1.\" $OpenBSD: pthread_rwlock_init.3,v 1.4 2000/04/12 21:48:02 aaron Exp $ 2.\" Copyright (c) 1998 Alex Nash 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD: pthread_rwlock_init.3,v 1.2 1999/08/28 00:03:09 peter Exp $ 27.\" 28.Dd August 4, 1998 29.Dt PTHREAD_RWLOCK_INIT 3 30.Os 31.Sh NAME 32.Nm pthread_rwlock_init 33.Nd initialize a read/write lock 34.Sh SYNOPSIS 35.Fd #include <pthread.h> 36.Ft int 37.Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr" 38.Sh DESCRIPTION 39The 40.Fn pthread_rwlock_init 41function is used to initialize a read/write lock, with attributes 42specified by 43.Fa attr . 44If 45.Fa attr 46is NULL, the default read/write lock attributes are used. 47.Pp 48The results of calling 49.Fn pthread_rwlock_init 50with an already initialized lock are undefined. 51.Sh RETURN VALUES 52If successful, the 53.Fn pthread_rwlock_init 54function will return zero. Otherwise an error number will be returned 55to indicate the error. 56.Sh SEE ALSO 57.Xr pthread_rwlock_destroy 3 , 58.Xr pthread_rwlockattr_init 3 , 59.Xr pthread_rwlockattr_setpshared 3 60.Sh STANDARDS 61The 62.Fn pthread_rwlock_init 63function is expected to conform to 64.St -susv2 . 65.Sh ERRORS 66The 67.Fn pthread_rwlock_init 68function will fail if: 69.Bl -tag -width Er 70.It Bq Er EAGAIN 71The system lacked the necessary resources (other than memory) to 72initialize the lock. 73.It Bq Er ENOMEM 74Insufficient memory exists to initialize the lock. 75.It Bq Er EPERM 76The caller does not have sufficient privilege to perform the 77operation. 78.El 79.Pp 80The 81.Fn pthread_rwlock_init 82function may fail if: 83.Bl -tag -width Er 84.It Bq Er EBUSY 85The system has detected an attempt to re-initialize the object 86referenced by 87.Fa lock , 88a previously initialized but not yet destroyed read/write lock. 89.It Bq Er EINVAL 90The value specified by 91.Fa attr 92is invalid. 93.El 94.Sh HISTORY 95The 96.Fn pthread_rwlock_init 97function first appeared in 98.Fx 3.0 99and 100.Ox 2.5 . 101.Sh BUGS 102The PTHREAD_PROCESS_SHARED attribute is not supported. 103