1/*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkAtomics_win_DEFINED
9#define SkAtomics_win_DEFINED
10
11/** Windows Interlocked atomics. */
12
13#include <intrin.h>
14#include <stdint.h>
15
16//MSDN says in order to declare an interlocked function for use as an
17//intrinsic, include intrin.h and put the function in a #pragma intrinsic
18//directive.
19//The pragma appears to be unnecessary, but doesn't hurt.
20#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement)
21#pragma intrinsic(_InterlockedCompareExchange)
22
23static inline int32_t sk_atomic_inc(int32_t* addr) {
24    // InterlockedIncrement returns the new value, we want to return the old.
25    return _InterlockedIncrement(reinterpret_cast<long*>(addr)) - 1;
26}
27
28static inline int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
29    return _InterlockedExchangeAdd(reinterpret_cast<long*>(addr), static_cast<long>(inc));
30}
31
32static inline int32_t sk_atomic_dec(int32_t* addr) {
33    // InterlockedDecrement returns the new value, we want to return the old.
34    return _InterlockedDecrement(reinterpret_cast<long*>(addr)) + 1;
35}
36
37static inline void sk_membar_acquire__after_atomic_dec() { }
38
39static inline bool sk_atomic_cas(int32_t* addr, int32_t before, int32_t after) {
40    return _InterlockedCompareExchange(reinterpret_cast<long*>(addr), after, before) == before;
41}
42
43static inline void* sk_atomic_cas(void** addr, void* before, void* after) {
44    return InterlockedCompareExchangePointer(addr, after, before);
45}
46
47static inline void sk_membar_acquire__after_atomic_conditional_inc() { }
48
49#endif
50