f\u3001\u5931\u8d25\u548c\u53d6\u6d88\u3002AsyncTaskMethodBuilder\u7684SetException\u65b9\u6cd5\u5904\u7406\u7279\u6b8a\u60c5\u51b5OperationCanceledException<\/a>\uff0c\u5c06\u4efb\u52a1\u8f6c\u6362\u4e3aTaskStatus\u3002\u5982\u679c\u63d0\u4f9b\u7684\u5f02\u5e38\u662fOperationCanceledException\u6216\u6e90\u81eaOperationCanceledException\uff0c\u5219\u5c06\u4efb\u52a1\u8f6c\u6362\u4e3aTaskStatus.Canceled\u6700\u7ec8\u72b6\u6001\uff1b\u5426\u5219\uff0c\u4efb\u52a1\u4ee5TaskStatus.Faulted\u7ed3\u675f;\u8fd9\u79cd\u533a\u522b\u5728\u4f7f\u7528\u4ee3\u7801\u65f6\u5f80\u5f80\u4e0d\u660e\u663e; \u56e0\u4e3a\u65e0\u8bba\u5f02\u5e38\u88ab\u6807\u8bb0\u4e3a\u53d6\u6d88\u8fd8\u662f\u6545\u969c\uff0c\u90fd\u4f1a\u88ab\u5b58\u50a8\u5230Task\u4e2d\uff0c\u7b49\u5f85\u8be5\u4efb\u52a1\u7684\u4ee3\u7801\u5c06\u65e0\u6cd5\u89c2\u5bdf\u5230\u72b6\u6001\u4e4b\u95f4\u7684\u533a\u522b\uff08\u65e0\u8bba\u54ea\u79cd\u60c5\u51b5\uff0c\u539f\u59cb\u5f02\u5e38\u90fd\u4f1a\u88ab\u4f20\u64ad\uff09…… \u5b83\u53ea\u5f71\u54cd\u4e0e\u4efb\u52a1\u76f4\u63a5\u4ea4\u4e92\u7684\u4ee3\u7801\uff0c\u4f8b\u5982\u901a\u8fc7ContinueWith\uff0c\u5b83\u5177\u6709\u91cd\u8f7d\uff0c\u5141\u8bb8\u4ec5\u4e3a\u5b8c\u6210\u72b6\u6001\u7684\u5b50\u96c6\u8c03\u7528continuation\u3002<\/p>\n
      \u73b0\u5728\u6211\u4eec\u4e86\u89e3\u4e86\u751f\u547d\u5468\u671f\u65b9\u9762\u7684\u5185\u5bb9\uff0c\u4e0b\u9762\u662f\u5728MoveNext\u7684try\u5757\u5185\u586b\u5199\u7684\u6240\u6709\u5185\u5bb9\uff1a<\/p>\n
      private void MoveNext()\r\n{\r\n    try\r\n    {\r\n        int num = <>1__state;\r\n\r\n        TaskAwaiter<int> awaiter;\r\n        if (num != 0)\r\n        {\r\n            if (num != 1)\r\n            {\r\n                <buffer>5__2 = new byte[4096];\r\n                goto IL_008b;\r\n            }\r\n\r\n            awaiter = <>u__2;\r\n            <>u__2 = default(TaskAwaiter<int>);\r\n            num = (<>1__state = -1);\r\n            goto IL_00f0;\r\n        }\r\n\r\n        TaskAwaiter awaiter2 = <>u__1;\r\n        <>u__1 = default(TaskAwaiter);\r\n        num = (<>1__state = -1);\r\n        IL_0084:\r\n        awaiter2.GetResult();\r\n\r\n        IL_008b:\r\n        awaiter = source.ReadAsync(<buffer>5__2, 0, <buffer>5__2.Length).GetAwaiter();\r\n        if (!awaiter.IsCompleted)\r\n        {\r\n            num = (<>1__state = 1);\r\n            <>u__2 = awaiter;\r\n            <>t__builder.AwaitUnsafeOnCompleted(ref awaiter, ref this);\r\n            return;\r\n        }\r\n        IL_00f0:\r\n        int result;\r\n        if ((result = awaiter.GetResult()) != 0)\r\n        {\r\n            awaiter2 = destination.WriteAsync(<buffer>5__2, 0, result).GetAwaiter();\r\n            if (!awaiter2.IsCompleted)\r\n            {\r\n                num = (<>1__state = 0);\r\n                <>u__1 = awaiter2;\r\n                <>t__builder.AwaitUnsafeOnCompleted(ref awaiter2, ref this);\r\n                return;\r\n            }\r\n            goto IL_0084;\r\n        }\r\n    }\r\n    catch (Exception exception)\r\n    {\r\n        <>1__state = -2;\r\n        <buffer>5__2 = null;\r\n        <>t__builder.SetException(exception);\r\n        return;\r\n    }\r\n\r\n    <>1__state = -2;\r\n    <buffer>5__2 = null;\r\n    <>t__builder.SetResult();\r\n}<\/code><\/pre>\n
      \u8fd9\u79cd\u590d\u6742\u7684\u60c5\u51b5\u53ef\u80fd\u611f\u89c9\u6709\u70b9\u719f\u6089\u3002\u8fd8\u8bb0\u5f97\u6211\u4eec\u57fa\u4e8eAPM\u624b\u52a8\u5b9e\u73b0\u7684BeginCopyStreamToStream\u6709\u591a\u590d\u6742\u5417?\u8fd9\u6ca1\u6709\u90a3\u4e48\u590d\u6742\uff0c\u4f46\u4e5f\u66f4\u597d\uff0c\u56e0\u4e3a\u7f16\u8bd1\u5668\u4e3a\u6211\u4eec\u505a\u4e86\u8fd9\u4e9b\u5de5\u4f5c\uff0c\u4ee5\u5ef6\u7eed\u4f20\u9012\u7684\u5f62\u5f0f\u91cd\u5199\u4e86\u65b9\u6cd5\uff0c\u540c\u65f6\u786e\u4fdd\u4e3a\u8fd9\u4e9b\u5ef6\u7eed\u4fdd\u7559\u4e86\u6240\u6709\u5fc5\u8981\u7684\u72b6\u6001\u3002\u5373\u4fbf\u5982\u6b64\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u772f\u7740\u773c\u775b\u8ddf\u7740\u8d70\u3002\u8bf7\u8bb0\u4f4f\uff0c\u72b6\u6001\u5728\u5165\u53e3\u70b9\u88ab\u521d\u59cb\u5316\u4e3a-1\u3002\u7136\u540e\u6211\u4eec\u8fdb\u5165MoveNext\uff0c\u53d1\u73b0\u8fd9\u4e2a\u72b6\u6001(\u73b0\u5728\u5b58\u50a8\u5728\u672c\u5730num\u4e2d)\u65e2\u4e0d\u662f0\u4e5f\u4e0d\u662f1\uff0c\u56e0\u6b64\u6267\u884c\u521b\u5efa\u4e34\u65f6\u7f13\u51b2\u533a\u7684\u4ee3\u7801\uff0c\u7136\u540e\u8df3\u8f6c\u5230\u6807\u7b7eIL_008b\uff0c\u5728\u8fd9\u91cc\u8c03\u7528stream.ReadAsync\u3002\u6ce8\u610f\uff0c\u5728\u8fd9\u4e00\u70b9\u4e0a\uff0c\u6211\u4eec\u4ecd\u7136\u4ece\u8c03\u7528MoveNext\u540c\u6b65\u8fd0\u884c\uff0c\u56e0\u6b64\u4ece\u5f00\u59cb\u5230\u5165\u53e3\u70b9\u90fd\u540c\u6b65\u8fd0\u884c\uff0c\u8fd9\u610f\u5473\u7740\u5f00\u53d1\u8005\u7684\u4ee3\u7801\u8c03\u7528\u4e86CopyStreamToStreamAsync\uff0c\u5b83\u4ecd\u7136\u5728\u540c\u6b65\u6267\u884c\uff0c\u8fd8\u6ca1\u6709\u8fd4\u56de\u4e00\u4e2aTask\u6765\u8868\u793a\u8fd9\u4e2a\u65b9\u6cd5\u7684\u6700\u7ec8\u5b8c\u6210\u3002\u8fd9\u53ef\u80fd\u8981\u6539\u53d8\u4e86…<\/p>\n
      \u6211\u4eec\u8c03\u7528Stream.ReadAsync\uff0c\u4ece\u4e2d\u5f97\u5230\u4e00\u4e2aTask<int>\u3002\u8bfb\u53d6\u53ef\u80fd\u662f\u540c\u6b65\u5b8c\u6210\u7684\uff0c\u4e5f\u53ef\u80fd\u662f\u5f02\u6b65\u5b8c\u6210\u7684\uff0c\u4f46\u901f\u5ea6\u5feb\u5230\u73b0\u5728\u5df2\u7ecf\u5b8c\u6210\uff0c\u4e5f\u53ef\u80fd\u8fd8\u6ca1\u6709\u5b8c\u6210\u3002\u4e0d\u7ba1\u600e\u4e48\u8bf4\uff0c\u6211\u4eec\u6709\u4e00\u4e2a\u8868\u793a\u6700\u7ec8\u5b8c\u6210\u7684Task<int>\uff0c\u7f16\u8bd1\u5668\u53d1\u51fa\u7684\u4ee3\u7801\u4f1a\u68c0\u67e5\u8be5Task<int>\u4ee5\u51b3\u5b9a\u5982\u4f55\u7ee7\u7eed\uff1a\u5982\u679c\u8be5Task<int>\u786e\u5b9e\u5df2\u7ecf\u5b8c\u6210\uff08\u4e0d\u7ba1\u5b83\u662f\u540c\u6b65\u5b8c\u6210\u8fd8\u662f\u53ea\u662f\u5728\u6211\u4eec\u68c0\u67e5\u65f6\u5b8c\u6210\uff09\uff0c\u90a3\u4e48\u8fd9\u4e2a\u65b9\u6cd5\u7684\u4ee3\u7801\u5c31\u53ef\u4ee5\u7ee7\u7eed\u540c\u6b65\u8fd0\u884c……\u5f53\u6211\u4eec\u53ef\u4ee5\u5728\u8fd9\u91cc\u7ee7\u7eed\u8fd0\u884c\u65f6\uff0c\u6ca1\u6709\u5fc5\u8981\u82b1\u4e0d\u5fc5\u8981\u7684\u5f00\u9500\u6392\u961f\u5904\u7406\u8be5\u65b9\u6cd5\u6267\u884c\u7684\u5269\u4f59\u90e8\u5206\u3002\u4f46\u662f\u4e3a\u4e86\u5904\u7406Task<int>\u8fd8\u6ca1\u6709\u5b8c\u6210\u7684\u60c5\u51b5\uff0c\u7f16\u8bd1\u5668\u9700\u8981\u53d1\u51fa\u4ee3\u7801\u6765\u4e3aTask\u6302\u4e0a\u4e00\u4e2a\u5ef6\u7eed\u3002\u56e0\u6b64\uff0c\u5b83\u9700\u8981\u53d1\u51fa\u4ee3\u7801\uff0c\u8be2\u95ee\u4efb\u52a1 “\u4f60\u5b8c\u6210\u4e86\u5417\uff1f” \u5b83\u662f\u5426\u662f\u76f4\u63a5\u4e0e\u4efb\u52a1\u5bf9\u8bdd\u6765\u95ee\u8fd9\u4e2a\u95ee\u9898\uff1f<\/p>\n
      \u5982\u679c\u4f60\u5728C#\u4e2d\u552f\u4e00\u53ef\u4ee5\u7b49\u5f85\u7684\u4e1c\u897f\u662fSystem.Threading.Tasks.Task\uff0c\u8fd9\u5c06\u662f\u4e00\u79cd\u9650\u5236\u3002\u540c\u6837\u5730\uff0c\u5982\u679cC#\u7f16\u8bd1\u5668\u5fc5\u987b\u77e5\u9053\u6bcf\u4e00\u79cd\u53ef\u80fd\u88ab\u7b49\u5f85\u7684\u7c7b\u578b\uff0c\u90a3\u4e5f\u662f\u4e00\u79cd\u9650\u5236\u3002\u76f8\u53cd\uff0cc#\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u901a\u5e38\u4f1a\u505a\u7684\u662f:\u5b83\u91c7\u7528\u4e86\u4e00\u79cdapi\u6a21\u5f0f\u3002\u4ee3\u7801\u53ef\u4ee5\u7b49\u5f85\u4efb\u4f55\u516c\u5f00\u9002\u5f53\u6a21\u5f0f(\u201cawaiter\u201d\u6a21\u5f0f)\u7684\u4e1c\u897f(\u5c31\u50cf\u60a8\u53ef\u4ee5\u7b49\u5f85\u4efb\u4f55\u63d0\u4f9b\u9002\u5f53\u7684\u201c\u53ef\u679a\u4e3e\u201d\u6a21\u5f0f\u7684\u4e1c\u897f\u4e00\u6837)\u3002\u4f8b\u5982\uff0c\u6211\u4eec\u53ef\u4ee5\u589e\u5f3a\u524d\u9762\u5199\u7684MyTask\u7c7b\u578b\u6765\u5b9e\u73b0awaiter\u6a21\u5f0f:<\/p>\n
      class MyTask\r\n{\r\n    ...\r\n    public MyTaskAwaiter GetAwaiter() => new MyTaskAwaiter { _task = this };\r\n\r\n    public struct MyTaskAwaiter : ICriticalNotifyCompletion\r\n    {\r\n        internal MyTask _task;\r\n\r\n        public bool IsCompleted => _task._completed;\r\n        public void OnCompleted(Action continuation) => _task.ContinueWith(_ => continuation());\r\n        public void UnsafeOnCompleted(Action continuation) => _task.ContinueWith(_ => continuation());\r\n        public void GetResult() => _task.Wait();\r\n    }\r\n}<\/code><\/pre>\n
      \u5982\u679c\u4e00\u4e2a\u7c7b\u578b\u516c\u5f00\u4e86getwaiter()\u65b9\u6cd5\uff0c\u5c31\u53ef\u4ee5\u7b49\u5f85\u5b83\uff0cTask\u5c31\u662f\u8fd9\u6837\u505a\u7684\u3002\u8fd9\u4e2a\u65b9\u6cd5\u9700\u8981\u8fd4\u56de\u4e00\u4e9b\u5185\u5bb9\uff0c\u800c\u8fd9\u4e9b\u5185\u5bb9\u53c8\u516c\u5f00\u4e86\u51e0\u4e2a\u6210\u5458\uff0c\u5305\u62ec\u4e00\u4e2aIsCompleted\u5c5e\u6027\uff0c\u7528\u4e8e\u5728\u8c03\u7528IsCompleted\u65f6\u68c0\u67e5\u64cd\u4f5c\u662f\u5426\u5df2\u7ecf\u5b8c\u6210\u3002\u4f60\u53ef\u4ee5\u770b\u5230\u6b63\u5728\u53d1\u751f\u7684\u4e8b\u60c5:\u5728IL_008b\uff0c\u4eceReadAsync\u8fd4\u56de\u7684\u4efb\u52a1\u5df2\u7ecf\u8c03\u7528\u4e86getwaiter\uff0c\u7136\u540e\u5728struct awaiter\u5b9e\u4f8b\u4e0a\u5b8c\u6210\u8bbf\u95ee\u3002\u5982\u679cIsCompleted\u8fd4\u56detrue\uff0c\u90a3\u4e48\u6700\u7ec8\u4f1a\u6267\u884c\u5230IL_00f0\uff0c\u5728\u8fd9\u91cc\u4ee3\u7801\u4f1a\u8c03\u7528awaiter\u7684\u53e6\u4e00\u4e2a\u6210\u5458:GetResult()\u3002\u5982\u679c\u64cd\u4f5c\u5931\u8d25\uff0cGetResult()\u8d1f\u8d23\u629b\u51fa\u5f02\u5e38\uff0c\u4ee5\u4fbf\u5c06\u5176\u4f20\u64ad\u5230async\u65b9\u6cd5\u4e2d\u7684await\u4e4b\u5916;\u5426\u5219\uff0cGetResult()\u8d1f\u8d23\u8fd4\u56de\u64cd\u4f5c\u7684\u7ed3\u679c(\u5982\u679c\u6709\u7684\u8bdd)\u3002\u5728ReadAsync\u7684\u4f8b\u5b50\u4e2d\uff0c\u5982\u679c\u7ed3\u679c\u4e3a0\uff0c\u90a3\u4e48\u6211\u4eec\u8df3\u51fa\u8bfb\u5199\u5faa\u73af\uff0c\u5230\u65b9\u6cd5\u7684\u672b\u5c3e\u8c03\u7528SetResult\uff0c\u5c31\u5b8c\u6210\u4e86\u3002<\/p>\n
      \u4e0d\u8fc7\uff0c\u56de\u8fc7\u5934\u6765\u770b\u4e00\u4e0b\uff0c\u771f\u6b63\u6709\u8da3\u7684\u90e8\u5206\u662f\uff0c\u5982\u679cIsCompleted\u68c0\u67e5\u5b9e\u9645\u4e0a\u8fd4\u56defalse\uff0c\u4f1a\u53d1\u751f\u4ec0\u4e48\u3002\u5982\u679c\u5b83\u8fd4\u56detrue\uff0c\u6211\u4eec\u5c31\u7ee7\u7eed\u5904\u7406\u5faa\u73af\uff0c\u7c7b\u4f3c\u4e8e\u5728APM\u6a21\u5f0f\u4e2dcompletedsynchronized\u8fd4\u56detrue, Begin\u65b9\u6cd5\u7684\u8c03\u7528\u8005\u8d1f\u8d23\u7ee7\u7eed\u6267\u884c\uff0c\u800c\u4e0d\u662f\u56de\u8c03\u51fd\u6570\u3002\u4f46\u662f\u5982\u679cIsCompleted\u8fd4\u56defalse\uff0c\u6211\u4eec\u9700\u8981\u6682\u505casync\u65b9\u6cd5\u7684\u6267\u884c\uff0c\u76f4\u5230await\u64cd\u4f5c\u5b8c\u6210\u3002\u8fd9\u610f\u5473\u7740\u4eceMoveNext\u4e2d\u8fd4\u56de\uff0c\u56e0\u4e3a\u8fd9\u662fStart\u7684\u4e00\u90e8\u5206\uff0c\u6211\u4eec\u4ecd\u7136\u5728\u5165\u53e3\u70b9\u65b9\u6cd5\u4e2d\uff0c\u8fd9\u610f\u5473\u7740\u5c06\u4efb\u52a1\u8fd4\u56de\u7ed9\u8c03\u7528\u8005\u3002\u4f46\u5728\u53d1\u751f\u4efb\u4f55\u4e8b\u60c5\u4e4b\u524d\uff0c\u6211\u4eec\u9700\u8981\u5c06continuation\u8fde\u63a5\u5230\u6b63\u5728\u7b49\u5f85\u7684\u4efb\u52a1(\u6ce8\u610f\uff0c\u4e3a\u4e86\u907f\u514d\u50cf\u5728APM\u60c5\u51b5\u4e2d\u90a3\u6837\u7684stack dives\uff0c\u5982\u679c\u5f02\u6b65\u64cd\u4f5c\u5728IsCompleted\u8fd4\u56defalse\u540e\u5b8c\u6210\uff0c\u4f46\u5728\u6211\u4eec\u8fde\u63a5continuation\u4e4b\u524d\uff0ccontinuation\u4ecd\u7136\u9700\u8981\u4ece\u8c03\u7528\u7ebf\u7a0b\u5f02\u6b65\u8c03\u7528\uff0c\u56e0\u6b64\u5b83\u5c06\u8fdb\u5165\u961f\u5217)\u3002\u7531\u4e8e\u6211\u4eec\u53ef\u4ee5\u7b49\u5f85\u4efb\u4f55\u4e1c\u897f\uff0c\u6211\u4eec\u4e0d\u80fd\u76f4\u63a5\u4e0e\u4efb\u52a1\u5b9e\u4f8b\u5bf9\u8bdd;\u76f8\u53cd\uff0c\u6211\u4eec\u9700\u8981\u901a\u8fc7\u4e00\u4e9b\u57fa\u4e8e\u6a21\u5f0f\u7684\u65b9\u6cd5\u6765\u6267\u884c\u6b64\u64cd\u4f5c\u3002<\/p>\n
      \u8fd9\u662f\u5426\u610f\u5473\u7740awaiter\u4e0a\u6709\u4e00\u4e2a\u65b9\u6cd5\u53ef\u4ee5\u8fde\u63a5continuation?\u8fd9\u662f\u6709\u9053\u7406\u7684;\u6bd5\u7adf\uff0cTask\u672c\u8eab\u652f\u6301continuation\uff0c\u6709\u4e00\u4e2aContinueWith\u65b9\u6cd5\u7b49\u7b49\u2026\u2026\u96be\u9053\u4e0d\u662f\u7531GetAwaiter\u8fd4\u56de\u7684TaskAwaiter\u516c\u5f00\u4e86\u8ba9\u6211\u4eec\u8bbe\u7f6econtinuation\u7684\u65b9\u6cd5\u5417?\u4e8b\u5b9e\u4e0a\uff0c\u786e\u5b9e\u5982\u6b64\u3002awaiter\u6a21\u5f0f\u8981\u6c42awaiter\u5b9e\u73b0INotifyCompletion\u63a5\u53e3\uff0c\u8be5\u63a5\u53e3\u5305\u542b\u4e00\u4e2a\u65b9\u6cd5void OnCompleted(\u64cd\u4f5c\u5ef6\u7eed)\u3002awaiter\u8fd8\u53ef\u4ee5\u9009\u62e9\u6027\u5730\u5b9e\u73b0ICriticalNotifyCompletion\u63a5\u53e3\uff0c\u8be5\u63a5\u53e3\u7ee7\u627f\u4e86INotifyCompletion\uff0c\u5e76\u6dfb\u52a0\u4e86\u4e00\u4e2a\u65e0\u6548\u7684UnsafeOnCompleted(\u64cd\u4f5c\u5ef6\u7eed)\u65b9\u6cd5\u3002\u6839\u636e\u6211\u4eec\u4e4b\u524d\u5bf9ExecutionContext\u7684\u8ba8\u8bba\uff0c\u4f60\u53ef\u4ee5\u731c\u5230\u8fd9\u4e24\u4e2a\u65b9\u6cd5\u4e4b\u95f4\u7684\u533a\u522b\u662f:\u90fd\u8fde\u63a5\u4e86continuation\uff0c\u4f46OnCompleted\u5e94\u8be5\u6d41\u5411ExecutionContext\uff0c\u800cUnsafeOnCompleted\u4e0d\u9700\u8981\u3002\u8fd9\u4e3b\u8981\u662f\u5386\u53f2\u539f\u56e0\uff0c\u4e0e\u4ee3\u7801\u8bbf\u95ee\u5b89\u5168\uff08CAS\uff09\u6709\u5173\u3002CAS\u5728.NET Core\u4e2d\u5df2\u7ecf\u4e0d\u5b58\u5728\u4e86\uff0c\u5728.NET Framework\u4e2d\u9ed8\u8ba4\u662f\u5173\u95ed\u7684\uff0c\u53ea\u6709\u5f53\u4f60\u9009\u62e9\u91cd\u65b0\u542f\u7528\u9057\u7559\u7684\u90e8\u5206\u4fe1\u4efb\u529f\u80fd\u65f6\uff0c\u5b83\u624d\u4f1a\u53d1\u6325\u4f5c\u7528\u3002\u5f53\u4f7f\u7528\u90e8\u5206\u4fe1\u4efb\u65f6\uff0cCAS\u4fe1\u606f\u6d41\u4f5c\u4e3aExecutionContext\u7684\u4e00\u90e8\u5206\uff0c\u56e0\u6b64\u4e0d\u6d41\u52a8\u5b83\u662f\u201c\u4e0d\u5b89\u5168\u7684\u201d\uff0c\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u4e0d\u6d41\u52a8ExecutionContext\u7684\u65b9\u6cd5\u8981\u52a0\u4e0a\u201c\u4e0d\u5b89\u5168\u7684\u201d\u524d\u7f00\u3002\u8fd9\u79cd\u65b9\u6cd5\u4e5f\u88ab\u5f52\u4e3a[SecurityCritical]\uff0c\u90e8\u5206\u53ef\u4fe1\u7684\u4ee3\u7801\u4e0d\u80fd\u8c03\u7528[SecurityCritical]\u65b9\u6cd5\u3002\u56e0\u6b64\uff0c\u521b\u5efa\u4e86\u4e24\u4e2aOnCompleted\u7684\u53d8\u4f53\uff0c\u5982\u679c\u63d0\u4f9b\uff0c\u7f16\u8bd1\u5668\u66f4\u559c\u6b22\u4f7f\u7528UnsafeOnCompleted\uff0c\u4f46OnCompleted\u53d8\u4f53\u603b\u662f\u81ea\u5df1\u63d0\u4f9b\uff0c\u4ee5\u9632awaiter\u9700\u8981\u652f\u6301\u90e8\u5206\u4fe1\u4efb\u3002\u7136\u800c\uff0c\u4ece\u5f02\u6b65\u65b9\u6cd5\u7684\u89d2\u5ea6\u6765\u770b\uff0c\u7f16\u8bd1\u5668\u603b\u662f\u5c06ExecutionContext\u6d41\u8fc7\u7b49\u5f85\u70b9\uff0c\u6240\u4ee5\u7b49\u5f85\u5668\u4e5f\u8fd9\u6837\u505a\u662f\u4e0d\u5fc5\u8981\u7684\uff0c\u800c\u4e14\u662f\u91cd\u590d\u7684\u5de5\u4f5c\u3002<\/p>\n
      Awaiter\u516c\u5f00\u4e86\u4e00\u4e2a\u65b9\u6cd5\u6765\u8fde\u63a5continuation\u3002\u7f16\u8bd1\u5668\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u5b83\uff0c\u9664\u4e86\u4e00\u4e2a\u975e\u5e38\u5173\u952e\u7684\u95ee\u9898:continuation\u5230\u5e95\u5e94\u8be5\u662f\u4ec0\u4e48?\u66f4\u91cd\u8981\u7684\u662f\uff0c\u5b83\u5e94\u8be5\u4e0e\u4ec0\u4e48\u5bf9\u8c61\u76f8\u5173\u8054?\u8bf7\u8bb0\u4f4f\uff0c\u72b6\u6001\u673a\u7ed3\u6784\u4f53\u5728\u6808\u4e0a\uff0c\u6211\u4eec\u5f53\u524d\u8fd0\u884c\u7684MoveNext\u8c03\u7528\u662f\u5bf9\u8be5\u5b9e\u4f8b\u7684\u65b9\u6cd5\u8c03\u7528\u3002\u6211\u4eec\u9700\u8981\u4fdd\u5b58\u72b6\u6001\u673a\uff0c\u4ee5\u4fbf\u5728\u6062\u590d\u65f6\u6211\u4eec\u62e5\u6709\u6240\u6709\u6b63\u786e\u7684\u72b6\u6001\uff0c\u8fd9\u610f\u5473\u7740\u72b6\u6001\u673a\u4e0d\u80fd\u4e00\u76f4\u5b58\u5728\u4e8e\u6808\u4e2d;\u5b83\u9700\u8981\u88ab\u590d\u5236\u5230\u5806\u4e0a\u7684\u67d0\u4e2a\u5730\u65b9\uff0c\u56e0\u4e3a\u6808\u6700\u7ec8\u5c06\u88ab\u7528\u4e8e\u8be5\u7ebf\u7a0b\u6267\u884c\u7684\u5176\u4ed6\u540e\u7eed\u7684\u3001\u65e0\u5173\u7684\u5de5\u4f5c\u3002\u7136\u540e\uff0c\u5ef6\u7eed\u9700\u8981\u5728\u5806\u4e0a\u7684\u72b6\u6001\u673a\u526f\u672c\u4e0a\u8c03\u7528MoveNext\u65b9\u6cd5\u3002<\/p>\n
      \u6b64\u5916\uff0cExecutionContext\u4e5f\u4e0e\u6b64\u76f8\u5173\u3002\u72b6\u6001\u673a\u9700\u8981\u786e\u4fdd\u5b58\u50a8\u5728ExecutionContext\u4e2d\u7684\u4efb\u4f55\u73af\u5883\u6570\u636e\u5728\u6682\u505c\u65f6\u88ab\u6355\u83b7\uff0c\u7136\u540e\u5728\u6062\u590d\u65f6\u88ab\u5e94\u7528\uff0c\u8fd9\u610f\u5473\u7740\u5ef6\u7eed\u4e5f\u9700\u8981\u5408\u5e76\u8be5ExecutionContext\u3002\u56e0\u6b64\uff0c\u4ec5\u4ec5\u5728\u72b6\u6001\u673a\u4e0a\u521b\u5efa\u4e00\u4e2a\u6307\u5411MoveNext\u7684\u59d4\u6258\u662f\u4e0d\u591f\u7684\u3002\u8fd9\u4e5f\u662f\u6211\u4eec\u4e0d\u60f3\u8981\u7684\u5f00\u9500\u3002\u5982\u679c\u5f53\u6211\u4eec\u6302\u8d77\u65f6\uff0c\u6211\u4eec\u5728\u72b6\u6001\u673a\u4e0a\u521b\u5efa\u4e86\u4e00\u4e2a\u6307\u5411MoveNext\u7684\u59d4\u6258\uff0c\u90a3\u4e48\u6bcf\u6b21\u8fd9\u6837\u505a\u6211\u4eec\u90fd\u8981\u5bf9\u72b6\u6001\u673a\u7ed3\u6784\u8fdb\u884c\u88c5\u7bb1(\u5373\u4f7f\u5b83\u5df2\u7ecf\u4f5c\u4e3a\u5176\u4ed6\u5bf9\u8c61\u7684\u4e00\u90e8\u5206\u5728\u5806\u4e0a)\u5e76\u5206\u914d\u4e00\u4e2a\u989d\u5916\u7684\u59d4\u6258(\u59d4\u6258\u7684\u8fd9\u4e2a\u5bf9\u8c61\u5f15\u7528\u5c06\u662f\u8be5\u7ed3\u6784\u4f53\u7684\u4e00\u4e2a\u65b0\u88c5\u7bb1\u7684\u526f\u672c)\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u9700\u8981\u505a\u4e00\u4e2a\u590d\u6742\u7684\u52a8\u4f5c\uff0c\u5373\u786e\u4fdd\u6211\u4eec\u53ea\u5728\u65b9\u6cd5\u7b2c\u4e00\u6b21\u6682\u505c\u6267\u884c\u65f6\u5c06\u8be5\u7ed3\u6784\u4ece\u5806\u6808\u4e2d\u63d0\u5347\u5230\u5806\u4e2d\uff0c\u800c\u5728\u5176\u4ed6\u65f6\u5019\u90fd\u4f7f\u7528\u76f8\u540c\u7684\u5806\u5bf9\u8c61\u4f5c\u4e3aMoveNext\u7684\u76ee\u6807\uff0c\u5e76\u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\u786e\u4fdd\u6211\u4eec\u6355\u83b7\u4e86\u6b63\u786e\u7684\u4e0a\u4e0b\u6587\uff0c\u5e76\u5728\u6062\u590d\u65f6\u786e\u4fdd\u6211\u4eec\u4f7f\u7528\u6355\u83b7\u7684\u4e0a\u4e0b\u6587\u6765\u8c03\u7528\u8be5\u64cd\u4f5c\u3002<\/p>\n
      \u8fd9\u6bd4\u6211\u4eec\u5e0c\u671b\u7f16\u8bd1\u5668\u53d1\u51fa\u7684\u903b\u8f91\u591a\u5f97\u591a\u2026\u2026\u51fa\u4e8e\u51e0\u4e2a\u539f\u56e0\uff0c\u6211\u4eec\u5e0c\u671b\u5b83\u5c01\u88c5\u5728\u4e00\u4e2ahelper\u4e2d\u3002\u7b2c\u4e00\uff0c\u6709\u5f88\u591a\u590d\u6742\u7684\u4ee3\u7801\u8981\u53d1\u9001\u5230\u6bcf\u4e2a\u7528\u6237\u7684\u7a0b\u5e8f\u96c6\u4e2d\u3002\u7b2c\u4e8c\uff0c\u6211\u4eec\u5e0c\u671b\u5141\u8bb8\u81ea\u5b9a\u4e49\u8be5\u903b\u8f91\u4f5c\u4e3a\u6784\u5efa\u5668\u6a21\u5f0f\u5b9e\u73b0\u7684\u4e00\u90e8\u5206(\u5728\u540e\u9762\u8ba8\u8bba\u6c60\u65f6\uff0c\u6211\u4eec\u5c06\u770b\u5230\u4e00\u4e2a\u4f8b\u5b50\u6765\u89e3\u91ca\u4e3a\u4ec0\u4e48)\u3002\u7b2c\u4e09\uff0c\u6211\u4eec\u5e0c\u671b\u80fd\u591f\u53d1\u5c55\u548c\u6539\u8fdb\u8fd9\u79cd\u903b\u8f91\uff0c\u5e76\u4f7f\u73b0\u6709\u7684\u5148\u524d\u7f16\u8bd1\u7684\u4e8c\u8fdb\u5236\u6587\u4ef6\u53d8\u5f97\u66f4\u597d\u3002\u8fd9\u4e0d\u662f\u5047\u8bbe; \u5728 .net Core 2.1\u4e2d\uff0c\u652f\u6301\u8fd9\u4e00\u529f\u80fd\u7684\u5e93\u4ee3\u7801\u88ab\u5f7b\u5e95\u4fee\u6539\u4e86\uff0c\u56e0\u6b64\u6bd4\u5728 .netFramewor\u4e0a\u64cd\u4f5c\u66f4\u52a0\u9ad8\u6548\u3002\u6211\u4eec\u5c06\u9996\u5148\u63a2\u7d22\u5b83\u5728 .net Framework\u4e0a\u662f\u5982\u4f55\u5de5\u4f5c\u7684\uff0c\u7136\u540e\u518d\u770b\u770b\u73b0\u5728\u5728 .net Core\u4e2d\u53d1\u751f\u4e86\u4ec0\u4e48\u3002<\/p>\n
      \u4f60\u53ef\u4ee5\u5728c#\u7f16\u8bd1\u5668\u751f\u6210\u7684\u4ee3\u7801\u4e2d\u770b\u5230\uff0c\u5f53\u6211\u4eec\u9700\u8981\u6302\u8d77\u65f6\u5c31\u4f1a\u53d1\u751f:<\/p>\n
      if (!awaiter.IsCompleted) \/\/ we need to suspend when IsCompleted is false\r\n{\r\n    <>1__state = 1;\r\n    <>u__2 = awaiter;\r\n    <>t__builder.AwaitUnsafeOnCompleted(ref awaiter, ref this);\r\n    return;\r\n}<\/code><\/pre>\n
      \u6211\u4eec\u5c06\u72b6\u6001id\u5b58\u50a8\u5230state\u5b57\u6bb5\u4e2d\uff0c\u8be5id\u8868\u793a\u5f53\u65b9\u6cd5\u6062\u590d\u65f6\u5e94\u8be5\u8df3\u8f6c\u5230\u7684\u4f4d\u7f6e\u3002\u7136\u540e\uff0c\u6211\u4eec\u5c06awaiter\u672c\u8eab\u6301\u4e45\u5316\u5230\u4e00\u4e2a\u5b57\u6bb5\u4e2d\uff0c\u4ee5\u4fbf\u5728\u6062\u590d\u540e\u53ef\u4ee5\u4f7f\u7528\u5b83\u6765\u8c03\u7528GetResult\u3002\u7136\u540e\u5728\u8fd4\u56deMoveNext\u8c03\u7528\u4e4b\u524d\uff0c\u6211\u4eec\u8981\u505a\u7684\u6700\u540e\u4e00\u4ef6\u4e8b\u662f\u8c03\u7528<>t__builder.AwaitUnsafeOnCompleted(ref awaiter, ref this)\uff0c\u8981\u6c42\u6784\u5efa\u5668\u4e3a\u8fd9\u4e2a\u72b6\u6001\u673a\u8fde\u63a5\u4e00\u4e2acontinuation\u5230awaiter\u3002(\u6ce8\u610f\uff0c\u5b83\u8c03\u7528\u6784\u5efa\u5668\u7684AwaitUnsafeOnCompleted\u800c\u4e0d\u662f\u6784\u5efa\u5668\u7684AwaitOnCompleted\uff0c\u56e0\u4e3aawaiter\u5b9e\u73b0\u4e86iccriticalnotifycompletion;\u72b6\u6001\u673a\u5904\u7406\u6d41\u52a8\u7684ExecutionContext\uff0c\u6240\u4ee5\u6211\u4eec\u4e0d\u9700\u8981awaiter\u4e5f\u2026\u2026\u6b63\u5982\u524d\u9762\u63d0\u5230\u7684\uff0c\u8fd9\u6837\u505a\u53ea\u4f1a\u5e26\u6765\u91cd\u590d\u548c\u4e0d\u5fc5\u8981\u7684\u5f00\u9500\u3002)<\/p>\n
      AwaitUnsafeOnCompleted\u65b9\u6cd5\u7684\u5b9e\u73b0\u592a\u590d\u6742\u4e86\uff0c\u4e0d\u80fd\u5728\u8fd9\u91cc\u590d\u5236\uff0c\u6240\u4ee5\u6211\u5c06\u603b\u7ed3\u5b83\u5728.NET Framework\u4e0a\u7684\u4f5c\u7528<\/a>:<\/p>\n
        \n
      1. \u5b83\u4f7f\u7528Capture()\u6765\u83b7\u53d6\u5f53\u524d\u4e0a\u4e0b\u6587\u3002<\/li>\n
      2. \u7136\u540e\u5b83\u5206\u914d\u4e00\u4e2aMoveNextRunner\u5bf9\u8c61\u6765\u5305\u88c5\u6355\u83b7\u7684\u4e0a\u4e0b\u6587\u548c\u88c5\u7bb1\u7684\u72b6\u6001\u673a(\u5982\u679c\u8fd9\u662f\u8be5\u65b9\u6cd5\u7b2c\u4e00\u6b21\u6302\u8d77\uff0c\u6211\u4eec\u8fd8\u6ca1\u6709\u72b6\u6001\u673a\uff0c\u6240\u4ee5\u6211\u4eec\u53ea\u4f7f\u7528null\u4f5c\u4e3a\u5360\u4f4d\u7b26)\u3002<\/li>\n
      3. \u7136\u540e\uff0c\u5b83\u521b\u5efa\u4e00\u4e2a\u64cd\u4f5c\u59d4\u6258\u7ed9\u8be5MoveNextRunner\u4e0a\u7684Run\u65b9\u6cd5;\u8fd9\u5c31\u662f\u5b83\u5982\u4f55\u80fd\u591f\u83b7\u5f97\u4e00\u4e2a\u59d4\u6258\uff0c\u8be5\u59d4\u6258\u5c06\u5728\u6355\u83b7\u7684ExecutionContext\u7684\u4e0a\u4e0b\u6587\u4e2d\u8c03\u7528\u72b6\u6001\u673a\u7684MoveNext\u3002<\/li>\n
      4. \u5982\u679c\u8fd9\u662f\u8be5\u65b9\u6cd5\u7b2c\u4e00\u6b21\u6302\u8d77\uff0c\u6211\u4eec\u8fd8\u6ca1\u6709\u88c5\u7bb1\u7684\u72b6\u6001\u673a\uff0c\u6240\u4ee5\u6b64\u65f6\u5b83\u4f1a\u5c06\u5176\u88c5\u7bb1\uff0c\u901a\u8fc7\u5c06\u5b9e\u4f8b\u5b58\u50a8\u5230\u672c\u5730\u7c7b\u578b\u7684IAsyncStateMachine\u63a5\u53e3\u4e2d\uff0c\u5728\u5806\u4e0a\u521b\u5efa\u4e00\u4e2a\u526f\u672c\u3002\u7136\u540e\uff0c\u8fd9\u4e2a\u76d2\u5b50\u4f1a\u88ab\u5b58\u50a8\u5230\u5df2\u5206\u914d\u7684MoveNextRunner\u4e2d\u3002<\/li>\n
      5. \u73b0\u5728\u5230\u4e86\u4e00\u4e2a\u6709\u4e9b\u4ee4\u4eba\u8d39\u89e3\u7684\u6b65\u9aa4\u3002\u5982\u679c\u60a8\u67e5\u770b\u72b6\u6001\u673a\u7ed3\u6784\u4f53\u7684\u5b9a\u4e49\uff0c\u5b83\u5305\u542b\u6784\u5efa\u5668\uff0cpublic AsyncTaskMethodBuilder <>t__builder;\uff0c\u5982\u679c\u4f60\u67e5\u770b\u6784\u5efa\u5668\u7684\u5b9a\u4e49\uff0c\u5b83\u5305\u542b\u5185\u90e8\u7684IAsyncStateMachine m_stateMachine;\u3002\u6784\u5efa\u5668\u9700\u8981\u5f15\u7528\u88c5\u7bb1\u7684\u72b6\u6001\u673a\uff0c\u4ee5\u4fbf\u5728\u540e\u7eed\u7684\u6302\u8d77\u4e2d\u5b83\u53ef\u4ee5\u770b\u5230\u5b83\u5df2\u7ecf\u88c5\u7bb1\u4e86\u72b6\u6001\u673a\uff0c\u5e76\u4e14\u4e0d\u9700\u8981\u518d\u6b21\u8fd9\u6837\u505a\u3002\u4f46\u662f\u6211\u4eec\u53ea\u662f\u88c5\u7bb1\u4e86\u72b6\u6001\u673a\uff0c\u5e76\u4e14\u8be5\u72b6\u6001\u673a\u5305\u542b\u4e00\u4e2am_stateMachine\u5b57\u6bb5\u4e3anull\u7684\u6784\u5efa\u5668\u3002\u6211\u4eec\u9700\u8981\u6539\u53d8\u88c5\u7bb1\u72b6\u6001\u673a\u7684\u6784\u5efa\u5668\u7684m_stateMachine\u6307\u5411\u5b83\u7684\u7236\u5bb9\u5668\u3002\u4e3a\u4e86\u5b9e\u73b0\u8fd9\u4e00\u70b9\uff0c\u7f16\u8bd1\u5668\u751f\u6210\u7684\u72b6\u6001\u673a\u7ed3\u6784\u4f53\u5b9e\u73b0\u4e86IAsyncStateMachine\u63a5\u53e3\uff0c\u5176\u4e2d\u5305\u62ec\u4e00\u4e2avoid SetStateMachine(IAsyncStateMachine stateMachine);\u65b9\u6cd5\uff0c\u8be5\u72b6\u6001\u673a\u7ed3\u6784\u4f53\u5305\u542b\u4e86\u8be5\u63a5\u53e3\u65b9\u6cd5\u7684\u5b9e\u73b0:<\/li>\n<\/ol>\n
        private void SetStateMachine(IAsyncStateMachine stateMachine) =>\r\n    <>t__builder.SetStateMachine(stateMachine);<\/code><\/pre>\n
        \u56e0\u6b64\uff0c\u6784\u5efa\u5668\u5bf9\u72b6\u6001\u673a\u8fdb\u884c\u88c5\u7bb1\uff0c\u7136\u540e\u5c06\u88c5\u7bb1\u4f20\u9012\u7ed9\u88c5\u7bb1\u7684SetStateMachine\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u4f1a\u8c03\u7528\u6784\u5efa\u5668\u7684SetStateMachine\u65b9\u6cd5\uff0c\u5c06\u88c5\u7bb1\u5b58\u50a8\u5230\u5b57\u6bb5\u4e2d\u3002<\/p>\n
          \n
        1. \u6700\u540e\uff0c\u6211\u4eec\u6709\u4e00\u4e2a\u8868\u793acontinuation\u7684Action\uff0c\u5b83\u88ab\u4f20\u9012\u7ed9awaiter\u7684UnsafeOnCompleted\u65b9\u6cd5\u3002\u5728TaskAwaiter\u7684\u60c5\u51b5\u4e0b\uff0c\u4efb\u52a1\u5c06\u5c06\u8be5\u64cd\u4f5c\u5b58\u50a8\u5230\u4efb\u52a1\u7684continuation\u5217\u8868\u4e2d\uff0c\u8fd9\u6837\u5f53\u4efb\u52a1\u5b8c\u6210\u65f6\uff0c\u5b83\u5c06\u8c03\u7528\u8be5\u64cd\u4f5c\uff0c\u901a\u8fc7Run\u56de\u8c03\uff0c\u901a\u8fc7ExecutionContext.Run\u56de\u8c03\uff0c\u6700\u540e\u8c03\u7528\u72b6\u6001\u673a\u7684MoveNext\u65b9\u6cd5\u91cd\u65b0\u8fdb\u5165\u72b6\u6001\u673a\uff0c\u5e76\u4ece\u5b83\u505c\u6b62\u7684\u5730\u65b9\u7ee7\u7eed\u8fd0\u884c\u3002<\/li>\n<\/ol>\n
          \u8fd9\u5c31\u662f\u5728.net Framework\u4e2d\u53d1\u751f\u7684\u4e8b\u60c5\uff0c\u4f60\u53ef\u4ee5\u5728\u5206\u6790\u5668\u4e2d\u770b\u5230\u7ed3\u679c\uff0c\u4f8b\u5982\u901a\u8fc7\u8fd0\u884c\u5206\u914d\u5206\u6790\u5668\u6765\u67e5\u770b\u6bcf\u4e2aawait\u4e0a\u7684\u5206\u914d\u60c5\u51b5\u3002\u8ba9\u6211\u4eec\u770b\u770b\u8fd9\u4e2a\u611a\u8822\u7684\u7a0b\u5e8f\uff0c\u6211\u5199\u8fd9\u4e2a\u7a0b\u5e8f\u53ea\u662f\u4e3a\u4e86\u5f3a\u8c03\u5176\u4e2d\u6d89\u53ca\u7684\u5206\u914d\u6210\u672c:<\/p>\n
          using System.Threading;\r\nusing System.Threading.Tasks;\r\n\r\nclass Program\r\n{\r\n    static async Task Main()\r\n    {\r\n        var al = new AsyncLocal<int>() { Value = 42 };\r\n        for (int i = 0; i < 1000; i++)\r\n        {\r\n            await SomeMethodAsync();\r\n        }\r\n    }\r\n\r\n    static async Task SomeMethodAsync()\r\n    {\r\n        for (int i = 0; i < 1000; i++)\r\n        {\r\n            await Task.Yield();\r\n        }\r\n    }\r\n}<\/code><\/pre>\n
          \u8fd9\u4e2a\u7a0b\u5e8f\u521b\u5efa\u4e86\u4e00\u4e2aAsyncLocal<int>\uff0c\u8ba9\u503c42\u901a\u8fc7\u6240\u6709\u540e\u7eed\u7684\u5f02\u6b65\u64cd\u4f5c\u3002\u7136\u540e\u5b83\u8c03\u7528SomeMethodAsync 1000\u6b21\uff0c\u6bcf\u6b21\u6682\u505c\/\u6062\u590d1000\u6b21\u3002\u5728Visual Studio\u4e2d\uff0c\u6211\u4f7f\u7528 .NET Object Allocation Tracking profiler<\/a>\u8fd0\u884c\u5b83\uff0c\u7ed3\u679c\u5982\u4e0b:<\/p>\n
          \"Image<\/a><\/p>\n
          \u90a3\u662f\u2026\u5f88\u591a\u7684\u5206\u914d!\u8ba9\u6211\u4eec\u6765\u7814\u7a76\u4e00\u4e0b\u5b83\u4eec\u7684\u6765\u6e90\u3002<\/p>\n
          ExecutionContext\u3002\u6709\u8d85\u8fc7\u4e00\u767e\u4e07\u4e2a\u8fd9\u6837\u7684\u5185\u5bb9\u88ab\u5206\u914d\u3002\u4e3a\u4ec0\u4e48?\u56e0\u4e3a\u5728 .net\u6846\u67b6\u4e2d\uff0cExecutionContext\u662f\u4e00\u4e2a\u53ef\u53d8\u7684\u6570\u636e\u7ed3\u6784\u3002\u7531\u4e8e\u6211\u4eec\u5e0c\u671b\u6d41\u8f6c\u4e00\u4e2a\u5f02\u6b65\u64cd\u4f5c\u88abfork\u65f6\u7684\u6570\u636e\uff0c\u5e76\u4e14\u6211\u4eec\u4e0d\u5e0c\u671b\u5b83\u5728fork\u4e4b\u540e\u770b\u5230\u6267\u884c\u7684\u53d8\u66f4\uff0c\u6211\u4eec\u9700\u8981\u590d\u5236ExecutionContext\u3002\u6bcf\u4e2a\u5355\u72ec\u7684fork\u64cd\u4f5c\u90fd\u9700\u8981\u8fd9\u6837\u7684\u526f\u672c\uff0c\u56e0\u6b64\u67091000\u6b21\u5bf9SomeMethodAsync\u7684\u8c03\u7528\uff0c\u6bcf\u4e2a\u8c03\u7528\u90fd\u4f1a\u6682\u505c\/\u6062\u590d1000\u6b21\uff0c\u6211\u4eec\u6709100\u4e07\u4e2aExecutionContext\u5b9e\u4f8b\u3002<\/p>\n
          Action\u3002\u7c7b\u4f3c\u5730\uff0c\u6bcf\u6b21\u6211\u4eec\u7b49\u5f85\u5c1a\u672a\u5b8c\u6210\u7684\u4efb\u52a1\u65f6(\u6211\u4eec\u7684\u767e\u4e07\u4e2aawait Task.Yield()s\u5c31\u662f\u8fd9\u79cd\u60c5\u51b5)\uff0c\u6211\u4eec\u6700\u7ec8\u5206\u914d\u4e00\u4e2a\u65b0\u7684\u64cd\u4f5c\u59d4\u6258\u6765\u4f20\u9012\u7ed9awaiter\u7684UnsafeOnCompleted\u65b9\u6cd5\u3002<\/p>\n
          MoveNextRunner\u3002\u540c\u6837\u7684\uff0c\u6709\u4e00\u767e\u4e07\u4e2a\u8fd9\u6837\u7684\u4f8b\u5b50\uff0c\u56e0\u4e3a\u5728\u524d\u9762\u7684\u6b65\u9aa4\u5927\u7eb2\u4e2d\uff0c\u6bcf\u6b21\u6211\u4eec\u6682\u505c\u65f6\uff0c\u6211\u4eec\u90fd\u8981\u5206\u914d\u4e00\u4e2a\u65b0\u7684MoveNextRunner\u6765\u5b58\u50a8Action\u548cExecutionContext\uff0c\u4ee5\u4fbf\u4f7f\u7528\u540e\u8005\u6765\u6267\u884c\u524d\u8005\u3002<\/p>\n
          LogicalCallContext\u3002\u53e6\u4e00\u4e2a\u4e00\u767e\u4e07\u3002\u8fd9\u4e9b\u662f.NET\u6846\u67b6\u4e0aAsyncLocal<T>\u7684\u5b9e\u73b0\u7ec6\u8282;AsyncLocal<T>\u5c06\u5176\u6570\u636e\u5b58\u50a8\u5230ExecutionContext\u7684\u201c\u903b\u8f91\u8c03\u7528\u4e0a\u4e0b\u6587\u201d\u4e2d\uff0c\u8fd9\u662f\u8868\u793a\u4e0eExecutionContext\u4e00\u8d77\u6d41\u52a8\u7684\u4e00\u822c\u72b6\u6001\u7684\u4e00\u79cd\u5947\u7279\u65b9\u5f0f\u3002\u5982\u679c\u6211\u4eec\u8981\u590d\u5236\u4e00\u767e\u4e07\u4e2aExecutionContext\uff0c\u6211\u4eec\u4e5f\u4f1a\u590d\u5236\u4e00\u767e\u4e07\u4e2aLogicalCallContext\u3002<\/p>\n
          QueueUserWorkItemCallback\u3002\u6bcf\u4e2aTask.Yield()\u90fd\u5c06\u4e00\u4e2a\u5de5\u4f5c\u9879\u6392\u961f\u5230\u7ebf\u7a0b\u6c60\u4e2d\uff0c\u5bfc\u81f4\u5206\u914d\u4e86100\u4e07\u4e2a\u5de5\u4f5c\u9879\u5bf9\u8c61\u7528\u4e8e\u8868\u793a\u8fd9100\u4e07\u4e2a\u64cd\u4f5c\u3002<\/p>\n
          Task< VoidResult >\u3002\u8fd9\u91cc\u6709\u4e00\u5343\u4e2a\u8fd9\u6837\u7684\uff0c\u6240\u4ee5\u81f3\u5c11\u6211\u4eec\u8131\u79bb\u4e86”\u767e\u4e07”\u4ff1\u4e50\u90e8\u3002\u6bcf\u4e2a\u5f02\u6b65\u5b8c\u6210\u7684\u5f02\u6b65\u4efb\u52a1\u8c03\u7528\u90fd\u9700\u8981\u5206\u914d\u4e00\u4e2a\u65b0\u7684Task\u5b9e\u4f8b\u6765\u8868\u793a\u8be5\u8c03\u7528\u7684\u6700\u7ec8\u5b8c\u6210\u3002<\/p>\n
          < SomeMethodAsync > d__1\u3002\u8fd9\u662f\u7f16\u8bd1\u5668\u751f\u6210\u7684\u72b6\u6001\u673a\u7ed3\u6784\u7684\u76d2\u5b50\u30021000\u4e2a\u65b9\u6cd5\u6302\u8d77\uff0c1000\u4e2a\u76d2\u5b50\u51fa\u73b0\u3002<\/p>\n
          QueueSegment \/ IThreadPoolWorkItem[]\u3002\u6709\u51e0\u5343\u4e2a\u8fd9\u6837\u7684\u65b9\u6cd5\uff0c\u4ece\u6280\u672f\u4e0a\u8bb2\uff0c\u5b83\u4eec\u4e0e\u5177\u4f53\u7684\u5f02\u6b65\u65b9\u6cd5\u65e0\u5173\uff0c\u800c\u662f\u4e0e\u7ebf\u7a0b\u6c60\u4e2d\u7684\u961f\u5217\u5de5\u4f5c\u6709\u5173\u3002\u5728 .net\u6846\u67b6\u4e2d\uff0c\u7ebf\u7a0b\u6c60\u7684\u961f\u5217\u662f\u4e00\u4e2a\u975e\u5faa\u73af\u6bb5\u7684\u94fe\u8868\u3002\u8fd9\u4e9b\u6bb5\u4e0d\u4f1a\u88ab\u91cd\u7528;\u5bf9\u4e8e\u957f\u5ea6\u4e3aN\u7684\u6bb5\uff0c\u4e00\u65e6N\u4e2a\u5de5\u4f5c\u9879\u88ab\u52a0\u5165\u5230\u8be5\u6bb5\u7684\u961f\u5217\u4e2d\u5e76\u4ece\u8be5\u6bb5\u4e2d\u9000\u51fa\uff0c\u8be5\u6bb5\u5c31\u4f1a\u88ab\u4e22\u5f03\u5e76\u5f53\u4f5c\u5783\u573e\u56de\u6536\u3002<\/p>\n
          \u8fd9\u5c31\u662f. net\u6846\u67b6\u3002\u8fd9<\/a>\u662f.NET Core:<\/p>\n
          \"Image<\/a><\/p>\n
          \u6f02\u4eae\u591a\u4e86!\u5bf9\u4e8e. net\u6846\u67b6\u4e0a\u7684\u8fd9\u4e2a\u793a\u4f8b\uff0c\u6709\u8d85\u8fc7500\u4e07\u6b21\u5206\u914d\uff0c\u603b\u5171\u5206\u914d\u4e86\u5927\u7ea6145MB\u7684\u5185\u5b58\u3002\u5bf9\u4e8e .net Core\u4e0a\u7684\u76f8\u540c\u793a\u4f8b\uff0c\u53ea\u6709\u5927\u7ea61000\u4e2a\u5185\u5b58\u5206\u914d\uff0c\u603b\u5171\u53ea\u6709\u5927\u7ea6109KB\u3002\u4e3a\u4ec0\u4e48\u8fd9\u4e48\u5c11?<\/p>\n
          ExecutionContext\u3002\u5728.net Core\u4e2d\uff0cExecutionContext\u73b0\u5728\u662f\u4e0d\u53ef\u53d8\u7684\u3002\u8fd9\u6837\u505a\u7684\u7f3a\u70b9\u662f\uff0c\u5bf9\u4e0a\u4e0b\u6587\u7684\u6bcf\u6b21\u66f4\u6539\uff0c\u4f8b\u5982\u5c06\u503c\u8bbe\u7f6e\u4e3aAsyncLocal<T>\uff0c\u90fd\u9700\u8981\u5206\u914d\u4e00\u4e2a\u65b0\u7684ExecutionContext\u3002\u7136\u800c\uff0c\u597d\u5904\u662f\uff0c\u6d41\u52a8\u7684\u4e0a\u4e0b\u6587\u6bd4\u6539\u53d8\u5b83\u66f4\u5e38\u89c1\uff0c\u800c\u4e14\u7531\u4e8eExecutionContext\u73b0\u5728\u662f\u4e0d\u53ef\u53d8\u7684\uff0c\u6211\u4eec\u4e0d\u518d\u9700\u8981\u4f5c\u4e3a\u6d41\u52a8\u7684\u4e00\u90e8\u5206\u8fdb\u884c\u514b\u9686\u3002\u201c\u6355\u83b7\u201d\u4e0a\u4e0b\u6587\u5b9e\u9645\u4e0a\u5c31\u662f\u4ece\u5b57\u6bb5\u4e2d\u8bfb\u53d6\u5b83\uff0c\u800c\u4e0d\u662f\u8bfb\u53d6\u5b83\u5e76\u590d\u5236\u5176\u5185\u5bb9\u3002\u56e0\u6b64\uff0c\u6d41\u52a8\u4e0d\u4ec5\u6bd4\u53d8\u5316\u66f4\u5e38\u89c1\uff0c\u800c\u4e14\u66f4\u4fbf\u5b9c\u3002<\/p>\n
          LogicalCallContext\u3002\u8fd9\u5728.NET Core\u4e2d\u5df2\u7ecf\u4e0d\u5b58\u5728\u4e86\u3002\u5728.NET Core\u4e2d\uff0cExecutionContext\u552f\u4e00\u5b58\u5728\u7684\u4e1c\u897f\u662fAsyncLocal<T>\u7684\u5b58\u50a8\u3002\u5176\u4ed6\u5728ExecutionContext\u4e2d\u6709\u81ea\u5df1\u7279\u6b8a\u4f4d\u7f6e\u7684\u4e1c\u897f\u90fd\u662f\u4ee5AsyncLocal<T>\u4e3a\u6a21\u578b\u7684\u3002\u4f8b\u5982\uff0c\u5728.NET Framework\u4e2d\uff0c\u6a21\u62df\u5c06\u4f5c\u4e3aSecurityContext\u7684\u4e00\u90e8\u5206\u6d41\u52a8\uff0c\u800cSecurityContext\u662fExecutionContext\u7684\u4e00\u90e8\u5206\uff1b\u5728.NET Core\u4e2d\uff0c\u6a21\u62df\u901a\u8fc7AsyncLocal<SafeAccessTokenHandle>\u6d41\u52a8\uff0c\u5b83\u4f7f\u7528valueChangedHandler\u6765\u5bf9\u5f53\u524d\u7ebf\u7a0b\u8fdb\u884c\u9002\u5f53\u7684\u66f4\u6539\u3002<\/p>\n
          QueueSegment \/ IThreadPoolWorkItem[]\u3002\u5728.net Core\u4e2d\uff0cThreadPool\u7684\u5168\u5c40\u961f\u5217\u73b0\u5728\u88ab\u5b9e\u73b0\u4e3aConcurrentQueue<T>\uff0c\u800cConcurrentQueue<T>\u5df2\u7ecf\u88ab\u91cd\u5199\u4e3a\u4e00\u4e2a\u7531\u975e\u56fa\u5b9a\u5927\u5c0f\u7684\u5faa\u73af\u6bb5\u7ec4\u6210\u7684\u94fe\u8868\u3002\u4e00\u65e6\u6bb5\u7684\u957f\u5ea6\u5927\u5230\u6c38\u8fdc\u4e0d\u4f1a\u88ab\u586b\u6ee1\u56e0\u4e3a\u7a33\u6001\u7684\u51fa\u961f\u5217\u80fd\u591f\u8ddf\u4e0a\u7a33\u6001\u7684\u5165\u961f\u5217\uff0c\u5c31\u4e0d\u9700\u8981\u518d\u5206\u914d\u989d\u5916\u7684\u6bb5\uff0c\u76f8\u540c\u7684\u8db3\u591f\u5927\u7684\u6bb5\u5c31\u4f1a\u88ab\u65e0\u4f11\u6b62\u5730\u4f7f\u7528\u3002<\/p>\n
          \u90a3\u4e48\u5176\u4ed6\u7684\u5206\u914d\u5462\uff0c\u6bd4\u5982Action\u3001MoveNextRunner\u548c<SomeMethodAsync>d__1?\u8981\u7406\u89e3\u5269\u4f59\u7684\u5206\u914d\u662f\u5982\u4f55\u88ab\u79fb\u9664\u7684\uff0c\u9700\u8981\u6df1\u5165\u4e86\u89e3\u5b83\u5728.net Core\u4e0a\u662f\u5982\u4f55\u5de5\u4f5c\u7684\u3002<\/p>\n
          \u8ba9\u6211\u4eec\u56de\u5230\u8ba8\u8bba\u6302\u8d77\u65f6\u53d1\u751f\u7684\u4e8b\u60c5:<\/p>\n
          if (!awaiter.IsCompleted) \/\/ we need to suspend when IsCompleted is false\r\n{\r\n    <>1__state = 1;\r\n    <>u__2 = awaiter;\r\n    <>t__builder.AwaitUnsafeOnCompleted(ref awaiter, ref this);\r\n    return;\r\n}<\/code><\/pre>\n
          \u4e0d\u7ba1\u76ee\u6807\u662f\u54ea\u4e2a\u5e73\u53f0\uff0c\u8fd9\u91cc\u53d1\u51fa\u7684\u4ee3\u7801\u90fd\u662f\u76f8\u540c\u7684\uff0c\u6240\u4ee5\u4e0d\u7ba1\u662f.net Framework\u8fd8\u662f\uff0c\u4e3a\u8fd9\u4e2a\u6302\u8d77\u751f\u6210\u7684IL\u90fd\u662f\u76f8\u540c\u7684\u3002\u4f46\u662f\uff0c\u6539\u53d8\u7684\u662fAwaitUnsafeOnCompleted\u65b9\u6cd5\u7684\u5b9e\u73b0\uff0c\u5728.net Core\u4e2d\u6709\u5f88\u5927\u7684\u4e0d\u540c:<\/p>\n
            \n
          1. \u4e8b\u60c5\u7684\u5f00\u59cb\u662f\u4e00\u6837\u7684:\u8be5\u65b9\u6cd5\u8c03\u7528Capture()\u6765\u83b7\u53d6\u5f53\u524d\u6267\u884c\u4e0a\u4e0b\u6587\u3002<\/li>\n
          2. \u7136\u540e\uff0c\u4e8b\u60c5\u504f\u79bb\u4e86.net Framework\u3002.NET Core\u4e2d\u7684builder\u53ea\u6709\u4e00\u4e2a\u5b57\u6bb5:<\/li>\n<\/ol>\n
            public struct AsyncTaskMethodBuilder\r\n{\r\n    private Task<VoidTaskResult>? m_task;\r\n    ...\r\n}<\/code><\/pre>\n
            \u5728\u6355\u83b7ExecutionContext\u4e4b\u540e\uff0c\u5b83\u68c0\u67e5m_task\u5b57\u6bb5\u662f\u5426\u5305\u542b\u4e00\u4e2aAsyncStateMachineBox<TStateMachine><\/a>\u7684\u5b9e\u4f8b\uff0c\u5176\u4e2dTStateMachine\u662f\u7f16\u8bd1\u5668\u751f\u6210\u7684\u72b6\u6001\u673a\u7ed3\u6784\u4f53\u7684\u7c7b\u578b\u3002AsyncStateMachineBox<TStateMachine>\u7c7b\u578b\u662f\u201c\u9b54\u6cd5\u201d\u3002\u5b83\u7684\u5b9a\u4e49\u5982\u4e0b:<\/p>\n
            private class AsyncStateMachineBox<TStateMachine> :\r\n    Task<TResult>, IAsyncStateMachineBox\r\n    where TStateMachine : IAsyncStateMachine\r\n{\r\n    private Action? _moveNextAction;\r\n    public TStateMachine? StateMachine;\r\n    public ExecutionContext? Context;\r\n    ...\r\n}<\/code><\/pre>\n
            \u4e0e\u5176\u8bf4\u8fd9\u662f\u4e00\u4e2a\u5355\u72ec\u7684Task\uff0c\u4e0d\u5982\u8bf4\u8fd9\u662f\u4e00\u4e2a\u4efb\u52a1\uff08\u6ce8\u610f\u5176\u57fa\u672c\u7c7b\u578b\uff09\u3002\u8be5\u7ed3\u6784\u5e76\u6ca1\u6709\u5bf9\u72b6\u6001\u673a\u8fdb\u884c\u88c5\u7bb1\uff0c\u800c\u662f\u4f5c\u4e3a\u8be5\u4efb\u52a1\u7684\u5f3a\u7c7b\u578b\u5b57\u6bb5\u5b58\u5728\u3002\u6211\u4eec\u4e0d\u9700\u8981\u7528\u5355\u72ec\u7684 MoveNextRunner \u6765\u5b58\u50a8 Action \u548c ExecutionContext\uff0c\u5b83\u4eec\u53ea\u662f\u8fd9\u4e2a\u7c7b\u578b\u7684\u5b57\u6bb5\uff0c\u800c\u4e14\u7531\u4e8e\u8fd9\u662f\u5b58\u50a8\u5728\u6784\u5efa\u5668\u7684 m_task \u5b57\u6bb5\u4e2d\u7684\u5b9e\u4f8b\uff0c\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u8bbf\u95ee\u5b83\uff0c\u4e0d\u9700\u8981\u5728\u6bcf\u6b21\u6682\u505c\u65f6\u91cd\u65b0\u5206\u914d\u3002\u5982\u679cExecutionContext\u53d1\u751f\u53d8\u5316\uff0c\u6211\u4eec\u53ef\u4ee5\u7528\u65b0\u7684\u4e0a\u4e0b\u6587\u8986\u76d6\u8be5\u5b57\u6bb5\uff0c\u800c\u4e0d\u9700\u8981\u5206\u914d\u5176\u4ed6\u4e1c\u897f\uff1b\u6211\u4eec\u7684\u4efb\u4f55Action\u4ecd\u7136\u6307\u5411\u6b63\u786e\u7684\u5730\u65b9\u3002\u6240\u4ee5\uff0c\u5728\u6355\u83b7\u4e86ExecutionContext\u4e4b\u540e\uff0c\u5982\u679c\u6211\u4eec\u5df2\u7ecf\u6709\u4e86\u8fd9\u4e2aAsyncStateMachineBox<TStateMachine>\u7684\u5b9e\u4f8b\uff0c\u8fd9\u5c31\u4e0d\u662f\u8fd9\u4e2a\u65b9\u6cd5\u7b2c\u4e00\u6b21\u6302\u8d77\u4e86\uff0c\u6211\u4eec\u53ef\u4ee5\u76f4\u63a5\u628a\u65b0\u6355\u83b7\u7684ExecutionContext\u5b58\u50a8\u5230\u5176\u4e2d\u3002\u5982\u679c\u6211\u4eec\u8fd8\u6ca1\u6709\u4e00\u4e2aAsyncStateMachineBox<TStateMachine>\u7684\u5b9e\u4f8b\uff0c\u90a3\u4e48\u6211\u4eec\u9700\u8981\u5206\u914d\u5b83\uff1a<\/p>\n
            var box = new AsyncStateMachineBox<TStateMachine>();\r\ntaskField = box; \/\/ important: this must be done before storing stateMachine into box.StateMachine!\r\nbox.StateMachine = stateMachine;\r\nbox.Context = currentContext;<\/code><\/pre>\n
            \u8bf7\u6ce8\u610f\u6e90\u6ce8\u91ca\u4e3a\u201c\u91cd\u8981\u201d\u7684\u90a3\u4e00\u884c\u3002\u8fd9\u53d6\u4ee3\u4e86.net\u6846\u67b6\u4e2d\u590d\u6742\u7684SetStateMachine\uff0c\u4f7f\u5f97SetStateMachine\u5728.net Core\u4e2d\u6839\u672c\u6ca1\u6709\u4f7f\u7528\u3002\u4f60\u770b\u5230\u7684taskField\u6709\u4e00\u4e2a\u6307\u5411AsyncTaskMethodBuilder\u7684m_task\u5b57\u6bb5\u7684ref\u3002\u6211\u4eec\u5206\u914dAsyncStateMachineBox< tstatemachinebox >\uff0c\u7136\u540e\u901a\u8fc7taskField\u5c06\u5bf9\u8c61\u5b58\u50a8\u5230\u6784\u5efa\u5668\u7684m_task\u4e2d(\u8fd9\u662f\u5728\u6808\u4e0a\u7684\u72b6\u6001\u673a\u7ed3\u6784\u4e2d\u7684\u6784\u5efa\u5668)\uff0c\u7136\u540e\u5c06\u57fa\u4e8e\u5806\u6808\u7684\u72b6\u6001\u673a(\u73b0\u5728\u5df2\u7ecf\u5305\u542b\u5bf9\u76d2\u5b50\u7684\u5f15\u7528)\u590d\u5236\u5230\u57fa\u4e8e\u5806\u7684AsyncStateMachineBox< tstatemachinebox >\u4e2d\uff0c\u8fd9\u6837AsyncStateMachineBox<TStateMachine>\u9002\u5f53\u5730\u5e76\u9012\u5f52\u5730\u7ed3\u675f\u5f15\u7528\u81ea\u5df1\u3002\u8fd9\u4ecd\u7136\u662f\u4ee4\u4eba\u8d39\u89e3\u7684\uff0c\u4f46\u5374\u662f\u4e00\u79cd\u66f4\u6709\u6548\u7684\u8d39\u89e3<\/p>\n
              \n
            1. \u7136\u540e\uff0c\u6211\u4eec\u53ef\u4ee5\u5bf9\u8fd9\u4e2aAction\u4e0a\u7684\u4e00\u4e2a\u65b9\u6cd5\u8fdb\u884c\u64cd\u4f5c\uff0c\u8be5\u65b9\u6cd5\u5c06\u8c03\u7528\u5176MoveNext\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u5c06\u5728\u8c03\u7528StateMachine\u7684MoveNext\u4e4b\u524d\u6267\u884c\u9002\u5f53\u7684ExecutionContext\u6062\u590d\u3002\u8be5Action\u00a0\u53ef\u4ee5\u7f13\u5b58\u5230_moveNextAction\u5b57\u6bb5\u4e2d\uff0c\u4ee5\u4fbf\u4efb\u4f55\u540e\u7eed\u4f7f\u7528\u90fd\u53ef\u4ee5\u91cd\u7528\u76f8\u540c\u7684Action\u00a0\u3002\u7136\u540e\uff0c\u8be5Action\u00a0\u88ab\u4f20\u9012\u7ed9awaiter\u7684UnsafeOnCompleted\u6765\u8fde\u63a5continuation\u3002<\/li>\n<\/ol>\n
               <\/p>\n
              \u5b83\u89e3\u91ca\u4e86\u4e3a\u4ec0\u4e48\u5269\u4e0b\u7684\u5927\u90e8\u5206\u5206\u914d\u90fd\u6ca1\u6709\u4e86:<SomeMethodAsync>d__1\u6ca1\u6709\u88ab\u88c5\u7bb1\uff0c\u800c\u662f\u4f5c\u4e3a\u4efb\u52a1\u672c\u8eab\u7684\u4e00\u4e2a\u5b57\u6bb5\u5b58\u5728\uff0cMoveNextRunner\u4e0d\u518d\u9700\u8981\uff0c\u56e0\u4e3a\u5b83\u7684\u5b58\u5728\u53ea\u662f\u4e3a\u4e86\u5b58\u50a8Action\u548cExecutionContext\u3002\u4f46\u662f\uff0c\u6839\u636e\u8fd9\u4e2a\u89e3\u91ca\uff0c\u6211\u4eec\u4ecd\u7136\u5e94\u8be5\u770b\u52301000\u4e2a\u64cd\u4f5c\u5206\u914d\uff0c\u6bcf\u4e2a\u65b9\u6cd5\u8c03\u7528\u4e00\u4e2a\uff0c\u4f46\u6211\u4eec\u6ca1\u6709\u3002\u4e3a\u4ec0\u4e48?\u8fd8\u6709\u90a3\u4e9bQueueUserWorkItemCallback\u5bf9\u8c61\u5462?\u6211\u4eec\u4ecd\u7136\u5728Task.Yield()\u4e2d\u8fdb\u884c\u6392\u961f\uff0c\u4e3a\u4ec0\u4e48\u5b83\u4eec\u6ca1\u6709\u51fa\u73b0\u5462?<\/p>\n
              \u6b63\u5982\u6211\u6240\u63d0\u5230\u7684\uff0c\u5c06\u5b9e\u73b0\u7ec6\u8282\u63a8\u5165\u6838\u5fc3\u5e93\u7684\u597d\u5904\u4e4b\u4e00\u662f\uff0c\u5b83\u53ef\u4ee5\u968f\u7740\u65f6\u95f4\u7684\u63a8\u79fb\u6539\u8fdb\u5b9e\u73b0\uff0c\u6211\u4eec\u5df2\u7ecf\u770b\u5230\u4e86\u5b83\u662f\u5982\u4f55\u4ece. net Framework\u53d1\u5c55\u5230. net core\u7684\u3002\u5b83\u5728\u6700\u521d\u4e3a.net Core\u91cd\u5199\u7684\u57fa\u7840\u4e0a\u8fdb\u4e00\u6b65\u53d1\u5c55\uff0c\u589e\u52a0\u4e86\u989d\u5916\u7684\u4f18\u5316\uff0c\u8fd9\u5f97\u76ca\u4e8e\u5bf9\u7cfb\u7edf\u5173\u952e\u7ec4\u4ef6\u7684\u5185\u90e8\u8bbf\u95ee\u3002\u7279\u522b\u662f\uff0c\u5f02\u6b65\u57fa\u7840\u8bbe\u65bd\u77e5\u9053Task\u548cTaskAwaiter\u7b49\u6838\u5fc3\u7c7b\u578b\u3002\u800c\u4e14\u56e0\u4e3a\u5b83\u77e5\u9053\u5b83\u4eec\u5e76\u5177\u6709\u5185\u90e8\u8bbf\u95ee\u6743\u9650\uff0c\u6240\u4ee5\u5b83\u4e0d\u5fc5\u9075\u5faa\u516c\u5f00\u5b9a\u4e49\u7684\u89c4\u5219\u3002c#\u8bed\u8a00\u9075\u5faa\u7684awaiter\u6a21\u5f0f\u8981\u6c42awaiter\u5177\u6709AwaitOnCompleted\u6216AwaitUnsafeOnCompleted\u65b9\u6cd5\uff0c\u8fd9\u4e24\u4e2a\u65b9\u6cd5\u90fd\u5c06continuation\u4f5c\u4e3a\u4e00\u4e2a\u64cd\u4f5c\uff0c\u8fd9\u610f\u5473\u7740\u57fa\u7840\u7ed3\u6784\u9700\u8981\u80fd\u591f\u521b\u5efa\u4e00\u4e2a\u64cd\u4f5c\u6765\u8868\u793acontinuation\uff0c\u4ee5\u4fbf\u4e0e\u57fa\u7840\u7ed3\u6784\u4e0d\u77e5\u9053\u7684\u4efb\u610fawaiter\u4e00\u8d77\u5de5\u4f5c\u3002\u4f46\u662f\uff0c\u5982\u679c\u57fa\u7840\u8bbe\u65bd\u9047\u5230\u5b83\u77e5\u9053\u7684awaiter\uff0c\u5b83\u6ca1\u6709\u4e49\u52a1\u91c7\u53d6\u76f8\u540c\u7684\u4ee3\u7801\u8def\u5f84\u3002\u5bf9\u4e8eSystem.Private\u4e2d\u5b9a\u4e49\u7684\u6240\u6709\u6838\u5fc3awaiter\u3002\u56e0\u6b64\uff0cCoreLib\u7684\u57fa\u7840\u8bbe\u65bd\u53ef\u4ee5\u9075\u5faa\u66f4\u7b80\u6d01\u7684\u8def\u5f84\uff0c\u5b8c\u5168\u4e0d\u9700\u8981\u64cd\u4f5c\u3002\u8fd9\u4e9bawaiter\u90fd\u77e5\u9053IAsyncStateMachineBoxes\uff0c\u5e76\u4e14\u80fd\u591f\u5c06box\u5bf9\u8c61\u672c\u8eab\u4f5c\u4e3acontinuation\u3002\u4f8b\u5982\uff0cTask\u8fd4\u56de\u7684YieldAwaitable.Yield\u80fd\u591f\u5c06IAsyncStateMachineBox\u672c\u8eab\u4f5c\u4e3a\u5de5\u4f5c\u9879\u76f4\u63a5\u653e\u5165ThreadPool\u4e2d\uff0c\u800c\u7b49\u5f85\u4efb\u52a1\u65f6\u4f7f\u7528\u7684TaskAwaiter\u80fd\u591f\u5c06IAsyncStateMachineBox\u672c\u8eab\u76f4\u63a5\u5b58\u50a8\u5230\u4efb\u52a1\u7684\u5ef6\u7eed\u5217\u8868\u4e2d\u3002\u4e0d\u9700\u8981\u64cd\u4f5c\uff0c\u4e5f\u4e0d\u9700\u8981QueueUserWorkItemCallback\u3002<\/p>\n
              \u56e0\u6b64\uff0c\u5728\u975e\u5e38\u5e38\u89c1\u7684\u60c5\u51b5\u4e0b\uff0casync\u65b9\u6cd5\u53ea\u7b49\u5f85System.Private.CoreLib (Task, Task<TResult>\uff0c ValueTask, ValueTask<TResult>\uff0c YieldAwaitable\uff0c\u4ee5\u53ca\u5b83\u4eec\u7684ConfigureAwait\u53d8\u4f53)\uff0c\u6700\u574f\u7684\u60c5\u51b5\u4e0b\uff0c\u53ea\u6709\u4e00\u6b21\u5f00\u9500\u5206\u914d\u4e0easync\u65b9\u6cd5\u7684\u6574\u4e2a\u751f\u547d\u5468\u671f\u76f8\u5173:\u5982\u679c\u8fd9\u4e2a\u65b9\u6cd5\u6302\u8d77\u4e86\uff0c\u5b83\u4f1a\u5206\u914d\u4e00\u4e2a\u5355\u4e00\u7684Task-derived\u7c7b\u578b\u6765\u5b58\u50a8\u6240\u6709\u5176\u4ed6\u9700\u8981\u7684\u72b6\u6001\uff0c\u5982\u679c\u8fd9\u4e2a\u65b9\u6cd5\u4ece\u6765\u6ca1\u6709\u6302\u8d77\uff0c\u5c31\u4e0d\u4f1a\u4ea7\u751f\u989d\u5916\u7684\u5206\u914d\u3002<\/p>\n
              \u5982\u679c\u613f\u610f\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u53bb\u6389\u6700\u540e\u4e00\u4e2a\u5206\u914d\uff0c\u81f3\u5c11\u4ee5\u5e73\u644a\u7684\u65b9\u5f0f\u3002\u5982\u6240\u793a\uff0c\u6709\u4e00\u4e2a\u9ed8\u8ba4\u6784\u5efa\u5668\u4e0eTask(AsyncTaskMethodBuilder)\u76f8\u5173\u8054\uff0c\u7c7b\u4f3c\u5730\uff0c\u6709\u4e00\u4e2a\u9ed8\u8ba4\u6784\u5efa\u5668\u4e0e\u4efb\u52a1<TResult> (AsyncTaskMethodBuilder<TResult>)\u548cValueTask\u548cValueTask<TResult> (AsyncValueTaskMethodBuilder\u548cAsyncValueTaskMethodBuilder<TResult>\uff0c\u5206\u522b)\u76f8\u5173\u8054\u3002\u5bf9\u4e8eValueTask\/ValueTask<TResult>\uff0c\u6784\u9020\u5668\u5b9e\u9645\u4e0a\u76f8\u5f53\u7b80\u5355\uff0c\u56e0\u4e3a\u5b83\u4eec\u672c\u8eab\u53ea\u5904\u7406\u540c\u6b65\u4e14\u6210\u529f\u5b8c\u6210\u7684\u60c5\u51b5\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0c\u5f02\u6b65\u65b9\u6cd5\u5b8c\u6210\u800c\u4e0d\u6302\u8d77\uff0c\u6784\u5efa\u5668\u53ef\u4ee5\u53ea\u8fd4\u56de\u4e00\u4e2aValueTask.Completed\u6216\u8005\u4e00\u4e2a\u5305\u542b\u7ed3\u679c\u503c\u7684ValueTask<TResult>\u3002\u5bf9\u4e8e\u5176\u4ed6\u6240\u6709\u4e8b\u60c5\uff0c\u5b83\u4eec\u53ea\u662f\u59d4\u6258\u7ed9AsyncTaskMethodBuilder\/AsyncTaskMethodBuilder<TResult>\uff0c\u56e0\u4e3aValueTask\/ValueTask<TResult>\u4f1a\u88ab\u8fd4\u56de\u5305\u88c5\u4e00\u4e2aTask\uff0c\u5b83\u53ef\u4ee5\u5171\u4eab\u6240\u6709\u76f8\u540c\u7684\u903b\u8f91\u3002\u4f46\u662f.NET 6 and C# 10<\/a>\u5f15\u5165\u4e86\u4e00\u4e2a\u65b9\u6cd5\u53ef\u4ee5\u8986\u76d6\u9010\u4e2a\u65b9\u6cd5\u4f7f\u7528\u7684\u6784\u5efa\u5668\u7684\u80fd\u529b\uff0c\u5e76\u4e3aValueTask\/ValueTask<TResult>\u5f15\u5165\u4e86\u51e0\u4e2a\u4e13\u95e8\u7684\u6784\u5efa\u5668\uff0c\u5b83\u4eec\u80fd\u591f\u6c60\u5316IValueTaskSource\/IValueTaskSource<TResult>\u5bf9\u8c61\u6765\u8868\u793a\u6700\u7ec8\u7684\u5b8c\u6210\uff0c\u800c\u4e0d\u662f\u4f7f\u7528Tasks\u3002<\/p>\n
              \u6211\u4eec\u53ef\u4ee5\u5728\u6211\u4eec\u7684\u6837\u672c\u4e2d\u770b\u5230\u8fd9\u4e00\u70b9\u7684\u5f71\u54cd\u3002\u7a0d\u5fae\u8c03\u6574\u4e00\u4e0b\u4e4b\u524d\u5206\u6790\u7684SomeMethodAsync\u51fd\u6570\uff0c\u8ba9\u5b83\u8fd4\u56deValueTask\u800c\u4e0d\u662fTask:<\/p>\n
              static async ValueTask SomeMethodAsync()\r\n{\r\n    for (int i = 0; i < 1000; i++)\r\n    {\r\n        await Task.Yield();\r\n    }\r\n}<\/code><\/pre>\n
              \u8fd9\u5c06\u751f\u6210\u4ee5\u4e0b\u5165\u53e3\u70b9:<\/p>\n
              [AsyncStateMachine(typeof(<SomeMethodAsync>d__1))]\r\nprivate static ValueTask SomeMethodAsync()\r\n{\r\n    <SomeMethodAsync>d__1 stateMachine = default;\r\n    stateMachine.<>t__builder = AsyncValueTaskMethodBuilder.Create();\r\n    stateMachine.<>1__state = -1;\r\n    stateMachine.<>t__builder.Start(ref stateMachine);\r\n    return stateMachine.<>t__builder.Task;\r\n}<\/code><\/pre>\n
              \u73b0\u5728\uff0c\u6211\u4eec\u6dfb\u52a0[AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]\u5230SomeMethodAsync\u7684\u58f0\u660e\u4e2d:<\/p>\n
              [AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]\r\nstatic async ValueTask SomeMethodAsync()\r\n{\r\n    for (int i = 0; i < 1000; i++)\r\n    {\r\n        await Task.Yield();\r\n    }\r\n}<\/code><\/pre>\n
              \u7f16\u8bd1\u5668\u8f93\u51fa\u5982\u4e0b:<\/p>\n
              [AsyncStateMachine(typeof(<SomeMethodAsync>d__1))]\r\n[AsyncMethodBuilder(typeof(PoolingAsyncValueTaskMethodBuilder))]\r\nprivate static ValueTask SomeMethodAsync()\r\n{\r\n    <SomeMethodAsync>d__1 stateMachine = default;\r\n    stateMachine.<>t__builder = PoolingAsyncValueTaskMethodBuilder.Create();\r\n    stateMachine.<>1__state = -1;\r\n    stateMachine.<>t__builder.Start(ref stateMachine);\r\n    return stateMachine.<>t__builder.Task;\r\n}<\/code><\/pre>\n
              \u6574\u4e2a\u5b9e\u73b0\u7684\u5b9e\u9645c#\u4ee3\u7801\u751f\u6210\uff0c\u5305\u62ec\u6574\u4e2a\u72b6\u6001\u673a(\u6ca1\u6709\u663e\u793a)\uff0c\u51e0\u4e4e\u662f\u76f8\u540c\u7684;\u552f\u4e00\u7684\u533a\u522b\u662f\u521b\u5efa\u548c\u5b58\u50a8\u7684\u6784\u5efa\u5668\u7684\u7c7b\u578b\uff0c\u56e0\u6b64\u5728\u6211\u4eec\u4e4b\u524d\u770b\u5230\u7684\u4efb\u4f55\u5f15\u7528\u6784\u5efa\u5668\u7684\u5730\u65b9\u90fd\u53ef\u4ee5\u4f7f\u7528\u3002\u5982\u679c\u4f60\u770b\u4e00\u4e0b PoolingAsyncValueTaskMethodBuilder\u7684\u4ee3\u7801<\/a>\uff0c\u4f60\u4f1a\u770b\u5230\u5b83\u7684\u7ed3\u6784\u51e0\u4e4e\u4e0eAsyncTaskMethodBuilder\u76f8\u540c\uff0c\u5305\u62ec\u4f7f\u7528\u4e00\u4e9b\u5b8c\u5168\u76f8\u540c\u7684\u5171\u4eab\u4f8b\u7a0b\u6765\u505a\u4e00\u4e9b\u4e8b\u60c5\uff0c\u5982\u7279\u6b8a\u5957\u7ba1\u5df2\u77e5\u7684awaiter\u7c7b\u578b\u3002\u5173\u952e\u7684\u533a\u522b\u662f\uff0c\u5f53\u65b9\u6cd5\u7b2c\u4e00\u6b21\u6302\u8d77\u65f6\uff0c\u5b83\u4e0d\u662f\u6267\u884c\u65b0\u7684AsyncStateMachineBox<TStateMachine>()\uff0c\u800c\u662f\u6267\u884cStateMachineBox<TStateMachine>. rentfromcache()\uff0c\u5e76\u4e14\u5728async\u65b9\u6cd5(SomeMethodAsync)\u5b8c\u6210\u5e76\u7b49\u5f85\u8fd4\u56de\u7684ValueTask\u5b8c\u6210\u65f6\uff0c\u79df\u7528\u7684\u76d2\u5b50\u4f1a\u88ab\u8fd4\u56de\u5230\u7f13\u5b58\u4e2d\u3002\u8fd9\u610f\u5473\u7740(\u5e73\u644a)\u96f6\u5206\u914d:<\/p>\n
              \"Image<\/a><\/p>\n
              \u8fd9\u4e2a\u7f13\u5b58\u672c\u8eab\u6709\u70b9\u610f\u601d\u3002\u5bf9\u8c61\u6c60\u53ef\u80fd\u662f\u4e00\u4e2a\u597d\u4e3b\u610f\uff0c\u4e5f\u53ef\u80fd\u662f\u4e00\u4e2a\u574f\u4e3b\u610f\u3002\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u7684\u6210\u672c\u8d8a\u9ad8\uff0c\u5171\u4eab\u5b83\u4eec\u7684\u4ef7\u503c\u5c31\u8d8a\u5927;\u56e0\u6b64\uff0c\u4f8b\u5982\uff0c\u5bf9\u975e\u5e38\u5927\u7684\u6570\u7ec4\u8fdb\u884c\u6c60\u5316\u6bd4\u5bf9\u975e\u5e38\u5c0f\u7684\u6570\u7ec4\u8fdb\u884c\u6c60\u5316\u66f4\u6709\u4ef7\u503c\uff0c\u56e0\u4e3a\u66f4\u5927\u7684\u6570\u7ec4\u4e0d\u4ec5\u9700\u8981\u66f4\u591a\u7684CPU\u5468\u671f\u548c\u5185\u5b58\u8bbf\u95ee\u4e3a\u96f6\uff0c\u5b83\u4eec\u8fd8\u4f1a\u7ed9\u5783\u573e\u6536\u96c6\u5668\u5e26\u6765\u66f4\u5927\u7684\u538b\u529b\uff0c\u4f7f\u5176\u66f4\u9891\u7e41\u5730\u6536\u96c6\u5783\u573e\u3002\u7136\u800c\uff0c\u5bf9\u4e8e\u975e\u5e38\u5c0f\u7684\u5bf9\u8c61\uff0c\u5c06\u5b83\u4eec\u6c60\u5316\u53ef\u80fd\u4f1a\u5e26\u6765\u8d1f\u9762\u5f71\u54cd\u3002\u6c60\u53ea\u662f\u5185\u5b58\u5206\u914d\u5668\uff0cGC\u4e5f\u662f\uff0c\u6240\u4ee5\u5f53\u60a8\u4f7f\u7528\u6c60\u65f6\uff0c\u60a8\u662f\u5728\u6743\u8861\u4e0e\u4e00\u4e2a\u5206\u914d\u5668\u76f8\u5173\u7684\u6210\u672c\u4e0e\u53e6\u4e00\u4e2a\u5206\u914d\u5668\u76f8\u5173\u7684\u6210\u672c\uff0c\u5e76\u4e14GC\u5728\u5904\u7406\u5927\u91cf\u5fae\u5c0f\u7684\u3001\u751f\u5b58\u671f\u77ed\u7684\u5bf9\u8c61\u65b9\u9762\u975e\u5e38\u9ad8\u6548\u3002\u5982\u679c\u4f60\u5728\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u4e2d\u505a\u4e86\u5f88\u591a\u5de5\u4f5c\uff0c\u907f\u514d\u8fd9\u4e9b\u5de5\u4f5c\u53ef\u4ee5\u4f7f\u5206\u914d\u5668\u672c\u8eab\u7684\u5f00\u9500\u76f8\u5f62\u89c1\u7ecc\uff0c\u4ece\u800c\u4f7f\u6c60\u53d8\u5f97\u6709\u4ef7\u503c\u3002\u4f46\u662f\uff0c\u5982\u679c\u60a8\u5728\u5bf9\u8c61\u7684\u6784\u9020\u51fd\u6570\u4e2d\u51e0\u4e4e\u6ca1\u6709\u505a\u4efb\u4f55\u5de5\u4f5c\uff0c\u5e76\u4e14\u5c06\u5176\u8fdb\u884c\u6c60\u5316\uff0c\u5219\u60a8\u5c06\u6253\u8d4c\u60a8\u7684\u5206\u914d\u5668(\u60a8\u7684\u6c60)\u5c31\u6240\u91c7\u7528\u7684\u8bbf\u95ee\u6a21\u5f0f\u800c\u8a00\u6bd4GC\u66f4\u6709\u6548\uff0c\u800c\u8fd9\u901a\u5e38\u662f\u4e00\u4e2a\u7cdf\u7cd5\u7684\u8d4c\u6ce8\u3002\u8fd8\u6d89\u53ca\u5176\u4ed6\u6210\u672c\uff0c\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u60a8\u53ef\u80fd\u6700\u7ec8\u4f1a\u6709\u6548\u5730\u5bf9\u6297GC\u7684\u542f\u53d1\u5f0f\u65b9\u6cd5;\u4f8b\u5982\uff0c\u5783\u573e\u56de\u6536\u662f\u57fa\u4e8e\u4e00\u4e2a\u524d\u63d0\u8fdb\u884c\u4f18\u5316\u7684\uff0c\u5373\u4ece\u8f83\u9ad8\u4ee3(\u5982gen2)\u5bf9\u8c61\u5230\u8f83\u4f4e\u4ee3(\u5982gen0)\u5bf9\u8c61\u7684\u5f15\u7528\u76f8\u5bf9\u8f83\u5c11\uff0c\u4f46\u6c60\u5316\u5bf9\u8c61\u53ef\u4ee5\u4f7f\u8fd9\u4e9b\u524d\u63d0\u5931\u6548\u3002<\/p>\n
              \u73b0\u5728\uff0c\u7531\u5f02\u6b65\u65b9\u6cd5\u521b\u5efa\u7684\u5bf9\u8c61\u5e76\u4e0d\u5c0f\uff0c\u800c\u4e14\u5b83\u4eec\u53ef\u80fd\u5728\u5f88\u70ed\u95e8\u7684\u8def\u5f84\u4e0a\uff0c\u6240\u4ee5\u6c60\u5316\u53ef\u80fd\u662f\u5408\u7406\u7684\u3002\u4f46\u4e3a\u4e86\u4f7f\u5b83\u5c3d\u53ef\u80fd\u6709\u4ef7\u503c\uff0c\u6211\u4eec\u4e5f\u60f3\u5c3d\u53ef\u80fd\u907f\u514d\u5f00\u9500\u3002\u56e0\u6b64\uff0c\u8fd9\u4e2a\u6c60\u5b50\u975e\u5e38\u7b80\u5355\uff0c\u9009\u62e9\u8ba9\u79df\u501f\u548c\u8fd4\u56de\u7684\u901f\u5ea6\u975e\u5e38\u5feb\uff0c\u51e0\u4e4e\u6ca1\u6709\u7ade\u4e89\uff0c\u5373\u4f7f\u8fd9\u610f\u5473\u7740\u5b83\u6700\u7ec8\u53ef\u80fd\u4f1a\u6bd4\u66f4\u79ef\u6781\u5730\u7f13\u5b58\u66f4\u591a\u7684\u4e1c\u897f\u6765\u5206\u914d\u3002\u5bf9\u4e8e\u6bcf\u79cd\u72b6\u6001\u673a\u7c7b\u578b\uff0c\u5b9e\u73b0\u6c60\u5316<\/a>\u5230\u6bcf\u4e2a\u7ebf\u7a0b\u4e00\u4e2a\u72b6\u6001\u673a\u76d2\uff0c\u6bcf\u4e2a\u6838\u5fc3\u4e00\u4e2a\u72b6\u6001\u673a\u76d2\uff1b\u8fd9\u4f7f\u5f97\u5b83\u80fd\u591f\u4ee5\u6700\u5c0f\u7684\u5f00\u9500\u548c\u6700\u5c0f\u7684\u7ade\u4e89\u6765\u79df\u7528\u548c\u8fd4\u56de\uff08\u6ca1\u6709\u5176\u4ed6\u7ebf\u7a0b\u53ef\u4ee5\u540c\u65f6\u8bbf\u95ee\u7ebf\u7a0b\u4e13\u7528\u7f13\u5b58\uff0c\u4e5f\u5f88\u5c11\u6709\u5176\u4ed6\u7ebf\u7a0b\u540c\u65f6\u8bbf\u95ee\u5185\u6838\u4e13\u7528\u7f13\u5b58\uff09\u3002\u867d\u7136\u8fd9\u770b\u8d77\u6765\u662f\u4e00\u4e2a\u76f8\u5bf9\u8f83\u5c0f\u7684\u6c60\u5b50\uff0c\u4f46\u5b83\u5728\u663e\u8457\u51cf\u5c11\u7a33\u6001\u5206\u914d\u65b9\u9762\u4e5f\u76f8\u5f53\u6709\u6548\uff0c\u56e0\u4e3a\u6c60\u5b50\u53ea\u8d1f\u8d23\u5b58\u50a8\u5f53\u524d\u4e0d\u4f7f\u7528\u7684\u5bf9\u8c61\uff1b\u4f60\u53ef\u4ee5\u5728\u4efb\u4f55\u65f6\u5019\u6709\u4e00\u767e\u4e07\u4e2a\u5f02\u6b65\u65b9\u6cd5\u90fd\u5728\u8fd0\u884c\uff0c\u5373\u4f7f\u6c60\u5b50\u5728\u6bcf\u4e2a\u7ebf\u7a0b\u548c\u6bcf\u4e2a\u6838\u5fc3\u53ea\u80fd\u5b58\u50a8\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5b83\u4ecd\u7136\u53ef\u4ee5\u907f\u514d\u4e22\u5f03\u5927\u91cf\u5bf9\u8c61\uff0c\u56e0\u4e3a\u5b83\u53ea\u9700\u8981\u5b58\u50a8\u4e00\u4e2a\u5bf9\u8c61\u8db3\u591f\u957f\u7684\u65f6\u95f4\u6765\u628a\u5b83\u4ece\u4e00\u4e2a\u64cd\u4f5c\u8f6c\u79fb\u5230\u53e6\u4e00\u4e2a\u64cd\u4f5c\uff0c\u800c\u4e0d\u662f\u5728\u5b83\u88ab\u8be5\u64cd\u4f5c\u4f7f\u7528\u65f6\u3002<\/p>\n
               <\/p>\n
              SynchronizationContext \u548c ConfigureAwait<\/h3>\n
              \u6211\u4eec\u4e4b\u524d\u5728EAP\u6a21\u5f0f\u7684\u4e0a\u4e0b\u6587\u4e2d\u8ba8\u8bba\u8fc7SynchronizationContext\uff0c\u5e76\u63d0\u5230\u5b83\u5c06\u518d\u6b21\u51fa\u73b0\u3002SynchronizationContext\u4f7f\u5f97\u8c03\u7528\u53ef\u91cd\u7528\u7684\u8f85\u52a9\u51fd\u6570\u6210\u4e3a\u53ef\u80fd\uff0c\u5e76\u81ea\u52a8\u88ab\u8c03\u5ea6\u56de\u8c03\u7528\u73af\u5883\u8ba4\u4e3a\u5408\u9002\u7684\u4efb\u4f55\u5730\u65b9\u3002\u56e0\u6b64\uff0c\u6211\u4eec\u5f88\u81ea\u7136\u5730\u8ba4\u4e3aasync\/await\u80fd\u201c\u6b63\u5e38\u5de5\u4f5c\u201d\uff0c\u4e8b\u5b9e\u4e5f\u7684\u786e\u5982\u6b64\u3002\u56de\u5230\u524d\u9762\u7684\u6309\u94ae\u5355\u51fb\u5904\u7406\u7a0b\u5e8f:<\/p>\n
              ThreadPool.QueueUserWorkItem(_ =>\r\n{\r\n    string message = ComputeMessage();\r\n    button1.BeginInvoke(() =>\r\n    {\r\n        button1.Text = message;\r\n    });\r\n});<\/code><\/pre>\n
              \u4f7f\u7528async\/await\uff0c\u6211\u4eec\u53ef\u4ee5\u8fd9\u6837\u5199:<\/p>\n
              button1.Text = await Task.Run(() => ComputeMessage());<\/code><\/pre>\n
              \u5bf9ComputeMessage\u7684\u8c03\u7528\u88ab\u8f6c\u79fb\u5230\u7ebf\u7a0b\u6c60\u4e2d\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u6267\u884c\u5b8c\u6bd5\u540e\uff0c\u6267\u884c\u53c8\u8f6c\u79fb\u56de\u4e0e\u6309\u94ae\u5173\u8054\u7684UI\u7ebf\u7a0b\uff0c\u8bbe\u7f6e\u6309\u94ae\u7684Text\u5c5e\u6027\u5c31\u662f\u5728\u8fd9\u4e2a\u7ebf\u7a0b\u4e2d\u8fdb\u884c\u7684\u3002<\/p>\n
              \u4e0eSynchronizationContext\u7684\u96c6\u6210\u7531awaiter\u5b9e\u73b0(\u4e3a\u72b6\u6001\u673a\u751f\u6210\u7684\u4ee3\u7801\u5bf9SynchronizationContext\u4e00\u65e0\u6240\u77e5)\uff0c\u56e0\u4e3a\u5f53\u6240\u8868\u793a\u7684\u5f02\u6b65\u64cd\u4f5c\u5b8c\u6210\u65f6\uff0c\u662fawaiter\u8d1f\u8d23\u5b9e\u9645\u8c03\u7528\u6216\u5c06\u6240\u63d0\u4f9b\u7684continuation\u6392\u961f\u3002\u800c\u81ea\u5b9a\u4e49awaiter\u4e0d\u9700\u8981\u8003\u8651SynchronizationContext\u3002\u76ee\u524d\uff0cTask\u3001Task<TResult>\u3001ValueTask\u3001ValueTask<TResult>\u7684\u7b49\u5f85\u5668\u90fd\u662fdo\u3002\u8fd9\u610f\u5473\u7740\uff0c\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u5f53\u4f60\u7b49\u5f85\u4e00\u4e2a\u4efb\u52a1\uff0c\u4e00\u4e2aTask<TResult>\uff0c\u4e00\u4e2aValueTask\uff0c\u4e00\u4e2aValueTask<TResult>\uff0c\u751a\u81f3Task. yield()\u8c03\u7528\u7684\u7ed3\u679c\u65f6\uff0cawaiter\u9ed8\u8ba4\u4f1a\u67e5\u627e\u5f53\u524d\u7684SynchronizationContext\uff0c\u5982\u679c\u5b83\u6210\u529f\u5730\u83b7\u5f97\u4e86\u4e00\u4e2a\u975e\u9ed8\u8ba4\u7684\u540c\u6b65\u4e0a\u4e0b\u6587\uff0c\u6700\u7ec8\u4f1a\u5c06continuation\u6392\u961f\u5230\u8be5\u4e0a\u4e0b\u6587\u3002<\/p>\n
               <\/p>\n
              \u5982\u679c\u6211\u4eec\u67e5\u770bTaskAwaiter\u4e2d\u6d89\u53ca\u7684\u4ee3\u7801\uff0c\u5c31\u53ef\u4ee5\u770b\u5230\u8fd9\u4e00\u70b9\u3002\u4ee5\u4e0b\u662fCorelib\u4e2d\u7684\u76f8\u5173\u4ee3\u7801<\/a>\u7247\u6bb5:<\/p>\n
              internal void UnsafeSetContinuationForAwait(IAsyncStateMachineBox stateMachineBox, bool continueOnCapturedContext)\r\n{\r\n    if (continueOnCapturedContext)\r\n    {\r\n        SynchronizationContext? syncCtx = SynchronizationContext.Current;\r\n        if (syncCtx != null && syncCtx.GetType() != typeof(SynchronizationContext))\r\n        {\r\n            var tc = new SynchronizationContextAwaitTaskContinuation(syncCtx, stateMachineBox.MoveNextAction, flowExecutionContext: false);\r\n            if (!AddTaskContinuation(tc, addBeforeOthers: false))\r\n            {\r\n                tc.Run(this, canInlineContinuationTask: false);\r\n            }\r\n            return;\r\n        }\r\n        else\r\n        {\r\n            TaskScheduler? scheduler = TaskScheduler.InternalCurrent;\r\n            if (scheduler != null && scheduler != TaskScheduler.Default)\r\n            {\r\n                var tc = new TaskSchedulerAwaitTaskContinuation(scheduler, stateMachineBox.MoveNextAction, flowExecutionContext: false);\r\n                if (!AddTaskContinuation(tc, addBeforeOthers: false))\r\n                {\r\n                    tc.Run(this, canInlineContinuationTask: false);\r\n                }\r\n                return;\r\n            }\r\n        }\r\n    }\r\n\r\n    ...\r\n}<\/code><\/pre>\n
              \u8fd9\u662f\u4e00\u4e2a\u65b9\u6cd5\u7684\u4e00\u90e8\u5206\uff0c\u7528\u4e8e\u786e\u5b9a\u5c06\u54ea\u4e2a\u5bf9\u8c61\u4f5c\u4e3acontinuation\u5b58\u50a8\u5230\u4efb\u52a1\u4e2d\u3002\u5b83\u88ab\u4f20\u9012\u7ed9stateMachineBox\uff0c\u5982\u524d\u6240\u8ff0\uff0c\u5b83\u53ef\u4ee5\u76f4\u63a5\u5b58\u50a8\u5230\u4efb\u52a1\u7684continuation\u5217\u8868\u4e2d\u3002\u4f46\u662f\uff0c\u8fd9\u4e2a\u7279\u6b8a\u7684\u903b\u8f91\u53ef\u80fd\u4f1a\u5c06IAsyncStateMachineBox\u5c01\u88c5\u8d77\u6765\uff0c\u4ee5\u5408\u5e76\u4e00\u4e2a\u8c03\u5ea6\u7a0b\u5e8f(\u5982\u679c\u5b58\u5728\u7684\u8bdd)\u3002\u5b83\u68c0\u67e5\u5f53\u524d\u662f\u5426\u6709\u975e\u9ed8\u8ba4\u7684SynchronizationContext\uff0c\u5982\u679c\u6709\uff0c\u5b83\u4f1a\u521b\u5efa\u4e00\u4e2aSynchronizationContextAwaitTaskContinuation\u4f5c\u4e3a\u5b9e\u9645\u7684\u5bf9\u8c61\uff0c\u5b83\u4f1a\u88ab\u5b58\u50a8\u4e3acontinuation;\u8be5\u5bf9\u8c61\u4f9d\u6b21\u5305\u88c5\u4e86\u539f\u59cb\u7684\u548c\u6355\u83b7\u7684SynchronizationContext\uff0c\u5e76\u77e5\u9053\u5982\u4f55\u5728\u4e0e\u540e\u8005\u6392\u961f\u7684\u5de5\u4f5c\u9879\u4e2d\u8c03\u7528\u524d\u8005\u7684MoveNext\u3002\u8fd9\u5c31\u662f\u5982\u4f55\u5728UI\u5e94\u7528\u7a0b\u5e8f\u4e2d\u4f5c\u4e3a\u4e8b\u4ef6\u5904\u7406\u7a0b\u5e8f\u7684\u4e00\u90e8\u5206\u7b49\u5f85\uff0c\u5e76\u5728\u7b49\u5f85\u5b8c\u6210\u540e\u8ba9\u4ee3\u7801\u7ee7\u7eed\u5728\u6b63\u786e\u7684\u7ebf\u7a0b\u4e0a\u8fd0\u884c\u3002\u8fd9\u91cc\u8981\u6ce8\u610f\u7684\u4e0b\u4e00\u4e2a\u6709\u8da3\u7684\u4e8b\u60c5\u662f\uff0c\u5b83\u4e0d\u4ec5\u4ec5\u5173\u6ce8\u4e00\u4e2aSynchronizationContext:\u5982\u679c\u5b83\u627e\u4e0d\u5230\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684SynchronizationContext\u6765\u4f7f\u7528\uff0c\u5b83\u8fd8\u4f1a\u67e5\u770bTasks\u4f7f\u7528\u7684TaskScheduler\u7c7b\u578b\u662f\u5426\u6709\u4e00\u4e2a\u9700\u8981\u8003\u8651\u7684\u81ea\u5b9a\u4e49\u7c7b\u578b\u3002\u548cSynchronizationContext\u4e00\u6837\uff0c\u5982\u679c\u6709\u4e00\u4e2a\u975e\u9ed8\u8ba4\u503c\uff0c\u5b83\u5c31\u4f1a\u548c\u539f\u59cb\u6846\u4e00\u8d77\u5305\u88c5\u5728TaskSchedulerAwaitTaskContinuation\u4e2d\uff0c\u7528\u4f5ccontinuation\u5bf9\u8c61\u3002<\/p>\n
              \u4f46\u8fd9\u91cc\u6700\u503c\u5f97\u6ce8\u610f\u7684\u53ef\u80fd\u662f\u65b9\u6cd5\u4e3b\u4f53\u7684\u7b2c\u4e00\u884c:if (continueOnCapturedContext)\u3002\u6211\u4eec\u53ea\u5728continueOnCapturedContext\u4e3atrue\u65f6\u624d\u5bf9SynchronizationContext\/TaskScheduler\u8fdb\u884c\u8fd9\u4e9b\u68c0\u67e5;\u5982\u679c\u8fd9\u4e2a\u503c\u4e3afalse\uff0c\u5b9e\u73b0\u65b9\u5f0f\u5c31\u597d\u50cf\u4e24\u8005\u90fd\u662f\u9ed8\u8ba4\u503c\u4e00\u6837\uff0c\u4f1a\u5ffd\u7565\u5b83\u4eec\u3002\u8bf7\u95ee\u662f\u4ec0\u4e48\u5c06continueOnCapturedContext\u8bbe\u7f6e\u4e3afalse?\u4f60\u53ef\u80fd\u5df2\u7ecf\u731c\u5230\u4e86:\u4f7f\u7528\u975e\u5e38\u6d41\u884c\u7684ConfigureAwait(false)\u3002<\/p>\n
              \u6211\u5728ConfigureAwait FAQ<\/a>\u4e2d\u8be6\u7ec6\u8ba8\u8bba\u4e86ConfigureAwait\u6240\u4ee5\u6211\u5efa\u8bae\u4f60\u9605\u8bfb\u8fd9\u7bc7\u6587\u7ae0\u4ee5\u83b7\u53d6\u66f4\u591a\u4fe1\u606f\u3002\u53ef\u4ee5\u8fd9\u6837\u8bf4\uff0c\u4f5c\u4e3aawait\u7684\u4e00\u90e8\u5206\uff0cConfigureAwait(false)\u505a\u7684\u552f\u4e00\u4e00\u4ef6\u4e8b\u662f\u5c06\u5b83\u7684\u53c2\u6570\u5e03\u5c14\u503c\u4f5c\u4e3acontinueOnCapturedContext\u503c\u63d0\u4f9b\u7ed9\u8fd9\u4e2a\u51fd\u6570(\u4ee5\u53ca\u5176\u4ed6\u7c7b\u4f3c\u7684\u51fd\u6570)\uff0c\u4ee5\u4fbf\u8df3\u8fc7\u5bf9SynchronizationContext\/TaskScheduler\u7684\u68c0\u67e5\uff0c\u8868\u73b0\u5f97\u597d\u50cf\u5b83\u4eec\u90fd\u4e0d\u5b58\u5728\u4e00\u6837\u3002\u5bf9\u4e8e\u8fdb\u7a0b\u6765\u8bf4\uff0c\u8fd9\u5141\u8bb8Task\u00a0\u5728\u5b83\u8ba4\u4e3a\u5408\u9002\u7684\u5730\u65b9\u8c03\u7528\u5176continuation\uff0c\u800c\u4e0d\u662f\u5f3a\u5236\u5c06\u5b83\u4eec\u6392\u961f\u5728\u67d0\u4e2a\u7279\u5b9a\u7684\u8c03\u5ea6\u5668\u4e0a\u6267\u884c\u3002<\/p>\n
              \u6211\u4e4b\u524d\u63d0\u5230\u8fc7SynchronizationContext\u7684\u53e6\u4e00\u4e2a\u65b9\u9762\uff0c\u6211\u8bf4\u8fc7\u6211\u4eec\u4f1a\u518d\u6b21\u770b\u5230\u5b83:OperationStarted\/OperationCompleted\u3002\u73b0\u5728\u662f\u65f6\u5019\u4e86\u3002\u8fd9\u662f\u4eba\u4eba\u90fd\u8ba8\u538c\u7684\u7279\u6027:\u5f02\u6b65void\u3002\u9664\u4e86configureawait\u4e4b\u5916\uff0casync void\u53ef\u4ee5\u8bf4\u662fasync\/await\u4e2d\u6700\u5177\u4e89\u8bae\u6027\u7684\u7279\u6027\u4e4b\u4e00\u3002\u5b83\u88ab\u6dfb\u52a0\u7684\u539f\u56e0\u53ea\u6709\u4e00\u4e2a:\u4e8b\u4ef6\u5904\u7406\u7a0b\u5e8f\u3002\u5728UI\u5e94\u7528\u7a0b\u5e8f\u4e2d\uff0c\u4f60\u53ef\u4ee5\u7f16\u5199\u5982\u4e0b\u4ee3\u7801:<\/p>\n
              button1.Click += async (sender, eventArgs) =>\r\n{\r\n  button1.Text = await Task.Run(() => ComputeMessage());  \r\n};<\/code><\/pre>\n
              \u4f46\u5982\u679c\u6240\u6709\u7684\u5f02\u6b65\u65b9\u6cd5\u90fd\u5fc5\u987b\u6709\u4e00\u4e2a\u50cfTask\u8fd9\u6837\u7684\u8fd4\u56de\u7c7b\u578b\uff0c\u4f60\u5c31\u4e0d\u80fd\u8fd9\u6837\u505a\u4e86\u3002Click\u4e8b\u4ef6\u6709\u4e00\u4e2a\u7b7e\u540dpublic event EventHandler? Click;\uff0c\u5176\u4e2dEventHandler\u5b9a\u4e49\u4e3apublic delegate void EventHandler(object? sender, EventArgs e);\uff0c\u56e0\u6b64\u8981\u63d0\u4f9b\u4e00\u4e2a\u7b26\u5408\u8be5\u7b7e\u540d\u7684\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u9700\u8981\u662fvoid-returning\u3002<\/p>\n
              \u6709\u5404\u79cd\u5404\u6837\u7684\u7406\u7531\u8ba4\u4e3aasync void\u662f\u4e0d\u597d\u7684\uff0c\u4e3a\u4ec0\u4e48\u6587\u7ae0<\/a>\u5efa\u8bae\u5c3d\u53ef\u80fd\u907f\u514d\u4f7f\u7528\u5b83\uff0c\u4ee5\u53ca\u4e3a\u4ec0\u4e48\u51fa\u73b0\u4e86\u5404\u79cd\u00a0analyzers<\/a>\u6765\u6807\u8bb0\u4f7f\u7528async void\u3002\u6700\u5927\u7684\u95ee\u9898\u4e4b\u4e00\u662f\u59d4\u6258\u63a8\u7406\u3002\u8003\u8651\u4e0b\u9762\u7684\u7a0b\u5e8f:<\/p>\n
              using System.Diagnostics;\r\n\r\nTime(async () =>\r\n{\r\n    Console.WriteLine(\"Enter\");\r\n    await Task.Delay(TimeSpan.FromSeconds(10));\r\n    Console.WriteLine(\"Exit\");\r\n});\r\n\r\nstatic void Time(Action action)\r\n{\r\n    Console.WriteLine(\"Timing...\");\r\n    Stopwatch sw = Stopwatch.StartNew();\r\n    action();\r\n    Console.WriteLine($\"...done timing: {sw.Elapsed}\");\r\n}<\/code><\/pre>\n
              \u4eba\u4eec\u5f88\u5bb9\u6613\u671f\u671b\u5b83\u8f93\u51fa\u81f3\u5c1110\u79d2\u7684\u8fd0\u884c\u65f6\u95f4\uff0c\u4f46\u5982\u679c\u4f60\u8fd0\u884c\u5b83\uff0c\u4f60\u4f1a\u53d1\u73b0\u8f93\u51fa\u662f\u8fd9\u6837\u7684:<\/p>\n
              Timing...\r\nEnter\r\n...done timing: 00:00:00.0037550<\/code><\/pre>\n
              \u55ef?\u5f53\u7136\uff0c\u6839\u636e\u6211\u4eec\u5728\u8fd9\u7bc7\u6587\u7ae0\u4e2d\u8ba8\u8bba\u7684\u6240\u6709\u5185\u5bb9\uff0c\u5e94\u8be5\u53ef\u4ee5\u7406\u89e3\u95ee\u9898\u662f\u4ec0\u4e48\u3002async lambda\u5b9e\u9645\u4e0a\u662f\u4e00\u4e2a\u5f02\u6b65void\u65b9\u6cd5\u3002\u5f02\u6b65\u65b9\u6cd5\u4f1a\u5728\u9047\u5230\u7b2c\u4e00\u4e2a\u6682\u505c\u70b9\u65f6\u8fd4\u56de\u8c03\u7528\u8005\u3002\u5982\u679c\u8fd9\u662f\u4e00\u4e2a\u5f02\u6b65Task\u00a0\u65b9\u6cd5\uff0cTask\u00a0\u5c31\u4f1a\u5728\u8fd9\u4e2a\u65f6\u95f4\u70b9\u8fd4\u56de\u3002\u4f46\u5bf9\u4e8easync void\uff0c\u4ec0\u4e48\u90fd\u4e0d\u4f1a\u8fd4\u56de\u3002Time\u65b9\u6cd5\u53ea\u77e5\u9053\u5b83\u8c03\u7528\u4e86action();\u59d4\u6258\u8c03\u7528\u8fd4\u56de;\u5b83\u4e0d\u77e5\u9053async\u65b9\u6cd5\u5b9e\u9645\u4e0a\u4ecd\u5728\u201c\u8fd0\u884c\u201d\uff0c\u5e76\u5c06\u5728\u7a0d\u540e\u5f02\u6b65\u5b8c\u6210\u3002<\/p>\n
              \u8fd9\u5c31\u662fOperationStarted\/OperationCompleted\u7684\u4f5c\u7528\u3002\u8fd9\u79cd\u5f02\u6b65void\u65b9\u6cd5\u672c\u8d28\u4e0a\u4e0e\u524d\u9762\u8ba8\u8bba\u7684EAP\u65b9\u6cd5\u7c7b\u4f3c:\u8fd9\u79cd\u65b9\u6cd5\u7684\u521d\u59cb\u5316\u662fvoid\uff0c\u56e0\u6b64\u9700\u8981\u4e00\u4e9b\u5176\u4ed6\u673a\u5236\u6765\u8ddf\u8e2a\u6240\u6709\u6b64\u7c7b\u64cd\u4f5c\u3002\u56e0\u6b64\uff0cEAP\u5b9e\u73b0\u5728\u64cd\u4f5c\u542f\u52a8\u65f6\u8c03\u7528\u5f53\u524dSynchronizationContext\u7684OperationStarted\uff0c\u5728\u64cd\u4f5c\u5b8c\u6210\u65f6\u8c03\u7528OperationCompleted, async void\u4e5f\u505a\u540c\u6837\u7684\u4e8b\u60c5\u3002\u4e0easync void\u76f8\u5173\u7684\u6784\u5efa\u5668\u662fAsyncVoidMethodBuilder\u3002\u8fd8\u8bb0\u5f97\u5728async\u65b9\u6cd5\u7684\u5165\u53e3\uff0c\u7f16\u8bd1\u5668\u751f\u6210\u7684\u4ee3\u7801\u5982\u4f55\u8c03\u7528\u6784\u5efa\u5668\u7684\u9759\u6001Create\u65b9\u6cd5\u6765\u83b7\u5f97\u9002\u5f53\u7684\u6784\u5efa\u5668\u5b9e\u4f8b\u5417?AsyncVoidMethodBuilder\u5229\u7528\u4e86\u8fd9\u4e00\u70b9\u6765\u6302\u94a9\u521b\u5efa\u548c\u8c03\u7528OperationStarted:<\/p>\n
              public static AsyncVoidMethodBuilder Create()\r\n{\r\n    SynchronizationContext? sc = SynchronizationContext.Current;\r\n    sc?.OperationStarted();\r\n    return new AsyncVoidMethodBuilder() { _synchronizationContext = sc };\r\n}<\/code><\/pre>\n
              \u7c7b\u4f3c\u5730\uff0c\u5f53\u901a\u8fc7SetResult\u6216SetException\u5c06\u6784\u5efa\u5668\u6807\u8bb0\u4e3a\u5b8c\u6210\u65f6\uff0c\u5b83\u4f1a\u8c03\u7528\u76f8\u5e94\u7684OperationCompleted\u65b9\u6cd5\u3002\u8fd9\u5c31\u662f\u50cfxunit\u8fd9\u6837\u7684\u5355\u5143\u6d4b\u8bd5\u6846\u67b6\u5982\u4f55\u80fd\u591f\u5177\u6709\u5f02\u6b65void\u6d4b\u8bd5\u65b9\u6cd5\uff0c\u5e76\u4ecd\u7136\u5728\u5e76\u53d1\u6d4b\u8bd5\u6267\u884c\u4e2d\u4f7f\u7528\u6700\u5927\u7a0b\u5ea6\u7684\u5e76\u53d1\uff0c\u4f8b\u5982\u5728xunit\u7684AsyncTestSyncContext<\/a>\u4e2d\u3002<\/p>\n
              \u6709\u4e86\u8fd9\u4e9b\u77e5\u8bc6\uff0c\u6211\u4eec\u73b0\u5728\u53ef\u4ee5\u91cd\u5199\u6211\u4eec\u7684timing\u793a\u4f8b:<\/p>\n
              using System.Diagnostics;\r\n\r\nTime(async () =>\r\n{\r\n    Console.WriteLine(\"Enter\");\r\n    await Task.Delay(TimeSpan.FromSeconds(10));\r\n    Console.WriteLine(\"Exit\");\r\n});\r\n\r\nstatic void Time(Action action)\r\n{\r\n    var oldCtx = SynchronizationContext.Current;\r\n    try\r\n    {\r\n        var newCtx = new CountdownContext();\r\n        SynchronizationContext.SetSynchronizationContext(newCtx);\r\n\r\n        Console.WriteLine(\"Timing...\");\r\n        Stopwatch sw = Stopwatch.StartNew();\r\n        \r\n        action();\r\n        newCtx.SignalAndWait();\r\n\r\n        Console.WriteLine($\"...done timing: {sw.Elapsed}\");\r\n    }\r\n    finally\r\n    {\r\n        SynchronizationContext.SetSynchronizationContext(oldCtx);\r\n    }\r\n}\r\n\r\nsealed class CountdownContext : SynchronizationContext\r\n{\r\n    private readonly ManualResetEventSlim _mres = new ManualResetEventSlim(false);\r\n    private int _remaining = 1;\r\n\r\n    public override void OperationStarted() => Interlocked.Increment(ref _remaining);\r\n\r\n    public override void OperationCompleted()\r\n    {\r\n        if (Interlocked.Decrement(ref _remaining) == 0)\r\n        {\r\n            _mres.Set();\r\n        }\r\n    }\r\n\r\n    public void SignalAndWait()\r\n    {\r\n        OperationCompleted();\r\n        _mres.Wait();\r\n    }\r\n}<\/code><\/pre>\n
              \u5728\u8fd9\u91cc\uff0c\u6211\u5df2\u7ecf\u521b\u5efa\u4e86\u4e00\u4e2aSynchronizationContext\uff0c\u5b83\u8ddf\u8e2a\u4e86\u4e00\u4e2a\u5f85\u5b9a\u64cd\u4f5c\u7684\u8ba1\u6570\uff0c\u5e76\u652f\u6301\u963b\u585e\u7b49\u5f85\u5b83\u4eec\u5168\u90e8\u5b8c\u6210\u3002\u5f53\u6211\u8fd0\u884c\u5b83\u65f6\uff0c\u6211\u5f97\u5230\u8fd9\u6837\u7684\u8f93\u51fa\uff1a<\/p>\n
              Timing...\r\nEnter\r\nExit\r\n...done timing: 00:00:10.0149074<\/code><\/pre>\n
              \u7136\u540e\uff01<\/p>\n
              State Machine Fields<\/h3>\n
              \u81f3\u6b64\uff0c\u6211\u4eec\u5df2\u7ecf\u770b\u5230\u4e86\u751f\u6210\u7684\u5165\u53e3\u70b9\u65b9\u6cd5\uff0c\u4ee5\u53caMoveNext\u5b9e\u73b0\u4e2d\u7684\u4e00\u5207\u662f\u5982\u4f55\u5de5\u4f5c\u7684\u3002\u6211\u4eec\u8fd8\u4e86\u89e3\u4e86\u5728\u72b6\u6001\u673a\u4e0a\u5b9a\u4e49\u7684\u4e00\u4e9b\u5b57\u6bb5\u3002\u8ba9\u6211\u4eec\u4ed4\u7ec6\u770b\u770b\u8fd9\u4e9b\u3002<\/p>\n
              \u5bf9\u4e8e\u524d\u9762\u7ed9\u51fa\u7684CopyStreamToStream\u65b9\u6cd5:<\/p>\n
              public async Task CopyStreamToStreamAsync(Stream source, Stream destination)\r\n{\r\n    var buffer = new byte[0x1000];\r\n    int numRead;\r\n    while ((numRead = await source.ReadAsync(buffer, 0, buffer.Length)) != 0)\r\n    {\r\n        await destination.WriteAsync(buffer, 0, numRead);\r\n    }\r\n}<\/code><\/pre>\n
              \u4e0b\u9762\u662f\u6211\u4eec\u6700\u7ec8\u5f97\u5230\u7684\u5b57\u6bb5:<\/p>\n
              private struct <CopyStreamToStreamAsync>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    public Stream source;\r\n    public Stream destination;\r\n    private byte[] <buffer>5__2;\r\n    private TaskAwaiter <>u__1;\r\n    private TaskAwaiter<int> <>u__2;\r\n\r\n    ...\r\n}<\/code><\/pre>\n
              \u8fd9\u4e9b\u90fd\u662f\u4ec0\u4e48?<\/p>\n
              < > 1 __state\u3002\u662f\u201c\u72b6\u6001\u673a\u201d\u4e2d\u7684\u201c\u72b6\u6001\u201d\u3002\u5b83\u5b9a\u4e49\u4e86\u72b6\u6001\u673a\u6240\u5904\u7684\u5f53\u524d\u72b6\u6001\uff0c\u6700\u91cd\u8981\u7684\u662f\u4e0b\u6b21\u8c03\u7528MoveNext\u65f6\u5e94\u8be5\u505a\u4ec0\u4e48\u3002\u5982\u679c\u72b6\u6001\u4e3a-2\uff0c\u5219\u64cd\u4f5c\u5b8c\u6210\u3002\u5982\u679c\u72b6\u6001\u662f-1\uff0c\u8981\u4e48\u662f\u6211\u4eec\u7b2c\u4e00\u6b21\u8c03\u7528MoveNext\uff0c\u8981\u4e48\u662fMoveNext\u4ee3\u7801\u6b63\u5728\u67d0\u4e2a\u7ebf\u7a0b\u4e0a\u8fd0\u884c\u3002\u5982\u679c\u4f60\u6b63\u5728\u8c03\u8bd5\u4e00\u4e2aasync\u65b9\u6cd5\u7684\u5904\u7406\u8fc7\u7a0b\uff0c\u5e76\u4e14\u4f60\u770b\u5230\u72b6\u6001\u4e3a-1\uff0c\u8fd9\u610f\u5473\u7740\u5728\u67d0\u5904\u6709\u67d0\u4e2a\u7ebf\u7a0b\u6b63\u5728\u6267\u884c\u5305\u542b\u5728\u65b9\u6cd5\u4e2d\u7684\u4ee3\u7801\u3002\u5982\u679c\u72b6\u6001\u5927\u4e8e\u7b49\u4e8e0\uff0c\u65b9\u6cd5\u4f1a\u88ab\u6302\u8d77\uff0c\u72b6\u6001\u7684\u503c\u4f1a\u544a\u8bc9\u4f60\u5728\u4ec0\u4e48\u65f6\u5019\u6302\u8d77\u3002\u867d\u7136\u8fd9\u4e0d\u662f\u4e00\u4e2a\u4e25\u683c\u7684\u89c4\u5219(\u67d0\u4e9b\u4ee3\u7801\u6a21\u5f0f\u53ef\u80fd\u4f1a\u6df7\u6dc6\u7f16\u53f7)\uff0c\u4f46\u901a\u5e38\u60c5\u51b5\u4e0b\uff0c\u5206\u914d\u7684\u72b6\u6001\u5bf9\u5e94\u4e8e\u4ece0\u5f00\u59cb\u7684await\u7f16\u53f7\uff0c\u6309\u7167\u6e90\u4ee3\u7801\u4ece\u4e0a\u5230\u4e0b\u7684\u987a\u5e8f\u6392\u5217\u3002\u4f8b\u5982\uff0c\u5982\u679casync\u65b9\u6cd5\u7684\u51fd\u6570\u4f53\u5b8c\u5168\u662f:<\/p>\n
              await A();\r\nawait B();\r\nawait C();\r\nawait D();<\/code><\/pre>\n
              \u4f60\u53d1\u73b0\u72b6\u6001\u503c\u662f2\uff0c\u8fd9\u51e0\u4e4e\u80af\u5b9a\u610f\u5473\u7740async\u65b9\u6cd5\u5f53\u524d\u88ab\u6302\u8d77\uff0c\u7b49\u5f85\u4eceC()\u8fd4\u56de\u7684\u4efb\u52a1\u5b8c\u6210\u3002<\/p>\n
              < > t__builder\u3002\u8fd9\u662f\u72b6\u6001\u673a\u7684\u6784\u5efa\u5668\uff0c\u4f8b\u5982\u7528\u4e8eTask\u7684AsyncTaskMethodBuilder\uff0c\u7528\u4e8eValueTask\u7684AsyncValueTaskMethodBuilder<TResult>\uff0c\u7528\u4e8easync void\u65b9\u6cd5\u7684AsyncVoidMethodBuilder\uff0c\u6216\u7528\u4e8easync\u8fd4\u56de\u7c7b\u578b\u7684AsyncMethodBuilder(\u2026)]\u6216\u901a\u8fc7async\u65b9\u6cd5\u672c\u8eab\u7684\u5c5e\u6027\u8986\u76d6\u7684\u4efb\u4f55\u6784\u5efa\u5668\u3002\u5982\u524d\u6240\u8ff0\uff0c\u6784\u5efa\u5668\u8d1f\u8d23async\u65b9\u6cd5\u7684\u751f\u547d\u5468\u671f\uff0c\u5305\u62ec\u521b\u5efareturn\u4efb\u52a1\uff0c\u6700\u7ec8\u5b8c\u6210\u8be5\u4efb\u52a1\uff0c\u5e76\u5145\u5f53\u6682\u505c\u7684\u4e2d\u4ecb\uff0casync\u65b9\u6cd5\u4e2d\u7684\u4ee3\u7801\u8981\u6c42\u6784\u5efa\u5668\u6682\u505c\uff0c\u76f4\u5230\u7279\u5b9a\u7684awaiter\u5b8c\u6210\u3002<\/p>\n
              \u6765\u6e90\/\u76ee\u7684\u5730\u3002\u8fd9\u4e9b\u662f\u65b9\u6cd5\u7684\u53c2\u6570\u3002\u4f60\u53ef\u4ee5\u770b\u51fa\uff0c\u5b83\u4eec\u6ca1\u6709\u88ab\u7be1\u6539\u540d\u5b57\uff1b\u7f16\u8bd1\u5668\u5b8c\u5168\u6309\u7167\u53c2\u6570\u540d\u79f0\u7684\u6307\u5b9a\u6765\u547d\u540d\u5b83\u4eec\u3002\u5982\u524d\u6240\u8ff0\uff0c\u6240\u6709\u88ab\u65b9\u6cd5\u4e3b\u4f53\u4f7f\u7528\u7684\u53c2\u6570\u90fd\u9700\u8981\u88ab\u5b58\u50a8\u5230\u72b6\u6001\u673a\u4e2d\uff0c\u4ee5\u4fbfMoveNext\u65b9\u6cd5\u80fd\u591f\u8bbf\u95ee\u5b83\u4eec\u3002\u6ce8\u610f\u6211\u8bf4\u7684\u662f “\u88ab\u4f7f\u7528”\u3002\u5982\u679c\u7f16\u8bd1\u5668\u53d1\u73b0\u4e00\u4e2a\u53c2\u6570\u6ca1\u6709\u88ab\u5f02\u6b65\u65b9\u6cd5\u7684\u4e3b\u4f53\u4f7f\u7528\uff0c\u5b83\u5c31\u53ef\u4ee5\u4f18\u5316\uff0c\u4e0d\u9700\u8981\u5b58\u50a8\u8fd9\u4e2a\u5b57\u6bb5\u3002\u4f8b\u5982\uff0c\u7ed9\u5b9a\u4e0b\u9762\u7684\u65b9\u6cd5\uff1a<\/p>\n
              public async Task M(int someArgument)\r\n{\r\n    await Task.Yield();\r\n}<\/code><\/pre>\n
              \u7f16\u8bd1\u5668\u4f1a\u5c06\u8fd9\u4e9b\u5b57\u6bb5\u53d1\u9001\u5230\u72b6\u6001\u673a:<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    private YieldAwaitable.YieldAwaiter <>u__1;\r\n    ...\r\n}<\/code><\/pre>\n
              \u8bf7\u6ce8\u610f\uff0c\u8fd9\u91cc\u660e\u663e\u7f3a\u5c11\u540d\u4e3asomeArgument\u7684\u53c2\u6570\u3002\u4f46\u662f\uff0c\u5982\u679c\u6211\u4eec\u6539\u53d8async\u65b9\u6cd5\uff0c\u8ba9\u5b83\u4ee5\u4efb\u4f55\u65b9\u5f0f\u4f7f\u7528\u5b9e\u53c2:<\/p>\n
              public async Task M(int someArgument)\r\n{\r\n    Console.WriteLine(someArgument);\r\n    await Task.Yield();\r\n}<\/code><\/pre>\n
              \u5b83\u663e\u793a:<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    public int someArgument;\r\n    private YieldAwaitable.YieldAwaiter <>u__1;\r\n    ...\r\n}<\/code><\/pre>\n
              <buffer>5__2;\u3002\u8fd9\u662f\u7f13\u51b2\u533a\u7684 “\u5c40\u90e8”\uff0c\u5b83\u88ab\u63d0\u5347\u4e3a\u4e00\u4e2a\u5b57\u6bb5\uff0c\u8fd9\u6837\u5b83\u5c31\u53ef\u4ee5\u5728\u7b49\u5f85\u70b9\u4e0a\u5b58\u6d3b\u3002\u7f16\u8bd1\u5668\u76f8\u5f53\u52aa\u529b\u5730\u9632\u6b62\u72b6\u6001\u88ab\u4e0d\u5fc5\u8981\u5730\u63d0\u5347\u3002\u6ce8\u610f\uff0c\u5728\u6e90\u7801\u4e2d\u8fd8\u6709\u4e00\u4e2a\u5c40\u90e8\u53d8\u91cfnumRead\uff0c\u5728\u72b6\u6001\u673a\u4e2d\u6ca1\u6709\u76f8\u5e94\u7684\u5b57\u6bb5\u3002\u4e3a\u4ec0\u4e48\uff1f\u56e0\u4e3a\u5b83\u6ca1\u6709\u5fc5\u8981\u3002\u8fd9\u4e2a\u5c40\u90e8\u53d8\u91cf\u88ab\u8bbe\u7f6e\u4e3aReadAsync\u8c03\u7528\u7684\u7ed3\u679c\uff0c\u7136\u540e\u88ab\u7528\u4f5cWriteAsync\u8c03\u7528\u7684\u8f93\u5165\u3002\u5728\u8fd9\u4e24\u8005\u4e4b\u95f4\u6ca1\u6709await\uff0c\u56e0\u6b64numRead\u7684\u503c\u9700\u8981\u88ab\u5b58\u50a8\u3002\u3002\u5c31\u50cf\u5728\u4e00\u4e2a\u540c\u6b65\u65b9\u6cd5\u4e2d\uff0cJIT\u7f16\u8bd1\u5668\u53ef\u4ee5\u9009\u62e9\u5c06\u8fd9\u6837\u7684\u503c\u5b8c\u5168\u5b58\u50a8\u5728\u4e00\u4e2a\u5bc4\u5b58\u5668\u4e2d\uff0c\u800c\u4e0d\u4f1a\u771f\u6b63\u5c06\u5176\u6ea2\u51fa\u5230\u5806\u6808\u4e2d\uff0cC#\u7f16\u8bd1\u5668\u53ef\u4ee5\u907f\u514d\u5c06\u8fd9\u4e2a\u5c40\u90e8\u53d8\u91cf\u63d0\u5347\u4e3a\u4e00\u4e2a\u5b57\u6bb5\uff0c\u56e0\u4e3a\u5b83\u4e0d\u9700\u8981\u5728\u4efb\u4f55\u7b49\u5f85\u4e2d\u4fdd\u5b58\u5b83\u7684\u503c\u3002\u4e00\u822c\u6765\u8bf4\uff0c\u5982\u679cC#\u7f16\u8bd1\u5668\u80fd\u591f\u8bc1\u660e\u5c40\u90e8\u53d8\u91cf\u7684\u503c\u4e0d\u9700\u8981\u5728\u7b49\u5f85\u4e2d\u4fdd\u5b58\uff0c\u5b83\u5c31\u53ef\u4ee5\u7701\u7565\u5c40\u90e8\u53d8\u91cf\u7684\u63d0\u5347\u3002<\/p>\n
              <>u__1\u548c<>u__2\u3002async\u65b9\u6cd5\u4e2d\u6709\u4e24\u4e2aawait:\u4e00\u4e2a\u7528\u4e8eReadAsync\u8fd4\u56de\u7684Task<int>\uff0c\u53e6\u4e00\u4e2a\u7528\u4e8eWriteAsync\u8fd4\u56de\u7684Task\u3002Task. getawaiter()\u8fd4\u56de\u4e00\u4e2aTaskAwaiter, Task<TResult>. getawaiter()\u8fd4\u56de\u4e00\u4e2aTaskAwaiter<TResult>\uff0c\u4e24\u8005\u90fd\u662f\u4e0d\u540c\u7684\u7ed3\u6784\u4f53\u7c7b\u578b\u3002\u7531\u4e8e\u7f16\u8bd1\u5668\u9700\u8981\u5728await (IsCompleted, UnsafeOnCompleted)\u4e4b\u524d\u83b7\u53d6\u8fd9\u4e9bawaiter\uff0c\u7136\u540e\u9700\u8981\u5728await (GetResult)\u4e4b\u540e\u8bbf\u95ee\u5b83\u4eec\uff0c\u56e0\u6b64\u9700\u8981\u5b58\u50a8\u8fd9\u4e9bawaiter\u3002\u7531\u4e8e\u5b83\u4eec\u662f\u4e0d\u540c\u7684\u7ed3\u6784\u7c7b\u578b\uff0c\u7f16\u8bd1\u5668\u9700\u8981\u7ef4\u62a4\u4e24\u4e2a\u5355\u72ec\u7684\u5b57\u6bb5\u6765\u505a\u5230\u8fd9\u4e00\u70b9(\u53e6\u4e00\u79cd\u9009\u62e9\u662f\u5c06\u5b83\u4eec\u88c5\u7bb1\uff0c\u5e76\u4e3aawaiter\u63d0\u4f9b\u4e00\u4e2a\u5bf9\u8c61\u5b57\u6bb5\uff0c\u4f46\u8fd9\u4f1a\u5bfc\u81f4\u989d\u5916\u7684\u5206\u914d\u6210\u672c)\u3002\u4e0d\u8fc7\uff0c\u7f16\u8bd1\u5668\u4f1a\u5c3d\u53ef\u80fd\u5730\u91cd\u590d\u4f7f\u7528\u5b57\u6bb5\u3002\u5982\u679c\u6211\u6709:<\/p>\n
              public async Task M()\r\n{\r\n    await Task.FromResult(1);\r\n    await Task.FromResult(true);\r\n    await Task.FromResult(2);\r\n    await Task.FromResult(false);\r\n    await Task.FromResult(3);\r\n}<\/code><\/pre>\n
              \u6709\u4e94\u4e2a\u7b49\u5f85\uff0c\u4f46\u53ea\u6d89\u53ca\u4e24\u79cd\u4e0d\u540c\u7c7b\u578b\u7684\u7b49\u5f85\u8005\uff1a\u4e09\u4e2a\u662fTaskAwaiter<int>\uff0c\u4e24\u4e2a\u662fTaskAwaiter<bool>\u3002\u56e0\u6b64\uff0c\u72b6\u6001\u673a\u4e0a\u6700\u7ec8\u53ea\u6709\u4e24\u4e2a\u7b49\u5f85\u8005\u5b57\u6bb5\uff1a<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    private TaskAwaiter<int> <>u__1;\r\n    private TaskAwaiter<bool> <>u__2;\r\n    ...\r\n}<\/code><\/pre>\n
              \u7136\u540e\uff0c\u5982\u679c\u6211\u5c06\u6211\u7684\u793a\u4f8b\u6539\u4e3a:<\/p>\n
              public async Task M()\r\n{\r\n    await Task.FromResult(1);\r\n    await Task.FromResult(true);\r\n    await Task.FromResult(2).ConfigureAwait(false);\r\n    await Task.FromResult(false).ConfigureAwait(false);\r\n    await Task.FromResult(3);\r\n}<\/code><\/pre>\n
              \u4ecd\u7136\u53ea\u6d89\u53caTask<int>s\u548cTask<bool>s\uff0c\u4f46\u5b9e\u9645\u4e0a\u6211\u4f7f\u7528\u4e86\u56db\u4e2a\u4e0d\u540c\u7684struct awaiter\u7c7b\u578b\uff0c\u56e0\u4e3a\u4eceConfigureAwait\u8fd4\u56de\u7684\u4e1c\u897f\u4e0a\u7684GetAwaiter()\u8c03\u7528\u8fd4\u56de\u7684awaiter\u4e0eTask.GetAwaiter()\u8fd4\u56de\u7684\u662f\u4e0d\u540c\u7684\u7c7b\u578b\u2026\u4ece\u7f16\u8bd1\u5668\u521b\u5efa\u7684awaiter\u5b57\u6bb5\u53ef\u4ee5\u518d\u6b21\u5f88\u660e\u663e\u7684\u770b\u51fa:<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder <>t__builder;\r\n    private TaskAwaiter<int> <>u__1;\r\n    private TaskAwaiter<bool> <>u__2;\r\n    private ConfiguredTaskAwaitable<int>.ConfiguredTaskAwaiter <>u__3;\r\n    private ConfiguredTaskAwaitable<bool>.ConfiguredTaskAwaiter <>u__4;\r\n    ...\r\n}<\/code><\/pre>\n
              \u5982\u679c\u60a8\u53d1\u73b0\u81ea\u5df1\u60f3\u8981\u4f18\u5316\u4e0e\u5f02\u6b65\u72b6\u6001\u673a\u76f8\u5173\u7684\u5927\u5c0f\uff0c\u60a8\u53ef\u4ee5\u67e5\u770b\u7684\u4e00\u4ef6\u4e8b\u662f\u662f\u5426\u53ef\u4ee5\u5408\u5e76\u6b63\u5728\u7b49\u5f85\u7684\u4e8b\u60c5\uff0c\u4ece\u800c\u5408\u5e76\u8fd9\u4e9bawaiter\u5b57\u6bb5\u3002<\/p>\n
              \u60a8\u53ef\u80fd\u8fd8\u4f1a\u770b\u5230\u5728\u72b6\u6001\u673a\u4e0a\u5b9a\u4e49\u7684\u5176\u4ed6\u7c7b\u578b\u7684\u5b57\u6bb5\u3002\u503c\u5f97\u6ce8\u610f\u7684\u662f\uff0c\u60a8\u53ef\u80fd\u4f1a\u770b\u5230\u4e00\u4e9b\u5b57\u6bb5\u5305\u542b\u5355\u8bcd\u201cwrap\u201d\u3002\u8003\u8651\u4e0b\u9762\u8fd9\u4e2a\u611a\u8822\u7684\u4f8b\u5b50:<\/p>\n
              public async Task<int> M() => await Task.FromResult(42) + DateTime.Now.Second;<\/code><\/pre>\n
              \u8fd9\u5c06\u751f\u6210\u4e00\u4e2a\u5305\u542b\u4ee5\u4e0b\u5b57\u6bb5\u7684\u72b6\u6001\u673a:<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder<int> <>t__builder;\r\n    private TaskAwaiter<int> <>u__1;\r\n    ...\r\n}<\/code><\/pre>\n
              \u5230\u76ee\u524d\u4e3a\u6b62\u6ca1\u6709\u4ec0\u4e48\u7279\u522b\u7684\u3002\u73b0\u5728\u98a0\u5012\u4e00\u4e0b\u6dfb\u52a0\u8868\u8fbe\u5f0f\u7684\u987a\u5e8f:<\/p>\n
              public async Task<int> M() => DateTime.Now.Second + await Task.FromResult(42);<\/code><\/pre>\n
              \u8fd9\u6837\uff0c\u4f60\u5c31\u5f97\u5230\u4e86\u8fd9\u4e9b\u5b57\u6bb5:<\/p>\n
              private struct <M>d__0 : IAsyncStateMachine\r\n{\r\n    public int <>1__state;\r\n    public AsyncTaskMethodBuilder<int> <>t__builder;\r\n    private int <>7__wrap1;\r\n    private TaskAwaiter<int> <>u__1;\r\n    ...\r\n}<\/code><\/pre>\n
              \u6211\u4eec\u73b0\u5728\u6709\u4e86\u53e6\u4e00\u4e2a\u51fd\u6570:<>7__wrap1\u3002\u4e3a\u4ec0\u4e48?\u56e0\u4e3a\u6211\u4eec\u8ba1\u7b97\u4e86DateTime.Now\u7684\u503c\u3002\u5176\u6b21\uff0c\u53ea\u6709\u5728\u8ba1\u7b97\u5b8c\u5b83\u4e4b\u540e\uff0c\u6211\u4eec\u624d\u9700\u8981\u7b49\u5f85\u4e00\u4e9b\u4e1c\u897f\uff0c\u5e76\u4e14\u9700\u8981\u4fdd\u7559\u7b2c\u4e00\u4e2a\u8868\u8fbe\u5f0f\u7684\u503c\uff0c\u4ee5\u4fbf\u5c06\u5176\u4e0e\u7b2c\u4e8c\u4e2a\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u76f8\u52a0\u3002\u56e0\u6b64\uff0c\u7f16\u8bd1\u5668\u9700\u8981\u786e\u4fdd\u7b2c\u4e00\u4e2a\u8868\u8fbe\u5f0f\u7684\u4e34\u65f6\u7ed3\u679c\u53ef\u4ee5\u6dfb\u52a0\u5230await\u7684\u7ed3\u679c\u4e2d\uff0c\u8fd9\u610f\u5473\u7740\u5b83\u9700\u8981\u5c06\u8868\u8fbe\u5f0f\u7684\u7ed3\u679c\u6ea2\u51fa\u5230\u4e34\u65f6\u4e2d\uff0c\u5b83\u4f7f\u7528<>7__wrap1\u5b57\u6bb5\u505a\u5230\u4e86\u8fd9\u4e00\u70b9\u3002\u5982\u679c\u4f60\u53d1\u73b0\u81ea\u5df1\u5bf9\u5f02\u6b65\u65b9\u6cd5\u7684\u5b9e\u73b0\u8fdb\u884c\u4e86\u8d85\u4f18\u5316\uff0c\u4ee5\u51cf\u5c11\u5206\u914d\u7684\u5185\u5b58\u91cf\uff0c\u4f60\u53ef\u4ee5\u5bfb\u627e\u8fd9\u6837\u7684\u5b57\u6bb5\uff0c\u5e76\u67e5\u770b\u5bf9\u6e90\u4ee3\u7801\u7684\u5fae\u8c03\u662f\u5426\u53ef\u4ee5\u907f\u514d\u6ea2\u51fa\u7684\u9700\u8981\uff0c\u4ece\u800c\u907f\u514d\u8fd9\u79cd\u4e34\u65f6\u7684\u9700\u8981\u3002<\/p>\n
              \u603b\u7ed3<\/h2>\n
              \u6211\u5e0c\u671b\u8fd9\u7bc7\u6587\u7ae0\u6709\u52a9\u4e8e\u89e3\u91ca\u5f53\u4f60\u4f7f\u7528async\/await\u65f6\u80cc\u540e\u5230\u5e95\u53d1\u751f\u4e86\u4ec0\u4e48\uff0c\u4f46\u5e78\u8fd0\u7684\u662f\uff0c\u4f60\u901a\u5e38\u4e0d\u9700\u8981\u77e5\u9053\u6216\u5173\u5fc3\u3002\u8fd9\u91cc\u6709\u5f88\u591a\u53d8\u5316\uff0c\u6240\u6709\u8fd9\u4e9b\u7ed3\u5408\u5728\u4e00\u8d77\uff0c\u521b\u5efa\u4e86\u4e00\u4e2a\u9ad8\u6548\u7684\u89e3\u51b3\u65b9\u6848\uff0c\u53ef\u4ee5\u7f16\u5199\u53ef\u62d3\u5c55\u7684\u5f02\u6b65\u4ee3\u7801\uff0c\u800c\u4e0d\u5fc5\u5904\u7406\u56de\u8c03\u3002\u7136\u800c\uff0c\u5f52\u6839\u7ed3\u5e95\uff0c\u8fd9\u4e9b\u90e8\u5206\u5b9e\u9645\u4e0a\u662f\u76f8\u5bf9\u7b80\u5355\u7684:\u4efb\u4f55\u5f02\u6b65\u64cd\u4f5c\u7684\u901a\u7528\u8868\u793a\uff0c\u4e00\u79cd\u80fd\u591f\u5c06\u666e\u901a\u63a7\u5236\u6d41\u91cd\u5199\u4e3a\u534f\u7a0b\u7684\u72b6\u6001\u673a\u5b9e\u73b0\u7684\u8bed\u8a00\u548c\u7f16\u8bd1\u5668\uff0c\u4ee5\u53ca\u5c06\u5b83\u4eec\u7ed1\u5b9a\u5728\u4e00\u8d77\u7684\u6a21\u5f0f\u3002\u5176\u4ed6\u4e00\u5207\u90fd\u662f\u4f18\u5316\u7684\u989d\u5916\u6536\u83b7\u3002<\/p>\n
               <\/p>\n
              \u7f16\u7a0b\u6109\u5feb!<\/p>\n
               <\/p>\n
               <\/p>\n
               <\/p>\n
               <\/p>\n","protected":false},"excerpt":{"rendered":"
              \u672c\u6587\u7ffb\u8bd1\u4e8eStephen Toub\u7684\u8fd9\u7bc7\u82f1\u6587\u6587\u7ae0\uff1aHow Async\/Await Really Works in C# – .NET Blog (microsoft.com) \u51e0\u5468\u524d\uff0c.NET Blog\u520a\u767b\u4e86\u4e00\u7bc7\u6587\u7ae0\u00a0\u4ec0\u4e48\u662f .NET\uff0c\u4e3a\u4ec0\u4e48\u8981\u9009\u62e9\u5b83\uff1f\u3002\u5b83\u63d0\u4f9b\u4e86\u5bf9\u5e73\u53f0\u7684\u9ad8\u5c42\u6b21\u6982\u8ff0\uff0c\u603b\u7ed3\u4e86\u5404\u79cd\u7ec4\u4ef6\u548c\u8bbe\u8ba1\u51b3\u7b56\uff0c\u5e76\u627f\u8bfa\u5bf9\u6240\u6d89\u53ca\u7684\u9886\u57df\u53d1\u8868\u66f4\u6df1\u5165\u7684\u6587\u7ae0\u3002\u8fd9\u662f\u7b2c\u4e00\u7bc7\u8fd9\u6837\u7684\u540e\u7eed\u6587\u7ae0\uff0c\u6df1\u5165\u63a2\u8ba8\u4e86C#\u548c.NET\u4e2dasync\/await\u7684\u5386\u53f2\u3001\u80cc\u540e\u7684\u8bbe\u8ba1\u51b3\u7b56\u548c\u5b9e\u73b0\u7ec6\u8282\u3002 \u5bf9async\/await\u7684\u652f\u6301\u5df2\u7ecf\u5b58\u5728\u4e86\u5341\u5e74\u4e4b\u4e45\u3002\u5728\u8fd9\u6bb5\u65f6\u95f4\u91cc\uff0c\u5b83\u6539\u53d8\u4e86\u4e3a.NET\u7f16\u5199\u53ef\u6269\u5c55\u4ee3\u7801\u7684\u65b9\u5f0f\uff0c\u800c\u5728\u4e0d\u4e86\u89e3\u5176\u5e95\u5c42\u903b\u8f91\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u8be5\u529f\u80fd\u662f\u53ef\u884c\u7684\uff0c\u4e5f\u662f\u975e\u5e38\u5e38\u89c1\u7684\u3002\u4f60\u53ef\u4ee5\u4ece\u4e00\u4e2a\u50cf\u4e0b\u9762\u8fd9\u6837\u7684\u540c\u6b65\u65b9\u6cd5\u5f00\u59cb\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f\u201c\u540c\u6b65\u7684\u201d\uff0c\u56e0\u4e3a\u8c03\u7528\u8005\u5c06\u65e0\u6cd5\u505a\u5176\u4ed6\u4efb\u4f55\u4e8b\u60c5\uff0c\u76f4\u5230\u6574\u4e2a\u64cd\u4f5c\u5b8c\u6210\u5e76\u5c06\u63a7\u5236\u6743\u8fd4\u56de\u7ed9\u8c03\u7528\u8005): \/\/ Synchronously copy all data from source to destination. public void CopyStreamToStream(Stream source, Stream destination) { var buffer = new byte[0x1000]; int numRead; while ((numRead = source.Read(buffer, 0, buffer.Length)) != 0) { destination.Write(buffer, 0, numRead); } } \u7136\u540e\u6dfb\u52a0\u51e0\u4e2a\u5173\u952e\u5b57\uff0c\u66f4\u6539\u51e0\u4e2a\u65b9\u6cd5\u540d\u79f0\uff0c\u6700\u7ec8\u5f97\u5230\u4ee5\u4e0b\u5f02\u6b65\u65b9\u6cd5\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f “\u5f02\u6b65 “\u7684\uff0c\u56e0\u4e3a\u63a7\u5236\u6743\u4f1a\u5f88\u5feb\u8fd4\u56de\u7ed9\u5b83\u7684\u8c03\u7528\u8005\uff0c\u800c\u4e14\u53ef\u80fd\u5728\u4e0e\u6574\u4e2a\u64cd\u4f5c\u76f8\u5173\u7684\u5de5\u4f5c\u5b8c\u6210\u4e4b\u524d\uff09\uff1a […]<\/p>\n","protected":false},"author":113098,"featured_media":363,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"image","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-332","post","type-post","status-publish","format-image","has-post-thumbnail","hentry","category-dotnet-ch","post_format-post-format-image"],"acf":[],"blog_post_summary":"
              \u672c\u6587\u7ffb\u8bd1\u4e8eStephen Toub\u7684\u8fd9\u7bc7\u82f1\u6587\u6587\u7ae0\uff1aHow Async\/Await Really Works in C# – .NET Blog (microsoft.com) \u51e0\u5468\u524d\uff0c.NET Blog\u520a\u767b\u4e86\u4e00\u7bc7\u6587\u7ae0\u00a0\u4ec0\u4e48\u662f .NET\uff0c\u4e3a\u4ec0\u4e48\u8981\u9009\u62e9\u5b83\uff1f\u3002\u5b83\u63d0\u4f9b\u4e86\u5bf9\u5e73\u53f0\u7684\u9ad8\u5c42\u6b21\u6982\u8ff0\uff0c\u603b\u7ed3\u4e86\u5404\u79cd\u7ec4\u4ef6\u548c\u8bbe\u8ba1\u51b3\u7b56\uff0c\u5e76\u627f\u8bfa\u5bf9\u6240\u6d89\u53ca\u7684\u9886\u57df\u53d1\u8868\u66f4\u6df1\u5165\u7684\u6587\u7ae0\u3002\u8fd9\u662f\u7b2c\u4e00\u7bc7\u8fd9\u6837\u7684\u540e\u7eed\u6587\u7ae0\uff0c\u6df1\u5165\u63a2\u8ba8\u4e86C#\u548c.NET\u4e2dasync\/await\u7684\u5386\u53f2\u3001\u80cc\u540e\u7684\u8bbe\u8ba1\u51b3\u7b56\u548c\u5b9e\u73b0\u7ec6\u8282\u3002 \u5bf9async\/await\u7684\u652f\u6301\u5df2\u7ecf\u5b58\u5728\u4e86\u5341\u5e74\u4e4b\u4e45\u3002\u5728\u8fd9\u6bb5\u65f6\u95f4\u91cc\uff0c\u5b83\u6539\u53d8\u4e86\u4e3a.NET\u7f16\u5199\u53ef\u6269\u5c55\u4ee3\u7801\u7684\u65b9\u5f0f\uff0c\u800c\u5728\u4e0d\u4e86\u89e3\u5176\u5e95\u5c42\u903b\u8f91\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528\u8be5\u529f\u80fd\u662f\u53ef\u884c\u7684\uff0c\u4e5f\u662f\u975e\u5e38\u5e38\u89c1\u7684\u3002\u4f60\u53ef\u4ee5\u4ece\u4e00\u4e2a\u50cf\u4e0b\u9762\u8fd9\u6837\u7684\u540c\u6b65\u65b9\u6cd5\u5f00\u59cb\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f\u201c\u540c\u6b65\u7684\u201d\uff0c\u56e0\u4e3a\u8c03\u7528\u8005\u5c06\u65e0\u6cd5\u505a\u5176\u4ed6\u4efb\u4f55\u4e8b\u60c5\uff0c\u76f4\u5230\u6574\u4e2a\u64cd\u4f5c\u5b8c\u6210\u5e76\u5c06\u63a7\u5236\u6743\u8fd4\u56de\u7ed9\u8c03\u7528\u8005): \/\/ Synchronously copy all data from source to destination. public void CopyStreamToStream(Stream source, Stream destination) { var buffer = new byte[0x1000]; int numRead; while ((numRead = source.Read(buffer, 0, buffer.Length)) != 0) { destination.Write(buffer, 0, numRead); } } \u7136\u540e\u6dfb\u52a0\u51e0\u4e2a\u5173\u952e\u5b57\uff0c\u66f4\u6539\u51e0\u4e2a\u65b9\u6cd5\u540d\u79f0\uff0c\u6700\u7ec8\u5f97\u5230\u4ee5\u4e0b\u5f02\u6b65\u65b9\u6cd5\uff08\u8fd9\u4e2a\u65b9\u6cd5\u662f “\u5f02\u6b65 “\u7684\uff0c\u56e0\u4e3a\u63a7\u5236\u6743\u4f1a\u5f88\u5feb\u8fd4\u56de\u7ed9\u5b83\u7684\u8c03\u7528\u8005\uff0c\u800c\u4e14\u53ef\u80fd\u5728\u4e0e\u6574\u4e2a\u64cd\u4f5c\u76f8\u5173\u7684\u5de5\u4f5c\u5b8c\u6210\u4e4b\u524d\uff09\uff1a […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/posts\/332","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/users\/113098"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/comments?post=332"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/posts\/332\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/media\/363"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/media?parent=332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/categories?post=332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet-ch\/wp-json\/wp\/v2\/tags?post=332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}