Function stop_timer

c/src/proactor/win_iocp.cpp:2113–2120

Either stops a timer before firing or returns after the callback has completed (in the threadpool thread). Never "in doubt".

// Either stops a timer before firing or returns after the callback has
// completed (in the threadpool thread).  Never "in doubt".
static bool stop_timer(HANDLE tqueue, HANDLE *timer) {
  if (!*timer) return true;
  if (DeleteTimerQueueTimer(tqueue, *timer, INVALID_HANDLE_VALUE)) {
    *timer = NULL;
    return true;
  }
  return false;  // error
}

static bool start_timer(HANDLE tqueue, HANDLE *timer, WAITORTIMERCALLBACK cb, void *cb_arg, DWORD time) {
  if (*timer) {