glib/gatomic.h

   1 /*
   2  * Copyright © 2011 Ryan Lortie
   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, but
  10  * 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, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Author: Ryan Lortie <desrt@desrt.ca>
  18  */
  19
  20 #ifndef __G_ATOMIC_H__
  21 #define __G_ATOMIC_H__
  22
  23 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  24 #error "Only <glib.h> can be included directly."
  25 #endif
  26
  27 #include <glib/gtypes.h>
  28
  29 G_BEGIN_DECLS
  30
  31 GLIB_AVAILABLE_IN_ALL
  32 gint                    g_atomic_int_get                      (const volatile gint *atomic);
  33 GLIB_AVAILABLE_IN_ALL
  34 void                    g_atomic_int_set                      (volatile gint  *atomic,
  35                                                                gint            newval);
  36 GLIB_AVAILABLE_IN_ALL
  37 void                    g_atomic_int_inc                      (volatile gint  *atomic);
  38 GLIB_AVAILABLE_IN_ALL
  39 gboolean                g_atomic_int_dec_and_test             (volatile gint  *atomic);
  40 GLIB_AVAILABLE_IN_ALL
  41 gboolean                g_atomic_int_compare_and_exchange     (volatile gint  *atomic,
  42                                                                gint            oldval,
  43                                                                gint            newval);
  44 GLIB_AVAILABLE_IN_ALL
  45 gint                    g_atomic_int_add                      (volatile gint  *atomic,
  46                                                                gint            val);
  47 GLIB_AVAILABLE_IN_2_30
  48 guint                   g_atomic_int_and                      (volatile guint *atomic,
  49                                                                guint           val);
  50 GLIB_AVAILABLE_IN_2_30
  51 guint                   g_atomic_int_or                       (volatile guint *atomic,
  52                                                                guint           val);
  53 GLIB_AVAILABLE_IN_ALL
  54 guint                   g_atomic_int_xor                      (volatile guint *atomic,
  55                                                                guint           val);
  56
  57 GLIB_AVAILABLE_IN_ALL
  58 gpointer                g_atomic_pointer_get                  (const volatile void *atomic);
  59 GLIB_AVAILABLE_IN_ALL
  60 void                    g_atomic_pointer_set                  (volatile void  *atomic,
  61                                                                gpointer        newval);
  62 GLIB_AVAILABLE_IN_ALL
  63 gboolean                g_atomic_pointer_compare_and_exchange (volatile void  *atomic,
  64                                                                gpointer        oldval,
  65                                                                gpointer        newval);
  66 GLIB_AVAILABLE_IN_ALL
  67 gssize                  g_atomic_pointer_add                  (volatile void  *atomic,
  68                                                                gssize          val);
  69 GLIB_AVAILABLE_IN_2_30
  70 gsize                   g_atomic_pointer_and                  (volatile void  *atomic,
  71                                                                gsize           val);
  72 GLIB_AVAILABLE_IN_2_30
  73 gsize                   g_atomic_pointer_or                   (volatile void  *atomic,
  74                                                                gsize           val);
  75 GLIB_AVAILABLE_IN_ALL
  76 gsize                   g_atomic_pointer_xor                  (volatile void  *atomic,
  77                                                                gsize           val);
  78
  79 GLIB_DEPRECATED_IN_2_30_FOR(g_atomic_int_add)
  80 gint                    g_atomic_int_exchange_and_add         (volatile gint  *atomic,
  81                                                                gint            val);
  82
  83 G_END_DECLS
  84
  85 #if defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
  86
  87 /* We prefer the new C11-style atomic extension of GCC if available */
  88 #if defined(__ATOMIC_SEQ_CST) && !defined(__clang__)
  89
  90 /* This assumes sizeof(int) is 4: gatomic.c statically
  91  * asserts that (using G_STATIC_ASSERT at top-level in a header was
  92  * problematic, see #730932) */
  93
  94 #define g_atomic_int_get(atomic) \
  95   (G_GNUC_EXTENSION ({                                                       \
  96     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
  97     (void) (0 ? *(atomic) ^ *(atomic) : 1);                                  \
  98     (gint) __atomic_load_4 ((atomic), __ATOMIC_SEQ_CST);                     \
  99   }))
 100 #define g_atomic_int_set(atomic, newval) \
 101   (G_GNUC_EXTENSION ({                                                       \
 102     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 103     (void) (0 ? *(atomic) ^ (newval) : 1);                                   \
 104     __atomic_store_4 ((atomic), (newval), __ATOMIC_SEQ_CST);                 \
 105   }))
 106
 107 #if GLIB_SIZEOF_VOID_P == 8
 108
 109 #define g_atomic_pointer_get(atomic) \
 110   (G_GNUC_EXTENSION ({                                                       \
 111     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 112     (gpointer) __atomic_load_8 ((atomic), __ATOMIC_SEQ_CST);                 \
 113   }))
 114 #define g_atomic_pointer_set(atomic, newval) \
 115   (G_GNUC_EXTENSION ({                                                       \
 116     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 117     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 118     __atomic_store_8 ((atomic), (gsize) (newval), __ATOMIC_SEQ_CST);         \
 119   }))
 120
 121 #else /* GLIB_SIZEOF_VOID_P == 8 */
 122
 123 /* This assumes that if sizeof(void *) is not 8, then it is 4:
 124  * gatomic.c statically asserts that (using G_STATIC_ASSERT
 125  * at top-level in a header was problematic, see #730932) */
 126
 127 #define g_atomic_pointer_get(atomic) \
 128   (G_GNUC_EXTENSION ({                                                       \
 129     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 130     (gpointer) __atomic_load_4 ((atomic), __ATOMIC_SEQ_CST);                 \
 131   }))
 132 #define g_atomic_pointer_set(atomic, newval) \
 133   (G_GNUC_EXTENSION ({                                                       \
 134     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 135     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 136     __atomic_store_4 ((atomic), (gsize) (newval), __ATOMIC_SEQ_CST);         \
 137   }))
 138
 139 #endif /* GLIB_SIZEOF_VOID_P == 8 */
 140
 141 #else /* defined(__ATOMIC_SEQ_CST) */
 142
 143 #define g_atomic_int_get(atomic) \
 144   (G_GNUC_EXTENSION ({                                                       \
 145     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 146     (void) (0 ? *(atomic) ^ *(atomic) : 1);                                  \
 147     __sync_synchronize ();                                                   \
 148     (gint) *(atomic);                                                        \
 149   }))
 150 #define g_atomic_int_set(atomic, newval) \
 151   (G_GNUC_EXTENSION ({                                                       \
 152     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 153     (void) (0 ? *(atomic) ^ (newval) : 1);                                   \
 154     *(atomic) = (newval);                                                    \
 155     __sync_synchronize ();                                                   \
 156   }))
 157 #define g_atomic_pointer_get(atomic) \
 158   (G_GNUC_EXTENSION ({                                                       \
 159     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 160     __sync_synchronize ();                                                   \
 161     (gpointer) *(atomic);                                                    \
 162   }))
 163 #define g_atomic_pointer_set(atomic, newval) \
 164   (G_GNUC_EXTENSION ({                                                       \
 165     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 166     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 167     *(atomic) = (__typeof__ (*(atomic))) (gsize) (newval);                   \
 168     __sync_synchronize ();                                                   \
 169   }))
 170
 171 #endif /* !defined(__ATOMIC_SEQ_CST) */
 172
 173 #define g_atomic_int_inc(atomic) \
 174   (G_GNUC_EXTENSION ({                                                       \
 175     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 176     (void) (0 ? *(atomic) ^ *(atomic) : 1);                                  \
 177     (void) __sync_fetch_and_add ((atomic), 1);                               \
 178   }))
 179 #define g_atomic_int_dec_and_test(atomic) \
 180   (G_GNUC_EXTENSION ({                                                       \
 181     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 182     (void) (0 ? *(atomic) ^ *(atomic) : 1);                                  \
 183     __sync_fetch_and_sub ((atomic), 1) == 1;                                 \
 184   }))
 185 #define g_atomic_int_compare_and_exchange(atomic, oldval, newval) \
 186   (G_GNUC_EXTENSION ({                                                       \
 187     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 188     (void) (0 ? *(atomic) ^ (newval) ^ (oldval) : 1);                        \
 189     (gboolean) __sync_bool_compare_and_swap ((atomic), (oldval), (newval));  \
 190   }))
 191 #define g_atomic_int_add(atomic, val) \
 192   (G_GNUC_EXTENSION ({                                                       \
 193     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 194     (void) (0 ? *(atomic) ^ (val) : 1);                                      \
 195     (gint) __sync_fetch_and_add ((atomic), (val));                           \
 196   }))
 197 #define g_atomic_int_and(atomic, val) \
 198   (G_GNUC_EXTENSION ({                                                       \
 199     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 200     (void) (0 ? *(atomic) ^ (val) : 1);                                      \
 201     (guint) __sync_fetch_and_and ((atomic), (val));                          \
 202   }))
 203 #define g_atomic_int_or(atomic, val) \
 204   (G_GNUC_EXTENSION ({                                                       \
 205     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 206     (void) (0 ? *(atomic) ^ (val) : 1);                                      \
 207     (guint) __sync_fetch_and_or ((atomic), (val));                           \
 208   }))
 209 #define g_atomic_int_xor(atomic, val) \
 210   (G_GNUC_EXTENSION ({                                                       \
 211     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gint));                     \
 212     (void) (0 ? *(atomic) ^ (val) : 1);                                      \
 213     (guint) __sync_fetch_and_xor ((atomic), (val));                          \
 214   }))
 215
 216 #define g_atomic_pointer_compare_and_exchange(atomic, oldval, newval) \
 217   (G_GNUC_EXTENSION ({                                                       \
 218     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 219     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 220     (gboolean) __sync_bool_compare_and_swap ((atomic), (oldval), (newval));  \
 221   }))
 222 #define g_atomic_pointer_add(atomic, val) \
 223   (G_GNUC_EXTENSION ({                                                       \
 224     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 225     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 226     (void) (0 ? (val) ^ (val) : 1);                                          \
 227     (gssize) __sync_fetch_and_add ((atomic), (val));                         \
 228   }))
 229 #define g_atomic_pointer_and(atomic, val) \
 230   (G_GNUC_EXTENSION ({                                                       \
 231     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 232     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 233     (void) (0 ? (val) ^ (val) : 1);                                          \
 234     (gsize) __sync_fetch_and_and ((atomic), (val));                          \
 235   }))
 236 #define g_atomic_pointer_or(atomic, val) \
 237   (G_GNUC_EXTENSION ({                                                       \
 238     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 239     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 240     (void) (0 ? (val) ^ (val) : 1);                                          \
 241     (gsize) __sync_fetch_and_or ((atomic), (val));                           \
 242   }))
 243 #define g_atomic_pointer_xor(atomic, val) \
 244   (G_GNUC_EXTENSION ({                                                       \
 245     G_STATIC_ASSERT (sizeof *(atomic) == sizeof (gpointer));                 \
 246     (void) (0 ? (gpointer) *(atomic) : NULL);                                \
 247     (void) (0 ? (val) ^ (val) : 1);                                          \
 248     (gsize) __sync_fetch_and_xor ((atomic), (val));                          \
 249   }))
 250
 251 #else /* defined(G_ATOMIC_LOCK_FREE) && defined(__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) */
 252
 253 #define g_atomic_int_get(atomic) \
 254   (g_atomic_int_get ((gint *) (atomic)))
 255 #define g_atomic_int_set(atomic, newval) \
 256   (g_atomic_int_set ((gint *) (atomic), (gint) (newval)))
 257 #define g_atomic_int_compare_and_exchange(atomic, oldval, newval) \
 258   (g_atomic_int_compare_and_exchange ((gint *) (atomic), (oldval), (newval)))
 259 #define g_atomic_int_add(atomic, val) \
 260   (g_atomic_int_add ((gint *) (atomic), (val)))
 261 #define g_atomic_int_and(atomic, val) \
 262   (g_atomic_int_and ((guint *) (atomic), (val)))
 263 #define g_atomic_int_or(atomic, val) \
 264   (g_atomic_int_or ((guint *) (atomic), (val)))
 265 #define g_atomic_int_xor(atomic, val) \
 266   (g_atomic_int_xor ((guint *) (atomic), (val)))
 267 #define g_atomic_int_inc(atomic) \
 268   (g_atomic_int_inc ((gint *) (atomic)))
 269 #define g_atomic_int_dec_and_test(atomic) \
 270   (g_atomic_int_dec_and_test ((gint *) (atomic)))
 271
 272 #define g_atomic_pointer_get(atomic) \
 273   (g_atomic_pointer_get (atomic))
 274 #define g_atomic_pointer_set(atomic, newval) \
 275   (g_atomic_pointer_set ((atomic), (gpointer) (newval)))
 276 #define g_atomic_pointer_compare_and_exchange(atomic, oldval, newval) \
 277   (g_atomic_pointer_compare_and_exchange ((atomic), (gpointer) (oldval), (gpointer) (newval)))
 278 #define g_atomic_pointer_add(atomic, val) \
 279   (g_atomic_pointer_add ((atomic), (gssize) (val)))
 280 #define g_atomic_pointer_and(atomic, val) \
 281   (g_atomic_pointer_and ((atomic), (gsize) (val)))
 282 #define g_atomic_pointer_or(atomic, val) \
 283   (g_atomic_pointer_or ((atomic), (gsize) (val)))
 284 #define g_atomic_pointer_xor(atomic, val) \
 285   (g_atomic_pointer_xor ((atomic), (gsize) (val)))
 286
 287 #endif /* defined(__GNUC__) && defined(G_ATOMIC_OP_USE_GCC_BUILTINS) */
 288
 289 #endif /* __G_ATOMIC_H__ */