pthread_setschedparam(3)				     Library Functions Manual					  pthread_setschedparam(3)

NAME

       pthread_setschedparam - Changes a thread's scheduling policy and scheduling parameters.

LIBRARY

       DECthreads POSIX 1003.1c Library (libpthread.so)

SYNOPSIS

       #include <pthread.h>

       int  pthread_setschedparam(
			  pthread_t		     thread,
			  int			     policy,
			  const struct sched_param   *param);

STANDARDS

       interfaces documented on this reference page conform to industry standards as follows:

       IEEE Std 1003.1c-1995, POSIX System Application Program Interface

PARAMETERS

       Thread whose scheduling policy and parameters are to be changed.  New scheduling policy value for the thread specified in thread.  The fol-
       lowing are valid values: SCHED_BG_NP SCHED_FG_NP SCHED_FIFO SCHED_OTHER SCHED_RR See Guide to DECthreads for a description of the  schedul-
       ing  policies.	New  values  of the scheduling parameters associated with the scheduling policy for the thread specified in thread.  Valid
       values for the sched_priority field  of	a  sched_param	structure  depend  on  the  chosen  scheduling	policy.  Use  the  POSIX  routines
       sched_get_priority_min(3)  or  sched_get_priority_max(3) to determine the low and high limits of each policy. Additionally, DECthreads pro-
       vides nonportable priority range constants, as follows: PRI_FIFO_MIN (low) to PRI_FIFO_MAX (high) PRI_RR_MIN  (low)  to	PRI_RR_MAX  (high)
       PRI_OTHER_MIN  (low)  to  PRI_OTHER_MAX	(high) PRI_FG_MIN_NP (low) to PRI_FG_MAX_NP (high) PRI_BG_MIN_NP (low) to PRI_BG_MAX_NP (high) The
       default priority varies by DECthreads platform.	On Tru64 UNIX, the default is 19 (that is,  the  POSIX	priority  of  a  normal  timeshare
       process).  On the non-UNIX platforms, the default priority is the midpoint between PRI_FG_MIN_NP and PRI_FG_MAX_NP.

DESCRIPTION

       This  routine changes both the current scheduling policy and associated scheduling parameters of the thread specified by thread to the pol-
       icy and associated parameters provided in policy and param, respectively.

       All currently implemented DECthreads scheduling policies have one scheduling parameter called sched_priority.  For the policy  you  choose,
       you must specify an appropriate value in the sched_priority field of the sched_param structure.

       Changing  the  scheduling policy or priority, or both, of a thread can cause it to start executing or to be preempted by another thread.  A
       thread changes its own scheduling policy and priority by using the handle returned by the pthread_self(3) routine.

       This routine differs from pthread_attr_setschedpolicy(3) and pthread_attr_setschedparam(3), in that those routines set the scheduling  pol-
       icy  and  parameter attributes that are used to establish the scheduling priority and scheduling policy of a new thread when it is created.
       However, this routine changes the scheduling policy and parameters of an existing thread.

RETURN VALUES

       If an error condition occurs, no scheduling policy or parameters are changed for the target thread, and this  routine  returns  an  integer
       value  indicating the type of error.  Possible return values are as follows: Successful completion.  The value specified by policy or param
       is invalid.  An attempt was made to set the scheduling policy or a parameter to an unsupported value.  The caller does not have the  appro-
       priate  privileges  to set the scheduling policy or parameters of the specified thread.	The value specified by thread does not refer to an
       existing thread.

ERRORS

       None

RELATED INFORMATION

       Functions: pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3), pthread_create(3), pthread_self(3), sched_yield(3)

       Manuals: Guide to DECthreads and Programmer's Guide delim off

															  pthread_setschedparam(3)