pthread_setprio(3thr)pthread_setprio(3thr)Namepthread_setprio - Changes the current priority of a thread
Syntax
#include <pthread.h>
int pthread_setprio (thread, priority)
pthread_t thread;
int priority;
Arguments
thread Thread whose priority is changed.
priority
New priority value of the thread specified in thread. The pri‐
ority value is dependent upon scheduling policy. Valid values
fall within one of the following three ranges.
Low High
PRI_FIFO_MIN PRI_FIFO_MAX
PRI_RR_MIN PRI_RR_MAX
PRI_OTHER_MIN PRI_OTHER_MAX
PRI_FG_MIN_NP
PRI_FG_MAX_NP
PRI_BG_MIN_NP
PRI_BG_MAX_NP
If you create a new thread without specifying a threads attributes
object that contains a changed priority attribute, the default priority
of the newly created thread is the midpoint between PRI_OTHER_MIN and
PRI_OTHER_MAX (the midpoint between the minimum and the maximum for the
SCHED_OTHER policy).
Description
This routine changes the current priority of a thread. A thread can
change its own priority using the identifier returned by pthread_self.
Changing the priority of a thread can cause it to start executing or be
preempted by another thread. The effect of setting different priority
values depends on the scheduling priority assigned to the thread. The
initial scheduling priority is set by calling the pthread_attr_setprio
routine.
Note that pthread_attr_setprio sets the priority attribute that is used
to establish the priority of a new thread when it is created. However,
pthread_setprio changes the priority of an existing thread.
Return Values
If an error condition occurs, this routine returns -1 and sets errno to
the corresponding error value. Possible return values are as follows.
Return Error Description
0 Successful comple‐
tion.
-1 [EINVAL] The value specified
by thread is
invalid.
-1 [ENOTSUP] An attempt is made
to set the policy
to an unsupported
value.
-1 [ESRCH] The value specified
by thread does not
refer to an exist‐
ing thread.
-1 [EPERM] The caller does not
have the appropri‐
ate privileges to
set the priority of
the specified
thread.
pthread_setprio(3thr)
