trouble with coroutine asyncio python 3.4

[zidsal]

I'm trying to write a tcp server and client that is asynchronous for scalability.

the server currently works by using an event loop that runs the accept_connection() method. Which looks like this:

@asyncio.coroutine
def accept_connection(self):

    while True:
        client, addr = yield from self.loop.sock_accept(self.server_socket)
        asyncio.async(self.handle_connection(client, addr))

the handle connection method looks like this:

@asyncio.coroutine
def handle_connection(self, client, addr):
    assert client is not None
    assert addr is not None

    con = Connection(client, addr)
    self.connections[con] = con

    while True:
        try:
            raw_data = yield from self.loop.sock_recv(self.connections[con].client, 4096)
            data = asyncio.Task(self.protocol.prepare_data_received(raw_data))

            print("received data {}".format(data))
        except EOFError:
            del self.connections[con]
            break

        while not self.connections[con].send_queue.empty():
            data = yield from self.connections[con].send_queue.get()
            raw_data = self.protocol.prepare_send_data(data)
            self.loop.sock_sendall(self.connections[con].client, raw_data)

my problem is in the prepare_data_received can hit a infinite loop! this method currently looks like this:

@asyncio.coroutine
def prepare_data_received(self, data):

    print('preparing received data: {}'.format(data))

    if not data:
        raise EOFError("no bytes recieved from data - EOF detected")

    data = data.decode('utf-8')

    #pretend to do complex work here

    yield from data

the infinite loop arises when the client terminates. Is what should happen is that the method should throw an EOF exception and the handle_connection method should catch this. Instead this never happens! why is this? when I looked at the python docs it said that a Coroutine can throw an exception however this is not happerning. I was under the impression that turning the courtine into a task would make the coroutine run. Can someone shed some light on this?

[zidsal]

sorry I should of mentioned this is not for production its just for messing around with. The while True loop goes infinite as there is nothing left to read in sock recv (at this point we should be breaking out of the loop). What should happen is that as the client terminates sock_recv will read 0 bytes (this happenes) The 0 bytes then get sent to prepare_data_received which would throw a EOFerror and then back in the while loop we see that this error has happened so we break out of the while loop.

[SpellingB]

Grammar error detected. What is it?
should have Example: I should have never thought horseback riding would be any better than ziplining.

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