pthread_attr_getscope man page

Prolog

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pthread_attr_getscope, pthread_attr_setscope — get and set the contentionscope attribute (REALTIME THREADS)

Synopsis

#include <pthread.h>

int pthread_attr_getscope(const pthread_attr_t *restrict attr,
    int *restrict contentionscope);
int pthread_attr_setscope(pthread_attr_t *attr, int contentionscope);

Description

The pthread_attr_getscope() and pthread_attr_setscope() functions, respectively, shall get and set the contentionscope attribute in the attr object.

The contentionscope attribute may have the values PTHREAD_SCOPE_SYSTEM, signifying system scheduling contention scope, or PTHREAD_SCOPE_PROCESS, signifying process scheduling contention scope. The symbols PTHREAD_SCOPE_SYSTEM and PTHREAD_SCOPE_PROCESS are defined in the <pthread.h> header.

The behavior is undefined if the value specified by the attr argument to pthread_attr_getscope() or pthread_attr_setscope() does not refer to an initialized thread attributes object.

Return Value

If successful, the pthread_attr_getscope() and pthread_attr_setscope() functions shall return zero; otherwise, an error number shall be returned to indicate the error.

Errors

The pthread_attr_setscope() function shall fail if:

ENOTSUP
An attempt was made to set the attribute to an unsupported value.

The pthread_attr_setscope() function may fail if:

EINVAL
The value of contentionscope is not valid.

These functions shall not return an error code of [EINTR].

The following sections are informative.

Application Usage

After these attributes have been set, a thread can be created with the specified attributes using pthread_create(). Using these routines does not affect the current running thread.

See Section 2.9.4, Thread Scheduling for further details on thread scheduling attributes and their default settings.

Rationale

If an implementation detects that the value specified by the attr argument to pthread_attr_getscope() or pthread_attr_setscope() does not refer to an initialized thread attributes object, it is recommended that the function should fail and report an [EINVAL] error.

See Also

pthread_attr_destroy(), pthread_attr_getinheritsched(), pthread_attr_getschedpolicy(), pthread_attr_getschedparam(), pthread_create()

The Base Definitions volume of POSIX.1‐2008, <pthread.h>, <sched.h>

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2013 IEEE/The Open Group POSIX Programmer's Manual