reactos/sdk/lib/crt/misc/lock.c

133 lines
3.4 KiB
C

/*
* Copyright (c) 2002, TransGaming Technologies Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <precomp.h>
typedef struct
{
BOOL bInit;
CRITICAL_SECTION crit;
} LOCKTABLEENTRY;
static LOCKTABLEENTRY lock_table[ _TOTAL_LOCKS ];
static __inline void msvcrt_mlock_set_entry_initialized( int locknum, BOOL initialized )
{
lock_table[ locknum ].bInit = initialized;
}
static __inline void msvcrt_initialize_mlock( int locknum )
{
InitializeCriticalSection( &(lock_table[ locknum ].crit) );
msvcrt_mlock_set_entry_initialized( locknum, TRUE );
}
static __inline void msvcrt_uninitialize_mlock( int locknum )
{
DeleteCriticalSection( &(lock_table[ locknum ].crit) );
msvcrt_mlock_set_entry_initialized( locknum, FALSE );
}
/**********************************************************************
* msvcrt_init_mt_locks (internal)
*
* Initialize the table lock. All other locks will be initialized
* upon first use.
*
*/
void msvcrt_init_mt_locks(void)
{
int i;
TRACE( "initializing mtlocks\n" );
/* Initialize the table */
for( i=0; i < _TOTAL_LOCKS; i++ )
{
msvcrt_mlock_set_entry_initialized( i, FALSE );
}
/* Initialize our lock table lock */
msvcrt_initialize_mlock( _LOCKTAB_LOCK );
}
/**********************************************************************
* msvcrt_free_mt_locks (internal)
*
* Uninitialize all mt locks. Assume that neither _lock or _unlock will
* be called once we're calling this routine (ie _LOCKTAB_LOCK can be deleted)
*
*/
void msvcrt_free_mt_locks(void)
{
int i;
TRACE(": uninitializing all mtlocks\n" );
/* Uninitialize the table */
for( i=0; i < _TOTAL_LOCKS; i++ )
{
if( lock_table[ i ].bInit )
{
msvcrt_uninitialize_mlock( i );
}
}
}
/**********************************************************************
* _lock (MSVCRT.@)
*/
void _lock( int locknum )
{
TRACE( "(%d)\n", locknum );
/* If the lock doesn't exist yet, create it */
if( lock_table[ locknum ].bInit == FALSE )
{
/* Lock while we're changing the lock table */
_lock( _LOCKTAB_LOCK );
/* Check again if we've got a bit of a race on lock creation */
if( lock_table[ locknum ].bInit == FALSE )
{
TRACE( ": creating lock #%d\n", locknum );
msvcrt_initialize_mlock( locknum );
}
/* Unlock ourselves */
_unlock( _LOCKTAB_LOCK );
}
EnterCriticalSection( &(lock_table[ locknum ].crit) );
}
/**********************************************************************
* _unlock (MSVCRT.@)
*
* NOTE: There is no error detection to make sure the lock exists and is acquired.
*/
void _unlock( int locknum )
{
TRACE( "(%d)\n", locknum );
LeaveCriticalSection( &(lock_table[ locknum ].crit) );
}