1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * g_atomic_*: atomic operations.
5 * Copyright (C) 2003 Sebastian Wilhelmi
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.
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.
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.
27 #include "gthreadinit.h"
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
34 g_atomic_int_exchange_and_add (gint *atomic,
39 __asm__ __volatile__ ("lock; xaddl %0,%1"
40 : "=r" (result), "=m" (*atomic)
41 : "0" (val), "m" (*atomic));
46 g_atomic_int_add (gint *atomic,
49 __asm__ __volatile__ ("lock; addl %1,%0"
51 : "ir" (val), "m" (*atomic));
55 g_atomic_int_compare_and_exchange (gint *atomic,
61 __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
62 : "=a" (result), "=m" (*atomic)
63 : "r" (newval), "m" (*atomic), "0" (oldval));
65 return result == oldval;
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 */
73 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
79 __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
80 : "=a" (result), "=m" (*atomic)
81 : "r" (newval), "m" (*atomic), "0" (oldval));
83 return result == oldval;
86 # elif defined (G_ATOMIC_SPARCV9)
87 /* Adapted from CVS version 1.3 of glibc's sysdeps/sparc/sparc64/bits/atomic.h
89 # define ATOMIC_INT_CMP_XCHG(atomic, oldval, newval) \
92 __asm__ __volatile__ ("cas [%4], %2, %0" \
93 : "=r" (__result), "=m" (*(atomic)) \
94 : "r" (oldval), "m" (*(atomic)), "r" (atomic),\
99 # if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
101 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
106 __asm__ __volatile__ ("cas [%4], %2, %0"
107 : "=r" (result), "=m" (*atomic)
108 : "r" (oldval), "m" (*atomic), "r" (atomic),
110 return result == oldval;
112 # elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
114 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
119 gpointer *a = atomic;
120 __asm__ __volatile__ ("casx [%4], %2, %0"
121 : "=r" (result), "=m" (*a)
122 : "r" (oldval), "m" (*a), "r" (a),
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")
133 # elif defined (G_ATOMIC_ALPHA)
134 /* Adapted from CVS version 1.3 of glibc's sysdeps/alpha/bits/atomic.h
136 # define ATOMIC_INT_CMP_XCHG(atomic, oldval, newval) \
140 __asm__ __volatile__ ( \
143 " cmpeq %0,%3,%1\n" \
158 # if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
160 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
166 __asm__ __volatile__ (
184 # elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
186 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
192 __asm__ __volatile__ (
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
218 g_atomic_int_exchange_and_add (gint *atomic,
223 __asm__ __volatile__ ("lock; xaddl %0,%1"
224 : "=r" (result), "=m" (*atomic)
225 : "0" (val), "m" (*atomic));
230 g_atomic_int_add (gint *atomic,
233 __asm__ __volatile__ ("lock; addl %1,%0"
235 : "ir" (val), "m" (*atomic));
239 g_atomic_int_compare_and_exchange (gint *atomic,
245 __asm__ __volatile__ ("lock; cmpxchgl %2, %1"
246 : "=a" (result), "=m" (*atomic)
247 : "r" (newval), "m" (*atomic), "0" (oldval));
249 return result == oldval;
253 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
259 __asm__ __volatile__ ("lock; cmpxchgq %q2, %1"
260 : "=a" (result), "=m" (*atomic)
261 : "r" (newval), "m" (*atomic), "0" (oldval));
263 return result == oldval;
266 # elif defined (G_ATOMIC_POWERPC)
267 /* Adapted from CVS version 1.12 of glibc's sysdeps/powerpc/bits/atomic.h
268 * and CVS version 1.3 of glibc's sysdeps/powerpc/powerpc32/bits/atomic.h
269 * and CVS version 1.2 of glibc's sysdeps/powerpc/powerpc64/bits/atomic.h
272 /* Non-optimizing compile bails on the following two asm statements
273 * for reasons unknown to the author */
275 g_atomic_int_exchange_and_add (gint *atomic,
279 __asm__ __volatile__ ("1: lwarx %0,0,%3\n"
283 : "=&b" (result), "=&r" (temp), "=m" (*atomic)
284 : "b" (atomic), "r" (val), "2" (*atomic)
289 /* The same as above, to save a function call repeated here */
291 g_atomic_int_add (gint *atomic,
295 __asm__ __volatile__ ("1: lwarx %0,0,%3\n"
299 : "=&b" (result), "=&r" (temp), "=m" (*atomic)
300 : "b" (atomic), "r" (val), "2" (*atomic)
303 # else /* !__OPTIMIZE__ */
305 g_atomic_int_exchange_and_add (gint *atomic,
311 while (!g_atomic_int_compare_and_exchange (atomic, result, result + val));
317 g_atomic_int_add (gint *atomic,
323 while (!g_atomic_int_compare_and_exchange (atomic, result, result + val));
325 # endif /* !__OPTIMIZE__ */
327 # if GLIB_SIZEOF_VOID_P == 4 /* 32-bit system */
329 g_atomic_int_compare_and_exchange (gint *atomic,
334 __asm__ __volatile__ ("sync\n"
342 : "b" (atomic), "r" (oldval), "r" (newval)
348 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
353 __asm__ __volatile__ ("sync\n"
361 : "b" (atomic), "r" (oldval), "r" (newval)
365 # elif GLIB_SIZEOF_VOID_P == 8 /* 64-bit system */
367 g_atomic_int_compare_and_exchange (gint *atomic,
372 __asm__ __volatile__ ("sync\n"
381 : "b" (atomic), "r" (oldval), "r" (newval)
387 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
392 __asm__ __volatile__ ("sync\n"
400 : "b" (atomic), "r" (oldval), "r" (newval)
404 # else /* What's that */
405 # error "Your system has an unsupported pointer size"
406 # endif /* GLIB_SIZEOF_VOID_P */
408 # define G_ATOMIC_MEMORY_BARRIER __asm__ ("sync" : : : "memory")
410 # elif defined (G_ATOMIC_IA64)
411 /* Adapted from CVS version 1.8 of glibc's sysdeps/ia64/bits/atomic.h
414 g_atomic_int_exchange_and_add (gint *atomic,
417 return __sync_fetch_and_add_si (atomic, val);
421 g_atomic_int_add (gint *atomic,
424 __sync_fetch_and_add_si (atomic, val);
428 g_atomic_int_compare_and_exchange (gint *atomic,
432 return __sync_bool_compare_and_swap_si (atomic, oldval, newval);
436 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
440 return __sync_bool_compare_and_swap_di ((long *)atomic,
441 (long)oldval, (long)newval);
444 # define G_ATOMIC_MEMORY_BARRIER __sync_synchronize ()
445 # else /* !G_ATOMIC */
446 # define DEFINE_WITH_MUTEXES
447 # endif /* G_ATOMIC */
448 #else /* !__GNUC__ */
449 # ifdef G_PLATFORM_WIN32
450 # define DEFINE_WITH_WIN32_INTERLOCKED
452 # define DEFINE_WITH_MUTEXES
454 #endif /* __GNUC__ */
456 #ifdef DEFINE_WITH_WIN32_INTERLOCKED
457 # include <windows.h>
459 g_atomic_int_exchange_and_add (gint32 *atomic,
462 return InterlockedExchangeAdd (atomic, val);
466 g_atomic_int_add (gint32 *atomic,
469 InterlockedExchangeAdd (atomic, val);
473 g_atomic_int_compare_and_exchange (gint32 *atomic,
477 return (guint32)InterlockedCompareExchange ((PVOID*)atomic,
479 (PVOID)oldval) == oldval;
483 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
487 # if GLIB_SIZEOF_VOID_P != 4 /* no 32-bit system */
488 # error "InterlockedCompareExchangePointer needed"
490 return InterlockedCompareExchange (atomic, newval, oldval) == oldval;
493 #endif /* DEFINE_WITH_WIN32_INTERLOCKED */
495 #ifdef DEFINE_WITH_MUTEXES
496 /* We have to use the slow, but safe locking method */
497 static GMutex *g_atomic_mutex;
500 g_atomic_int_exchange_and_add (gint *atomic,
505 g_mutex_lock (g_atomic_mutex);
508 g_mutex_unlock (g_atomic_mutex);
515 g_atomic_int_add (gint *atomic,
518 g_mutex_lock (g_atomic_mutex);
520 g_mutex_unlock (g_atomic_mutex);
524 g_atomic_int_compare_and_exchange (gint *atomic,
530 g_mutex_lock (g_atomic_mutex);
531 if (*atomic == oldval)
538 g_mutex_unlock (g_atomic_mutex);
544 g_atomic_pointer_compare_and_exchange (gpointer *atomic,
550 g_mutex_lock (g_atomic_mutex);
551 if (*atomic == oldval)
558 g_mutex_unlock (g_atomic_mutex);
563 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
565 g_atomic_int_get (gint *atomic)
569 g_mutex_lock (g_atomic_mutex);
571 g_mutex_unlock (g_atomic_mutex);
577 g_atomic_pointer_get (gpointer *atomic)
581 g_mutex_lock (g_atomic_mutex);
583 g_mutex_unlock (g_atomic_mutex);
587 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
588 #elif defined (G_ATOMIC_OP_MEMORY_BARRIER_NEEDED)
590 g_atomic_int_get (gint *atomic)
592 gint result = *atomic;
594 G_ATOMIC_MEMORY_BARRIER;
600 g_atomic_pointer_get (gpointer *atomic)
602 gpointer result = *atomic;
604 G_ATOMIC_MEMORY_BARRIER;
608 #endif /* DEFINE_WITH_MUTEXES || G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
610 #ifdef ATOMIC_INT_CMP_XCHG
612 g_atomic_int_compare_and_exchange (gint *atomic,
616 return ATOMIC_INT_CMP_XCHG (atomic, oldval, newval);
620 g_atomic_int_exchange_and_add (gint *atomic,
626 while (!ATOMIC_INT_CMP_XCHG (atomic, result, result + val));
632 g_atomic_int_add (gint *atomic,
638 while (!ATOMIC_INT_CMP_XCHG (atomic, result, result + val));
640 #endif /* ATOMIC_INT_CMP_XCHG */
643 _g_atomic_thread_init (void)
645 #ifdef DEFINE_WITH_MUTEXES
646 g_atomic_mutex = g_mutex_new ();
647 #endif /* DEFINE_WITH_MUTEXES */