停止生成的进程继承绑定端口

Question

我正在编写一个小型 HTTP 服务器，它根据请求生成一个 VLC 实例。但是，如果我停止我的服务器并尝试在启动的 VLC 实例仍然是运行时重新启动它，它会失败并显示 error: [Errno 48] Address already in use

服务器：

class Handler(BaseHTTPRequestHandler):
    def do_GET(self):
        vlcPort = 8191
        linkArg = "example.mp4"
        os.system('~/scripts/backVlcNoBorder.sh --http-port %s %s'%(vlcPort,linkArg))

class ThreadingHTTPServer(ThreadingMixIn, HTTPServer):
    def server_bind(self):
        print "self.allow_reuse_address",self.allow_reuse_address
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind(self.server_address)
        # HTTPServer.server_bind(self)

if __name__ == "__main__":
    server = ThreadingHTTPServer(("localhost",1111), Handler)
    server.serve_forever()

启动VLC调用的脚本(~/scripts/backVlcNoBorder.sh)

#!/bin/bash
nohup /Applications/VLC.app/Contents/MacOS/VLC $@ >/dev/null 2>/dev/null &

如果我向服务器发出请求，VLC 就会启动。如果我然后关闭服务器，但不是 VLC，并尝试重新启动服务器，它会失败：

self.allow_reuse_address 1
Exception in thread Thread-1:
Traceback (most recent call last):
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "./http_request_server.py", line 263, in serve_on_port
    server = ThreadingHTTPServer(("localhost",1111), Handler)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/SocketServer.py", line 420, in __init__
    self.server_bind()
  File "./http_request_server.py", line 256, in server_bind
    self.socket.bind(self.server_address)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/socket.py", line 224, in meth
    return getattr(self._sock,name)(*args)
error: [Errno 48] Address already in use

之后我运行 lsof -n -i4TCP:1111 | grep LISTEN 看看什么仍然绑定到 1111

bash    24365 admin    3u  IPv4 0x6d73e857a76dcad5      0t0  TCP 127.0.0.1:lmsocialserver (LISTEN)
VLC     24366 admin    3u  IPv4 0x6d73e857a76dcad5      0t0  TCP 127.0.0.1:lmsocialserver (LISTEN)

我不明白为什么 bash 和 VLC 都在监听 1111，我想这与 os.system 和使用 fork() 可能有关？

如何在不关闭 VLC 的情况下重新启动服务器，或者如何阻止 VLC 继承绑定端口？

OS 是 Mac OSX 10.9

Answer 1

有两个问题：

使用subprocess并通过close_fds=True修复第一个；如果 http 服务器进程以外的其他进程保持 fd 打开
配置您的服务器以使用 SO_REUSEADDR or its analog on your system 如果您重新启动速度太快（TIME_WAIT 状态）。

停止生成的进程继承绑定端口

Stop spawned process from inherting bound port

python

macos

bash

port

subprocess