Dispatcher XPI functions

The XPI provides six dispatcher functions. These functions are the DFHDSSRX calls ADD_SUSPEND, SUSPEND, RESUME, DELETE_SUSPEND, and WAIT_MVS, and the DFHDSATX call CHANGE_PRIORITY.

Use of these dispatcher calls is limited. Check the details supplied for each exit in Global user exit programs before using any functions.

Note:
  1. You must issue an ADD_SUSPEND call to create a suspend token before you issue a SUSPEND or RESUME call.
  2. If a suspended task is canceled, the SUSPEND fails with a RESPONSE value of 'PURGED' and a REASON value of 'TASK_CANCELLED'. A corresponding RESUME call returns with a RESPONSE value of 'EXCEPTION' and a REASON value of 'TASK_CANCELLED'.
  3. If a suspended task is timed out, the SUSPEND fails with a RESPONSE value of 'PURGED' and a REASON value of 'TIMED_OUT'. A corresponding RESUME call returns with a RESPONSE value of 'EXCEPTION' and a REASON value of 'TIMED_OUT'.
  4. Dispatcher protocols require that you issue a RESUME even if the SUSPEND was purged (due to task cancel or time out). You must issue only one RESUME for each SUSPEND call.