dlls/msvcrt/lock.c

   1 /*
   2  * Copyright (c) 2002, TransGaming Technologies Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  17  */
  18
  19 #include <stdarg.h>
  20
  21 #include "mtdll.h"
  22
  23 #include "wine/debug.h"
  24 #include "windef.h"
  25 #include "winbase.h"
  26
  27 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  28
  29 typedef struct
  30 {
  31   BOOL             bInit;
  32   CRITICAL_SECTION crit;
  33 } LOCKTABLEENTRY;
  34
  35 static LOCKTABLEENTRY lock_table[ _TOTAL_LOCKS ];
  36
  37 static inline void msvcrt_mlock_set_entry_initialized( int locknum, BOOL initialized )
  38 {
  39   lock_table[ locknum ].bInit = initialized;
  40 }
  41
  42 static inline void msvcrt_initialize_mlock( int locknum )
  43 {
  44   InitializeCriticalSection( &(lock_table[ locknum ].crit) );
  45   msvcrt_mlock_set_entry_initialized( locknum, TRUE );
  46 }
  47
  48 static inline void msvcrt_uninitialize_mlock( int locknum )
  49 {
  50   DeleteCriticalSection( &(lock_table[ locknum ].crit) );
  51   msvcrt_mlock_set_entry_initialized( locknum, FALSE );
  52 }
  53
  54 /**********************************************************************
  55  *     msvcrt_init_mt_locks (internal)
  56  *
  57  * Initialize the table lock. All other locks will be initialized
  58  * upon first use.
  59  *
  60  */
  61 void msvcrt_init_mt_locks(void)
  62 {
  63   int i;
  64
  65   TRACE( "initializing mtlocks\n" );
  66
  67   /* Initialize the table */
  68   for( i=0; i < _TOTAL_LOCKS; i++ )
  69   {
  70     msvcrt_mlock_set_entry_initialized( i, FALSE );
  71   }
  72
  73   /* Initialize our lock table lock */
  74   msvcrt_initialize_mlock( _LOCKTAB_LOCK );
  75 }
  76
  77 /**********************************************************************
  78  *     msvcrt_free_mt_locks (internal)
  79  *
  80  * Uninitialize all mt locks. Assume that neither _lock or _unlock will
  81  * be called once we're calling this routine (ie _LOCKTAB_LOCK can be deleted)
  82  *
  83  */
  84 void msvcrt_free_mt_locks(void)
  85 {
  86   int i;
  87
  88   TRACE( ": uninitializing all mtlocks\n" );
  89
  90   /* Uninitialize the table */
  91   for( i=0; i < _TOTAL_LOCKS; i++ )
  92   {
  93     if( lock_table[ i ].bInit )
  94     {
  95       msvcrt_uninitialize_mlock( i );
  96     }
  97   }
  98 }
  99
 100
 101 /**********************************************************************
 102  *              _lock (MSVCRT.@)
 103  */
 104 void CDECL _lock( int locknum )
 105 {
 106   TRACE( "(%d)\n", locknum );
 107
 108   /* If the lock doesn't exist yet, create it */
 109   if( lock_table[ locknum ].bInit == FALSE )
 110   {
 111     /* Lock while we're changing the lock table */
 112     _lock( _LOCKTAB_LOCK );
 113
 114     /* Check again if we've got a bit of a race on lock creation */
 115     if( lock_table[ locknum ].bInit == FALSE )
 116     {
 117       TRACE( ": creating lock #%d\n", locknum );
 118       msvcrt_initialize_mlock( locknum );
 119     }
 120
 121     /* Unlock ourselves */
 122     _unlock( _LOCKTAB_LOCK );
 123   }
 124
 125   EnterCriticalSection( &(lock_table[ locknum ].crit) );
 126 }
 127
 128 /**********************************************************************
 129  *              _unlock (MSVCRT.@)
 130  *
 131  * NOTE: There is no error detection to make sure the lock exists and is acquired.
 132  */
 133 void CDECL _unlock( int locknum )
 134 {
 135   TRACE( "(%d)\n", locknum );
 136
 137   LeaveCriticalSection( &(lock_table[ locknum ].crit) );
 138 }
 139