buf = 8192 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.connect(('192.168.1.10', 2000)) sock.sendall(data) data = sock.recv(buf) sock.close()
上面是最简单的socket连接程序,网上很多例子也是这样,但是recv这个地方如果服务器突然不响应了会产生阻塞,避免的办法网上大概有以下几个:
1. socket.settimeout() ,这个无法避免阻塞的,行不通
2. socket.setblocking(0) 这个必须再加个time.sleep(5)模拟阻塞,此方法兼容性很不友好。
想请问大家有什么特别好的方法没?比如异步的写法,给个示例也行。
![]() | 1 est 2015-06-16 18:39:09 +08:00 via Android tornado, gevent, asyncio |
![]() | 2 binux 2015-06-16 18:42:39 +08:00 select |
![]() | 3 fangjinmin 2015-06-16 18:46:42 +08:00 用epoll |
4 lilydjwg 2015-06-16 19:12:20 +08:00 @binux @fangjinmin 这两个都无法解决 recv(2) 阻塞的问题除非把套接字设置成非阻塞。 不知道你的「无法避免阻塞」是什么意思。settimeout 会在你指定的时间之后返回的,并不会一直阻塞下去啊。你一刻也不想阻塞?可 setblocking(False) 之后,你为什么还要 sleep 呢,按之前的逻辑,这样不就「阻塞」了吗?所以,你的需求到底是什么? |
5 lilydjwg 2015-06-16 19:12:48 +08:00 ![]() |
![]() | 7 hualuogeng 2015-06-16 19:19:06 +08:00 @lilydjwg 多好的XY |
![]() | 8 nirocfz 2015-06-16 20:28:12 +08:00 @binux 有可能,linux 的 man select 有这么一段话 Under Linux, select() may report a socket file descriptor as "ready for reading", while nevertheless a subsequent read blocks. This could for example happen when data has arrived but upon examination has wrong checksum and is discarded. There may be other circumstances in which a file descriptor is spuriously reported as ready. Thus it may be safer to use O_NONBLOCK on sockets that should not block. |
![]() | 9 way2exluren 2015-06-16 20:53:40 +08:00 python 的socket在设置timeout后。 sock.timeout(5) socket就变成非阻塞socket了…… 楼主注意 |
![]() | 10 zeayes 2015-06-17 09:00:52 +08:00 setblocking或者settimeout,然后catch住特定的异常处理掉,就好了。 |
11 feisan 2015-06-17 10:33:17 +08:00 |