1PTHREAD_BARRIER_DESTROY(3P)POSIX Programmer's ManualPTHREAD_BARRIER_DESTROY(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 pthread_barrier_destroy, pthread_barrier_init — destroy and initialize
14 a barrier object
15
17 #include <pthread.h>
18 int pthread_barrier_destroy(pthread_barrier_t *barrier);
20 int pthread_barrier_init(pthread_barrier_t *restrict barrier,
21 const pthread_barrierattr_t *restrict attr, unsigned count);
22
24 The pthread_barrier_destroy() function shall destroy the barrier refer‐
25 enced by barrier and release any resources used by the barrier. The
26 effect of subsequent use of the barrier is undefined until the barrier
27 is reinitialized by another call to pthread_barrier_init(). An imple‐
28 mentation may use this function to set barrier to an invalid value. The
29 results are undefined if pthread_barrier_destroy() is called when any
30 thread is blocked on the barrier, or if this function is called with an
31 uninitialized barrier.
32 The pthread_barrier_init() function shall allocate any resources
34 required to use the barrier referenced by barrier and shall initialize
35 the barrier with attributes referenced by attr. If attr is NULL, the
36 default barrier attributes shall be used; the effect is the same as
37 passing the address of a default barrier attributes object. The results
38 are undefined if pthread_barrier_init() is called when any thread is
39 blocked on the barrier (that is, has not returned from the pthread_bar‐
40 rier_wait() call). The results are undefined if a barrier is used with‐
41 out first being initialized. The results are undefined if pthread_bar‐
42 rier_init() is called specifying an already initialized barrier.
43 The count argument specifies the number of threads that must call
45 pthread_barrier_wait() before any of them successfully return from the
46 call. The value specified by count must be greater than zero.
47 If the pthread_barrier_init() function fails, the barrier shall not be
49 initialized and the contents of barrier are undefined.
50 Only the object referenced by barrier may be used for performing syn‐
52 chronization. The result of referring to copies of that object in calls
53 to pthread_barrier_destroy() or pthread_barrier_wait() is undefined.
54
56 Upon successful completion, these functions shall return zero; other‐
57 wise, an error number shall be returned to indicate the error.
58
60 The pthread_barrier_init() function shall fail if:
61 EAGAIN The system lacks the necessary resources to initialize another
63 barrier.
64 EINVAL The value specified by count is equal to zero.
66 ENOMEM Insufficient memory exists to initialize the barrier.
68 These functions shall not return an error code of [EINTR].
70 The following sections are informative.
72
74 None.
75
77 None.
78
80 If an implementation detects that the value specified by the barrier
81 argument to pthread_barrier_destroy() does not refer to an initialized
82 barrier object, it is recommended that the function should fail and
83 report an [EINVAL] error.
84 If an implementation detects that the value specified by the attr argu‐
86 ment to pthread_barrier_init() does not refer to an initialized barrier
87 attributes object, it is recommended that the function should fail and
88 report an [EINVAL] error.
89 If an implementation detects that the value specified by the barrier
91 argument to pthread_barrier_destroy() or pthread_barrier_init() refers
92 to a barrier that is in use (for example, in a pthread_barrier_wait()
93 call) by another thread, or detects that the value specified by the
94 barrier argument to pthread_barrier_init() refers to an already ini‐
95 tialized barrier object, it is recommended that the function should
96 fail and report an [EBUSY] error.
97
99 None.
100
102 pthread_barrier_wait()
103 The Base Definitions volume of POSIX.1‐2008, <pthread.h>
105
107 Portions of this text are reprinted and reproduced in electronic form
108 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
109 -- Portable Operating System Interface (POSIX), The Open Group Base
110 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
111 cal and Electronics Engineers, Inc and The Open Group. (This is
112 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
113 event of any discrepancy between this version and the original IEEE and
114 The Open Group Standard, the original IEEE and The Open Group Standard
115 is the referee document. The original Standard can be obtained online
116 at http://www.unix.org/online.html .
117 Any typographical or formatting errors that appear in this page are
119 most likely to have been introduced during the conversion of the source
120 files to man page format. To report such errors, see https://www.ker‐
121 nel.org/doc/man-pages/reporting_bugs.html .
122IEEE/The Open Group 2013 PTHREAD_BARRIER_DESTROY(3P)