2003-07-04 14:19:42 +04:00
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.\" $NetBSD: pthread_spin_lock.3,v 1.4 2003/07/04 10:19:42 wiz Exp $
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2003-06-04 01:31:36 +04:00
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.\"
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.\" Copyright (c) 2002 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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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 NetBSD Foundation nor the names of its
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.\" contributors may be used to endorse or promote products derived
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.\" from this software without specific prior written permission.
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.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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.\" POSSIBILITY OF SUCH DAMAGE.
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.\"
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.Dd January 30, 2003
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.Dt PTHREAD_SPIN_LOCK 3
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.Os
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.Sh NAME
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.Nm pthread_spin_lock ,
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.Nm pthread_spin_trylock
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.Nd acquire a spin lock
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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_spin_lock "pthread_spinlock_t *lock"
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.Ft int
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.Fn pthread_spin_trylock "pthread_spinlock_t *lock"
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.Sh DESCRIPTION
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The
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.Fn pthread_spin_lock
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function acquires a spin lock on
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.Fa lock
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provided that
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.Fa lock
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2003-07-04 14:19:42 +04:00
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is not presently held.
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If the lock cannot be
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2003-06-04 01:31:36 +04:00
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immediately acquired, the calling thread repeatedly retries until it can
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acquire the lock.
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.Pp
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The
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.Fn pthread_spin_trylock
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function performs the same action, but does not block if the lock
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cannot be immediately obtained (i.e., the lock is held).
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.Sh RETURN VALUES
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If successful, the
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.Fn pthread_spin_lock
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and
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.Fn pthread_spin_trylock
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functions will return zero. Otherwise an error number will be returned
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to indicate the error.
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.Sh ERRORS
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The
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.Fn pthread_spin_trylock
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function shall fail if:
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.Bl -tag -width Er
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.It Bq Er EBUSY
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The lock could not be acquired because a writer holds the lock or
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was blocked on it.
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.El
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.Pp
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The
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.Fn pthread_spin_lock
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function may fail if:
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.Bl -tag -width Er
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.It Bq Er EDEADLK
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The current thread already owns
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.Fa lock
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for writing.
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.El
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.Pp
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The
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.Fn pthread_spin_lock
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and
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.Fn pthread_spin_trylock
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functions may 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 lock
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is invalid.
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.El
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.Sh SEE ALSO
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.Xr pthread_spin_destroy 3 ,
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2003-07-04 12:41:25 +04:00
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.Xr pthread_spin_init 3 ,
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.Xr pthread_spin_unlock 3
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.Sh STANDARDS
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.Fn pthread_spin_lock
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and
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.Fn pthread_spin_trylock
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conform to
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.St -p1003.1-2001 .
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