Because synchronous invocation does not generate new problems, because service caller gets blocked until reply is received, this section talks about how to use Af-Arch asynchronous invocation model with Graphical User Interfaces toolkits.
Inside the Asynchronous invocation, the caller makes a petition using a local function stored inside the STUB connector. This STUB connector takes users arguments, marshall them and create an XML message to be sent to the remote node.
Once the request response has been received, user's space code is notified through a callback. This callback, which is a user defined function, is executed inside a newly created (or previously created but idle) thread. This callback is usually called the process function because it process a request reply.
Due to the execution nature of the process function, which runs inside a thread, this creates some problems while updating Graphical User Interfaces.
The following documents are short tutorials explaining how to mix your Graphical toolkit with Af-Arch so you can get better results.