HP 3000 Manuals

Process Management Programmer's Guide

Rescheduling a Process (PH Capability Required) 

If your program has PH capability, it can call the GETPRIORITY intrinsic
to change its priority class or the priority class of a child process.  A
process is scheduled on the basis of a particular priority class when it
is created.

Generally, MPE XL schedules processes in linear or circular subqueues:

 *  AS subqueue, a linear subqueue containing system processes only

 *  BS subqueue, a linear subqueue containing processes of very high
    priority

 *  CS subqueue, a circular subqueue recommended for interactive
    processes

 *  DS subqueue, a circular subqueue available for general use at a lower
    priority than the CS subqueue and recommended for batch jobs

 *  ES subqueue, a circular subqueue operating at a very low priority
    (background)

The following is an example of a GETPRIORITY intrinsic call:

     GETPRIORITY (PIN,PRIORITYCLASS);

The parameters specified in the above example are described below.

PIN              Passes the Process Identification Number of the process
                 whose priority class is to change.  For example, a value
                 of zero indicates the calling process.

PRIORITYCLASS    Passes a value indicating the priority class in which
                 the specified process is rescheduled.  For example, the
                 value 17,235 indicates that the process is rescheduled
                 in the CS priority class.

MPE/iX 5.0 Documentation