pthread_barrier_destroy.3p (5118B)
- '\" et
- .TH PTHREAD_BARRIER_DESTROY "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
- .\"
- .SH PROLOG
- This manual page is part of the POSIX Programmer's Manual.
- The Linux implementation of this interface may differ (consult
- the corresponding Linux manual page for details of Linux behavior),
- or the interface may not be implemented on Linux.
- .\"
- .SH NAME
- pthread_barrier_destroy,
- pthread_barrier_init
- \(em destroy and initialize a barrier object
- .SH SYNOPSIS
- .LP
- .nf
- #include <pthread.h>
- .P
- int pthread_barrier_destroy(pthread_barrier_t *\fIbarrier\fP);
- int pthread_barrier_init(pthread_barrier_t *restrict \fIbarrier\fP,
- const pthread_barrierattr_t *restrict \fIattr\fP, unsigned \fIcount\fP);
- .fi
- .SH DESCRIPTION
- The
- \fIpthread_barrier_destroy\fR()
- function shall destroy the barrier referenced by
- .IR barrier
- and release any resources used by the barrier. The effect of
- subsequent use of the barrier is undefined until the barrier is
- reinitialized by another call to
- \fIpthread_barrier_init\fR().
- An implementation may use this function to set
- .IR barrier
- to an invalid value. The results are undefined if
- \fIpthread_barrier_destroy\fR()
- is called when any thread is blocked on the barrier, or if this
- function is called with an uninitialized barrier.
- .P
- The
- \fIpthread_barrier_init\fR()
- function shall allocate any resources required to use the barrier
- referenced by
- .IR barrier
- and shall initialize the barrier with attributes referenced by
- .IR attr .
- If
- .IR attr
- is NULL, the default barrier attributes shall be used; the effect is
- the same as passing the address of a default barrier attributes
- object. The results are undefined if
- \fIpthread_barrier_init\fR()
- is called when any thread is blocked on the barrier (that is, has not
- returned from the
- \fIpthread_barrier_wait\fR()
- call). The results are undefined if a barrier is used without first
- being initialized. The results are undefined if
- \fIpthread_barrier_init\fR()
- is called specifying an already initialized barrier.
- .P
- The
- .IR count
- argument specifies the number of threads that must call
- \fIpthread_barrier_wait\fR()
- before any of them successfully return from the call. The value
- specified by
- .IR count
- must be greater than zero.
- .P
- If the
- \fIpthread_barrier_init\fR()
- function fails, the barrier shall not be initialized and the contents
- of
- .IR barrier
- are undefined.
- .P
- See
- .IR "Section 2.9.9" ", " "Synchronization Object Copies and Alternative Mappings"
- for further requirements.
- .SH "RETURN VALUE"
- Upon successful completion, these functions shall return zero;
- otherwise, an error number shall be returned to indicate the error.
- .SH ERRORS
- The
- \fIpthread_barrier_init\fR()
- function shall fail if:
- .TP
- .BR EAGAIN
- The system lacks the necessary resources to initialize another barrier.
- .TP
- .BR EINVAL
- The value specified by
- .IR count
- is equal to zero.
- .TP
- .BR ENOMEM
- Insufficient memory exists to initialize the barrier.
- .P
- These functions shall not return an error code of
- .BR [EINTR] .
- .LP
- .IR "The following sections are informative."
- .SH EXAMPLES
- None.
- .SH "APPLICATION USAGE"
- None.
- .SH RATIONALE
- If an implementation detects that the value specified by the
- .IR barrier
- argument to
- \fIpthread_barrier_destroy\fR()
- does not refer to an initialized barrier object, it is recommended that
- the function should fail and report an
- .BR [EINVAL]
- error.
- .P
- If an implementation detects that the value specified by the
- .IR attr
- argument to
- \fIpthread_barrier_init\fR()
- does not refer to an initialized barrier attributes object, it is
- recommended that the function should fail and report an
- .BR [EINVAL]
- error.
- .P
- If an implementation detects that the value specified by the
- .IR barrier
- argument to
- \fIpthread_barrier_destroy\fR()
- or
- \fIpthread_barrier_init\fR()
- refers to a barrier that is in use (for example, in a
- \fIpthread_barrier_wait\fR()
- call) by another thread, or detects that the value specified by the
- .IR barrier
- argument to
- \fIpthread_barrier_init\fR()
- refers to an already initialized barrier object, it is recommended
- that the function should fail and report an
- .BR [EBUSY]
- error.
- .SH "FUTURE DIRECTIONS"
- None.
- .SH "SEE ALSO"
- .IR "\fIpthread_barrier_wait\fR\^(\|)"
- .P
- The Base Definitions volume of POSIX.1\(hy2017,
- .IR "\fB<pthread.h>\fP"
- .\"
- .SH COPYRIGHT
- Portions of this text are reprinted and reproduced in electronic form
- from IEEE Std 1003.1-2017, Standard for Information Technology
- -- Portable Operating System Interface (POSIX), The Open Group Base
- Specifications Issue 7, 2018 Edition,
- Copyright (C) 2018 by the Institute of
- Electrical and Electronics Engineers, Inc and The Open Group.
- In the event of any discrepancy between this version and the original IEEE and
- The Open Group Standard, the original IEEE and The Open Group Standard
- is the referee document. The original Standard can be obtained online at
- http://www.opengroup.org/unix/online.html .
- .PP
- Any typographical or formatting errors that appear
- in this page are most likely
- to have been introduced during the conversion of the source files to
- man page format. To report such errors, see
- https://www.kernel.org/doc/man-pages/reporting_bugs.html .