1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/ports/SkAtomics_win.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,62 @@
1.4 +/*
1.5 + * Copyright 2013 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkAtomics_win_DEFINED
1.12 +#define SkAtomics_win_DEFINED
1.13 +
1.14 +/** Windows Interlocked atomics. */
1.15 +
1.16 +#include <intrin.h>
1.17 +#include <stdint.h>
1.18 +
1.19 +//MSDN says in order to declare an interlocked function for use as an
1.20 +//intrinsic, include intrin.h and put the function in a #pragma intrinsic
1.21 +//directive.
1.22 +//The pragma appears to be unnecessary, but doesn't hurt.
1.23 +#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement)
1.24 +#pragma intrinsic(_InterlockedCompareExchange)
1.25 +
1.26 +static inline int32_t sk_atomic_inc(int32_t* addr) {
1.27 + // InterlockedIncrement returns the new value, we want to return the old.
1.28 + return _InterlockedIncrement(reinterpret_cast<long*>(addr)) - 1;
1.29 +}
1.30 +
1.31 +static inline int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
1.32 + return _InterlockedExchangeAdd(reinterpret_cast<long*>(addr), static_cast<long>(inc));
1.33 +}
1.34 +
1.35 +static inline int32_t sk_atomic_dec(int32_t* addr) {
1.36 + // InterlockedDecrement returns the new value, we want to return the old.
1.37 + return _InterlockedDecrement(reinterpret_cast<long*>(addr)) + 1;
1.38 +}
1.39 +
1.40 +static inline void sk_membar_acquire__after_atomic_dec() { }
1.41 +
1.42 +static inline int32_t sk_atomic_conditional_inc(int32_t* addr) {
1.43 + long value = *addr;
1.44 + while (true) {
1.45 + if (value == 0) {
1.46 + return 0;
1.47 + }
1.48 +
1.49 + long before = _InterlockedCompareExchange(reinterpret_cast<long*>(addr), value + 1, value);
1.50 +
1.51 + if (before == value) {
1.52 + return value;
1.53 + } else {
1.54 + value = before;
1.55 + }
1.56 + }
1.57 +}
1.58 +
1.59 +static inline bool sk_atomic_cas(int32_t* addr, int32_t before, int32_t after) {
1.60 + return _InterlockedCompareExchange(reinterpret_cast<long*>(addr), after, before) == before;
1.61 +}
1.62 +
1.63 +static inline void sk_membar_acquire__after_atomic_conditional_inc() { }
1.64 +
1.65 +#endif
