mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
140 lines
3.5 KiB
Groff
140 lines
3.5 KiB
Groff
.\" Copyright (c) 2004 Michael Telahun Makonnen
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd January 22, 2004
|
|
.Dt PTHREAD_SPIN_LOCK 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm pthread_spin_lock , pthread_spin_trylock , pthread_spin_unlock
|
|
.Nd "lock or unlock a spin lock"
|
|
.Sh LIBRARY
|
|
.Lb libpthread
|
|
.Lb libthr
|
|
.Sh SYNOPSIS
|
|
.In pthread.h
|
|
.Ft int
|
|
.Fn pthread_spin_lock "pthread_spinlock_t *lock"
|
|
.Ft int
|
|
.Fn pthread_spin_trylock "pthread_spinlock_t *lock"
|
|
.Ft int
|
|
.Fn pthread_spin_unlock "pthread_spinlock_t *lock"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn pthread_spin_lock
|
|
function will acquire
|
|
.Fa lock
|
|
if it is not currently owned by another thread.
|
|
If the lock cannot be acquired immediately, it will
|
|
spin attempting to acquire the lock (it will not sleep) until
|
|
it becomes available.
|
|
.Pp
|
|
The
|
|
.Fn pthread_spin_trylock
|
|
function is the same as
|
|
.Fn pthread_spin_lock
|
|
except that if it cannot acquire
|
|
.Fa lock
|
|
immediately it will return with an error.
|
|
.Pp
|
|
The
|
|
.Fn pthread_spin_unlock
|
|
function will release
|
|
.Fa lock ,
|
|
which must have been previously locked by a call to
|
|
.Fn pthread_spin_lock
|
|
or
|
|
.Fn pthread_spin_trylock .
|
|
.Sh RETURN VALUES
|
|
If successful, all these functions will return zero.
|
|
Otherwise, an error number will be returned to indicate the error.
|
|
.Pp
|
|
None of these functions will return
|
|
.Er EINTR .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn pthread_spin_lock ,
|
|
.Fn pthread_spin_trylock
|
|
and
|
|
.Fn pthread_spin_unlock
|
|
functions will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The value specified by
|
|
.Fa lock
|
|
is invalid or is not initialized.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn pthread_spin_lock
|
|
function may fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EDEADLK
|
|
The calling thread already owns the lock.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn pthread_spin_trylock
|
|
function will fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EBUSY
|
|
Another thread currently holds
|
|
.Fa lock .
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn pthread_spin_unlock
|
|
function may fail if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EPERM
|
|
The calling thread does not own
|
|
.Fa lock .
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr pthread_spin_destroy 3 ,
|
|
.Xr pthread_spin_init 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn pthread_spin_lock ,
|
|
.Fn pthread_spin_trylock
|
|
and
|
|
.Fn pthread_spin_unlock
|
|
functions first appeared in
|
|
.Lb libpthread
|
|
in
|
|
.Fx 5.2 ,
|
|
and in
|
|
.Lb libthr
|
|
in
|
|
.Fx 5.3 .
|
|
.Sh BUGS
|
|
The implementation of
|
|
.Fn pthread_spin_lock ,
|
|
.Fn pthread_spin_trylock
|
|
and
|
|
.Fn pthread_spin_unlock
|
|
is expected to conform to
|
|
.St -p1003.2 .
|