pthread_getattr_np(3)      Library Functions Manual      pthread_getattr_np(3)

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       pthread_getattr_np - <?><?><?><?><?><?><?><?><?><?>
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LIBRARY
       POSIX threads library (libpthread, -lpthread)

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       #define _GNU_SOURCE             /* <?><?><?><?><?><?><?><?> feature_test_macros(7) */
       #include <pthread.h>

       int pthread_getattr_np(pthread_t thread, pthread_attr_t *attr);

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       <?><?><?><?><?><?><?> pthread_getattr_np()
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       +----------------------------+----------------------------------------------------------+--------------------------+
       |<?><?><?><?><?><?><?><?><?> | <?><?><?><?><?><?><?>                                    | <?><?><?><?><?><?><?><?> |
       +----------------------------+----------------------------------------------------------+--------------------------+
       |pthread_getattr_np()        | <?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?> | MT-Safe                  |
       +----------------------------+----------------------------------------------------------+--------------------------+
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       GNU; hence the suffix "_np" (nonportable) in the name.

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       glibc 2.2.3.

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       <?><?><?><?><?><?><?><?> (4096 <?><?><?><?> <?><?> x86-32):

           $ ./a.out -g 4097
           Thread attributes object after initializations:
                   Guard size          = 4097 bytes
                   Stack address       = (nil)
                   Stack size          = 0x0 (0) bytes

           Attributes of created thread:
                   Guard size          = 8192 bytes
                   Stack address       = 0x40196000 (EOS = 0x40397000)
                   Stack size          = 0x201000 (2101248) bytes

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           $ ./a.out -g 4096 -s 0x8000 -a
           Allocated thread stack at 0x804d000

           Thread attributes object after initializations:
                   Guard size          = 4096 bytes
                   Stack address       = 0x804d000 (EOS = 0x8055000)
                   Stack size          = 0x8000 (32768) bytes

           Attributes of created thread:
                   Guard size          = 0 bytes
                   Stack address       = 0x804d000 (EOS = 0x8055000)
                   Stack size          = 0x8000 (32768) 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_stack_related_attributes(pthread_attr_t *attr, char *prefix)
       {
           int s;
           size_t stack_size, guard_size;
           void *stack_addr;

           s = pthread_attr_getguardsize(attr, &guard_size);
           if (s != 0)
               errc(EXIT_FAILURE, s, "pthread_attr_getguardsize");
           printf("%sGuard size          = %zu bytes\n", prefix, guard_size);

           s = pthread_attr_getstack(attr, &stack_addr, &stack_size);
           if (s != 0)
               errc(EXIT_FAILURE, s, "pthread_attr_getstack");
           printf("%sStack address       = %p", prefix, stack_addr);
           if (stack_size > 0)
               printf(" (EOS = %p)", (char *) stack_addr + stack_size);
           printf("\n");
           printf("%sStack size          = %#zx (%zu) bytes\n",
                  prefix, stack_size, stack_size);
       }

       static void
       display_thread_attributes(pthread_t thread, char *prefix)
       {
           int s;
           pthread_attr_t attr;

           s = pthread_getattr_np(thread, &attr);
           if (s != 0)
               errc(EXIT_FAILURE, s, "pthread_getattr_np");

           display_stack_related_attributes(&attr, prefix);

           s = pthread_attr_destroy(&attr);
           if (s != 0)
               errc(EXIT_FAILURE, s, "pthread_attr_destroy");
       }

       static void *           /* Start function for thread we create */
       thread_start(void *arg)
       {
           printf("Attributes of created thread:\n");
           display_thread_attributes(pthread_self(), "\t");

           exit(EXIT_SUCCESS);         /* Terminate all threads */
       }

       static void
       usage(char *pname, char *msg)
       {
           if (msg != NULL)
               fputs(msg, stderr);
           fprintf(stderr, "Usage: %s [-s stack-size [-a]]"
                   " [-g guard-size]\n", pname);
           fprintf(stderr, "\t\t-a means program should allocate stack\n");
           exit(EXIT_FAILURE);
       }

       static pthread_attr_t *   /* Get thread attributes from command line */
       get_thread_attributes_from_cl(int argc, char *argv[],
                                     pthread_attr_t *attrp)
       {
           int s, opt, allocate_stack;
           size_t stack_size, guard_size;
           void *stack_addr;
           pthread_attr_t *ret_attrp = NULL;   /* Set to attrp if we initialize
                                                  a thread attributes object */
           allocate_stack = 0;
           stack_size = -1;
           guard_size = -1;

           while ((opt = getopt(argc, argv, "ag:s:")) != -1) {
               switch (opt) {
               case 'a':   allocate_stack = 1;                     break;
               case 'g':   guard_size = strtoul(optarg, NULL, 0);  break;
               case 's':   stack_size = strtoul(optarg, NULL, 0);  break;
               default:    usage(argv[0], NULL);
               }
           }

           if (allocate_stack && stack_size == -1)
               usage(argv[0], "Specifying -a without -s makes no sense\n");

           if (argc > optind)
               usage(argv[0], "Extraneous command-line arguments\n");

           if (stack_size != -1 || guard_size > 0) {
               ret_attrp = attrp;

               s = pthread_attr_init(attrp);
               if (s != 0)
                   errc(EXIT_FAILURE, s, "pthread_attr_init");
           }

           if (stack_size != -1) {
               if (!allocate_stack) {
                   s = pthread_attr_setstacksize(attrp, stack_size);
                   if (s != 0)
                       errc(EXIT_FAILURE, s, "pthread_attr_setstacksize");
               } else {
                   s = posix_memalign(&stack_addr, sysconf(_SC_PAGESIZE),
                                      stack_size);
                   if (s != 0)
                       errc(EXIT_FAILURE, s, "posix_memalign");
                   printf("Allocated thread stack at %p\n\n", stack_addr);

                   s = pthread_attr_setstack(attrp, stack_addr, stack_size);
                   if (s != 0)
                       errc(EXIT_FAILURE, s, "pthread_attr_setstacksize");
               }
           }

           if (guard_size != -1) {
               s = pthread_attr_setguardsize(attrp, guard_size);
               if (s != 0)
                   errc(EXIT_FAILURE, s, "pthread_attr_setstacksize");
           }

           return ret_attrp;
       }

       int
       main(int argc, char *argv[])
       {
           int s;
           pthread_t thr;
           pthread_attr_t attr;
           pthread_attr_t *attrp = NULL;    /* Set to &attr if we initialize
                                               a thread attributes object */

           attrp = get_thread_attributes_from_cl(argc, argv, &attr);

           if (attrp != NULL) {
               printf("Thread attributes object after initializations:\n");
               display_stack_related_attributes(attrp, "\t");
               printf("\n");
           }

           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_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)

<?><?><?><?><?><?><?>
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       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> Alexey, Azamat Hackimov <azamat.hackimov@gmail.com>,
       kogamatranslator49 <r.podarov@yandex.ru>, Kogan, Max Is
       <ismax799@gmail.com>, Yuri Kozlov <yuray@komyakino.ru> <?> <?><?><?><?>
       <?><?><?><?><?><?> <pavia00@gmail.com>

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       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> GNU
       <?><?><?><?><?><?> 3 <https://www.gnu.org/licenses/gpl-3.0.html>
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       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <man-pages-ru-talks@lists.sourceforge.net>.

Linux man-pages 6.06  31 <?><?><?><?><?><?><?> 2023 <?>. pthread_getattr_np(3)