общий атрибут объекта барьерных атрибутов (shared attribute of the barrier attributes object)
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_barrierattr_getpshared, pthread_barrierattr_setpshared —
get and set the process-shared attribute of the barrier
attributes object
Синопсис (Synopsis)
#include <pthread.h>
int pthread_barrierattr_getpshared(const pthread_barrierattr_t
*restrict attr, int *restrict pshared);
int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr,
int pshared);
Описание (Description)
The pthread_barrierattr_getpshared() function shall obtain the
value of the process-shared attribute from the attributes object
referenced by attr. The pthread_barrierattr_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 barrier to be operated upon by any thread that has
access to the memory where the barrier is allocated. 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. Both constants PTHREAD_PROCESS_SHARED
and PTHREAD_PROCESS_PRIVATE are defined in <pthread.h>.
Additional attributes, their default values, and the names of the
associated functions to get and set those attribute values are
implementation-defined.
The behavior is undefined if the value specified by the attr
argument to pthread_barrierattr_getpshared() or
pthread_barrierattr_setpshared() does not refer to an initialized
barrier attributes object.
Возвращаемое значение (Return value)
If successful, the pthread_barrierattr_getpshared() function
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.
If successful, the pthread_barrierattr_setpshared() function
shall return zero; otherwise, an error number shall be returned
to indicate the error.
Ошибки (Error)
The pthread_barrierattr_setpshared() function may fail if:
EINVAL The new value specified for the process-shared attribute
is not one of the legal values PTHREAD_PROCESS_SHARED or
PTHREAD_PROCESS_PRIVATE.
These functions shall not return an error code of [EINTR].
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
The pthread_barrierattr_getpshared() and
pthread_barrierattr_setpshared() functions are part of the Thread
Process-Shared Synchronization option and need not be provided on
all implementations.
Обоснование (Rationale)
If an implementation detects that the value specified by the attr
argument to pthread_barrierattr_getpshared() or
pthread_barrierattr_setpshared() does not refer to an initialized
barrier 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_barrier_destroy(3p), pthread_barrierattr_destroy(3p)
The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)
