(PureBasic) Async Accept Socket Connection

Demonstrates how to get the connected client socket after accepting a connection asynchronously.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkSocket.pb"
IncludeFile "CkTask.pb"

Procedure ChilkatExample()

    ;  This example assumes the Chilkat Socket API to have been previously unlocked.
    ;  See Socket Unlock Sample for sample code.

    listenSocket.i = CkSocket::ckCreate()
    If listenSocket.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ;  Bind to a port and listen.
    ;  This example will listen at port 5555 and allows for a backlog
    ;  of 25 pending connection requests.
    success.i = CkSocket::ckBindAndListen(listenSocket,5555,25)
    If success <> 1
        Debug CkSocket::ckLastErrorText(listenSocket)
        CkSocket::ckDispose(listenSocket)
        ProcedureReturn
    EndIf

    ;  Start a background task to accept an incoming connection ...
    maxWaitMs.i = 20000
    acceptTask.i = CkSocket::ckAcceptNextConnectionAsync(listenSocket,maxWaitMs)
    CkTask::ckRun(acceptTask)

    ;  ...
    ;  ...
    ;  ...

    ;  Imagine at this point the task has completed successfully,
    ;  and a connection was accepted.  Here's how to get the connected socket...
    connectedClient.i = CkSocket::ckCreate()
    If connectedClient.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkSocket::ckLoadTaskResult(connectedClient,acceptTask)

    ;  Here's how it works:  The AcceptNextConnection method would normally
    ;  return a socket object when called synchronously.  When called asynchronously,
    ;  it cannot do so because it returns the task object.  When the async method
    ;  (running in a background thread) completes, the socket object that is the client
    ;  connection is contained within the task object.
    ; 
    ;  This can be generalized for any case where a Chilkat method returns an object.
    ;  The async version of that method is such that the object returned in the background
    ;  thread is contained within the task object.

    ;  To get the result object, we create a new object instance of that type.
    ;  In this case, we create a socket object (connectedClient).  There is a LoadTaskResult
    ;  method in all Chilkat classes that can be a return value of an async method call.
    ;  The LoadTaskResult method transfers the returned object from the task to the caller.


    CkSocket::ckDispose(listenSocket)
    CkSocket::ckDispose(connectedClient)


    ProcedureReturn
EndProcedure