Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

sem_close(3rt) [sunos man page]

sem_close(3RT)						    Realtime Library Functions						    sem_close(3RT)

NAME
sem_close - close a named semaphore SYNOPSIS
cc [ flag... ] file... -lrt [ library... ] #include <semaphore.h> int sem_close(sem_t *sem); DESCRIPTION
The sem_close() function is used to 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(3RT)) are undefined. The sem_close() function deallocates (that is, make available for reuse by a subsequent sem_open(3RT) 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(3RT), then sem_close() has no effect on the state of the semaphore. If the sem_unlink(3RT) function has been successfully invoked for name after the most recent call to sem_open(3RT) with O_CREAT for this sema- phore, then when all processes that have opened the semaphore close it, the semaphore is no longer be accessible. RETURN VALUES
If successful, sem_close() returns 0, otherwise it returns -1 and sets errno to indicate the error. ERRORS
The sem_close() function will fail if: EINVAL The sem argument is not a valid semaphore descriptor. ENOSYS The sem_close() function is not supported by the system. USAGE
The sem_close() function should not be called for an unnamed semaphore initialized by sem_init(3RT). ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
sem_init(3RT), sem_open(3RT), sem_unlink(3RT), attributes(5), standards(5) NOTES
Solaris 2.6 was the first release to support the Asynchronous Input and Output option. Prior to this release, this function always returned -1 and set errno to ENOSYS. SunOS 5.10 28 Jun 2002 sem_close(3RT)

Check Out this Related Man Page

sem_unlink(3C)						   Standard C Library Functions 					    sem_unlink(3C)

NAME
sem_unlink - remove a named semaphore SYNOPSIS
#include <semaphore.h> int sem_unlink(const char *name); DESCRIPTION
The sem_unlink() function removes the semaphore named by the string name. If the semaphore named by name is currently referenced by other processes, then sem_unlink() has no effect on the state of the semaphore. If one or more processes have the semaphore open when sem_unlink() is called, destruction of the semaphore is postponed until all references to the semaphore have been destroyed by calls to sem_close(3C), _Exit(2), or one of the exec functions (see exec(2)) . Calls to sem_open(3C) to re-create or re-connect to the semaphore refer to a new semaphore after sem_unlink() is called. The sem_unlink() call does not block until all references have been destroyed; it returns immediately. RETURN VALUES
Upon successful completion, sem_unlink() returns 0. Otherwise, the semaphore is not changed and the function returns a value of -1 and sets errno to indicate the error. ERRORS
The sem_unlink() function will fail if: EACCES Permission is denied to unlink the named semaphore. ENAMETOOLONG The length of name string exceeds PATH_MAX, or a pathname component is longer than NAME_MAX while _POSIX_NO_TRUNC is in effect. ENOENT The named semaphore does not exist. ENOSYS The sem_unlink() function is not supported by the system. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ |ATTRIBUTE TYPE |ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Committed | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ |Standard |See standards(5). | +-----------------------------+-----------------------------+ SEE ALSO
exec(2), exit(2), sem_close(3C), sem_open(3C), attributes(5), standards(5) NOTES
Solaris 2.6 was the first release to support the Asynchronous Input and Output option. Prior to this release, this function always returned -1 and set errno to ENOSYS. SunOS 5.11 5 Feb 2008 sem_unlink(3C)
Man Page