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yap-6.3/packages/semweb/lock.h

88 lines
2.2 KiB
C

/* $Id$
Part of the SWI-Prolog Semweb package
Author: Jan Wielemaker
E-mail: wielemak@science.uva.nl
WWW: http://www.swi-prolog.org
Copyright (C): 2006, University of Amsterdam
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef LOCK_H_INCLUDED
#define LOCK_H_INCLUDED
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef __WINDOWS__
#include <windows.h>
#if defined(_REENTRANT) && defined(__WINDOWS__)
enum
{ SIGNAL = 0,
MAX_EVENTS = 1
} win32_event_t;
typedef struct
{ HANDLE events[MAX_EVENTS]; /* events to be signalled */
int waiters; /* # waiters */
} win32_cond_t;
#endif
#else
#include <pthread.h>
#endif
typedef struct rwlock
{
#ifdef _REENTRANT
#ifdef __WINDOWS__
CRITICAL_SECTION mutex;
CRITICAL_SECTION misc_mutex;
win32_cond_t rdcondvar;
win32_cond_t wrcondvar;
win32_cond_t upcondvar;
#else
pthread_mutex_t mutex;
pthread_mutex_t misc_mutex;
pthread_cond_t rdcondvar;
pthread_cond_t wrcondvar;
pthread_cond_t upcondvar;
#endif
int waiting_readers;
int waiting_writers;
int waiting_upgrade;
size_t thread_max;
int *read_by_thread;
int allow_readers;
int lock_level; /* recursive locks */
#endif
int writer;
int readers;
} rwlock;
int rdlock(rwlock *lock);
int wrlock(rwlock *lock, int allow_readers);
int lockout_readers(rwlock *lock);
void reallow_readers(rwlock *lock);
int unlock(rwlock *lock, int rd);
int lock_misc(rwlock *lock);
int unlock_misc(rwlock *lock);
int init_lock(rwlock *lock);
int destroy_lock(rwlock *lock);
#endif /*LOCK_H_INCLUDED*/