如何让 Posix 线程在一定时间后完成其工作？

Question

我想让 Posix 线程在经过一定时间后完成其工作。您可以在简单的 C + Python 伪代码中看到我的解决方案。但我认为这不是一个有效和准确的解决方案。实现这一目标的最佳方法是什么？

Mutex incrementLock
BigInteger n = 0
int milliToWork = 5000

Worker()
    int elapsedMilli = 0
    while elapsedMilli < milliToWork
        clock_t startClock = clock()
        Lock(incrementLock)
        n += 1
        Unlock(incrementLock)
        clock_t endClock = clock()
        elapsedMilli += (double)(endClock - startClock) / (double)CLOCKS_PER_SEC * 1000.0

main()
    int nThreads = 100
    Thread threads[nThreads]
    for i = 1 to nThreads
        ThreadCreate(threads[i], Worker)
    for i = 1 to nThreads
        ThreadJoin(threads[i])

Answer 1

您可以设置一个计时器，以便在您的时间到时向您发送信号。伪代码：

sig_action_handler()
{
  /*cleanup*/
  pthread_exit();
}

worker()
{
  sigaction(sig_action_handler);
  timer_create();
  timer_settime();
  while(true)
    {
      /*do work*/
    }
 }

或者，为了更容易穿线：

sig_action_handler(int, siginfo_t *t, void *)
{
  volatile sig_atomic_t *at = t->si_value.sival_ptr;
  *at = true;
}

worker()
{
  volatile sig_atomic_t at = 0;
  struct sigevent si = {/*...*/, .sigev_value.sival_ptr = &at};
  sigaction(sig_action_handler);
  timer_create(/*...*/, &si, /*...*/);
  timer_settime();
  while(!at)
    {
      /*do work*/
    }
  /*cleanup*/
 }