Question

我有一个用select阻止读取的程序，但是我想让它在发送SIGINT信号时正常返回。并使用处理程序处理信号。遗憾的是，块程序不会从select系统调用返回，而是接收SIGINT和interupt。任何人都可以帮我弄清问题是什么？非常感谢。

import select
import socket
import signal

class Test(object):
    def __init__(self):
        self._read, self._write = socket.socketpair()

    def wait(self):
        readable = [self._read.fileno()]
        return select.select(readable, [], readable)

    def wakeup(self):
        self._write.send('1')


t = Test()

def handler(signum, frame):
    t.wakeup()


signal.signal(signal.SIGINT, handler)

if __name__ == '__main__':
    print t.wait()
    print 'over.'

Answer 1

您误解了程序的行为：它确实从select系统调用返回，但是您必须处理错误“Interrupted system call”。

import errno
import select
import socket
import signal

class Test(object):
    def __init__(self):
        self._read, self._write = socket.socketpair()

    def wait(self):
        readable = [self._read.fileno()]
        try: 
         return select.select(readable, [], readable)
        except select.error as e:
         if e.args[0] == errno.EINTR:
                return
         else:
                pass

    def wakeup(self):
        self._write.send('1')


t = Test()

def handler(signum, frame):
    t.wakeup()


signal.signal(signal.SIGINT, handler)

if __name__ == '__main__':
    print t.wait()
    print 'over.'

系统调用和信号处理程序

1 个答案: