c - Windows线程-调试版本不发布-尝试在启动时从线程获取值

我正在尝试获取线程的ID，以便存储在线程列表中。
为此，我启动了一个线程，该线程的指针指向一个存储线程ID的long。线程函数执行后，应该立即存储线程ID。一旦存储了ID，启动函数就应该能够继续。
此代码似乎只在调试模式下工作，但在发布模式下挂起。我用的是Visual C++ 2008 Express。
我需要这些代码才能在Windows XP上运行，所以很遗憾我不能简单地使用GetThreadId，因为它只在Windows Server 2003和更新版本上受支持。

thread_wrapper* spawn_thread(void *entryPoint, void *params)
{
    thread_wrapper *newThread = calloc(1, sizeof(thread_wrapper));

    _beginthread(spawned_thread_wrapper_func, 0, &newThread->_win32ThreadID);

    while (newThread->_win32ThreadID == 0) ; // Hangs here in Release mode

    ... // Safely add thread to list using critical section

    return newThread;
}

void spawned_thread_wrapper_func(void *params)
{
    long *outThreadIDPtr = (long *)params;
    *outThreadIDPtr = GetCurrentThreadId();

    // spawn_thread function should now be able to add thread to list
    // but still hangs on while waiting loop in Release mode.
    // Works fine in Debug mode.

    ...
}

这里出什么事了？

最佳答案

如果希望在该成员变量中包含当前线程id，这是使用_beginthreadex()的一种方法。该api使您能够更好地控制线程创建过程，并在需要时提供一个用于检测线程终止的等待句柄。注意，thread proc的原型和下面的实现更改非常重要。

thread_wrapper* spawn_thread(void *entryPoint, void *params)
{
    thread_wrapper *newThread = calloc(1, sizeof(thread_wrapper));

    // hThread is an OS thread handle you can wait on with
    // wait functions like WaitForSingleObject.
    HANDLE hThread = (HANDLE)_beginthreadex(NULL, 0,
            spawned_thread_wrapper_func, newThread,
            CREATE_SUSPENDED, &newThread->_win32ThreadID);

    // TODO: add new thread (which is created, but not started yet)
    //  to your list.


    // now resume the thread.
    ResumeThread(hThread);

    // if you don't need this any longer, close it, otherwise save it
    //  somewhere else (such as *before* the resume above, you can save
    //  it as a member of your thread_wrapper). No matter what, you have
    //  to close it eventually

    // CloseHandle(hThread);

    return newThread;
}

// note return value difference when using _beginthreadex.
unsigned int _stdcall spawned_thread_wrapper_func(void *params)
{
    thread_wrapper* p = params; // note: with MS you may have to cast this.

    // spawn_thread function should now be able to add thread to list
    // but still hangs on while waiting loop in Release mode.
    // Works fine in Debug mode.

    ...
}

关于c - Windows线程-调试版本不发布-尝试在启动时从线程获取值，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/18669046/