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SEM_CLOSE(3P) POSIX Programmer's Manual SEM_CLOSE(3P)
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.
sem_close — close a named semaphore
#include <semaphore.h>
int sem_close(sem_t *sem);
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 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.
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.
The sem_close() function may fail if:
EINVAL The sem argument is not a valid semaphore descriptor.
The following sections are informative.
None.
None.
None.
None.
semctl(3p), semget(3p), semop(3p), sem_init(3p), sem_open(3p),
sem_unlink(3p)
The Base Definitions volume of POSIX.1‐2008, semaphore.h(0p)
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) In the event of any discrepancy between this version and
the original IEEE and The Open Group Standard, the original IEEE and
The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 SEM_CLOSE(3P)
Pages that refer to this page: semaphore.h(0p), _Exit(3p), semctl(3p), semget(3p), semop(3p), sem_open(3p), sem_unlink(3p)