c - 中断正在线程中执行的函数调用

Question

我有一个 DLL，其中包含一个线程函数，其伪代码如下所示:

volatile BOOL stopped = FALSE;

void StopEverything()
{
    /* Enter critical section */
    stopped = TRUE;
    /* Leave critical section */
}

void workerThreadFunc()
{
    Initialize();

    /* Checkpoint 1 */
    if(stopped)
    {
        /* Do cleanup */
        return;
    }

    doLaboriousTask1();

    /* Checkpoint 2 */
    if(stopped)
    {
        /* Do cleanup */
        return;
    }

    doLaboriousTask2();

    Uninitialize();
}

在使用这个 DLL 的代码中，清理函数如下所示:

void cleanup()
{
    StopEverything();

    /* Wait for all threads to exit */
    /* Do other cleanup */
}

我的问题有两个:

1. 有没有更好的方法来阻止我的 workerThreadFunc() 执行而不是像在各个检查点那样进行检查？
2. 假设当主应用程序调用 StopEverything() 时，workerThreadFunc() 卡在 doLaboriousTask2() 中。有没有办法中断 doLaboriousTask2() 并让它立即退出？

谢谢!

Answer 1

Is there a better way to stop my workerThreadFunc() from executing instead of doing checks like that at various checkpoints?

可能不会。没有完全可靠的方法可以先发制人地停止非托管代码中的线程。任何声称这样做都会导致 TerminateThread .文档列出了使用该功能的各种可怕后果。例如:

• If the target thread owns a critical section, the critical section will not be released.
• If the target thread is allocating memory from the heap, the heap lock will not be released.
• If the target thread is executing certain kernel32 calls when it is terminated, the kernel32 state for the thread's process could be inconsistent.
• If the target thread is manipulating the global state of a shared DLL, the state of the DLL could be destroyed, affecting other users of the DLL.

你问:

Is there a way to interrupt doLaboriousTask2() and have it exit immediately?

好吧，您可以调用 TerminateThread，但是由于文档中描述的所有原因，您几乎肯定不应该这样做。