pthread_attr_init(3)       Library Functions Manual       pthread_attr_init(3)

<?><?><?><?><?>
       pthread_attr_init, pthread_attr_destroy - <?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?> <?><?><?><?><?>

<?><?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?> POSIX (libpthread<?> -lpthread)

<?><?><?><?>
       #include <pthread.h>

       int pthread_attr_init(pthread_attr_t *attr);
       int pthread_attr_destroy(pthread_attr_t *attr);

<?><?><?><?><?>
       <?><?><?><?><?><?> pthread_attr_init() <?><?><?><?> <?><?><?><?>
       <?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?> attr <?><?><?><?> <?><?><?><?> <?><?><?><?><?><?>.
       <?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?> <?><?><?>
       <?><?><?><?><?><?> (<?><?><?><?><?> <?><?><?> <?><?><?><?>
       <?><?><?><?><?>)<?> <?><?> <?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?> <?><?><?><?> <?><?>
       <?><?><?><?> <?><?> pthread_create(3) <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?>.

       <?><?><?><?><?><?><?> pthread_attr_init() <?><?><?> <?><?><?><?>
       <?><?><?><?> <?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?> <?><?><?><?> <?><?><?> <?><?><?><?>.

       <?><?><?><?><?> <?><?> <?><?><?><?> <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?> pthread_attr_destroy().
       <?><?><?><?><?> <?><?><?><?> <?><?><?><?> <?><?><?><?><?> <?><?>
       <?><?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?>.

       <?><?><?><?><?> <?><?><?><?><?> <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> pthread_attr_init(). <?><?>
       <?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?> <?><?><?><?> <?><?><?>
       <?><?><?><?> <?><?><?><?> <?><?><?> <?><?><?><?><?> <?><?><?>
       <?><?><?><?><?>.

<?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?> 0<?> <?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?> <?><?><?> <?><?><?> <?><?><?>
       <?><?><?><?>.

<?><?><?><?><?><?><?>
       <?><?><?><?><?> POSIX.1 <?><?><?> ENOMEM <?><?> pthread_attr_init()<?>
       <?><?><?> <?><?><?><?><?> <?><?><?><?> <?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?> (<?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?> <?><?> <?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?> <?><?><?><?><?>).

<?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?> <?><?><?> <?><?><?><?><?><?>
       <?><?><?><?> attributes(7).

       +------------+------------------------------------+--------------------+
       |<?><?><?><?><?><?><?>|<?><?><?><?><?>            | <?><?><?><?><?><?> |
       +------------+------------------------------------+--------------------+
       |pthread_attr_init(),|<?><?><?><?><?>             | MT-Safe            |
       |pthread_attr_destroy()|<?><?><?><?><?><?>        |                    |
       +------------+------------------------------------+--------------------+
<?><?><?><?><?><?><?><?>
       POSIX.1-2008.

<?><?><?><?><?><?><?>
       POSIX.1-2001.

<?><?><?><?><?><?><?>
       <?><?><?> <?><?><?><?><?><?> <?><?><?><?><?> pthread_attr_t <?><?><?>
       <?><?><?> <?><?><?><?>: <?><?> <?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?> pthreads <?><?><?>
       <?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?> <?><?><?>
       <?><?><?><?><?>.

<?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> pthread_attr_init() <?><?><?><?><?>
       <?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?> <?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?> <?><?><?><?>. <?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>
       pthread_getattr_np(3) (<?><?><?><?><?> GNU <?><?><?>
       <?><?><?><?><?><?>) <?><?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?> <?><?> <?><?><?><?> <?><?><?> <?><?><?><?><?><?>.

       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?>
       NULL <?><?><?><?><?> attr <?><?> pthread_create(3)<?> <?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?>.
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?> Linux/x86-32
       <?><?> <?><?><?><?><?> <?><?><?><?> NPTL<?> <?><?><?> <?><?> <?><?><?>:

           $ ulimit -s       # No stack limit ==> default stack size is 2 MB
           unlimited
           $ ./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

       <?><?><?><?><?> <?><?><?><?> <?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?> <?><?> <?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?> pthread_create(3).
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?> Linux/x86-32
       <?><?> <?><?><?><?><?> <?><?><?><?> NPTL<?> <?><?><?> <?><?> <?><?><?>:

           $ ./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

   <?><?><?><?> <?><?><?><?><?><?><?><?>
       #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\n", 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\n", 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\n", 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\n", 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\n", 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\n", prefix, v);

           s = pthread_attr_getstack(attr, &stkaddr, &v);
           if (s != 0)
               errc(EXIT_FAILURE, s, "pthread_attr_getstack");
           printf("%sStack address       = %p\n", prefix, stkaddr);
           printf("%sStack size          = %#zx bytes\n", 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:\n");
           display_pthread_attr(&gattr, "\t");

           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\n", 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() */
       }

<?><?><?><?> <?><?><?><?><?>
       pthread_attr_setaffinity_np(3), pthread_attr_setdetachstate(3),
       pthread_attr_setguardsize(3), pthread_attr_setinheritsched(3),
       pthread_attr_setschedparam(3), pthread_attr_setschedpolicy(3),
       pthread_attr_setscope(3), pthread_attr_setsigmask_np(3),
       pthread_attr_setstack(3), pthread_attr_setstackaddr(3),
       pthread_attr_setstacksize(3), pthread_create(3), pthread_getattr_np(3),
       pthread_setattr_default_np(3), pthreads(7)

<?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?> <zayed.alsaidi@gmail.com>

       <?><?><?> <?><?><?><?><?><?><?> <?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?> 3
       <https://www.gnu.org/licenses/gpl-3.0.html> <?><?> <?><?> <?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?> <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?>.  <?><?> <?><?><?><?> <?><?> <?><?><?><?><?><?>.

       <?><?><?> <?><?><?><?> <?><?> <?><?><?><?><?> <?><?> <?><?><?><?><?>
       <?><?><?><?> <?><?><?><?><?><?> <?><?><?><?> <?><?><?><?>
       <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?>:
       <kde-l10n-ar@kde.org>.


<?><?><?><?><?> <?><?><?><?> <?><?><?><?><?> 6.18
                          21 <?><?><?><?><?><?> 2025      pthread_attr_init(3)