Thread Initialization

The initialization phase of the thread is defined as code execution of the entire prolog until beginning of processing of metadata. The child thread is responsible to signal it has finished its initialization to the main thread by resetting Scheduled flag to 0 and setting Running flag to 1 as soon as there is a high confidence the thread can run successfully (typically after all parameter values have been validated). The scheduled flag should be cleared as very last command of the process prolog section.