What exactly does listen() do from winsock 1.1

This is a discussion on What exactly does listen() do from winsock 1.1 within the Networking/Device Communication forums, part of the General Programming Boards category; Hi, im designing a login server for a game, and every time the server receives a connection i intend to ...

  1. #1
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    What exactly does listen() do from winsock 1.1

    Hi, im designing a login server for a game, and every time the server receives a connection i intend to a launch a new thread. I was playing with the code from another server i made which was only capable of connecting to one client, and basically it does this.

    Code:
    //define the listening socket above
    listen(listenSock, 10)
    //define a server socket
    serverSock = accept(listenSock, NULL, NULL);
    //terminate server thread, as this is just a test
    what i was expecting was the server thread to block at listen(), and then continue after the client tried to connect. The client, ofcourse, timed out. however, i then tried running two clients, and both of them found the server (im not sure if they both got "accepted") and then timed out.

    So what does listen() actually. Im really confused, as i was intending to make a loop using listen to block until a client tried to connect and then launch a thread. But it would appear as though listen did more than just block. Could someone please explain whats going on there. Thanks.

  2. #2
    Cat without Hat CornedBee's Avatar
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    listen() puts the socket in listening mode. It doesn't wait for an actual connection, though. That's accept()'s job.
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  3. #3
    and the hat of wrongness Salem's Avatar
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    listen() goes in the main thread, then you pass the accept()'ed socket into a new thread to deal with that connection. The main thread loops round for another listen.
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    ok, so accept() will block and should be in the loop, and theres some sort of magical queue created in the background. I hate magic, so confusing.

    Thx, im pretty sure i can work from there.

  5. #5
    Super Moderator VirtualAce's Avatar
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    There's no queue. Accept will block if the socket is blocking and won't if it's not. Where is this queue you are speaking of?

  6. #6
    Cat without Hat CornedBee's Avatar
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    This queue is internal to the network driver and holds client connections until accept fetches them.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  7. #7
    Super Moderator VirtualAce's Avatar
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    Ok there's no queue from a software standpoint.

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