does signal handler code block the main process?

Question

I am registering an alarm signal handler as follows and an alarm signal is set every second.

  sigact.sa_handler = time_handler;
  sigemptyset(&sigact.sa_mask);
  sigact.sa_flags = SA_RESTART;
  if (sigaction(SIGALRM, &sigact, NULL) < 0)
      panic("sigaction SIGALRM: %s\n", strerror(errno));

  /* Set alarm signal every second */
  alarm(1);

My question is does the function time_handler follow a separate execution path like a thread or does it block the main process.

Answer 1

您可以通过在回调中添加sleep（）来查看是否正在使用GNU C，然后查看之后的代码是否延迟。