WaitForMultipleObjects(bWaitAll=true)双事件触发时返回值咨询

Hey there! Let's break this down in simple terms since you're new to WinAPI and MSDN can feel overwhelming at first.

First, let's recap your code's intent: you're using WaitForMultipleObjects with the third parameter set to TRUE, which tells the function to only return when both of your 2 event handles are in a signaled state (since you set the timeout to 0, it's a quick check instead of blocking).

The Correct Return Value to Check #

When bWaitAll = TRUE (the third argument), the function returns WAIT_OBJECT_0 if all objects in the handle array are signaled. That's the value you need to fill in the blank.

So your updated code will look like this:

if (WaitForMultipleObjects(2, lpHandles, TRUE, 0) == WAIT_OBJECT_0) { 
    // Execute your desired action when both events are triggered
} else { 
    continue; 
}

Quick Clarifications to Avoid Confusion #

• If not all objects are signaled (and your timeout is 0), the function will return WAIT_TIMEOUT immediately, so your else block will run.
• If something goes wrong (like invalid handles), the function returns WAIT_FAILED—you can call GetLastError() to debug the issue if needed, but that's optional for your current flow.
• Note that when bWaitAll = FALSE (waiting for any single event), the return value would be WAIT_OBJECT_0 or WAIT_OBJECT_0 + 1 (indicating which specific event triggered). But since you're waiting for both, WAIT_OBJECT_0 is the right check here.

内容的提问来源于stack exchange，提问作者Karim Zaher