Fire and Forget vs. Awaiting in Async/Await: When Should You Wait for Async Tasks to Complete?-C++-php.cn

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Fire and Forget vs. Awaiting in Async/Await: When Should You Wait for Async Tasks to Complete?

Susan Sarandon

Jan 12, 2025 pm 01:11 PM

Fire and Forget vs. Awaiting in Async/Await: When Should You Wait for Async Tasks to Complete?

Async/Await: Fire and Forget vs. Waiting for Completion

Understanding the interaction between a caller function and a called asynchronous function is crucial for efficient and correct code. Let's examine different approaches:

Scenario 1: Fire and Forget (Simple): The called function (Callee) is initiated but its completion is disregarded by the caller (Caller). The Caller proceeds immediately.
Scenario 2: Waiting for Completion: The Caller explicitly waits for the Callee to finish before continuing execution.

Now, let's introduce the complexity of thread pools:

Scenario 3: Fire and Forget on a ThreadPool Thread: The Callee runs on a thread pool thread, but the Caller ignores its completion status.
Scenario 4: Awaiting Completion on a ThreadPool Thread: The Caller patiently waits for the Callee to complete, even though it's running asynchronously on a thread pool thread.

Finally, let's consider the impact of async keywords:

Scenario 5: Fire and Forget with Async on ThreadPool Thread: Similar to Scenario 3, but the Callee is declared async, yet its completion is still ignored.
Scenario 6: Awaiting Completion with Async on ThreadPool Thread: The Caller utilizes await to ensure the Callee's completion before proceeding, even when the Callee runs on a thread pool thread. This is the most robust approach.

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