1sem_close(3C)            Standard C Library Functions            sem_close(3C)
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NAME

6       sem_close - close a named semaphore
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SYNOPSIS

9       #include <semaphore.h>
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11       int sem_close(sem_t *sem);
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DESCRIPTION

15       The  sem_close()  function is used to indicate that the calling process
16       is finished using the named semaphore indicated by sem. The effects  of
17       calling   sem_close()   for   an  unnamed  semaphore  (one  created  by
18       sem_init(3C)) are undefined. The sem_close() function deallocates (that
19       is,  make  available  for  reuse  by  a subsequent sem_open(3C) by this
20       process) any system resources allocated by the system for use  by  this
21       process  for  this semaphore. The effect of subsequent use of the sema‐
22       phore indicated by sem by this process is undefined. If  the  semaphore
23       has  not  been  removed  with a successful call to sem_unlink(3C), then
24       sem_close() has no effect  on  the  state  of  the  semaphore.  If  the
25       sem_unlink(3C)  function  has  been successfully invoked for name after
26       the most recent call to sem_open(3C) with O_CREAT for  this  semaphore,
27       then  when  all  processes that have opened the semaphore close it, the
28       semaphore is no longer be accessible.
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RETURN VALUES

31       If successful, sem_close() returns 0, otherwise it returns −1 and  sets
32       errno to indicate the error.
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ERRORS

35       The sem_close() function will fail if:
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37       EINVAL     The sem argument is not a valid semaphore descriptor.
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40       ENOSYS     The sem_close() function is not supported by the system.
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USAGE

44       The  sem_close() function should not be called for an unnamed semaphore
45       initialized by sem_init(3C).
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ATTRIBUTES

48       See attributes(5) for descriptions of the following attributes:
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53       ┌─────────────────────────────┬─────────────────────────────┐
54       │ATTRIBUTE TYPE               │ATTRIBUTE VALUE              │
55       ├─────────────────────────────┼─────────────────────────────┤
56       │Interface Stability          │Committed                    │
57       ├─────────────────────────────┼─────────────────────────────┤
58       │MT-Level                     │MT-Safe                      │
59       ├─────────────────────────────┼─────────────────────────────┤
60       │Standard                     │See standards(5).            │
61       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

64       sem_init(3C), sem_open(3C), sem_unlink(3C), attributes(5), standards(5)
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NOTES

67       Solaris 2.6 was the first release to support the Asynchronous Input and
68       Output  option. Prior to this release, this function always returned −1
69       and set errno to ENOSYS.
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73SunOS 5.11                        5 Feb 2008                     sem_close(3C)
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