glib/gatomic.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * g_atomic_*: atomic operations.
   5  * Copyright (C) 2003 Sebastian Wilhelmi
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include "config.h"
  24
  25 #include "glib.h"
  26 #include "gthreadinit.h"
  27 #include "galias.h"
  28
  29 #if defined (__GNUC__)
  30 # if defined (G_ATOMIC_I486)
  31 /* Adapted from CVS version 1.10 of glibc's sysdeps/i386/i486/bits/atomic.h
  32  */
  33 gint
  34 g_atomic_int_exchange_and_add (volatile gint *atomic,
  35                                gint           val)
  36 {
  37   gint result;
  38
  39   __asm__ __volatile__ ("lock; xaddl %0,%1"
  40                         : "=r" (result), "=m" (*atomic)
  41                         : "0" (val), "m" (*atomic));
  42   return result;
  43 }
  44
  45 void
  46 g_atomic_int_add (volatile gint *atomic,
  47                   gint           val)
  48 {
  49   __asm__ __volatile__ ("lock; addl %1,%0"
  50                         : "=m" (*atomic)
  51                         : "ir" (val), "m" (*atomic));
  52 }
  53
  54 gboolean
  55 g_atomic_int_compare_and_exchange (volatile gint *atomic,
  56                                    gint           oldval,
  57                                    gint           newval)
  58 {
  59   gint result;
  60
  61   __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
  62                         : "=a" (result), "=m" (*atomic)
  63                         : "r" (newval), "m" (*atomic), "0" (oldval));
  64
  65   return result == oldval;
  66 }
  67
  68 /* The same code as above, as on i386 gpointer is 32 bit as well.
  69  * Duplicating the code here seems more natural than casting the
  70  * arguments and calling the former function */
  71
  72 gboolean
  73 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
  74                                        gpointer           oldval,
  75                                        gpointer           newval)
  76 {
  77   gpointer result;
  78
  79   __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
  80                         : "=a" (result), "=m" (*atomic)
  81                         : "r" (newval), "m" (*atomic), "0" (oldval));
  82
  83   return result == oldval;
  84 }
  85
  86 # elif defined (G_ATOMIC_SPARCV9)
  87 /* Adapted from CVS version 1.3 of glibc's sysdeps/sparc/sparc64/bits/atomic.h
  88  */
  89 #  define ATOMIC_INT_CMP_XCHG(atomic, oldval, newval)                   \
  90   ({                                                                    \
  91      gint __result;                                                     \
  92      __asm__ __volatile__ ("cas [%4], %2, %0"                           \
  93                            : "=r" (__result), "=m" (*(atomic))          \
  94                            : "r" (oldval), "m" (*(atomic)), "r" (atomic),\
  95                            "0" (newval));                               \
  96      __result == oldval;                                                \
  97   })
  98
  99 #  if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
 100 gboolean
 101 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 102                                        gpointer           oldval,
 103                                        gpointer           newval)
 104 {
 105   gpointer result;
 106   __asm__ __volatile__ ("cas [%4], %2, %0"
 107                         : "=r" (result), "=m" (*atomic)
 108                         : "r" (oldval), "m" (*atomic), "r" (atomic),
 109                         "0" (newval));
 110   return result == oldval;
 111 }
 112 #  elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
 113 gboolean
 114 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 115                                        gpointer           oldval,
 116                                        gpointer           newval)
 117 {
 118   gpointer result;
 119   gpointer *a = atomic;
 120   __asm__ __volatile__ ("casx [%4], %2, %0"
 121                         : "=r" (result), "=m" (*a)
 122                         : "r" (oldval), "m" (*a), "r" (a),
 123                         "0" (newval));
 124   return result == oldval;
 125 }
 126 #  else /* What's that */
 127 #    error "Your system has an unsupported pointer size"
 128 #  endif /* GLIB_SIZEOF_VOID_P */
 129 #  define G_ATOMIC_MEMORY_BARRIER                                       \
 130   __asm__ __volatile__ ("membar #LoadLoad | #LoadStore"                 \
 131                         " | #StoreLoad | #StoreStore" : : : "memory")
 132
 133 # elif defined (G_ATOMIC_ALPHA)
 134 /* Adapted from CVS version 1.3 of glibc's sysdeps/alpha/bits/atomic.h
 135  */
 136 #  define ATOMIC_INT_CMP_XCHG(atomic, oldval, newval)                   \
 137   ({                                                                    \
 138      gint __result;                                                     \
 139      gint __prev;                                                       \
 140      __asm__ __volatile__ (                                             \
 141         "       mb\n"                                                   \
 142         "1:     ldl_l   %0,%2\n"                                        \
 143         "       cmpeq   %0,%3,%1\n"                                     \
 144         "       beq     %1,2f\n"                                        \
 145         "       mov     %4,%1\n"                                        \
 146         "       stl_c   %1,%2\n"                                        \
 147         "       beq     %1,1b\n"                                        \
 148         "       mb\n"                                                   \
 149         "2:"                                                            \
 150         : "=&r" (__prev),                                               \
 151           "=&r" (__result)                                              \
 152         : "m" (*(atomic)),                                              \
 153           "Ir" (oldval),                                                \
 154           "Ir" (newval)                                                 \
 155         : "memory");                                                    \
 156      __result != 0;                                                     \
 157   })
 158 #  if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
 159 gboolean
 160 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 161                                        gpointer           oldval,
 162                                        gpointer           newval)
 163 {
 164   gint result;
 165   gpointer prev;
 166   __asm__ __volatile__ (
 167         "       mb\n"
 168         "1:     ldl_l   %0,%2\n"
 169         "       cmpeq   %0,%3,%1\n"
 170         "       beq     %1,2f\n"
 171         "       mov     %4,%1\n"
 172         "       stl_c   %1,%2\n"
 173         "       beq     %1,1b\n"
 174         "       mb\n"
 175         "2:"
 176         : "=&r" (prev),
 177           "=&r" (result)
 178         : "m" (*atomic),
 179           "Ir" (oldval),
 180           "Ir" (newval)
 181         : "memory");
 182   return result != 0;
 183 }
 184 #  elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
 185 gboolean
 186 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 187                                        gpointer           oldval,
 188                                        gpointer           newval)
 189 {
 190   gint result;
 191   gpointer prev;
 192   __asm__ __volatile__ (
 193         "       mb\n"
 194         "1:     ldq_l   %0,%2\n"
 195         "       cmpeq   %0,%3,%1\n"
 196         "       beq     %1,2f\n"
 197         "       mov     %4,%1\n"
 198         "       stq_c   %1,%2\n"
 199         "       beq     %1,1b\n"
 200         "       mb\n"
 201         "2:"
 202         : "=&r" (prev),
 203           "=&r" (result)
 204         : "m" (*atomic),
 205           "Ir" (oldval),
 206           "Ir" (newval)
 207         : "memory");
 208   return result != 0;
 209 }
 210 #  else /* What's that */
 211 #   error "Your system has an unsupported pointer size"
 212 #  endif /* GLIB_SIZEOF_VOID_P */
 213 #  define G_ATOMIC_MEMORY_BARRIER  __asm__ ("mb" : : : "memory")
 214 # elif defined (G_ATOMIC_X86_64)
 215 /* Adapted from CVS version 1.9 of glibc's sysdeps/x86_64/bits/atomic.h
 216  */
 217 gint
 218 g_atomic_int_exchange_and_add (volatile gint *atomic,
 219                                gint           val)
 220 {
 221   gint result;
 222
 223   __asm__ __volatile__ ("lock; xaddl %0,%1"
 224                         : "=r" (result), "=m" (*atomic)
 225                         : "0" (val), "m" (*atomic));
 226   return result;
 227 }
 228
 229 void
 230 g_atomic_int_add (volatile gint *atomic,
 231                   gint           val)
 232 {
 233   __asm__ __volatile__ ("lock; addl %1,%0"
 234                         : "=m" (*atomic)
 235                         : "ir" (val), "m" (*atomic));
 236 }
 237
 238 gboolean
 239 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 240                                    gint           oldval,
 241                                    gint           newval)
 242 {
 243   gint result;
 244
 245   __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
 246                         : "=a" (result), "=m" (*atomic)
 247                         : "r" (newval), "m" (*atomic), "0" (oldval));
 248
 249   return result == oldval;
 250 }
 251
 252 gboolean
 253 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 254                                        gpointer           oldval,
 255                                        gpointer           newval)
 256 {
 257   gpointer result;
 258
 259   __asm__ __volatile__ ("lock; cmpxchgq %q2, %1"
 260                         : "=a" (result), "=m" (*atomic)
 261                         : "r" (newval), "m" (*atomic), "0" (oldval));
 262
 263   return result == oldval;
 264 }
 265
 266 # elif defined (G_ATOMIC_POWERPC)
 267 /* Adapted from CVS version 1.16 of glibc's sysdeps/powerpc/bits/atomic.h
 268  * and CVS version 1.4 of glibc's sysdeps/powerpc/powerpc32/bits/atomic.h
 269  * and CVS version 1.7 of glibc's sysdeps/powerpc/powerpc64/bits/atomic.h
 270  */
 271 #   ifdef __OPTIMIZE__
 272 /* Non-optimizing compile bails on the following two asm statements
 273  * for reasons unknown to the author */
 274 gint
 275 g_atomic_int_exchange_and_add (volatile gint *atomic,
 276                                gint           val)
 277 {
 278   gint result, temp;
 279   __asm__ __volatile__ ("1:       lwarx   %0,0,%3\n"
 280                         "         add     %1,%0,%4\n"
 281                         "         stwcx.  %1,0,%3\n"
 282                         "         bne-    1b"
 283                         : "=&b" (result), "=&r" (temp), "=m" (*atomic)
 284                         : "b" (atomic), "r" (val), "m" (*atomic)
 285                         : "cr0", "memory");
 286   return result;
 287 }
 288
 289 /* The same as above, to save a function call repeated here */
 290 void
 291 g_atomic_int_add (volatile gint *atomic,
 292                   gint           val)
 293 {
 294   gint result, temp;
 295   __asm__ __volatile__ ("1:       lwarx   %0,0,%3\n"
 296                         "         add     %1,%0,%4\n"
 297                         "         stwcx.  %1,0,%3\n"
 298                         "         bne-    1b"
 299                         : "=&b" (result), "=&r" (temp), "=m" (*atomic)
 300                         : "b" (atomic), "r" (val), "m" (*atomic)
 301                         : "cr0", "memory");
 302 }
 303 #   else /* !__OPTIMIZE__ */
 304 gint
 305 g_atomic_int_exchange_and_add (volatile gint *atomic,
 306                                gint           val)
 307 {
 308   gint result;
 309   do
 310     result = *atomic;
 311   while (!g_atomic_int_compare_and_exchange (atomic, result, result + val));
 312
 313   return result;
 314 }
 315
 316 void
 317 g_atomic_int_add (volatile gint *atomic,
 318                   gint           val)
 319 {
 320   gint result;
 321   do
 322     result = *atomic;
 323   while (!g_atomic_int_compare_and_exchange (atomic, result, result + val));
 324 }
 325 #   endif /* !__OPTIMIZE__ */
 326
 327 #   if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
 328 gboolean
 329 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 330                                    gint           oldval,
 331                                    gint           newval)
 332 {
 333   gint result;
 334   __asm__ __volatile__ ("sync\n"
 335                         "1: lwarx   %0,0,%1\n"
 336                         "   subf.   %0,%2,%0\n"
 337                         "   bne     2f\n"
 338                         "   stwcx.  %3,0,%1\n"
 339                         "   bne-    1b\n"
 340                         "2: isync"
 341                         : "=&r" (result)
 342                         : "b" (atomic), "r" (oldval), "r" (newval)
 343                         : "cr0", "memory");
 344   return result == 0;
 345 }
 346
 347 gboolean
 348 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 349                                        gpointer           oldval,
 350                                        gpointer           newval)
 351 {
 352   gpointer result;
 353   __asm__ __volatile__ ("sync\n"
 354                         "1: lwarx   %0,0,%1\n"
 355                         "   subf.   %0,%2,%0\n"
 356                         "   bne     2f\n"
 357                         "   stwcx.  %3,0,%1\n"
 358                         "   bne-    1b\n"
 359                         "2: isync"
 360                         : "=&r" (result)
 361                         : "b" (atomic), "r" (oldval), "r" (newval)
 362                         : "cr0", "memory");
 363   return result == 0;
 364 }
 365 #   elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
 366 gboolean
 367 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 368                                    gint           oldval,
 369                                    gint           newval)
 370 {
 371   gpointer result;
 372   __asm__ __volatile__ ("sync\n"
 373                         "1: lwarx   %0,0,%1\n"
 374                         "   extsw   %0,%0\n"
 375                         "   subf.   %0,%2,%0\n"
 376                         "   bne     2f\n"
 377                         "   stwcx.  %3,0,%1\n"
 378                         "   bne-    1b\n"
 379                         "2: isync"
 380                         : "=&r" (result)
 381                         : "b" (atomic), "r" (oldval), "r" (newval)
 382                         : "cr0", "memory");
 383   return result == 0;
 384 }
 385
 386 gboolean
 387 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 388                                        gpointer           oldval,
 389                                        gpointer           newval)
 390 {
 391   gpointer result;
 392   __asm__ __volatile__ ("sync\n"
 393                         "1: ldarx   %0,0,%1\n"
 394                         "   subf.   %0,%2,%0\n"
 395                         "   bne     2f\n"
 396                         "   stdcx.  %3,0,%1\n"
 397                         "   bne-    1b\n"
 398                         "2: isync"
 399                         : "=&r" (result)
 400                         : "b" (atomic), "r" (oldval), "r" (newval)
 401                         : "cr0", "memory");
 402   return result == 0;
 403 }
 404 #  else /* What's that */
 405 #   error "Your system has an unsupported pointer size"
 406 #  endif /* GLIB_SIZEOF_VOID_P */
 407
 408 #  define G_ATOMIC_MEMORY_BARRIER __asm__ ("sync" : : : "memory")
 409
 410 # elif defined (G_ATOMIC_IA64)
 411 /* Adapted from CVS version 1.8 of glibc's sysdeps/ia64/bits/atomic.h
 412  */
 413 gint
 414 g_atomic_int_exchange_and_add (volatile gint *atomic,
 415                                gint           val)
 416 {
 417   return __sync_fetch_and_add_si (atomic, val);
 418 }
 419
 420 void
 421 g_atomic_int_add (volatile gint *atomic,
 422                   gint val)
 423 {
 424   __sync_fetch_and_add_si (atomic, val);
 425 }
 426
 427 gboolean
 428 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 429                                    gint           oldval,
 430                                    gint           newval)
 431 {
 432   return __sync_bool_compare_and_swap_si (atomic, oldval, newval);
 433 }
 434
 435 gboolean
 436 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 437                                        gpointer           oldval,
 438                                        gpointer           newval)
 439 {
 440   return __sync_bool_compare_and_swap_di ((long *)atomic,
 441                                           (long)oldval, (long)newval);
 442 }
 443
 444 #  define G_ATOMIC_MEMORY_BARRIER __sync_synchronize ()
 445 # elif defined (G_ATOMIC_S390)
 446 /* Adapted from glibc's sysdeps/s390/bits/atomic.h
 447  */
 448 #  define ATOMIC_INT_CMP_XCHG(atomic, oldval, newval)                   \
 449   ({                                                                    \
 450      gint __result = oldval;                                    \
 451      __asm__ __volatile__ ("cs %0, %2, %1"                              \
 452                            : "+d" (__result), "=Q" (*(atomic))          \
 453                            : "d" (newval), "m" (*(atomic)) : "cc" );    \
 454      __result == oldval;                                                \
 455   })
 456
 457 #  if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
 458 gboolean
 459 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 460                                        gpointer           oldval,
 461                                        gpointer           newval)
 462 {
 463   gpointer result = oldval;
 464   __asm__ __volatile__ ("cs %0, %2, %1"
 465                         : "+d" (result), "=Q" (*(atomic))
 466                         : "d" (newval), "m" (*(atomic)) : "cc" );
 467   return result == oldval;
 468 }
 469 #  elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
 470 gboolean
 471 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 472                                        gpointer           oldval,
 473                                        gpointer           newval)
 474 {
 475   gpointer result = oldval;
 476   gpointer *a = atomic;
 477   __asm__ __volatile__ ("csg %0, %2, %1"
 478                         : "+d" (result), "=Q" (*a)
 479                         : "d" ((long)(newval)), "m" (*a) : "cc" );
 480   return result == oldval;
 481 }
 482 #  else /* What's that */
 483 #    error "Your system has an unsupported pointer size"
 484 #  endif /* GLIB_SIZEOF_VOID_P */
 485 # else /* !G_ATOMIC_IA64 */
 486 #  define DEFINE_WITH_MUTEXES
 487 # endif /* G_ATOMIC_IA64 */
 488 #else /* !__GNUC__ */
 489 # ifdef G_PLATFORM_WIN32
 490 #  define DEFINE_WITH_WIN32_INTERLOCKED
 491 # else
 492 #  define DEFINE_WITH_MUTEXES
 493 # endif
 494 #endif /* __GNUC__ */
 495
 496 #ifdef DEFINE_WITH_WIN32_INTERLOCKED
 497 # include <windows.h>
 498 gint32
 499 g_atomic_int_exchange_and_add (volatile gint32 *atomic,
 500                                gint32           val)
 501 {
 502   return InterlockedExchangeAdd (atomic, val);
 503 }
 504
 505 void
 506 g_atomic_int_add (volatile gint32 *atomic,
 507                   gint32           val)
 508 {
 509   InterlockedExchangeAdd (atomic, val);
 510 }
 511
 512 gboolean
 513 g_atomic_int_compare_and_exchange (volatile gint32 *atomic,
 514                                    gint32           oldval,
 515                                    gint32           newval)
 516 {
 517   return (guint32) InterlockedCompareExchange ((PVOID*)atomic,
 518                                                (PVOID)newval,
 519                                                (PVOID)oldval) == oldval;
 520 }
 521
 522 gboolean
 523 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 524                                        gpointer           oldval,
 525                                        gpointer           newval)
 526 {
 527 # if GLIB_SIZEOF_VOID_P != 4 /* no 32-bit system */
 528 #  error "InterlockedCompareExchangePointer needed"
 529 # else
 530    return InterlockedCompareExchange (atomic, newval, oldval) == oldval;
 531 # endif
 532 }
 533 #endif /* DEFINE_WITH_WIN32_INTERLOCKED */
 534
 535 #ifdef DEFINE_WITH_MUTEXES
 536 /* We have to use the slow, but safe locking method */
 537 static GMutex *g_atomic_mutex;
 538
 539 gint
 540 g_atomic_int_exchange_and_add (volatile gint *atomic,
 541                                gint           val)
 542 {
 543   gint result;
 544
 545   g_mutex_lock (g_atomic_mutex);
 546   result = *atomic;
 547   *atomic += val;
 548   g_mutex_unlock (g_atomic_mutex);
 549
 550   return result;
 551 }
 552
 553
 554 void
 555 g_atomic_int_add (volatile gint *atomic,
 556                   gint           val)
 557 {
 558   g_mutex_lock (g_atomic_mutex);
 559   *atomic += val;
 560   g_mutex_unlock (g_atomic_mutex);
 561 }
 562
 563 gboolean
 564 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 565                                    gint           oldval,
 566                                    gint           newval)
 567 {
 568   gboolean result;
 569
 570   g_mutex_lock (g_atomic_mutex);
 571   if (*atomic == oldval)
 572     {
 573       result = TRUE;
 574       *atomic = newval;
 575     }
 576   else
 577     result = FALSE;
 578   g_mutex_unlock (g_atomic_mutex);
 579
 580   return result;
 581 }
 582
 583 gboolean
 584 g_atomic_pointer_compare_and_exchange (volatile gpointer *atomic,
 585                                        gpointer           oldval,
 586                                        gpointer           newval)
 587 {
 588   gboolean result;
 589
 590   g_mutex_lock (g_atomic_mutex);
 591   if (*atomic == oldval)
 592     {
 593       result = TRUE;
 594       *atomic = newval;
 595     }
 596   else
 597     result = FALSE;
 598   g_mutex_unlock (g_atomic_mutex);
 599
 600   return result;
 601 }
 602
 603 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 604 gint
 605 g_atomic_int_get (volatile gint *atomic)
 606 {
 607   gint result;
 608
 609   g_mutex_lock (g_atomic_mutex);
 610   result = *atomic;
 611   g_mutex_unlock (g_atomic_mutex);
 612
 613   return result;
 614 }
 615
 616 gpointer
 617 g_atomic_pointer_get (volatile gpointer *atomic)
 618 {
 619   gpointer result;
 620
 621   g_mutex_lock (g_atomic_mutex);
 622   result = *atomic;
 623   g_mutex_unlock (g_atomic_mutex);
 624
 625   return result;
 626 }
 627 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 628 #elif defined (G_ATOMIC_OP_MEMORY_BARRIER_NEEDED)
 629 gint
 630 g_atomic_int_get (volatile gint *atomic)
 631 {
 632   gint result = *atomic;
 633
 634   G_ATOMIC_MEMORY_BARRIER;
 635
 636   return result;
 637 }
 638
 639 gpointer
 640 g_atomic_pointer_get (volatile gpointer *atomic)
 641 {
 642   gpointer result = *atomic;
 643
 644   G_ATOMIC_MEMORY_BARRIER;
 645
 646   return result;
 647 }
 648 #endif /* DEFINE_WITH_MUTEXES || G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 649
 650 #ifdef ATOMIC_INT_CMP_XCHG
 651 gboolean
 652 g_atomic_int_compare_and_exchange (volatile gint *atomic,
 653                                    gint           oldval,
 654                                    gint           newval)
 655 {
 656   return ATOMIC_INT_CMP_XCHG (atomic, oldval, newval);
 657 }
 658
 659 gint
 660 g_atomic_int_exchange_and_add (volatile gint *atomic,
 661                                gint           val)
 662 {
 663   gint result;
 664   do
 665     result = *atomic;
 666   while (!ATOMIC_INT_CMP_XCHG (atomic, result, result + val));
 667
 668   return result;
 669 }
 670
 671 void
 672 g_atomic_int_add (volatile gint *atomic,
 673                   gint           val)
 674 {
 675   gint result;
 676   do
 677     result = *atomic;
 678   while (!ATOMIC_INT_CMP_XCHG (atomic, result, result + val));
 679 }
 680 #endif /* ATOMIC_INT_CMP_XCHG */
 681
 682 void
 683 _g_atomic_thread_init (void)
 684 {
 685 #ifdef DEFINE_WITH_MUTEXES
 686   g_atomic_mutex = g_mutex_new ();
 687 #endif /* DEFINE_WITH_MUTEXES */
 688 }
 689
 690 #ifndef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 691 gint
 692 (g_atomic_int_get) (volatile gint *atomic)
 693 {
 694   return g_atomic_int_get (atomic);
 695 }
 696
 697 gpointer
 698 (g_atomic_pointer_get) (volatile gpointer *atomic)
 699 {
 700   return g_atomic_pointer_get (atomic);
 701 }
 702 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 703
 704 #define __G_ATOMIC_C__
 705 #include "galiasdef.c"