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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  */
  18
  19 #include "mtdll.h"
  20
  21 #include "wine/debug.h"
  22 #include "winbase.h"
  23
  24 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  25
  26 typedef struct
  27 {
  28   BOOL             bInit;
  29   CRITICAL_SECTION crit;
  30 } LOCKTABLEENTRY;
  31
  32 static LOCKTABLEENTRY lock_table[ _TOTAL_LOCKS ];
  33
  34 static inline void msvcrt_mlock_set_entry_initialized( int locknum, BOOL initialized )
  35 {
  36   lock_table[ locknum ].bInit = initialized;
  37 }
  38
  39 static inline void msvcrt_initialize_mlock( int locknum )
  40 {
  41   InitializeCriticalSection( &(lock_table[ locknum ].crit) );
  42   msvcrt_mlock_set_entry_initialized( locknum, TRUE );
  43 }
  44
  45 static inline void msvcrt_uninitialize_mlock( int locknum )
  46 {
  47   DeleteCriticalSection( &(lock_table[ locknum ].crit) );
  48   msvcrt_mlock_set_entry_initialized( locknum, FALSE );
  49 }
  50
  51 /**********************************************************************
  52  *     msvcrt_init_mt_locks (internal)
  53  *
  54  * Initialize the table lock. All other locks will be initialized
  55  * upon first use.
  56  *
  57  */
  58 void msvcrt_init_mt_locks(void)
  59 {
  60   int i;
  61
  62   TRACE( "initializing mtlocks\n" );
  63
  64   /* Initialize the table */
  65   for( i=0; i < _TOTAL_LOCKS; i++ )
  66   {
  67     msvcrt_mlock_set_entry_initialized( i, FALSE );
  68   }
  69
  70   /* Initialize our lock table lock */
  71   msvcrt_initialize_mlock( _LOCKTAB_LOCK );
  72 }
  73
  74 /**********************************************************************
  75  *     msvcrt_free_mt_locks (internal)
  76  *
  77  * Uninitialize all mt locks. Assume that neither _lock or _unlock will
  78  * be called once we're calling this routine (ie _LOCKTAB_LOCK can be deleted)
  79  *
  80  */
  81 void msvcrt_free_mt_locks(void)
  82 {
  83   int i;
  84
  85   TRACE( ": uninitializing all mtlocks\n" );
  86
  87   /* Uninitialize the table */
  88   for( i=0; i < _TOTAL_LOCKS; i++ )
  89   {
  90     if( lock_table[ i ].bInit == TRUE )
  91     {
  92       msvcrt_uninitialize_mlock( i );
  93     }
  94   }
  95 }
  96
  97
  98 /**********************************************************************
  99  *              _lock (MSVCRT.@)
 100  */
 101 void _lock( int locknum )
 102 {
 103   TRACE( "(%d)\n", locknum );
 104
 105   /* If the lock doesn't exist yet, create it */
 106   if( lock_table[ locknum ].bInit == FALSE )
 107   {
 108     /* Lock while we're changing the lock table */
 109     _lock( _LOCKTAB_LOCK );
 110
 111     /* Check again if we've got a bit of a race on lock creation */
 112     if( lock_table[ locknum ].bInit == FALSE )
 113     {
 114       TRACE( ": creating lock #%d\n", locknum );
 115       msvcrt_initialize_mlock( locknum );
 116     }
 117
 118     /* Unlock ourselves */
 119     _unlock( _LOCKTAB_LOCK );
 120   }
 121
 122   EnterCriticalSection( &(lock_table[ locknum ].crit) );
 123 }
 124
 125 /**********************************************************************
 126  *              _unlock (MSVCRT.@)
 127  *
 128  * NOTE: There is no error detection to make sure the lock exists and is acquired.
 129  */
 130 void _unlock( int locknum )
 131 {
 132   TRACE( "(%d)\n", locknum );
 133
 134   LeaveCriticalSection( &(lock_table[ locknum ].crit) );
 135 }
 136