When Should You Dispose of a CancellationTokenSource?

Correctly release the CancellationTokenSource resource

In .NET, CancellationTokenSource is used to manage thread cancellation and needs to be released explicitly to avoid resource leaks. Although this step is often omitted from MSDN examples, managing resources correctly is critical.

Why do you need to release CancellationTokenSource?

• CancellationTokenSource Use unmanaged resources (e.g., kernel events) that must be cleaned up to prevent memory leaks.
• The garbage collector (GC) will not automatically release the CancellationTokenSource object because it does not have a finalizer.

Correct release method

• using statement: If you are waiting for a parallel task to complete, you can use the using statement to automatically release the token source.
• ContinueWith: Attach a ContinueWith method to the task that calls Dispose() on the token source.
• Explicit release: Manually call Dispose() on the token source after the parallel task or PLINQ query has completed.

Reusability

CancellationTokenSource cannot be reused. After starting a task or PLINQ query, create a new token source. Resetting IsCancellationRequested and Token is not supported.

Recommended strategies

To efficiently manage multiple CancellationTokenSource instances, consider the following:

• Use using statements whenever possible (for example, when waiting for parallel tasks).
• For long-running tasks, adopt a pattern: create a token source, pass the chained token to the task, and explicitly release the source when the task completes (e.g., using ContinueWith or explicit release) .
• Ensure that all code paths that could lead to cancellation release the token source to avoid memory leaks.

The above is the detailed content of When Should You Dispose of a CancellationTokenSource?. For more information, please follow other related articles on the PHP Chinese website!