.\" Copyright (c) 1998 Alex Nash .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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. .\" .\" $Id: pthread_rwlock_init.3,v 1.2 1999/04/21 20:36:40 alex Exp $ .\" $OpenBSD: pthread_rwlock_init.3,v 1.2 1999/04/21 20:36:40 alex Exp $ .\" .Dd August 4, 1998 .Dt PTHREAD_RWLOCK_INIT 3 .Os .Sh NAME .Nm pthread_rwlock_init .Nd initialize a read/write lock .Sh SYNOPSIS .Fd #include <pthread.h> .Ft int .Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr" .Sh DESCRIPTION The .Fn pthread_rwlock_init function is used to initialize a read/write lock, with attributes specified by .Fa attr . If .Fa attr is NULL, the default read/write lock attributes are used. .Pp The results of calling .Fn pthread_rwlock_init with an already initialized lock are undefined. .Sh RETURN VALUES If successful, the .Fn pthread_rwlock_init function will return zero. Otherwise an error number will be returned to indicate the error. .Sh SEE ALSO .Xr pthread_rwlock_destroy 3 , .Xr pthread_rwlockattr_init 3 , .Xr pthread_rwlockattr_setpshared 3 .Sh STANDARDS The .Fn pthread_rwlock_init function is expected to conform to .St -susv2 . .Sh ERRORS The .Fn pthread_rwlock_init function will fail if: .Bl -tag -width Er .It Bq Er EAGAIN The system lacked the necessary resources (other than memory) to initialize the lock. .It Bq Er ENOMEM Insufficient memory exists to initialize the lock. .It Bq Er EPERM The caller does not have sufficient privilege to perform the operation. .El .Pp The .Fn pthread_rwlock_init function may fail if: .Bl -tag -width Er .It Bq Er EBUSY The system has detected an attempt to re-initialize the object referenced by .Fa lock , a previously initialized but not yet destroyed read/write lock. .It Bq Er EINVAL The value specified by .Fa attr is invalid. .El .Sh HISTORY The .Fn pthread_rwlock_init function first appeared in .Ox 2.5 . .Sh BUGS The PTHREAD_PROCESS_SHARED attribute is not supported.