process.py 文件源码

def __init__(self, reactor, proc, name, fileno, forceReadHack=False):
        """Initialize, specifying a Process instance to connect to.
        """
        abstract.FileDescriptor.__init__(self, reactor)
        fdesc.setNonBlocking(fileno)
        self.proc = proc
        self.name = name
        self.fd = fileno

        if forceReadHack:
            self.enableReadHack = True
        else:
            # Detect if this fd is actually a write-only fd. If it's
            # valid to read, don't try to detect closing via read.
            # This really only means that we cannot detect a TTY's write
            # pipe being closed.
            try:
                os.read(self.fileno(), 0)
            except OSError:
                # It's a write-only pipe end, enable hack
                self.enableReadHack = True

        if self.enableReadHack:
            self.startReading()