The AR System C API supports multithreaded clients through the use of sessions. Each session maintains its own state information, enabling simultaneous operations against AR System server. This feature enables more sophisticated client programs to perform multiple operations simultaneously against the same or different servers.
You establish a session with a call to ARInitialization and terminate it with a call to ARTermination. The session identifier returned in the control record from an ARInitialization call must be present in the control record for all subsequent API function calls intended to operate within that session. Operations for a session are not restricted to a single thread; however, each session can only be active on one thread at any one time.