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Diffstat (limited to 'man3/pthread_attr_init.3')
| -rw-r--r-- | man3/pthread_attr_init.3 | 313 |
1 files changed, 0 insertions, 313 deletions
diff --git a/man3/pthread_attr_init.3 b/man3/pthread_attr_init.3 deleted file mode 100644 index 2f23061..0000000 --- a/man3/pthread_attr_init.3 +++ /dev/null @@ -1,313 +0,0 @@ -'\" t -.\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk -.\" <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.TH pthread_attr_init 3 2023-10-31 "Linux man-pages 6.7" -.SH NAME -pthread_attr_init, pthread_attr_destroy \- initialize and destroy -thread attributes object -.SH LIBRARY -POSIX threads library -.RI ( libpthread ", " \-lpthread ) -.SH SYNOPSIS -.nf -.B #include <pthread.h> -.P -.BI "int pthread_attr_init(pthread_attr_t *" attr ); -.BI "int pthread_attr_destroy(pthread_attr_t *" attr ); -.fi -.SH DESCRIPTION -The -.BR pthread_attr_init () -function initializes the thread attributes object pointed to by -.I attr -with default attribute values. -After this call, individual attributes of the object can be set -using various related functions (listed under SEE ALSO), -and then the object can be used in one or more -.BR pthread_create (3) -calls that create threads. -.P -Calling -.BR pthread_attr_init () -on a thread attributes object that has already been initialized -results in undefined behavior. -.P -When a thread attributes object is no longer required, -it should be destroyed using the -.BR pthread_attr_destroy () -function. -Destroying a thread attributes object has no effect -on threads that were created using that object. -.P -Once a thread attributes object has been destroyed, -it can be reinitialized using -.BR pthread_attr_init (). -Any other use of a destroyed thread attributes object -has undefined results. -.SH RETURN VALUE -On success, these functions return 0; -on error, they return a nonzero error number. -.SH ERRORS -POSIX.1 documents an -.B ENOMEM -error for -.BR pthread_attr_init (); -on Linux these functions always succeed -(but portable and future-proof applications should nevertheless -handle a possible error return). -.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_attr_init (), -.BR pthread_attr_destroy () -T} Thread safety MT-Safe -.TE -.SH STANDARDS -POSIX.1-2008. -.SH HISTORY -POSIX.1-2001. -.SH NOTES -The -.I pthread_attr_t -type should be treated as opaque: -any access to the object other than via pthreads functions -is nonportable and produces undefined results. -.SH EXAMPLES -The program below optionally makes use of -.BR pthread_attr_init () -and various related functions to initialize a thread attributes -object that is used to create a single thread. -Once created, the thread uses the -.BR pthread_getattr_np (3) -function (a nonstandard GNU extension) to retrieve the thread's -attributes, and then displays those attributes. -.P -If the program is run with no command-line argument, -then it passes NULL as the -.I attr -argument of -.BR pthread_create (3), -so that the thread is created with default attributes. -Running the program on Linux/x86-32 with the NPTL threading implementation, -we see the following: -.P -.in +4n -.EX -.\" Results from glibc 2.8, SUSE 11.0; Oct 2008 -.RB "$" " ulimit \-s" " # No stack limit ==> default stack size is 2 MB" -unlimited -.RB "$" " ./a.out" -Thread attributes: - Detach state = PTHREAD_CREATE_JOINABLE - Scope = PTHREAD_SCOPE_SYSTEM - Inherit scheduler = PTHREAD_INHERIT_SCHED - Scheduling policy = SCHED_OTHER - Scheduling priority = 0 - Guard size = 4096 bytes - Stack address = 0x40196000 - Stack size = 0x201000 bytes -.EE -.in -.P -When we supply a stack size as a command-line argument, -the program initializes a thread attributes object, -sets various attributes in that object, -and passes a pointer to the object in the call to -.BR pthread_create (3). -Running the program on Linux/x86-32 with the NPTL threading implementation, -we see the following: -.P -.in +4n -.EX -.\" Results from glibc 2.8, SUSE 11.0; Oct 2008 -.RB "$" " ./a.out 0x3000000" -posix_memalign() allocated at 0x40197000 -Thread attributes: - Detach state = PTHREAD_CREATE_DETACHED - Scope = PTHREAD_SCOPE_SYSTEM - Inherit scheduler = PTHREAD_EXPLICIT_SCHED - Scheduling policy = SCHED_OTHER - Scheduling priority = 0 - Guard size = 0 bytes - Stack address = 0x40197000 - Stack size = 0x3000000 bytes -.EE -.in -.SS Program source -\& -.\" SRC BEGIN (pthread_attr_init.c) -.EX -#define _GNU_SOURCE /* To get pthread_getattr_np() declaration */ -#include <err.h> -#include <errno.h> -#include <pthread.h> -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -\& -static void -display_pthread_attr(pthread_attr_t *attr, char *prefix) -{ - int s, i; - size_t v; - void *stkaddr; - struct sched_param sp; -\& - s = pthread_attr_getdetachstate(attr, &i); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getdetachstate"); - printf("%sDetach state = %s\en", prefix, - (i == PTHREAD_CREATE_DETACHED) ? "PTHREAD_CREATE_DETACHED" : - (i == PTHREAD_CREATE_JOINABLE) ? "PTHREAD_CREATE_JOINABLE" : - "???"); -\& - s = pthread_attr_getscope(attr, &i); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getscope"); - printf("%sScope = %s\en", prefix, - (i == PTHREAD_SCOPE_SYSTEM) ? "PTHREAD_SCOPE_SYSTEM" : - (i == PTHREAD_SCOPE_PROCESS) ? "PTHREAD_SCOPE_PROCESS" : - "???"); -\& - s = pthread_attr_getinheritsched(attr, &i); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getinheritsched"); - printf("%sInherit scheduler = %s\en", prefix, - (i == PTHREAD_INHERIT_SCHED) ? "PTHREAD_INHERIT_SCHED" : - (i == PTHREAD_EXPLICIT_SCHED) ? "PTHREAD_EXPLICIT_SCHED" : - "???"); -\& - s = pthread_attr_getschedpolicy(attr, &i); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getschedpolicy"); - printf("%sScheduling policy = %s\en", prefix, - (i == SCHED_OTHER) ? "SCHED_OTHER" : - (i == SCHED_FIFO) ? "SCHED_FIFO" : - (i == SCHED_RR) ? "SCHED_RR" : - "???"); -\& - s = pthread_attr_getschedparam(attr, &sp); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getschedparam"); - printf("%sScheduling priority = %d\en", prefix, sp.sched_priority); -\& - s = pthread_attr_getguardsize(attr, &v); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getguardsize"); - printf("%sGuard size = %zu bytes\en", prefix, v); -\& - s = pthread_attr_getstack(attr, &stkaddr, &v); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_getstack"); - printf("%sStack address = %p\en", prefix, stkaddr); - printf("%sStack size = %#zx bytes\en", prefix, v); -} -\& -static void * -thread_start(void *arg) -{ - int s; - pthread_attr_t gattr; -\& - /* pthread_getattr_np() is a non\-standard GNU extension that - retrieves the attributes of the thread specified in its - first argument. */ -\& - s = pthread_getattr_np(pthread_self(), &gattr); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_getattr_np"); -\& - printf("Thread attributes:\en"); - display_pthread_attr(&gattr, "\et"); -\& - exit(EXIT_SUCCESS); /* Terminate all threads */ -} -\& -int -main(int argc, char *argv[]) -{ - pthread_t thr; - pthread_attr_t attr; - pthread_attr_t *attrp; /* NULL or &attr */ - int s; -\& - attrp = NULL; -\& - /* If a command\-line argument was supplied, use it to set the - stack\-size attribute and set a few other thread attributes, - and set attrp pointing to thread attributes object. */ -\& - if (argc > 1) { - size_t stack_size; - void *sp; -\& - attrp = &attr; -\& - s = pthread_attr_init(&attr); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_init"); -\& - s = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_setdetachstate"); -\& - s = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_setinheritsched"); -\& - stack_size = strtoul(argv[1], NULL, 0); -\& - s = posix_memalign(&sp, sysconf(_SC_PAGESIZE), stack_size); - if (s != 0) - errc(EXIT_FAILURE, s, "posix_memalign"); -\& - printf("posix_memalign() allocated at %p\en", sp); -\& - s = pthread_attr_setstack(&attr, sp, stack_size); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_setstack"); - } -\& - s = pthread_create(&thr, attrp, &thread_start, NULL); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_create"); -\& - if (attrp != NULL) { - s = pthread_attr_destroy(attrp); - if (s != 0) - errc(EXIT_FAILURE, s, "pthread_attr_destroy"); - } -\& - pause(); /* Terminates when other thread calls exit() */ -} -.EE -.\" SRC END -.SH SEE ALSO -.ad l -.nh -.BR pthread_attr_setaffinity_np (3), -.BR pthread_attr_setdetachstate (3), -.BR pthread_attr_setguardsize (3), -.BR pthread_attr_setinheritsched (3), -.BR pthread_attr_setschedparam (3), -.BR pthread_attr_setschedpolicy (3), -.BR pthread_attr_setscope (3), -.BR pthread_attr_setsigmask_np (3), -.BR pthread_attr_setstack (3), -.BR pthread_attr_setstackaddr (3), -.BR pthread_attr_setstacksize (3), -.BR pthread_create (3), -.BR pthread_getattr_np (3), -.BR pthread_setattr_default_np (3), -.BR pthreads (7) |