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Docs/manual.texi: Portability updates, user addition and changelog for 3.23.24 mysys/thr_rwlock.c: Portability fix scripts/make_binary_distribution.sh: Added use of sbindir scripts/mysql_install_db.sh: Fixed usage of defaults files sql/ha_myisam.cc: Cleanup sql/sql_base.cc: Cleanup
136 lines
4.0 KiB
C
136 lines
4.0 KiB
C
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public
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License as published by the Free Software Foundation; either
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version 2 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with this library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
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MA 02111-1307, USA */
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/* Synchronization - readers / writer thread locks */
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#include "mysys_priv.h"
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#include <my_pthread.h>
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#if defined(THREAD) && !defined(HAVE_PTHREAD_RWLOCK_RDLOCK) && !defined(HAVE_RWLOCK_INIT)
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/*
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* Source base from Sun Microsystems SPILT, simplified
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* for MySQL use -- Joshua Chamas
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*/
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/*
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* Multithreaded Demo Source
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*
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* Copyright (C) 1995 by Sun Microsystems, Inc.
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* All rights reserved.
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*
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* This file is a product of SunSoft, Inc. and is provided for
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* unrestricted use provided that this legend is included on all
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* media and as a part of the software program in whole or part.
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* Users may copy, modify or distribute this file at will.
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*
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* THIS FILE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
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* THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
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*
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* This file is provided with no support and without any obligation on the
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* part of SunSoft, Inc. to assist in its use, correction, modification or
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* enhancement.
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*
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* SUNSOFT AND SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT
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* TO THE INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS
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* FILE OR ANY PART THEREOF.
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*
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* IN NO EVENT WILL SUNSOFT OR SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY
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* LOST REVENUE OR PROFITS OR OTHER SPECIAL, INDIRECT AND CONSEQUENTIAL
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* DAMAGES, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGES.
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*
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* SunSoft, Inc.
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* 2550 Garcia Avenue
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* Mountain View, California 94043
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*/
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int my_rwlock_init( rw_lock_t *rwp, void *arg __attribute__((unused)))
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{
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pthread_condattr_t cond_attr;
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pthread_mutex_init( &rwp->lock, NULL );
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pthread_condattr_init( &cond_attr );
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pthread_cond_init( &rwp->readers, &cond_attr );
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pthread_cond_init( &rwp->writers, &cond_attr );
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pthread_condattr_destroy(&cond_attr);
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rwp->state = 0;
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rwp->waiters = 0;
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return( 0 );
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}
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int my_rwlock_destroy( rw_lock_t *rwp ) {
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pthread_mutex_destroy( &rwp->lock );
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pthread_cond_destroy( &rwp->readers );
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pthread_cond_destroy( &rwp->writers );
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return( 0 );
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}
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int my_rw_rdlock( rw_lock_t *rwp ) {
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pthread_mutex_lock(&rwp->lock);
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/* active or queued writers */
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while ( ( rwp->state < 0 ) || rwp->waiters )
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pthread_cond_wait( &rwp->readers, &rwp->lock);
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rwp->state++;
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pthread_mutex_unlock(&rwp->lock);
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return( 0 );
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}
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int my_rw_wrlock( rw_lock_t *rwp ) {
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pthread_mutex_lock(&rwp->lock);
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rwp->waiters++; /* another writer queued */
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while ( rwp->state )
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pthread_cond_wait( &rwp->writers, &rwp->lock);
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rwp->state = -1;
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--rwp->waiters;
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pthread_mutex_unlock( &rwp->lock );
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return( 0 );
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}
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int my_rw_unlock( rw_lock_t *rwp ) {
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DBUG_PRINT("rw_unlock",
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("state: %d waiters: %d", rwp->state, rwp->waiters));
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pthread_mutex_lock(&rwp->lock);
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if ( rwp->state == -1 ) { /* writer releasing */
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rwp->state = 0; /* mark as available */
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if ( rwp->waiters ) /* writers queued */
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pthread_cond_signal( &rwp->writers );
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else
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pthread_cond_broadcast( &rwp->readers );
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} else {
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if ( --rwp->state == 0 ) /* no more readers */
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pthread_cond_signal( &rwp->writers );
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}
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pthread_mutex_unlock( &rwp->lock );
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return( 0 );
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}
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#endif
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