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The danger of TaskCompletionSource class

... when used with async/await. TaskCompletionSource class is a very useful facility if you want to control the lifetime of a task manually. I share a canonical example when TaskCompletionSource is used for converting the event-based asynchronous code to the Task-based pattern.

Combining iterator blocks and async methods in C#

One of the best traits of a well-designed system is composability. Large systems are complex and hierarchical and one of the best ways to fight accidental complexity is to compose a system from smaller components. You write and test each component independently then you glue them together to achieve a higher-level behavior. Programming ...

One user scenario to rule them all

The async series Almost every non-trivial behavior of the async methods in C# can be explained based on one user scenario: migration of the existing synchronous code to asynchronous should be as simple as possible. You should be able to add async keyword before a method's return type, add Async suffix to its name, add ...

TaskSchedulers and semaphores

When you write multi-threaded code, it's important to be aware of whether the code in other libraries you call into is also thread-safe. By my observation, most code written is not thread-safe. So if you're writing thread-safe code, kudos to you. But as you'll sometimes need to call non-thread-safe code from your multi-threaded code, this post...