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   lock_table[ locknum ].crit.DebugInfo->Spare[0] = (DWORD_PTR)(__FILE__ ": LOCKTABLEENTRY.crit");
  46   msvcrt_mlock_set_entry_initialized( locknum, TRUE );
  47 }
  48
  49 static inline void msvcrt_uninitialize_mlock( int locknum )
  50 {
  51   lock_table[ locknum ].crit.DebugInfo->Spare[0] = 0;
  52   DeleteCriticalSection( &(lock_table[ locknum ].crit) );
  53   msvcrt_mlock_set_entry_initialized( locknum, FALSE );
  54 }
  55
  56 /**********************************************************************
  57  *     msvcrt_init_mt_locks (internal)
  58  *
  59  * Initialize the table lock. All other locks will be initialized
  60  * upon first use.
  61  *
  62  */
  63 void msvcrt_init_mt_locks(void)
  64 {
  65   int i;
  66
  67   TRACE( "initializing mtlocks\n" );
  68
  69   /* Initialize the table */
  70   for( i=0; i < _TOTAL_LOCKS; i++ )
  71   {
  72     msvcrt_mlock_set_entry_initialized( i, FALSE );
  73   }
  74
  75   /* Initialize our lock table lock */
  76   msvcrt_initialize_mlock( _LOCKTAB_LOCK );
  77 }
  78
  79 /**********************************************************************
  80  *     msvcrt_free_mt_locks (internal)
  81  *
  82  * Uninitialize all mt locks. Assume that neither _lock or _unlock will
  83  * be called once we're calling this routine (ie _LOCKTAB_LOCK can be deleted)
  84  *
  85  */
  86 void msvcrt_free_mt_locks(void)
  87 {
  88   int i;
  89
  90   TRACE( ": uninitializing all mtlocks\n" );
  91
  92   /* Uninitialize the table */
  93   for( i=0; i < _TOTAL_LOCKS; i++ )
  94   {
  95     if( lock_table[ i ].bInit )
  96     {
  97       msvcrt_uninitialize_mlock( i );
  98     }
  99   }
 100 }
 101
 102
 103 /**********************************************************************
 104  *              _lock (MSVCRT.@)
 105  */
 106 void CDECL _lock( int locknum )
 107 {
 108   TRACE( "(%d)\n", locknum );
 109
 110   /* If the lock doesn't exist yet, create it */
 111   if( lock_table[ locknum ].bInit == FALSE )
 112   {
 113     /* Lock while we're changing the lock table */
 114     _lock( _LOCKTAB_LOCK );
 115
 116     /* Check again if we've got a bit of a race on lock creation */
 117     if( lock_table[ locknum ].bInit == FALSE )
 118     {
 119       TRACE( ": creating lock #%d\n", locknum );
 120       msvcrt_initialize_mlock( locknum );
 121     }
 122
 123     /* Unlock ourselves */
 124     _unlock( _LOCKTAB_LOCK );
 125   }
 126
 127   EnterCriticalSection( &(lock_table[ locknum ].crit) );
 128 }
 129
 130 /**********************************************************************
 131  *              _unlock (MSVCRT.@)
 132  *
 133  * NOTE: There is no error detection to make sure the lock exists and is acquired.
 134  */
 135 void CDECL _unlock( int locknum )
 136 {
 137   TRACE( "(%d)\n", locknum );
 138
 139   LeaveCriticalSection( &(lock_table[ locknum ].crit) );
 140 }