*
*/
+#include "no_extern_c.h"
+
#ifndef U_ATOMIC_H
#define U_ATOMIC_H
#include <stdbool.h>
+#include <stdint.h>
/* Favor OS-provided implementations.
*
#define PIPE_ATOMIC "GCC Sync Intrinsics"
+#if defined(USE_GCC_ATOMIC_BUILTINS)
+
+/* The builtins with explicit memory model are available since GCC 4.7. */
+#define p_atomic_set(_v, _i) __atomic_store_n((_v), (_i), __ATOMIC_RELEASE)
+#define p_atomic_read(_v) __atomic_load_n((_v), __ATOMIC_ACQUIRE)
+#define p_atomic_dec_zero(v) (__atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL) == 0)
+#define p_atomic_inc(v) (void) __atomic_add_fetch((v), 1, __ATOMIC_ACQ_REL)
+#define p_atomic_dec(v) (void) __atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL)
+#define p_atomic_add(v, i) (void) __atomic_add_fetch((v), (i), __ATOMIC_ACQ_REL)
+#define p_atomic_inc_return(v) __atomic_add_fetch((v), 1, __ATOMIC_ACQ_REL)
+#define p_atomic_dec_return(v) __atomic_sub_fetch((v), 1, __ATOMIC_ACQ_REL)
+#define p_atomic_add_return(v, i) __atomic_add_fetch((v), (i), __ATOMIC_ACQ_REL)
+#define p_atomic_xchg(v, i) __atomic_exchange_n((v), (i), __ATOMIC_ACQ_REL)
+#define PIPE_NATIVE_ATOMIC_XCHG
+
+#else
+
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
#define p_atomic_dec_zero(v) (__sync_sub_and_fetch((v), 1) == 0)
#define p_atomic_add(v, i) (void) __sync_add_and_fetch((v), (i))
#define p_atomic_inc_return(v) __sync_add_and_fetch((v), 1)
#define p_atomic_dec_return(v) __sync_sub_and_fetch((v), 1)
+#define p_atomic_add_return(v, i) __sync_add_and_fetch((v), (i))
+
+#endif
+
+/* There is no __atomic_* compare and exchange that returns the current value.
+ * Also, GCC 5.4 seems unable to optimize a compound statement expression that
+ * uses an additional stack variable with __atomic_compare_exchange[_n].
+ */
#define p_atomic_cmpxchg(v, old, _new) \
__sync_val_compare_and_swap((v), (old), (_new))
#define p_atomic_dec_zero(_v) (p_atomic_dec_return(_v) == 0)
#define p_atomic_inc(_v) ((void) p_atomic_inc_return(_v))
#define p_atomic_dec(_v) ((void) p_atomic_dec_return(_v))
-#define p_atomic_add(_v, _i) (*(_v) = *(_v) + (_i))
+#define p_atomic_add(_v, _i) ((void) p_atomic_add_return((_v), (_i)))
#define p_atomic_inc_return(_v) (++(*(_v)))
#define p_atomic_dec_return(_v) (--(*(_v)))
+#define p_atomic_add_return(_v, _i) (*(_v) = *(_v) + (_i))
#define p_atomic_cmpxchg(_v, _old, _new) (*(_v) == (_old) ? (*(_v) = (_new), (_old)) : *(_v))
#endif
#include <intrin.h>
#include <assert.h>
-#if _MSC_VER < 1600
-
-/* Implement _InterlockedCompareExchange8 in terms of _InterlockedCompareExchange16 */
-static __inline char
-_InterlockedCompareExchange8(char volatile *Destination8, char Exchange8, char Comparand8)
-{
- INT_PTR DestinationAddr = (INT_PTR)Destination8;
- short volatile *Destination16 = (short volatile *)(DestinationAddr & ~1);
- const short Shift8 = (DestinationAddr & 1) * 8;
- const short Mask8 = 0xff << Shift8;
- short Initial16 = *Destination16;
- char Initial8 = Initial16 >> Shift8;
- while (Initial8 == Comparand8) {
- /* initial *Destination8 matches, so try exchange it while keeping the
- * neighboring byte untouched */
- short Exchange16 = (Initial16 & ~Mask8) | ((short)Exchange8 << Shift8);
- short Comparand16 = Initial16;
- short Initial16 = _InterlockedCompareExchange16(Destination16, Exchange16, Comparand16);
- if (Initial16 == Comparand16) {
- /* succeeded */
- return Comparand8;
- }
- /* something changed, retry with the new initial value */
- Initial8 = Initial16 >> Shift8;
- }
- return Initial8;
-}
-
-/* Implement _InterlockedExchangeAdd16 in terms of _InterlockedCompareExchange16 */
-static __inline short
-_InterlockedExchangeAdd16(short volatile *Addend, short Value)
-{
- short Initial = *Addend;
- short Comparand;
- do {
- short Exchange = Initial + Value;
- Comparand = Initial;
- /* if *Addend==Comparand then *Addend=Exchange, return original *Addend */
- Initial = _InterlockedCompareExchange16(Addend, Exchange, Comparand);
- } while(Initial != Comparand);
- return Comparand;
-}
-
-/* Implement _InterlockedExchangeAdd8 in terms of _InterlockedCompareExchange8 */
-static __inline char
-_InterlockedExchangeAdd8(char volatile *Addend, char Value)
-{
- char Initial = *Addend;
- char Comparand;
- do {
- char Exchange = Initial + Value;
- Comparand = Initial;
- Initial = _InterlockedCompareExchange8(Addend, Exchange, Comparand);
- } while(Initial != Comparand);
- return Comparand;
-}
-
-#endif /* _MSC_VER < 1600 */
-
/* MSVC supports decltype keyword, but it's only supported on C++ and doesn't
* quite work here; and if a C++-only solution is worthwhile, then it would be
* better to use templates / function overloading, instead of decltype magic.
sizeof *(_v) == sizeof(__int64) ? InterlockedDecrement64 ((__int64 *)(_v)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_add(_v, _i) (\
+#define p_atomic_add(_v, _i) \
+ ((void) p_atomic_add_return((_v), (_i)))
+
+#define p_atomic_add_return(_v, _i) (\
sizeof *(_v) == sizeof(char) ? _InterlockedExchangeAdd8 ((char *) (_v), (_i)) : \
sizeof *(_v) == sizeof(short) ? _InterlockedExchangeAdd16((short *) (_v), (_i)) : \
sizeof *(_v) == sizeof(long) ? _InterlockedExchangeAdd ((long *) (_v), (_i)) : \
sizeof(*v) == sizeof(uint64_t) ? atomic_inc_64((uint64_t *)(v)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_inc_return(v) ((typeof(*v)) \
+#define p_atomic_inc_return(v) (__typeof(*v))( \
sizeof(*v) == sizeof(uint8_t) ? atomic_inc_8_nv ((uint8_t *)(v)) : \
sizeof(*v) == sizeof(uint16_t) ? atomic_inc_16_nv((uint16_t *)(v)) : \
sizeof(*v) == sizeof(uint32_t) ? atomic_inc_32_nv((uint32_t *)(v)) : \
sizeof(*v) == sizeof(uint64_t) ? atomic_inc_64_nv((uint64_t *)(v)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_dec(v) ((void) \
+#define p_atomic_dec(v) (void) ( \
sizeof(*v) == sizeof(uint8_t) ? atomic_dec_8 ((uint8_t *)(v)) : \
sizeof(*v) == sizeof(uint16_t) ? atomic_dec_16((uint16_t *)(v)) : \
sizeof(*v) == sizeof(uint32_t) ? atomic_dec_32((uint32_t *)(v)) : \
sizeof(*v) == sizeof(uint64_t) ? atomic_dec_64((uint64_t *)(v)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_dec_return(v) ((typeof(*v)) \
+#define p_atomic_dec_return(v) (__typeof(*v))( \
sizeof(*v) == sizeof(uint8_t) ? atomic_dec_8_nv ((uint8_t *)(v)) : \
sizeof(*v) == sizeof(uint16_t) ? atomic_dec_16_nv((uint16_t *)(v)) : \
sizeof(*v) == sizeof(uint32_t) ? atomic_dec_32_nv((uint32_t *)(v)) : \
sizeof(*v) == sizeof(uint64_t) ? atomic_dec_64_nv((uint64_t *)(v)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_add(v, i) ((void) \
+#define p_atomic_add(v, i) (void) ( \
sizeof(*v) == sizeof(uint8_t) ? atomic_add_8 ((uint8_t *)(v), (i)) : \
sizeof(*v) == sizeof(uint16_t) ? atomic_add_16((uint16_t *)(v), (i)) : \
sizeof(*v) == sizeof(uint32_t) ? atomic_add_32((uint32_t *)(v), (i)) : \
sizeof(*v) == sizeof(uint64_t) ? atomic_add_64((uint64_t *)(v), (i)) : \
(assert(!"should not get here"), 0))
-#define p_atomic_cmpxchg(v, old, _new) ((typeof(*v)) \
+#define p_atomic_add_return(v, i) (__typeof(*v)) ( \
+ sizeof(*v) == sizeof(uint8_t) ? atomic_add_8_nv ((uint8_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint16_t) ? atomic_add_16_nv((uint16_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint32_t) ? atomic_add_32_nv((uint32_t *)(v), (i)) : \
+ sizeof(*v) == sizeof(uint64_t) ? atomic_add_64_nv((uint64_t *)(v), (i)) : \
+ (assert(!"should not get here"), 0))
+
+#define p_atomic_cmpxchg(v, old, _new) (__typeof(*v))( \
sizeof(*v) == sizeof(uint8_t) ? atomic_cas_8 ((uint8_t *)(v), (uint8_t )(old), (uint8_t )(_new)) : \
sizeof(*v) == sizeof(uint16_t) ? atomic_cas_16((uint16_t *)(v), (uint16_t)(old), (uint16_t)(_new)) : \
sizeof(*v) == sizeof(uint32_t) ? atomic_cas_32((uint32_t *)(v), (uint32_t)(old), (uint32_t)(_new)) : \
#error "No pipe_atomic implementation selected"
#endif
+#ifndef PIPE_NATIVE_ATOMIC_XCHG
+static inline uint32_t p_atomic_xchg_32(uint32_t *v, uint32_t i)
+{
+ uint32_t actual = p_atomic_read(v);
+ uint32_t expected;
+ do {
+ expected = actual;
+ actual = p_atomic_cmpxchg(v, expected, i);
+ } while (expected != actual);
+ return actual;
+}
+
+static inline uint64_t p_atomic_xchg_64(uint64_t *v, uint64_t i)
+{
+ uint64_t actual = p_atomic_read(v);
+ uint64_t expected;
+ do {
+ expected = actual;
+ actual = p_atomic_cmpxchg(v, expected, i);
+ } while (expected != actual);
+ return actual;
+}
+#define p_atomic_xchg(v, i) (__typeof(*(v)))( \
+ sizeof(*(v)) == sizeof(uint32_t) ? p_atomic_xchg_32((uint32_t *)(v), (uint32_t)(i)) : \
+ sizeof(*(v)) == sizeof(uint64_t) ? p_atomic_xchg_64((uint64_t *)(v), (uint64_t)(i)) : \
+ (assert(!"should not get here"), 0))
+#endif
#endif /* U_ATOMIC_H */