закрыть именованный семафор (close a named semaphore)
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)
sem_close — close a named semaphore
Синопсис (Synopsis)
#include <semaphore.h>
int sem_close(sem_t *sem);
Описание (Description)
The sem_close() function shall indicate that the calling process
is finished using the named semaphore indicated by sem. The
effects of calling sem_close() for an unnamed semaphore (one
created by sem_init()) are undefined. The sem_close() function
shall deallocate (that is, make available for reuse by a
subsequent sem_open() by this process) any system resources
allocated by the system for use by this process for this
semaphore. The effect of subsequent use of the semaphore
indicated by sem by this process is undefined. If any threads in
the calling process are currently blocked on the semaphore, the
behavior is undefined. If the semaphore has not been removed
with a successful call to sem_unlink(), then sem_close() has no
effect on the state of the semaphore. If the sem_unlink()
function has been successfully invoked for name after the most
recent call to sem_open() with O_CREAT for this semaphore, then
when all processes that have opened the semaphore close it, the
semaphore is no longer accessible.
Возвращаемое значение (Return value)
Upon successful completion, a value of zero shall be returned.
Otherwise, a value of -1 shall be returned and errno set to
indicate the error.
Ошибки (Error)
The sem_close() function may fail if:
EINVAL The sem argument is not a valid semaphore descriptor.
The following sections are informative.
Примеры (Examples)
None.
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
semctl(3p), semget(3p), semop(3p), sem_init(3p), sem_open(3p),
sem_unlink(3p)
The Base Definitions volume of POSIX.1‐2017, semaphore.h(0p)
