#ifdef ACL_UNIX
	struct timeval tv;
	tv.tv_sec = delay / 1000;
	tv.tv_usec = (suseconds_t) (delay - tv.tv_sec * 1000) * 1000;
	while (select(0, (fd_set *) 0, (fd_set *) 0, (fd_set *) 0, &tv) < 0)
		if (acl_last_error() != ACL_EINTR) {
			char tbuf[256];
			acl_msg_fatal("doze: select: %s",
				acl_last_strerror(tbuf, sizeof(tbuf)));
		}
#elif	defined(ACL_WINDOWS)
	Sleep(delay);
#else
#error "unknown OS"
#endif
原文:https://www.cnblogs.com/winstonet/p/9645823.html