mono/utils/atomic.c

   1 /*
   2  * atomic.c:  Workarounds for atomic operations for platforms that dont have
   3  *            really atomic asm functions in atomic.h
   4  *
   5  * Author:
   6  *      Dick Porter (dick@ximian.com)
   7  *
   8  * (C) 2002 Ximian, Inc.
   9  */
  10
  11 #include <config.h>
  12 #include <glib.h>
  13 #include <pthread.h>
  14
  15 #include <mono/utils/atomic.h>
  16
  17 #ifdef WAPI_NO_ATOMIC_ASM
  18
  19 static pthread_mutex_t spin = PTHREAD_MUTEX_INITIALIZER;
  20 static mono_once_t spin_once=MONO_ONCE_INIT;
  21
  22 static void spin_init(void)
  23 {
  24         g_warning("Using non-atomic functions!  Expect race conditions when using process-shared handles!");
  25 }
  26
  27 gint32 InterlockedCompareExchange(volatile gint32 *dest, gint32 exch,
  28                                   gint32 comp)
  29 {
  30         gint32 old;
  31         int ret;
  32
  33         mono_once(&spin_once, spin_init);
  34
  35         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
  36                               (void *)&spin);
  37         ret = pthread_mutex_lock(&spin);
  38         g_assert (ret == 0);
  39
  40         old= *dest;
  41         if(old==comp) {
  42                 *dest=exch;
  43         }
  44
  45         ret = pthread_mutex_unlock(&spin);
  46         g_assert (ret == 0);
  47
  48         pthread_cleanup_pop (0);
  49
  50         return(old);
  51 }
  52
  53 gpointer InterlockedCompareExchangePointer(volatile gpointer *dest,
  54                                            gpointer exch, gpointer comp)
  55 {
  56         gpointer old;
  57         int ret;
  58
  59         mono_once(&spin_once, spin_init);
  60
  61         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
  62                               (void *)&spin);
  63         ret = pthread_mutex_lock(&spin);
  64         g_assert (ret == 0);
  65
  66         old= *dest;
  67         if(old==comp) {
  68                 *dest=exch;
  69         }
  70
  71         ret = pthread_mutex_unlock(&spin);
  72         g_assert (ret == 0);
  73
  74         pthread_cleanup_pop (0);
  75
  76         return(old);
  77 }
  78
  79 gint32 InterlockedIncrement(volatile gint32 *dest)
  80 {
  81         gint32 ret;
  82         int thr_ret;
  83
  84         mono_once(&spin_once, spin_init);
  85
  86         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
  87                               (void *)&spin);
  88         thr_ret = pthread_mutex_lock(&spin);
  89         g_assert (thr_ret == 0);
  90
  91         (*dest)++;
  92         ret= *dest;
  93
  94         thr_ret = pthread_mutex_unlock(&spin);
  95         g_assert (thr_ret == 0);
  96
  97         pthread_cleanup_pop (0);
  98
  99         return(ret);
 100 }
 101
 102 gint32 InterlockedDecrement(volatile gint32 *dest)
 103 {
 104         gint32 ret;
 105         int thr_ret;
 106
 107         mono_once(&spin_once, spin_init);
 108
 109         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
 110                               (void *)&spin);
 111         thr_ret = pthread_mutex_lock(&spin);
 112         g_assert (thr_ret == 0);
 113
 114         (*dest)--;
 115         ret= *dest;
 116
 117         thr_ret = pthread_mutex_unlock(&spin);
 118         g_assert (thr_ret == 0);
 119
 120         pthread_cleanup_pop (0);
 121
 122         return(ret);
 123 }
 124
 125 gint32 InterlockedExchange(volatile gint32 *dest, gint32 exch)
 126 {
 127         gint32 ret;
 128         int thr_ret;
 129
 130         mono_once(&spin_once, spin_init);
 131
 132         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
 133                               (void *)&spin);
 134         thr_ret = pthread_mutex_lock(&spin);
 135         g_assert (thr_ret == 0);
 136
 137         ret=*dest;
 138         *dest=exch;
 139
 140         thr_ret = pthread_mutex_unlock(&spin);
 141         g_assert (thr_ret == 0);
 142
 143         pthread_cleanup_pop (0);
 144
 145         return(ret);
 146 }
 147
 148 gpointer InterlockedExchangePointer(volatile gpointer *dest, gpointer exch)
 149 {
 150         gpointer ret;
 151         int thr_ret;
 152
 153         mono_once(&spin_once, spin_init);
 154
 155         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
 156                               (void *)&spin);
 157         thr_ret = pthread_mutex_lock(&spin);
 158         g_assert (thr_ret == 0);
 159
 160         ret=*dest;
 161         *dest=exch;
 162
 163         thr_ret = pthread_mutex_unlock(&spin);
 164         g_assert (thr_ret == 0);
 165
 166         pthread_cleanup_pop (0);
 167
 168         return(ret);
 169 }
 170
 171 gint32 InterlockedExchangeAdd(volatile gint32 *dest, gint32 add)
 172 {
 173         gint32 ret;
 174         int thr_ret;
 175
 176         mono_once(&spin_once, spin_init);
 177
 178         pthread_cleanup_push ((void(*)(void *))pthread_mutex_unlock,
 179                               (void *)&spin);
 180         thr_ret = pthread_mutex_lock(&spin);
 181         g_assert (thr_ret == 0);
 182
 183         ret= *dest;
 184         *dest+=add;
 185
 186         thr_ret = pthread_mutex_unlock(&spin);
 187         g_assert (thr_ret == 0);
 188
 189         pthread_cleanup_pop (0);
 190
 191         return(ret);
 192 }
 193
 194 #endif