Where a secondary thread is created only to process a specific event, and where the thread terminates upon completion of that event, communication between the primary and secondary threads is usually not required. Necessary data is communicated to the secondary thread as part of the DosCreateThread() function, including pointers to the data objects upon which the thread must operate. The secondary thread then proceeds to process the event, independently of the primary thread.
The only communication from the secondary thread to the primary thread occurs upon completion of the event, when the secondary thread signals this completion to the primary thread. Completion may be signalled by Presentation Manager messages or via semaphores; see Maintaining Synchronization for further discussion.