pthread_barrier_destroy(3p)

1PTHREAD_BARRIER_DESTROY(P) POSIX Programmer's ManualPTHREAD_BARRIER_DESTROY(P)
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NAME

6       pthread_barrier_destroy,  pthread_barrier_init - destroy and initialize
7       a barrier object (ADVANCED REALTIME THREADS)
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SYNOPSIS

10       #include <pthread.h>
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12       int pthread_barrier_destroy(pthread_barrier_t *barrier);
13       int pthread_barrier_init(pthread_barrier_t *restrict barrier,
14              const pthread_barrierattr_t *restrict attr, unsigned count);
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DESCRIPTION

18       The pthread_barrier_destroy() function shall destroy the barrier refer‐
19       enced  by  barrier  and  release any resources used by the barrier. The
20       effect of subsequent use of the barrier is undefined until the  barrier
21       is  reinitialized  by another call to pthread_barrier_init(). An imple‐
22       mentation may use this function to set barrier to an invalid value. The
23       results  are  undefined if pthread_barrier_destroy() is called when any
24       thread is blocked on the barrier, or if this function is called with an
25       uninitialized barrier.
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27       The   pthread_barrier_init()  function  shall  allocate  any  resources
28       required to use the barrier referenced by barrier and shall  initialize
29       the  barrier  with attributes referenced by attr.  If attr is NULL, the
30       default barrier attributes shall be used; the effect  is  the  same  as
31       passing the address of a default barrier attributes object. The results
32       are undefined if pthread_barrier_init() is called when  any  thread  is
33       blocked on the barrier (that is, has not returned from the pthread_bar‐
34       rier_wait() call). The results are undefined if a barrier is used with‐
35       out  first being initialized. The results are undefined if pthread_bar‐
36       rier_init() is called specifying an already initialized barrier.
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38       The count argument specifies the  number  of  threads  that  must  call
39       pthread_barrier_wait()  before any of them successfully return from the
40       call.  The value specified by count must be greater than zero.
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42       If the pthread_barrier_init() function fails, the barrier shall not  be
43       initialized and the contents of barrier are undefined.
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45       Only  the  object referenced by barrier may be used for performing syn‐
46       chronization. The result of referring to copies of that object in calls
47       to pthread_barrier_destroy() or pthread_barrier_wait() is undefined.
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RETURN VALUE

50       Upon  successful  completion, these functions shall return zero; other‐
51       wise, an error number shall be returned to indicate the error.
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ERRORS

54       The pthread_barrier_destroy() function may fail if:
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56       EBUSY  The implementation has detected an attempt to destroy a  barrier
57              while  it  is  in  use  (for  example,  while  being  used  in a
58              pthread_barrier_wait() call) by another thread.
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60       EINVAL The value specified by barrier is invalid.
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63       The pthread_barrier_init() function shall fail if:
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65       EAGAIN The system lacks the necessary resources to  initialize  another
66              barrier.
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68       EINVAL The value specified by count is equal to zero.
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70       ENOMEM Insufficient memory exists to initialize the barrier.
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73       The pthread_barrier_init() function may fail if:
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75       EBUSY  The  implementation  has  detected  an attempt to reinitialize a
76              barrier while it is in use (for example, while being used  in  a
77              pthread_barrier_wait() call) by another thread.
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79       EINVAL The value specified by attr is invalid.
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82       These functions shall not return an error code of [EINTR].
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84       The following sections are informative.
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EXAMPLES

87       None.
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APPLICATION USAGE

90       The  pthread_barrier_destroy() and pthread_barrier_init() functions are
91       part of the Barriers option and need not be provided on all implementa‐
92       tions.
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RATIONALE

95       None.
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FUTURE DIRECTIONS

98       None.
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COPYRIGHT

105       Portions of this text are reprinted and reproduced in  electronic  form
106       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
107       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
108       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
109       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
110       event of any discrepancy between this version and the original IEEE and
111       The Open Group Standard, the original IEEE and The Open Group  Standard
112       is  the  referee document. The original Standard can be obtained online
113       at http://www.opengroup.org/unix/online.html .
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117IEEE/The Open Group                  2003           PTHREAD_BARRIER_DESTROY(P)