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.\" $FreeBSD$ 29.\" 30.Dd August 7, 2019 31.Dt PTHREAD_MUTEX_LOCK 3 32.Os 33.Sh NAME 34.Nm pthread_mutex_lock 35.Nd lock a mutex 36.Sh LIBRARY 37.Lb libpthread 38.Sh SYNOPSIS 39.In pthread.h 40.Ft int 41.Fn pthread_mutex_lock "pthread_mutex_t *mutex" 42.Sh DESCRIPTION 43The 44.Fn pthread_mutex_lock 45function locks 46.Fa mutex . 47If the mutex is already locked, the calling thread will block until the 48mutex becomes available. 49.Sh RETURN VALUES 50If successful, 51.Fn pthread_mutex_lock 52will return zero, otherwise an error number will be returned to 53indicate the error. 54.Sh ERRORS 55The 56.Fn pthread_mutex_lock 57function will fail if: 58.Bl -tag -width "Er ENOTRECOVERABLE" 59.It Bq Er EINVAL 60The value specified by 61.Fa mutex 62is invalid. 63.It Bq Er EDEADLK 64A deadlock would occur if the thread blocked waiting for 65.Fa mutex . 66.It Bq Er EOWNERDEAD 67The argument 68.Fa mutex 69points to a robust mutex and the process containing the previous owning 70thread terminated while holding the mutex lock. 71The lock was granted to the caller and it is up to the new owner 72to make the state consistent. 73.It Bq Er ENOTRECOVERABLE 74The state protected by the 75.Fa mutex 76is not recoverable. 77.El 78.Sh SEE ALSO 79.Xr pthread_mutex_consistent 3 , 80.Xr pthread_mutex_destroy 3 , 81.Xr pthread_mutex_init 3 , 82.Xr pthread_mutex_trylock 3 , 83.Xr pthread_mutex_unlock 3 84.Sh STANDARDS 85The 86.Fn pthread_mutex_lock 87function conforms to 88.St -p1003.1-96 . 89