{"id":56065,"date":"2010-11-04T13:53:00","date_gmt":"2010-11-04T13:53:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/pfxteam\/2010\/11\/04\/new-feature-delayed-cancellation\/"},"modified":"2010-11-04T13:53:00","modified_gmt":"2010-11-04T13:53:00","slug":"new-feature-delayed-cancellation","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/dotnet\/new-feature-delayed-cancellation\/","title":{"rendered":"New Feature? :: Delayed cancellation"},"content":{"rendered":"

 <\/p>\n

We’re interested in adding support for scheduling\ncancellation.  For example:<\/p>\n

 <\/p>\n

\/\/ Create a\ntoken source that will Cancel() after a delay
\nvar cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(100));<\/span><\/p>\n


<\/span><\/p>\n

\/\/ And\/or\nschedule a Cancel() call
\ncts.CancelAfter(TimeSpan.FromMilliseconds(100));<\/span><\/p>\n


<\/span><\/p>\n

We’ve heard from many folks that this is a desired feature\nand have found good uses for it ourselves. \nInterestingly, we would also allow CancelAfter() to be called multiple\ntimes to reset the delay (provided the token source was not already canceled,\nof course).  One could also effectively\ncancel the cancellation by calling CancelAfter() with TimeSpan.MaxValue.<\/p>\n

 <\/p>\n

One potential issue we’ve been thinking through is whether\/how\nto deal with exceptions that fly out of user-registered delegates.  Recall that we strongly discourage throwing\nexceptions from callbacks registered with a CancellationToken, though it is\npossible to handle such exceptions today:<\/p>\n

 <\/p>\n

cts.Token.Register(()\n=> { throw new Exception(“HA!”); });<\/p>\n

try { cts.Cancel(); } \/\/ invokes the callbacks
\ncatch { \/\/ Caught it! }<\/span><\/p>\n


<\/span><\/p>\n

However, if you use this new feature to cancel\nasynchronously, you won’t ever have a chance to handle the exception, and it\nwould likely bring down your application. \nSome are of the opinion that we need not do anything about this, but\nwe’ve been brainstorming potential solutions anyway.  We’re definitely curious what you think\n=).  Feel free to answer these questions\nif you want:<\/p>\n

    \n
  1. What do you think about unhandled exceptions\nflying out of user-created token callbacks? \nShould we support this use case?<\/li>\n
  2. Any feedback about the general feature?<\/li>\n<\/ol>\n

    Thanks!<\/p>\n

     <\/p><\/p>\n","protected":false},"excerpt":{"rendered":"

      We’re interested in adding support for scheduling cancellation.  For example:   \/\/ Create a token source that will Cancel() after a delay var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(100)); \/\/ And\/or schedule a Cancel() call cts.CancelAfter(TimeSpan.FromMilliseconds(100)); We’ve heard from many folks that this is a desired feature and have found good uses for it ourselves.  Interestingly, […]<\/p>\n","protected":false},"author":485,"featured_media":58792,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[7908],"tags":[7907,7915,7921,7927,7909],"class_list":["post-56065","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-pfxteam","tag-net-4","tag-cancellation","tag-feedback-requested","tag-new-feature","tag-parallel-extensions"],"acf":[],"blog_post_summary":"

      We’re interested in adding support for scheduling cancellation.  For example:   \/\/ Create a token source that will Cancel() after a delay var cts = new CancellationTokenSource(TimeSpan.FromMilliseconds(100)); \/\/ And\/or schedule a Cancel() call cts.CancelAfter(TimeSpan.FromMilliseconds(100)); We’ve heard from many folks that this is a desired feature and have found good uses for it ourselves.  Interestingly, […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/56065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/users\/485"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/comments?post=56065"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/posts\/56065\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media\/58792"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/media?parent=56065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/categories?post=56065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/dotnet\/wp-json\/wp\/v2\/tags?post=56065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}