scope (ULONG) - input

The extent of the priority change.

The values of this field are shown in the following list:

• PRTYS_PROCESS
  All the threads of any process.

• PRTYS_PROCESSTREE
  All the threads of a process and any descendants. The indicated process must be the current process or a process created by the current process. Detached processes may not be specified. The indicated process may have terminated.

• PRTYS_THREAD
  A single thread of the current process.

ulClass (ULONG) - input

Priority class of a process.

The values of this field are shown in the following list:

• PRTYC_NOCHANGE No change, leave as is

• PRTYC_IDLETIME
  Idle-time

• PRTYC_REGULAR
  Regular

• PRTYC_TIMECRITICAL
  Time-critical

• PRTYC_FOREGROUNDSERVER
  Fixed high

delta (LONG) - input

Change to apply to the current base priority level of the process.

This value must range from -31 (PRTYD_MINIMUM) to +31 (PRTYD_MAXIMUM).

PorTid (ULONG) - input

A process identifier (scope == PRTYS_PROCESS or PRTYS_PROCESSTREE) or a thread identifier (scope == PRTYS_THREAD).

If this operand is equal to zero, the current process or thread is assumed.

ulrc (APIRET) - returns

Return Code.

DosSetPriority returns one of the following values:

• NO_ERROR 303
  ERROR_INVALID_PROCID
  304
  ERROR_INVALID_PDELTA
  305
  ERROR_NOT_DESCENDANT
  307
  ERROR_INVALID_PCLASS
  308
  ERROR_INVALID_SCOPE
  309
  ERROR_INVALID_THREADID
  For a full list of error codes, see Errors.