为什么这个Python 3异步IO客户端只在Python进程中断后才发送字节？

为什么我的客户在代码行超时：

response=yield from asyncio.wait_for（reader.read（），timeout=3.0）

而不是收到回信

服务器只在客户端超时后注册它从该客户端收到一条消息，我实际上发出了一个

ctrl+d

来终止Python解释器

---

client.py

---

问题可能是您正在服务器端（以及客户端）调用

reader.read（）

，这将一直阻止，直到服务器发送

EOF

。但你可能没有这样做——你只是发送了一些字节，并保持连接打开

相反，您需要调用

readline（）

并确保将

b'\n'

附加到您的mess有效负载，调用

read

以限制等待的字节数，或者在写入消息有效负载后调用，假设您不再计划使用

writer

。使用

readline（）

或

write\eof

可能是最安全的选择。下面是一个完整的示例，演示如何使用

readline（）

：

client.py server.py 下面是使用

write_eof（）

的更改：

client.py server.py

@asyncio.coroutine
def test_connection(host, port):
    # Get the streams for the socket
    print('Starting client connection')
    reader, writer = yield from asyncio.open_connection(host, port)

    message = 'Test Message'.encode('ascii')

    # Start communication
    print('Sending message to {}:{} - {}'.format(host, port, message))
    writer.write(message)

    print('Waiting 3 sec for response...')
    response = yield from asyncio.wait_for(reader.read(), timeout=3.0)
    print('Got response: {}'.format(response.decode('ascii')))

    writer.close()


def run():
    loop = asyncio.get_event_loop()
    task = asyncio.async(test_connection())
    loop.run_until_complete(task)
    loop.close()

import asyncio

@asyncio.coroutine
def test_connection(host, port):
    # Get the streams for the socket
    print('Starting client connection')
    reader, writer = yield from asyncio.open_connection(host, port)

    message = 'Test Message\n'.encode('ascii')

    # Start communication
    print('Sending message to {}:{} - {}'.format(host, port, message))
    writer.write(message)

    print('Waiting 3 sec for response...')
    response = yield from asyncio.wait_for(reader.readline(), timeout=5.0)
    print('Got response: {}'.format(response.decode('ascii')))

    writer.close()


def run():
    loop = asyncio.get_event_loop()
    task = asyncio.async(test_connection('localhost', 5000))
    loop.run_until_complete(task)
    loop.close()

run()

import asyncio

@asyncio.coroutine
def got_connection(reader, writer):
    msg = yield from reader.readline()
    message = 'another Test Message\n'.encode('ascii')
    print('Sending message to {}:{} - {}'.format('localhost', 5000, message))
    writer.write(message)


def run():
    loop = asyncio.get_event_loop()
    server = loop.run_until_complete(asyncio.start_server(
                                        got_connection, 'localhost', 5000))
    loop.run_until_complete(server.wait_closed())
    loop.close()

run()

@asyncio.coroutine
def test_connection(host, port):
    # Get the streams for the socket
    print('Starting client connection')
    reader, writer = yield from asyncio.open_connection(host, port)

    message = 'Test Message'.encode('ascii')

    # Start communication
    print('Sending message to {}:{} - {}'.format(host, port, message))
    writer.write(message)
    writer.write_eof()

    print('Waiting 3 sec for response...')
    response = yield from asyncio.wait_for(reader.read(), timeout=5.0)
    print('Got response: {}'.format(response.decode('ascii')))

    writer.close()

@asyncio.coroutine
def got_connection(reader, writer):
    msg = yield from reader.read()
    message = 'another Test Message'.encode('ascii')
    print('Sending message to {}:{} - {}'.format('localhost', 5000, message))
    writer.write(message)
    writer.write_eof()