Section (3) pthread_getattr_default_np
Name
pthread_getattr_default_np, pthread_setattr_default_np — get or set default thread-creation attributes
Synopsis
#define _GNU_SOURCE /* See feature_test_macros(7) */ #include <pthread.h>
int
pthread_getattr_default_np( |
pthread_attr_t *attr); |
int
pthread_setattr_default_np( |
pthread_attr_t *attr); |
![[Note]](../stylesheet/note.png) |
Note |
|---|---|
|
Compile and link with |
DESCRIPTION
The pthread_setattr_default_np() function sets
the default attributes used for creation of a new
thread—that is, the attributes that are used when
pthread_create(3) is called
with a second argument that is NULL. The default attributes
are set using the attributes supplied in *attr, a previously initialized
thread attributes object. Note the following details about
the supplied attributes object:
-
The attribute settings in the object must be valid.
-
The stack address attribute must not be set in the object.
-
Setting the stack size attribute to zero means leave the default stack size unchanged.
The pthread_getattr_default_np() function
initializes the thread attributes object referred to by
attr so that it
contains the default attributes used for thread creation.
ERRORS
- EINVAL
-
(
pthread_setattr_default_np()) One of the attribute settings inattris invalid, or the stack address attribute is set inattr. - ENOMEM
-
(
pthread_setattr_default_np()) Insufficient memory.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
pthread_getattr_default_np(),
pthread_setattr_default_np() |
Thread safety | MT-Safe |
CONFORMING TO
These functions are nonstandard GNU extensions; hence the suffix _np (nonportable) in their names.
EXAMPLE
The program below uses pthread_getattr_default_np() to fetch the
default thread-creation attributes and then displays various
settings from the returned thread attributes object. When
running the program, we see the following output:
$./a.outStack size: 8388608 Guard size: 4096 Scheduling policy: SCHED_OTHER Scheduling priority: 0 Detach state: JOINABLE Inherit scheduler: INHERIT
Program source
#define _GNU_SOURCE
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#define errExitEN(en, msg)
do { errno = en; perror(msg);
exit(EXIT_FAILURE); } while (0)
static void
display_pthread_attr(pthread_attr_t *attr)
{
int s;
size_t stacksize;
size_t guardsize;
int policy;
struct sched_param schedparam;
int detachstate;
int inheritsched;
s = pthread_attr_getstacksize(attr, &stacksize);
if (s != 0)
errExitEN(s, pthread_attr_getstacksize);
printf(Stack size: %zd
, stacksize);
s = pthread_attr_getguardsize(attr, &guardsize);
if (s != 0)
errExitEN(s, pthread_attr_getguardsize);
printf(Guard size: %zd
, guardsize);
s = pthread_attr_getschedpolicy(attr, &policy);
if (s != 0)
errExitEN(s, pthread_attr_getschedpolicy);
printf(Scheduling policy: %s
,
(policy == SCHED_FIFO) ? SCHED_FIFO :
(policy == SCHED_RR) ? SCHED_RR :
(policy == SCHED_OTHER) ? SCHED_OTHER : [unknown]);
s = pthread_attr_getschedparam(attr, &schedparam);
if (s != 0)
errExitEN(s, pthread_attr_getschedparam);
printf(Scheduling priority: %d
, schedparam.sched_priority);
s = pthread_attr_getdetachstate(attr, &detachstate);
if (s != 0)
errExitEN(s, pthread_attr_getdetachstate);
printf(Detach state: %s
,
(detachstate == PTHREAD_CREATE_DETACHED) ? DETACHED :
(detachstate == PTHREAD_CREATE_JOINABLE) ? JOINABLE :
???);
s = pthread_attr_getinheritsched(attr, &inheritsched);
if (s != 0)
errExitEN(s, pthread_attr_getinheritsched);
printf(Inherit scheduler: %s
,
(inheritsched == PTHREAD_INHERIT_SCHED) ? INHERIT :
(inheritsched == PTHREAD_EXPLICIT_SCHED) ? EXPLICIT :
???);
}
int
main(int argc, char *argv[])
{
int s;
pthread_attr_t attr;
s = pthread_getattr_default_np(&attr);
if (s != 0)
errExitEN(s, pthread_getattr_default_np);
display_pthread_attr(&attr);
exit(EXIT_SUCCESS);
}
SEE ALSO
pthread_attr_getaffinity_np(3), pthread_attr_getdetachstate(3), pthread_attr_getguardsize(3), pthread_attr_getinheritsched(3), pthread_attr_getschedparam(3), pthread_attr_getschedpolicy(3), pthread_attr_getscope(3), pthread_attr_getstack(3), pthread_attr_getstackaddr(3), pthread_attr_getstacksize(3), pthread_attr_init(3), pthread_create(3), pthreads(7)
COLOPHON
This page is part of release 5.04 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright (c) 2016 Michael Kerrisk <mtk.manpagesgmail.com> %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END |