102 lines
3.2 KiB
Groff
102 lines
3.2 KiB
Groff
.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the author nor the names of any co-contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd August 7, 2019
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.Dt PTHREAD_COND_WAIT 3
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.Os
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.Sh NAME
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.Nm pthread_cond_wait
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.Nd wait on a condition variable
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.Sh LIBRARY
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.Lb libpthread
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.Sh SYNOPSIS
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.In pthread.h
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.Ft int
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.Fn pthread_cond_wait "pthread_cond_t *restrict cond" "pthread_mutex_t *restrict mutex"
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.Sh DESCRIPTION
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The
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.Fn pthread_cond_wait
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function atomically blocks the current thread waiting on the condition
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variable specified by
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.Fa cond ,
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and releases the mutex specified by
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.Fa mutex .
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The waiting thread unblocks only after another thread calls
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.Xr pthread_cond_signal 3 ,
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or
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.Xr pthread_cond_broadcast 3
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with the same condition variable, and the current thread reacquires the lock
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on
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.Fa mutex .
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.Sh RETURN VALUES
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If successful, the
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.Fn pthread_cond_wait
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function will return zero.
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Otherwise an error number will be returned to
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indicate the error.
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.Sh ERRORS
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The
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.Fn pthread_cond_wait
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function will fail if:
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.Bl -tag -width Er
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.It Bq Er EINVAL
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The value specified by
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.Fa cond
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or the value specified by
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.Fa mutex
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is invalid.
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.It Bq Er EPERM
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The specified
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.Fa mutex
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was not locked by the calling thread.
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.It Bq Er EOWNERDEAD
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The argument
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.Fa mutex
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points to a robust mutex and the process containing the previous owning
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thread terminated while holding the mutex lock.
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The lock was granted to the caller and it is up to the new owner
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to make the state consistent.
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.It Bq Er ENOTRECOVERABLE
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The state protected by the
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.Fa mutex
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is not recoverable.
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.El
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.Sh SEE ALSO
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.Xr pthread_cond_broadcast 3 ,
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.Xr pthread_cond_destroy 3 ,
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.Xr pthread_cond_init 3 ,
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.Xr pthread_cond_signal 3 ,
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.Xr pthread_cond_timedwait 3 ,
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.Xr pthread_mutex_consistent 3
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.Sh STANDARDS
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The
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.Fn pthread_cond_wait
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function conforms to
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.St -p1003.1-96 .
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