[apple/libpthread.git] / man / 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.
.\"
.\" $FreeBSD$
.\"
.Dd January 31, 2006
.Dt PTHREAD_MUTEX_LOCK 3
.Os
.Sh NAME
.Nm pthread_mutex_lock
.Nd lock a mutex
.Sh SYNOPSIS
.In pthread.h
.Ft int
.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
.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
The
.Fn pthread_mutex_lock
function will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The value specified by
.Fa mutex
is invalid.
.It Bq Er EDEADLK
A deadlock would occur if the thread blocked waiting for
.Fa mutex .
.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
The
.Fn pthread_mutex_lock
function conforms to
.St -p1003.1-96 .
Commit	Line	Data
f1a1da6c 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	.\"
2546420a	28	.\" $FreeBSD$
f1a1da6c	29	.\"
2546420a	30	.Dd January 31, 2006
f1a1da6c A	31	.Dt PTHREAD_MUTEX_LOCK 3
	32	.Os
	33	.Sh NAME
	34	.Nm pthread_mutex_lock
	35	.Nd lock a mutex
	36	.Sh SYNOPSIS
2546420a	37	.In pthread.h
f1a1da6c	38	.Ft int
2546420a	39	.Fn pthread_mutex_lock "pthread_mutex_t *mutex"
f1a1da6c A	40	.Sh DESCRIPTION
	41	The
	42	.Fn pthread_mutex_lock
	43	function locks
	44	.Fa mutex .
	45	If the mutex is already locked, the calling thread will block until the
	46	mutex becomes available.
	47	.Sh RETURN VALUES
	48	If successful,
	49	.Fn pthread_mutex_lock
2546420a A	50	will return zero, otherwise an error number will be returned to
2546420a A	51	indicate the error.
f1a1da6c	52	.Sh ERRORS
2546420a	53	The
f1a1da6c	54	.Fn pthread_mutex_lock
2546420a	55	function will fail if:
f1a1da6c	56	.Bl -tag -width Er
f1a1da6c A	57	.It Bq Er EINVAL
	58	The value specified by
	59	.Fa mutex
	60	is invalid.
2546420a A	61	.It Bq Er EDEADLK
	62	A deadlock would occur if the thread blocked waiting for
	63	.Fa mutex .
f1a1da6c A	64	.El
	65	.Sh SEE ALSO
	66	.Xr pthread_mutex_destroy 3 ,
	67	.Xr pthread_mutex_init 3 ,
	68	.Xr pthread_mutex_trylock 3 ,
	69	.Xr pthread_mutex_unlock 3
	70	.Sh STANDARDS
2546420a	71	The
f1a1da6c	72	.Fn pthread_mutex_lock
2546420a	73	function conforms to
f1a1da6c	74	.St -p1003.1-96 .