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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2001 by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#ifndef _NISDB_RW_H
#define _NISDB_RW_H
#include <pthread.h>
#include <thread.h>
#include <synch.h>
#include <stdlib.h>
#include <malloc.h>
#include <sys/errno.h>
#ifdef __cplusplus
extern "C" {
#endif
#define INV_PTHREAD_ID 0
/*
* DEFAULTNISDBRWLOCK_RW is the default initializer that does _not_
* force read lock requests to write locks, while DEFAULTNISDBRWLOCK_W
* does force all locks to be exclusive.
*
* Locks should be initialized DEFAULTNISDBRWLOCK_W until it's been
* determined that non-exclusive locking can be safely used; see
* comments in __nisdb_rwinit() in nisdb_rw.c.
*/
#define DEFAULTNISDBRWLOCK_RW {DEFAULTMUTEX, DEFAULTCV, 0, 0, \
0, {INV_PTHREAD_ID, 0, 0, 0}, \
0, 0, {INV_PTHREAD_ID, 0, 0, 0}}
#define DEFAULTNISDBRWLOCK_W {DEFAULTMUTEX, DEFAULTCV, 0, 1, \
0, {INV_PTHREAD_ID, 0, 0, 0}, \
0, 0, {INV_PTHREAD_ID, 0, 0, 0}}
#define DEFAULTNISDBRWLOCK DEFAULTNISDBRWLOCK_W
/*
* The value used for the 'force_write' field initialization in
* __nisdb_rwinit(). Should be one unless it's been determined that
* read locks can safely be used in for _all_ locks initialized
* by __nisdb_rwinit().
*/
#define NISDB_FORCE_WRITE 1
#ifdef NISDB_MT_DEBUG
#define DECLMUTEXLOCK(var) pthread_mutex_t var ## _pmutex = \
PTHREAD_MUTEX_INITIALIZER; \
pthread_t var ## _owner = INV_PTHREAD_ID
#define USEMUTEXLOCK(var) extern pthread_mutex_t var ## _pmutex; \
extern pthread_t var ## _owner
#define STRUCTMUTEXLOCK(var) pthread_mutex_t var ## _pmutex; \
pthread_t var ## _owner
#define INITMUTEX(var) (void) pthread_mutex_init(&var ## _pmutex, 0)
#define MUTEXLOCK(var, msg) if (var ## _owner != pthread_self()) { \
pthread_mutex_lock(&var ## _pmutex); \
var ## _owner = pthread_self(); \
} else \
abort();
#define MUTEXUNLOCK(var, msg) if (var ## _owner == pthread_self()) { \
var ## _owner = INV_PTHREAD_ID; \
pthread_mutex_unlock(&var ## _pmutex);\
} else \
abort();
#define ASSERTMUTEXHELD(var) if (var ## _owner != pthread_self()) \
abort();
#define DECLRWLOCK(var) __nisdb_rwlock_t var ## _rwlock = \
DEFAULTNISDBRWLOCK
#define USERWLOCK(var) extern __nisdb_rwlock_t var ## _rwlock
#define STRUCTRWLOCK(var) __nisdb_rwlock_t var ## _rwlock
#define INITRW(var) (void) __nisdb_rwinit(&var ## _rwlock)
#define READLOCKOK(var) (void) __nisdb_rw_readlock_ok(&var ## _rwlock)
#define RLOCK(var) __nisdb_rlock(&var ## _rwlock)
#define WLOCK(var) __nisdb_wlock(&var ## _rwlock)
#define TRYWLOCK(var) __nisdb_wlock_trylock(&var ## _rwlock, 1)
#define RULOCK(var) __nisdb_rulock(&var ## _rwlock)
#define WULOCK(var) __nisdb_wulock(&var ## _rwlock)
#define DESTROYRW(var) __nisdb_destroy_lock(&var ## _rwlock)
#define ASSERTWHELD(var) if (__nisdb_assert_wheld(&var ## _rwlock) \
!= 0) \
abort();
#define ASSERTRHELD(var) if (__nisdb_assert_rheld(&var ## _rwlock) \
!= 0) \
abort();
#else /* NISDB_MT_DEBUG */
#define DECLMUTEXLOCK(var) pthread_mutex_t var ## _pmutex = \
PTHREAD_MUTEX_INITIALIZER
#define USEMUTEXLOCK(var) extern pthread_mutex_t var ## _pmutex
#define STRUCTMUTEXLOCK(var) pthread_mutex_t var ## _pmutex
#define INITMUTEX(var) (void) pthread_mutex_init(&var ## _pmutex, 0)
#define MUTEXLOCK(var, msg) pthread_mutex_lock(&var ## _pmutex)
#define MUTEXUNLOCK(var, msg) pthread_mutex_unlock(&var ## _pmutex)
#define DECLRWLOCK(var) __nisdb_rwlock_t var ## _rwlock = \
DEFAULTNISDBRWLOCK
#define USERWLOCK(var) extern __nisdb_rwlock_t var ## _rwlock
#define STRUCTRWLOCK(var) __nisdb_rwlock_t var ## _rwlock
#define INITRW(var) (void) __nisdb_rwinit(&var ## _rwlock)
#define READLOCKOK(var) (void) __nisdb_rw_readlock_ok(&var ## _rwlock)
#define RLOCK(var) __nisdb_rlock(&var ## _rwlock)
#define WLOCK(var) __nisdb_wlock(&var ## _rwlock)
#define TRYWLOCK(var) __nisdb_wlock_trylock(&var ## _rwlock, 1)
#define RULOCK(var) __nisdb_rulock(&var ## _rwlock)
#define WULOCK(var) __nisdb_wulock(&var ## _rwlock)
#define DESTROYRW(var) __nisdb_destroy_lock(&var ## _rwlock)
#define ASSERTMUTEXHELD(var)
#define ASSERTWHELD(var)
#define ASSERTRHELD(var)
#endif /* NISDB_MT_DEBUG */
/* Nesting-safe RW locking */
typedef struct __nisdb_rwlock {
pthread_t id; /* Which thread */
uint32_t count; /* Lock depth for thread */
uint32_t wait; /* Blocked on mutex */
struct __nisdb_rwlock *next; /* Next reader record */
} __nisdb_rl_t;
typedef struct {
mutex_t mutex; /* Exclusive access to structure */
cond_t cv; /* CV for signaling */
uint32_t destroyed; /* Set if lock has been destroyed */
uint32_t force_write; /* Set if read locks forced to write */
uint32_t writer_count; /* Number of writer threads [0, 1] */
__nisdb_rl_t writer; /* Writer record */
uint32_t reader_count; /* # of reader threads [0, N] */
uint32_t reader_blocked; /* # of readers blocked on mutex */
__nisdb_rl_t reader; /* List of reader records */
} __nisdb_rwlock_t;
extern int __nisdb_rwinit(__nisdb_rwlock_t *);
extern int __nisdb_rw_readlock_ok(__nisdb_rwlock_t *rw);
extern int __nisdb_rw_force_writelock(__nisdb_rwlock_t *rw);
extern int __nisdb_wlock(__nisdb_rwlock_t *);
extern int __nisdb_wlock_trylock(__nisdb_rwlock_t *, int);
extern int __nisdb_rlock(__nisdb_rwlock_t *);
extern int __nisdb_wulock(__nisdb_rwlock_t *);
extern int __nisdb_rulock(__nisdb_rwlock_t *);
extern int __nisdb_assert_wheld(__nisdb_rwlock_t *);
extern int __nisdb_assert_rheld(__nisdb_rwlock_t *);
extern int __nisdb_destroy_lock(__nisdb_rwlock_t *);
extern void __nisdb_lock_report(__nisdb_rwlock_t *rw);
#ifdef __cplusplus
}
#endif
#endif /* _NISDB_RW_H */
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