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AIX Version 4.3 Base Operating System and Extensions Technical Reference, Volume 1

pthread_getschedparam Subroutine

Purpose

Returns the current schedpolicy and schedparam attributes of a thread.

Library

Threads Library (libpthreads.a)

Syntax

#include <pthread.h>
#include <sys/sched.h>
int pthread_getschedparam (thread, schedpolicy, schedparam)
pthread_t thread;
int *schedpolicy;
struct sched_param *schedparam;

Description

The pthread_getschedparam subroutine returns the current schedpolicy and schedparam attributes of the thread thread. The schedpolicy attribute specifies the scheduling policy of a thread. It may have one of the following values:

SCHED_FIFO Denotes first-in first-out scheduling.
SCHED_RR Denotes round-robin scheduling.
SCHED_OTHER Denotes the default AIX scheduling policy. It is the default value.

The schedparam attribute specifies the scheduling parameters of a thread created with this attributes object. The sched_priority field of the sched_param structure contains the priority of the thread. It is an integer value.

Note: The pthread.h header file must be the first included file of each source file using the threads library. Otherwise, the -D_THREAD_SAFE compilation flag should be used, or the cc_r compiler used. In this case, the flag is automatically set.

Parameters

thread Specifies the target thread.
schedpolicy Points to where the schedpolicy attribute value will be stored.
schedparam Points to where the schedparam attribute value will be stored.

Return Values

Upon successful completion, the current value of the schedpolicy and schedparam attributes are returned via the schedpolicy and schedparam parameters, and 0 is returned. Otherwise, an error code is returned.

Error Codes

The pthread_getschedparam subroutine is unsuccessful if the following is true:

ESRCH The thread thread does not exist.

Implementation Specifics

This subroutine is part of the Base Operating System (BOS) Runtime.

The implementation of this subroutine is dependent on the priority scheduling POSIX option. The priority scheduling POSIX option is implemented in AIX.

Related Information

The pthread_attr_getschedparam subroutine.

Threads Scheduling in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.

Threads Library Options in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.

Threads Library Quick Reference in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.


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