139 lines
3.5 KiB
Groff
139 lines
3.5 KiB
Groff
.\" Copyright (c) 2004 Michael Telahun Makonnen
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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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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 January 22, 2004
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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 , pthread_spin_trylock , pthread_spin_unlock
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.Nd "lock or unlock 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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.Ft int
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.Fn pthread_spin_unlock "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 will acquire
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.Fa lock
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if it is not currently owned by another thread.
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If the lock cannot be acquired immediately, it will
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spin attempting to acquire the lock (it will not sleep) until
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it becomes available.
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.Pp
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The
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.Fn pthread_spin_trylock
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function is the same as
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.Fn pthread_spin_lock
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except that if it cannot acquire
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.Fa lock
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immediately it will return with an error.
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.Pp
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The
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.Fn pthread_spin_unlock
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function will release
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.Fa lock ,
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which must have been previously locked by a call to
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.Fn pthread_spin_lock
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or
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.Fn pthread_spin_trylock .
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.Sh RETURN VALUES
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If successful, all these functions will return zero.
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Otherwise, an error number will be returned to indicate the error.
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.Pp
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None of these functions will return
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.Er EINTR .
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.Sh ERRORS
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The
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.Fn pthread_spin_lock ,
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.Fn pthread_spin_trylock
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and
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.Fn pthread_spin_unlock
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functions 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 lock
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is invalid or is not initialized.
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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 calling thread already owns the lock.
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.El
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.Pp
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The
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.Fn pthread_spin_trylock
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function will fail if:
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.Bl -tag -width Er
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.It Bq Er EBUSY
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Another thread currently holds
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.Fa lock .
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.El
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.Pp
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The
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.Fn pthread_spin_unlock
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function may fail if:
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.Bl -tag -width Er
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.It Bq Er EPERM
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The calling thread does not own
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.Fa lock .
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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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.Xr pthread_spin_init 3
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.Sh HISTORY
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The
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.Fn pthread_spin_lock ,
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.Fn pthread_spin_trylock
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and
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.Fn pthread_spin_unlock
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functions first appeared in
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.Lb libkse
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in
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.Fx 5.2 ,
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and in
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.Lb libthr
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in
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.Fx 5.3 .
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.Sh BUGS
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The implementation of
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.Fn pthread_spin_lock ,
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.Fn pthread_spin_trylock
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and
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.Fn pthread_spin_unlock
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is expected to conform to
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.St -p1003.2 .
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