Manual Pages for UNIX Operating System command usage for man sem_close

Standard C Library Functions                        sem_close(3C)



NAME
     sem_close - close a named semaphore

SYNOPSIS
     #include 

     int sem_close(sem_t *sem);


DESCRIPTION
     The sem_close() function is used to indicate that  the  cal-
     ling 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(3C)) are undefined. The
     sem_close() function deallocates (that  is,  make  available
     for  reuse by a subsequent sem_open(3C) 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(3C), then sem_close() has  no  effect  on  the
     state  of  the semaphore. If the sem_unlink(3C) function has
     been successfully invoked for name  after  the  most  recent
     call  to  sem_open(3C) with O_CREAT for this semaphore, 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(3C).

ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:






SunOS 5.11           Last change: 5 Feb 2008                    1






Standard C Library Functions                        sem_close(3C)



     ____________________________________________________________
    | ATTRIBUTE TYPE              | ATTRIBUTE VALUE             |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|
    | Standard                    | See standards(5).           |
    |_____________________________|_____________________________|


SEE ALSO
     sem_init(3C), sem_open(3C),  sem_unlink(3C),  attributes(5),
     standards(5)

NOTES
     Solaris 2.6 was the first release to support  the  Asynchro-
     nous  Input  and  Output option. Prior to this release, this
     function always returned -1 and set errno to ENOSYS.




































SunOS 5.11           Last change: 5 Feb 2008                    2