...
Spawning of the threads is managed by the main thread itself. It will pass important all process parameters to all of the child threads, such as including the dimension for parallelization, the total count of threads (including the main thread), and the unique thread number. The main thread always has a thread ID of 0, while child threads are assigned numbers starting from 1. Thread number also serves purpose during data allocation to each thread.
Monitoring of the threads runs in two phases, first during the initiation of the child threads and second during their execution. The main thread watches for timeouts during both phases.
...
Monitoring of both above phases is performed by thread status polling method described below.
The main thread waits till Once all child threads have finished completed their processing and have signalled completed status. Then it continues in its execution to collect messages from all child threads and to consolidate them into one message that will be written into tasks and signaled their finished status, the main thread resumes execution. It collects messages from every child thread, consolidates them, and then writes a message to the }APQ Process Message Response cube. Process messaging concepts are described in chapter Messaging from Backend to Frontend .