Subsystem task dispatcher - EQQZMAIN

After IBM Z Workload Scheduler is started and initialization is complete, the subsystem task waits for more work. EQQZMAIN, the subsystem task dispatcher, then performs one of the following:
  • Attaches subtasks (if required)
  • Requests subtasks to terminate (if IBM Z Workload Scheduler is stopping)
  • Returns to caller (if no events are pending)
  • Invokes the wait routine.
IBM Z Workload Scheduler monitors its subtasks by referring to a table that has one entry for each possible subtask. Each entry in this table contains:
  • The name of the task
  • The name of the load module to be given control
  • The TCB address of the subtask
  • The ECB that each IBM Z Workload Scheduler will post when the subtask is to terminate
  • Status information.

All subtasks are expected to terminate only when their stop-ECBs are posted. If a subtask has ended unexpectedly, IBM Z Workload Scheduler checks the corresponding entry in the subtask table to determine if the task should be reattached. If so, the task is restarted.

If IBM Z Workload Scheduler is requested to stop, all the active subtasks are posted to stop processing. The product then waits for the subtasks to end.