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libuv/src/unix/signal.c  view on Meta::CPAN

  err = uv__signal_loop_once_init(loop);
  if (err)
    return err;

  uv__handle_init(loop, (uv_handle_t*) handle, UV_SIGNAL);
  handle->signum = 0;
  handle->caught_signals = 0;
  handle->dispatched_signals = 0;

  return 0;
}


void uv__signal_close(uv_signal_t* handle) {

  uv__signal_stop(handle);

  /* If there are any caught signals "trapped" in the signal pipe, we can't
   * call the close callback yet. Otherwise, add the handle to the finish_close
   * queue.
   */
  if (handle->caught_signals == handle->dispatched_signals) {
    uv__make_close_pending((uv_handle_t*) handle);
  }
}


int uv_signal_start(uv_signal_t* handle, uv_signal_cb signal_cb, int signum) {
  return uv__signal_start(handle, signal_cb, signum, 0);
}


int uv_signal_start_oneshot(uv_signal_t* handle,
                            uv_signal_cb signal_cb,
                            int signum) {
  return uv__signal_start(handle, signal_cb, signum, 1);
}


static int uv__signal_start(uv_signal_t* handle,
                            uv_signal_cb signal_cb,
                            int signum,
                            int oneshot) {
  sigset_t saved_sigmask;
  int err;
  uv_signal_t* first_handle;

  assert(!uv__is_closing(handle));

  /* If the user supplies signum == 0, then return an error already. If the
   * signum is otherwise invalid then uv__signal_register will find out
   * eventually.
   */
  if (signum == 0)
    return UV_EINVAL;

  /* Short circuit: if the signal watcher is already watching {signum} don't
   * go through the process of deregistering and registering the handler.
   * Additionally, this avoids pending signals getting lost in the small time
   * time frame that handle->signum == 0.
   */
  if (signum == handle->signum) {
    handle->signal_cb = signal_cb;
    return 0;
  }

  /* If the signal handler was already active, stop it first. */
  if (handle->signum != 0) {
    uv__signal_stop(handle);
  }

  uv__signal_block_and_lock(&saved_sigmask);

  /* If at this point there are no active signal watchers for this signum (in
   * any of the loops), it's time to try and register a handler for it here.
   * Also in case there's only one-shot handlers and a regular handler comes in.
   */
  first_handle = uv__signal_first_handle(signum);
  if (first_handle == NULL ||
      (!oneshot && (first_handle->flags & UV_SIGNAL_ONE_SHOT))) {
    err = uv__signal_register_handler(signum, oneshot);
    if (err) {
      /* Registering the signal handler failed. Must be an invalid signal. */
      uv__signal_unlock_and_unblock(&saved_sigmask);
      return err;
    }
  }

  handle->signum = signum;
  if (oneshot)
    handle->flags |= UV_SIGNAL_ONE_SHOT;

  RB_INSERT(uv__signal_tree_s, &uv__signal_tree, handle);

  uv__signal_unlock_and_unblock(&saved_sigmask);

  handle->signal_cb = signal_cb;
  uv__handle_start(handle);

  return 0;
}


static void uv__signal_event(uv_loop_t* loop,
                             uv__io_t* w,
                             unsigned int events) {
  uv__signal_msg_t* msg;
  uv_signal_t* handle;
  char buf[sizeof(uv__signal_msg_t) * 32];
  size_t bytes, end, i;
  int r;

  bytes = 0;
  end = 0;

  do {
    r = read(loop->signal_pipefd[0], buf + bytes, sizeof(buf) - bytes);

    if (r == -1 && errno == EINTR)
      continue;