PTHREAD_SETSCHEDPARAM

NAME

pthread_setschedparam, pthread_getschedparam - control thread scheduling parameters

SYNOPSIS

#include <pthread.h>

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

int pthread_getschedparam(pthread_t target_thread, int *policy, struct sched_param *param);

DESCRIPTION

pthread_setschedparam sets the scheduling parameters for the thread target_thread as indicated by policy and param. policy can be either SCHED_OTHER (regular, non-realtime scheduling), SCHED_RR (realtime, round-robin) or SCHED_FIFO (realtime, first-in first-out). param specifies the scheduling priority for the two realtime policies. See sched_setpolicy(2) for more information on scheduling policies.

The realtime scheduling policies SCHED_RR and SCHED_FIFO are available only to processes with superuser privileges.

pthread_getschedparam retrieves the scheduling policy and scheduling parameters for the thread target_thread and store them in the locations pointed to by policy and param, respectively.

RETURN VALUE

pthread_setschedparam and pthread_getschedparam return 0 on success and a non-zero error code on error.

ERRORS

On error, pthread_setschedparam returns the following error codes:

EINVAL: policy is not one of SCHED_OTHER, SCHED_RR, SCHED_FIFO
EINVAL: the priority value specified by param is not valid for the specified policy
EPERM: the calling process does not have superuser permissions
ESRCH: the target_thread is invalid or has already terminated
EFAULT: param points outside the process memory space

On error, pthread_getschedparam returns the following error codes:

ESRCH: the target_thread is invalid or has already terminated
EFAULT: policy or param point outside the process memory space

AUTHOR

Xavier Leroy <Xavier.Leroy@inria.fr>