freebsd-skq/lib/libthr/thread/thr_rwlockattr.c
kib e76eb4255b Implement process-shared locks support for libthr.so.3, without
breaking the ABI.  Special value is stored in the lock pointer to
indicate shared lock, and offline page in the shared memory is
allocated to store the actual lock.

Reviewed by:	vangyzen (previous version)
Discussed with:	deischen, emaste, jhb, rwatson,
	Martin Simmons <martin@lispworks.com>
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-02-28 17:52:33 +00:00

92 lines
2.7 KiB
C

/*-
* 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.
*
* $FreeBSD$
*/
#include "namespace.h"
#include <errno.h>
#include <stdlib.h>
#include <pthread.h>
#include "un-namespace.h"
#include "thr_private.h"
__weak_reference(_pthread_rwlockattr_destroy, pthread_rwlockattr_destroy);
__weak_reference(_pthread_rwlockattr_getpshared, pthread_rwlockattr_getpshared);
__weak_reference(_pthread_rwlockattr_init, pthread_rwlockattr_init);
__weak_reference(_pthread_rwlockattr_setpshared, pthread_rwlockattr_setpshared);
int
_pthread_rwlockattr_destroy(pthread_rwlockattr_t *rwlockattr)
{
pthread_rwlockattr_t prwlockattr;
if (rwlockattr == NULL)
return (EINVAL);
prwlockattr = *rwlockattr;
if (prwlockattr == NULL)
return (EINVAL);
free(prwlockattr);
return (0);
}
int
_pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *rwlockattr,
int *pshared)
{
*pshared = (*rwlockattr)->pshared;
return (0);
}
int
_pthread_rwlockattr_init(pthread_rwlockattr_t *rwlockattr)
{
pthread_rwlockattr_t prwlockattr;
if (rwlockattr == NULL)
return (EINVAL);
prwlockattr = malloc(sizeof(struct pthread_rwlockattr));
if (prwlockattr == NULL)
return (ENOMEM);
prwlockattr->pshared = PTHREAD_PROCESS_PRIVATE;
*rwlockattr = prwlockattr;
return (0);
}
int
_pthread_rwlockattr_setpshared(pthread_rwlockattr_t *rwlockattr, int pshared)
{
if (pshared != PTHREAD_PROCESS_PRIVATE &&
pshared != PTHREAD_PROCESS_SHARED)
return (EINVAL);
(*rwlockattr)->pshared = pshared;
return (0);
}