общий атрибут (shared 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_getpshared, pthread_mutexattr_setpshared — get
and set the process-shared attribute
Синопсис (Synopsis)
#include <pthread.h>
int pthread_mutexattr_getpshared(const pthread_mutexattr_t
*restrict attr, int *restrict pshared);
int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr,
int pshared);
Описание (Description)
The pthread_mutexattr_getpshared() function shall obtain the
value of the process-shared attribute from the attributes object
referenced by attr.
The pthread_mutexattr_setpshared() function shall set the
process-shared attribute in an initialized attributes object
referenced by attr.
The process-shared attribute is set to PTHREAD_PROCESS_SHARED to
permit a mutex to be operated upon by any thread that has access
to the memory where the mutex is allocated, even if the mutex is
allocated in memory that is shared by multiple processes. See
Section 2.9.9, Synchronization Object Copies and Alternative
Mappings for further requirements. The default value of the
attribute shall be PTHREAD_PROCESS_PRIVATE.
The behavior is undefined if the value specified by the attr
argument to pthread_mutexattr_getpshared() or
pthread_mutexattr_setpshared() does not refer to an initialized
mutex attributes object.
Возвращаемое значение (Return value)
Upon successful completion, pthread_mutexattr_setpshared() shall
return zero; otherwise, an error number shall be returned to
indicate the error.
Upon successful completion, pthread_mutexattr_getpshared() shall
return zero and store the value of the process-shared attribute
of attr into the object referenced by the pshared parameter.
Otherwise, an error number shall be returned to indicate the
error.
Ошибки (Error)
The pthread_mutexattr_setpshared() function may fail if:
EINVAL The new value specified for the attribute is outside the
range of legal values for that attribute.
These functions shall not return an error code of [EINTR].
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
If an implementation detects that the value specified by the attr
argument to pthread_mutexattr_getpshared() or
pthread_mutexattr_setpshared() 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_destroy(3p), pthread_create(3p),
pthread_mutex_destroy(3p), pthread_mutexattr_destroy(3p)
The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)
