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Diffstat (limited to 'man/man3/pthread_getattr_default_np.3')
| -rw-r--r-- | man/man3/pthread_getattr_default_np.3 | 192 |
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diff --git a/man/man3/pthread_getattr_default_np.3 b/man/man3/pthread_getattr_default_np.3 new file mode 100644 index 000000000..97f734eb9 --- /dev/null +++ b/man/man3/pthread_getattr_default_np.3 @@ -0,0 +1,192 @@ +'\" t +.\" Copyright (c) 2016 Michael Kerrisk <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH pthread_getattr_default_np 3 (date) "Linux man-pages (unreleased)" +.SH NAME +pthread_getattr_default_np, pthread_setattr_default_np, \- +get or set default thread-creation attributes +.SH LIBRARY +POSIX threads library +.RI ( libpthread ", " \-lpthread ) +.SH SYNOPSIS +.nf +.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" +.B #include <pthread.h> +.P +.BI "int pthread_getattr_default_np(pthread_attr_t *" attr ); +.BI "int pthread_setattr_default_np(const pthread_attr_t *" attr ); +.fi +.SH DESCRIPTION +The +.BR pthread_setattr_default_np () +function sets the default attributes used for creation of a new +thread\[em]that is, the attributes that are used when +.BR pthread_create (3) +is called with a second argument that is NULL. +The default attributes are set using the attributes supplied in +.IR *attr , +a previously initialized thread attributes object. +Note the following details about the supplied attributes object: +.IP \[bu] 3 +The attribute settings in the object must be valid. +.IP \[bu] +The +.I stack address +attribute must not be set in the object. +.IP \[bu] +Setting the +.I stack size +attribute to zero means leave the default stack size unchanged. +.P +The +.BR pthread_getattr_default_np () +function initializes the thread attributes object referred to by +.I attr +so that it contains the default attributes used for thread creation. +.SH ERRORS +.TP +.B EINVAL +.RB ( pthread_setattr_default_np ()) +One of the attribute settings in +.I attr +is invalid, or the stack address attribute is set in +.IR attr . +.TP +.B ENOMEM +.\" Can happen (but unlikely) while trying to allocate memory for cpuset +.RB ( pthread_setattr_default_np ()) +Insufficient memory. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR pthread_getattr_default_np (), +.BR pthread_setattr_default_np () +T} Thread safety MT-Safe +.TE +.SH STANDARDS +GNU; +hence the suffix "_np" (nonportable) in their names. +.SH HISTORY +glibc 2.18. +.SH EXAMPLES +The program below uses +.BR 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: +.P +.in +4n +.EX +$ \fB./a.out\fP +Stack size: 8388608 +Guard size: 4096 +Scheduling policy: SCHED_OTHER +Scheduling priority: 0 +Detach state: JOINABLE +Inherit scheduler: INHERIT +.EE +.in +.SS Program source +\& +.\" SRC BEGIN (pthread_getattr_default_np.c) +.EX +#define _GNU_SOURCE +#include <err.h> +#include <errno.h> +#include <pthread.h> +#include <stdio.h> +#include <stdlib.h> +\& +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) + errc(EXIT_FAILURE, s, "pthread_attr_getstacksize"); + printf("Stack size: %zu\en", stacksize); +\& + s = pthread_attr_getguardsize(attr, &guardsize); + if (s != 0) + errc(EXIT_FAILURE, s, "pthread_attr_getguardsize"); + printf("Guard size: %zu\en", guardsize); +\& + s = pthread_attr_getschedpolicy(attr, &policy); + if (s != 0) + errc(EXIT_FAILURE, s, "pthread_attr_getschedpolicy"); + printf("Scheduling policy: %s\en", + (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) + errc(EXIT_FAILURE, s, "pthread_attr_getschedparam"); + printf("Scheduling priority: %d\en", schedparam.sched_priority); +\& + s = pthread_attr_getdetachstate(attr, &detachstate); + if (s != 0) + errc(EXIT_FAILURE, s, "pthread_attr_getdetachstate"); + printf("Detach state: %s\en", + (detachstate == PTHREAD_CREATE_DETACHED) ? "DETACHED" : + (detachstate == PTHREAD_CREATE_JOINABLE) ? "JOINABLE" : + "???"); +\& + s = pthread_attr_getinheritsched(attr, &inheritsched); + if (s != 0) + errc(EXIT_FAILURE, s, "pthread_attr_getinheritsched"); + printf("Inherit scheduler: %s\en", + (inheritsched == PTHREAD_INHERIT_SCHED) ? "INHERIT" : + (inheritsched == PTHREAD_EXPLICIT_SCHED) ? "EXPLICIT" : + "???"); +} +\& +int +main(void) +{ + int s; + pthread_attr_t attr; +\& + s = pthread_getattr_default_np(&attr); + if (s != 0) + errc(EXIT_FAILURE, s, "pthread_getattr_default_np"); +\& + display_pthread_attr(&attr); +\& + exit(EXIT_SUCCESS); +} +.EE +.\" SRC END +.SH SEE ALSO +.ad l +.nh +.BR pthread_attr_getaffinity_np (3), +.BR pthread_attr_getdetachstate (3), +.BR pthread_attr_getguardsize (3), +.BR pthread_attr_getinheritsched (3), +.BR pthread_attr_getschedparam (3), +.BR pthread_attr_getschedpolicy (3), +.BR pthread_attr_getscope (3), +.BR pthread_attr_getstack (3), +.BR pthread_attr_getstackaddr (3), +.BR pthread_attr_getstacksize (3), +.BR pthread_attr_init (3), +.BR pthread_create (3), +.BR pthreads (7) |