`pthread_mutexattr_gettype.3p` ( 3 )

получить и установить атрибут типа мьютекса (get and set the mutex type attribute)

Пролог (Prolog)

This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

Имя (Name)

pthread_mutexattr_gettype, pthread_mutexattr_settype — get and
       set the mutex type attribute

Синопсис (Synopsis)

#include <pthread.h>

       int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict attr,
           int *restrict type);
       int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);

Описание (Description)

The pthread_mutexattr_gettype() and pthread_mutexattr_settype() functions, respectively, shall get and set the mutex type attribute. This attribute is set in the type parameter to these functions. The default value of the type attribute is PTHREAD_MUTEX_DEFAULT.

The type of mutex is contained in the type attribute of the mutex attributes. Valid mutex types include:

PTHREAD_MUTEX_NORMAL PTHREAD_MUTEX_ERRORCHECK PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_DEFAULT

The mutex type affects the behavior of calls which lock and unlock the mutex. See pthread_mutex_lock(3p) for details. An implementation may map PTHREAD_MUTEX_DEFAULT to one of the other mutex types.

The behavior is undefined if the value specified by the attr argument to pthread_mutexattr_gettype() or pthread_mutexattr_settype() does not refer to an initialized mutex attributes object.

Возвращаемое значение (Return value)

Upon successful completion, the pthread_mutexattr_gettype()
       function shall return zero and store the value of the type
       attribute of attr into the object referenced by the type
       parameter. Otherwise, an error shall be returned to indicate the
       error.

       If successful, the pthread_mutexattr_settype() function shall
       return zero; otherwise, an error number shall be returned to
       indicate the error.

Ошибки (Error)

The pthread_mutexattr_settype() function shall fail if:

       EINVAL The value type is invalid.

       These functions shall not return an error code of [EINTR].

       The following sections are informative.

Примеры (Examples)

None.

Использование в приложениях (Application usage)

It is advised that an application should not use a
       PTHREAD_MUTEX_RECURSIVE mutex with condition variables because
       the implicit unlock performed for a pthread_cond_timedwait() or
       pthread_cond_wait() may not actually release the mutex (if it had
       been locked multiple times). If this happens, no other thread can
       satisfy the condition of the predicate.

Обоснование (Rationale)

If an implementation detects that the value specified by the attr
       argument to pthread_mutexattr_gettype() or
       pthread_mutexattr_settype() does not refer to an initialized
       mutex attributes object, it is recommended that the function
       should fail and report an [EINVAL] error.

Будущие направления (Future directions)

None.

Смотри также (See also)

pthread_cond_timedwait(3p), pthread_mutex_lock(3p)

       The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)

Исходный текст на man7.org

pthread_mutexattr_gettype.3p ( 3 )