(Tcl) Async Accept Socket Connection

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

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load ./chilkat.dll

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

set listenSocket [new_CkSocket]

# Bind to a port and listen.
# This example will listen at port 5555 and allows for a backlog
# of 25 pending connection requests.
set success [CkSocket_BindAndListen $listenSocket 5555 25]
if {$success != 1} then {
    puts [CkSocket_lastErrorText $listenSocket]
    delete_CkSocket $listenSocket
    exit
}

# Start a background task to accept an incoming connection ...
set maxWaitMs 20000
# acceptTask is a CkTask
set acceptTask [CkSocket_AcceptNextConnectionAsync $listenSocket $maxWaitMs]
CkTask_Run $acceptTask

# ...
# ...
# ...

# Imagine at this point the task has completed successfully,
# and a connection was accepted.  Here's how to get the connected socket...
set connectedClient [new_CkSocket]

set success [CkSocket_LoadTaskResult $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.

delete_CkSocket $listenSocket
delete_CkSocket $connectedClient