python - 如何检测客户端何时与 UDS(Unix 域套接字)断开连接

Question

当客户端连接到管道并发送数据时，我可以很好地接收到数据，并且可以继续接收数据。当客户端断开连接并且 while 循环仍然处于事件状态时，问题就来了，connection.recv() 不会阻塞，因此会继续疯狂循环!所以我需要一种方法来检测客户端是否仍处于连接状态。

我有以下代码:

    pipe = './pipes/uds_defzone-lrecv'

    try:
        os.unlink(pipe)
    except OSError:
        if os.path.exists(pipe):
            raise
    self.logger.debug('Created UDS pipe: ' + pipe)

    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    sock.bind(pipe)
    sock.listen(1)

    self.logger.debug('Waiting for connection: ' + pipe)
    connection, client_address = sock.accept()
    self.logger.debug('Connection from: ' + client_address)

    while True:

        self.logger.debug('Waiting for data')
        data = connection.recv(4096)
        self.logger.debug('Received: ' + str(data))

作为引用，sender.py 代码:

# Create a UDS socket
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)

# Connect the socket to the port where the server is listening
pipe = './pipes/uds_defzone-lrecv'

logger.debug('connecting to: ' + pipe)

try:
    sock.connect(pipe)
except socket.error, msg:
    logger.debug(msg)
    sys.exit(1)

try:
    message = 'THIS IS A TEST'
    logger.debug('sending: ' + message)
    sock.sendall(message)
    time.sleep(2)

finally:
    logger.debug('closing socket')
    sock.close()

TIA!

更新

我想我可以用下面的代码减慢它的速度，但不是我想要的。

    while True:

        try:
            self.logger.debug('Waiting for data')
            data_present = select.select([sock], [], [], 30)
            if data_present[0]:
                data = connection.recv(4096)
                self.logger.debug('Received: ' + data)
        except select.timeout:
            pass

更新 2

作为引用，这是我想出的代码:

        while True:

            logger.debug('Waiting for data')
            data = connection.recv(4096)
            if not data == '':
                logger.debug('Received: ' + data)
            else:
                logger.debug('Nothing received')
                break

我在这个过程中想出的一个黑客...可能在客户端可能发送空数据合法的地方可用，也许是为了发信号？

        while True:

            try:
                logger.debug('Waiting for data')
                data = connection.recv(4096)
                # *** This throws an exception when client has disconnected
                x = connection.getpeername()
                logger.debug('Received: ' + data)
            except:
                logger.debug('Client disconnected')
                break

Answer 1

connection.recv() doesn't block and therefore keeps looping frantically! So I need a way to detect if a client is still connected.

如果对等方断开连接，recv 数据将返回空数据 ('')。您需要检查它并退出循环。