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   pthread_setattr_default_np    ( 3 )

получить или установить атрибуты создания потока по умолчанию (get or set default thread-creation attributes)

Имя (Name)

pthread_getattr_default_np, pthread_setattr_default_np, - get or
       set default thread-creation attributes

Синопсис (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(const pthread_attr_t *attr);

Compile and link with -pthread.


Описание (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.


Ошибки (Error)

EINVAL (pthread_setattr_default_np()) One of the attribute
              settings in attr is invalid, or the stack address
              attribute is set in attr.

ENOMEM (pthread_setattr_default_np()) Insufficient memory.


Версии (Versions)

These functions are available in glibc since version 2.18.

Атрибуты (Attributes)

For an explanation of the terms used in this section, see
       attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface Attribute Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │pthread_getattr_default_np(), │ Thread safety │ MT-Safe │ │pthread_setattr_default_np() │ │ │ └──────────────────────────────────────┴───────────────┴─────────┘


Стандарты (Conforming to)

These functions are nonstandard GNU extensions; hence the suffix
       "_np" (nonportable) in their names.

Примеры (Examples)

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.out Stack 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\n", stacksize);

s = pthread_attr_getguardsize(attr, &guardsize); if (s != 0) errExitEN(s, "pthread_attr_getguardsize"); printf("Guard size: %zd\n", guardsize);

s = pthread_attr_getschedpolicy(attr, &policy); if (s != 0) errExitEN(s, "pthread_attr_getschedpolicy"); printf("Scheduling policy: %s\n", (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\n", schedparam.sched_priority);

s = pthread_attr_getdetachstate(attr, &detachstate); if (s != 0) errExitEN(s, "pthread_attr_getdetachstate"); printf("Detach state: %s\n", (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\n", (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); }


Смотри также (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)