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_TRYLOCK 3 32.Os 33.Sh NAME 34.Nm pthread_mutex_trylock 35.Nd attempt to lock a mutex without blocking 36.Sh LIBRARY 37.Lb libpthread 38.Sh SYNOPSIS 39.In pthread.h 40.Ft int 41.Fn pthread_mutex_trylock "pthread_mutex_t *mutex" 42.Sh DESCRIPTION 43The 44.Fn pthread_mutex_trylock 45function locks 46.Fa mutex . 47If the mutex is already locked, 48.Fn pthread_mutex_trylock 49will not block waiting for the mutex, but will return an error condition. 50.Sh RETURN VALUES 51If successful, 52.Fn pthread_mutex_trylock 53will return zero, otherwise an error number will be returned to 54indicate the error. 55.Sh ERRORS 56The 57.Fn pthread_mutex_trylock 58function will fail if: 59.Bl -tag -width "Er ENOTRECOVERABLE" 60.It Bq Er EINVAL 61The value specified by 62.Fa mutex 63is invalid. 64.It Bq Er EBUSY 65.Fa Mutex 66is already locked. 67.It Bq Er EOWNERDEAD 68The argument 69.Fa mutex 70points to a robust mutex and the process containing the previous owning 71thread terminated while holding the mutex lock. 72The lock was granted to the caller and it is up to the new owner 73to make the state consistent. 74.It Bq Er ENOTRECOVERABLE 75The state protected by the 76.Fa mutex 77is not recoverable. 78.El 79.Sh SEE ALSO 80.Xr pthread_mutex_consistent 3 , 81.Xr pthread_mutex_destroy 3 , 82.Xr pthread_mutex_init 3 , 83.Xr pthread_mutex_lock 3 , 84.Xr pthread_mutex_unlock 3 85.Sh STANDARDS 86The 87.Fn pthread_mutex_trylock 88function conforms to 89.St -p1003.1-96 . 90