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.Dd August 7, 2019 29.Dt PTHREAD_MUTEX_TRYLOCK 3 30.Os 31.Sh NAME 32.Nm pthread_mutex_trylock 33.Nd attempt to lock a mutex without blocking 34.Sh LIBRARY 35.Lb libpthread 36.Sh SYNOPSIS 37.In pthread.h 38.Ft int 39.Fn pthread_mutex_trylock "pthread_mutex_t *mutex" 40.Sh DESCRIPTION 41The 42.Fn pthread_mutex_trylock 43function locks 44.Fa mutex . 45If the mutex is already locked, 46.Fn pthread_mutex_trylock 47will not block waiting for the mutex, but will return an error condition. 48.Sh RETURN VALUES 49If successful, 50.Fn pthread_mutex_trylock 51will return zero, otherwise an error number will be returned to 52indicate the error. 53.Sh ERRORS 54The 55.Fn pthread_mutex_trylock 56function will fail if: 57.Bl -tag -width "Er ENOTRECOVERABLE" 58.It Bq Er EINVAL 59The value specified by 60.Fa mutex 61is invalid. 62.It Bq Er EBUSY 63.Fa Mutex 64is already locked. 65.It Bq Er EOWNERDEAD 66The argument 67.Fa mutex 68points to a robust mutex and the process containing the previous owning 69thread terminated while holding the mutex lock. 70The lock was granted to the caller and it is up to the new owner 71to make the state consistent. 72.It Bq Er ENOTRECOVERABLE 73The state protected by the 74.Fa mutex 75is not recoverable. 76.El 77.Sh SEE ALSO 78.Xr pthread_mutex_consistent 3 , 79.Xr pthread_mutex_destroy 3 , 80.Xr pthread_mutex_init 3 , 81.Xr pthread_mutex_lock 3 , 82.Xr pthread_mutex_unlock 3 83.Sh STANDARDS 84The 85.Fn pthread_mutex_trylock 86function conforms to 87.St -p1003.1-96 . 88