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MDEV-34530 dead code in the thr_rwlock.c

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remove it
This commit is contained in:
Sergei Golubchik 2024-07-04 14:10:37 +02:00
parent 7ba12d42de
commit f12634f5a4
2 changed files with 5 additions and 170 deletions
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4
configure.cmake
View file

@ -414,6 +414,10 @@ CHECK_FUNCTION_EXISTS (vsnprintf HAVE_VSNPRINTF)
CHECK_FUNCTION_EXISTS (memalign HAVE_MEMALIGN)
CHECK_FUNCTION_EXISTS (nl_langinfo HAVE_NL_LANGINFO)
IF(NOT HAVE_PTHREAD_RWLOCK_RDLOCK AND NOT HAVE_RWLOCK_INIT AND NOT WIN32)
MESSAGE(FATAL_ERROR "No usable rwlock implementation found")
ENDIF()
IF(HAVE_SYS_EVENT_H)
CHECK_FUNCTION_EXISTS (kqueue HAVE_KQUEUE)
ENDIF()

171
mysys/thr_rwlock.c
View file

@ -81,176 +81,7 @@ int my_rw_destroy(my_rw_lock_t* rwp)
}
#else
/*
Source base from Sun Microsystems SPILT, simplified for MySQL use
-- Joshua Chamas
Some cleanup and additional code by Monty
*/
/*
* Multithreaded Demo Source
*
* Copyright (C) 1995 by Sun Microsystems, Inc.
*
*
* This file is a product of SunSoft, Inc. and is provided for
* unrestricted use provided that this legend is included on all
* media and as a part of the software program in whole or part.
* Users may copy, modify or distribute this file at will.
*
* THIS FILE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
* THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
* PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
*
* This file is provided with no support and without any obligation on the
* part of SunSoft, Inc. to assist in its use, correction, modification or
* enhancement.
*
* SUNSOFT AND SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT
* TO THE INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS
* FILE OR ANY PART THEREOF.
*
* IN NO EVENT WILL SUNSOFT OR SUN MICROSYSTEMS, INC. BE LIABLE FOR ANY
* LOST REVENUE OR PROFITS OR OTHER SPECIAL, INDIRECT AND CONSEQUENTIAL
* DAMAGES, EVEN IF THEY HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGES.
*
* SunSoft, Inc.
* 2550 Garcia Avenue
* Mountain View, California 94043
*/
int my_rw_init(my_rw_lock_t *rwp)
{
pthread_condattr_t cond_attr;
pthread_mutex_init( &rwp->lock, MY_MUTEX_INIT_FAST);
pthread_condattr_init( &cond_attr );
pthread_cond_init( &rwp->readers, &cond_attr );
pthread_cond_init( &rwp->writers, &cond_attr );
pthread_condattr_destroy(&cond_attr);
rwp->state = 0;
rwp->waiters = 0;
#ifdef SAFE_MUTEX
rwp->write_thread = 0;
#endif
return(0);
}
int my_rw_destroy(my_rw_lock_t *rwp)
{
DBUG_ASSERT(rwp->state == 0);
pthread_mutex_destroy( &rwp->lock );
pthread_cond_destroy( &rwp->readers );
pthread_cond_destroy( &rwp->writers );
return(0);
}
int my_rw_rdlock(my_rw_lock_t *rwp)
{
pthread_mutex_lock(&rwp->lock);
/* active or queued writers */
while (( rwp->state < 0 ) || rwp->waiters)
pthread_cond_wait( &rwp->readers, &rwp->lock);
rwp->state++;
pthread_mutex_unlock(&rwp->lock);
return(0);
}
int my_rw_tryrdlock(my_rw_lock_t *rwp)
{
int res;
pthread_mutex_lock(&rwp->lock);
if ((rwp->state < 0 ) || rwp->waiters)
res= EBUSY; /* Can't get lock */
else
{
res=0;
rwp->state++;
}
pthread_mutex_unlock(&rwp->lock);
return(res);
}
int my_rw_wrlock(my_rw_lock_t *rwp)
{
pthread_mutex_lock(&rwp->lock);
rwp->waiters++; /* another writer queued */
my_rw_lock_assert_not_write_owner(rwp);
while (rwp->state)
pthread_cond_wait(&rwp->writers, &rwp->lock);
rwp->state = -1;
rwp->waiters--;
#ifdef SAFE_MUTEX
rwp->write_thread= pthread_self();
#endif
pthread_mutex_unlock(&rwp->lock);
return(0);
}
int my_rw_trywrlock(my_rw_lock_t *rwp)
{
int res;
pthread_mutex_lock(&rwp->lock);
if (rwp->state)
res= EBUSY; /* Can't get lock */
else
{
res=0;
rwp->state = -1;
#ifdef SAFE_MUTEX
rwp->write_thread= pthread_self();
#endif
}
pthread_mutex_unlock(&rwp->lock);
return(res);
}
int my_rw_unlock(my_rw_lock_t *rwp)
{
DBUG_PRINT("rw_unlock",
("state: %d waiters: %d", rwp->state, rwp->waiters));
pthread_mutex_lock(&rwp->lock);
DBUG_ASSERT(rwp->state != 0);
if (rwp->state == -1) /* writer releasing */
{
my_rw_lock_assert_write_owner(rwp);
rwp->state= 0; /* mark as available */
#ifdef SAFE_MUTEX
rwp->write_thread= 0;
#endif
if ( rwp->waiters ) /* writers queued */
pthread_cond_signal( &rwp->writers );
else
pthread_cond_broadcast( &rwp->readers );
}
else
{
if ( --rwp->state == 0 && /* no more readers */
rwp->waiters)
pthread_cond_signal( &rwp->writers );
}
pthread_mutex_unlock( &rwp->lock );
return(0);
}
#error no pthread_rwlock_init
#endif /* !defined _WIN32 */
#endif /* NEED_MY_RW_LOCK*/