[apple/libc.git] / pthreads / pthread_mutex_lock.3

.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
.\" 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.
.\" 3. Neither the name of the author nor the names of any co-contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL 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 REGENTS 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: src/lib/libc_r/man/pthread_mutex_lock.3,v 1.5.2.4 2001/08/17 15:42:51 ru Exp $
.\"
.Dd July 30, 1998
.Dt PTHREAD_MUTEX_LOCK 3
.Os
.Sh NAME
.Nm pthread_mutex_lock
.Nd lock a mutex
.Sh SYNOPSIS
.Fd #include <pthread.h>
.Ft int
.Fo pthread_mutex_lock
.Fa "pthread_mutex_t *mutex"
.Fc
.Sh DESCRIPTION
The
.Fn pthread_mutex_lock
function locks
.Fa mutex .
If the mutex is already locked, the calling thread will block until the
mutex becomes available.
.Sh RETURN VALUES
If successful,
.Fn pthread_mutex_lock
will return zero.
Otherwise, an error number will be returned to indicate the error.
.Sh ERRORS
.Fn pthread_mutex_lock
will fail if:
.Bl -tag -width Er
.It Bq Er EDEADLK
A deadlock would occur if the thread blocked waiting for
.Fa mutex .
.It Bq Er EINVAL
The value specified by
.Fa mutex
is invalid.
.El
.Sh SEE ALSO
.Xr pthread_mutex_destroy 3 ,
.Xr pthread_mutex_init 3 ,
.Xr pthread_mutex_trylock 3 ,
.Xr pthread_mutex_unlock 3
.Sh STANDARDS
.Fn pthread_mutex_lock
conforms to
.St -p1003.1-96 .
Commit	Line	Data
5b2abdfb A	1	.\" Copyright (c) 1997 Brian Cully <shmit@kublai.com>
	2	.\" All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. Neither the name of the author nor the names of any co-contributors
	13	.\" may be used to endorse or promote products derived from this software
	14	.\" without specific prior written permission.
	15	.\"
	16	.\" THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
	17	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	18	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	19	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	20	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	21	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	22	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	23	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	24	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	25	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	26	.\" SUCH DAMAGE.
	27	.\"
	28	.\" $FreeBSD: src/lib/libc_r/man/pthread_mutex_lock.3,v 1.5.2.4 2001/08/17 15:42:51 ru Exp $
	29	.\"
	30	.Dd July 30, 1998
	31	.Dt PTHREAD_MUTEX_LOCK 3
	32	.Os
	33	.Sh NAME
	34	.Nm pthread_mutex_lock
	35	.Nd lock a mutex
	36	.Sh SYNOPSIS
	37	.Fd #include <pthread.h>
	38	.Ft int
224c7076 A	39	.Fo pthread_mutex_lock
	40	.Fa "pthread_mutex_t *mutex"
	41	.Fc
5b2abdfb A	42	.Sh DESCRIPTION
	43	The
	44	.Fn pthread_mutex_lock
	45	function locks
	46	.Fa mutex .
	47	If the mutex is already locked, the calling thread will block until the
	48	mutex becomes available.
	49	.Sh RETURN VALUES
	50	If successful,
	51	.Fn pthread_mutex_lock
224c7076 A	52	will return zero.
224c7076 A	53	Otherwise, an error number will be returned to indicate the error.
5b2abdfb A	54	.Sh ERRORS
	55	.Fn pthread_mutex_lock
	56	will fail if:
	57	.Bl -tag -width Er
224c7076 A	58	.It Bq Er EDEADLK
	59	A deadlock would occur if the thread blocked waiting for
	60	.Fa mutex .
5b2abdfb A	61	.It Bq Er EINVAL
	62	The value specified by
	63	.Fa mutex
	64	is invalid.
5b2abdfb A	65	.El
	66	.Sh SEE ALSO
	67	.Xr pthread_mutex_destroy 3 ,
	68	.Xr pthread_mutex_init 3 ,
	69	.Xr pthread_mutex_trylock 3 ,
	70	.Xr pthread_mutex_unlock 3
	71	.Sh STANDARDS
	72	.Fn pthread_mutex_lock
	73	conforms to
	74	.St -p1003.1-96 .