Index: src/ports/SkAtomics_win.h |
=================================================================== |
--- src/ports/SkAtomics_win.h (revision 0) |
+++ src/ports/SkAtomics_win.h (working copy) |
@@ -0,0 +1,58 @@ |
+/* |
+ * Copyright 2013 Google Inc. |
+ * |
+ * Use of this source code is governed by a BSD-style license that can be |
+ * found in the LICENSE file. |
+ */ |
+ |
+#ifndef SkAtomics_win_DEFINED |
+#define SkAtomics_win_DEFINED |
+ |
+/** Windows Interlocked atomics. */ |
+ |
+#include <intrin.h> |
+#include <stdint.h> |
+ |
+//MSDN says in order to declare an interlocked function for use as an |
+//intrinsic, include intrin.h and put the function in a #pragma intrinsic |
+//directive. |
+//The pragma appears to be unnecessary, but doesn't hurt. |
+#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement) |
+#pragma intrinsic(_InterlockedCompareExchange) |
+ |
+static inline int32_t sk_atomic_inc(int32_t* addr) { |
+ // InterlockedIncrement returns the new value, we want to return the old. |
+ return _InterlockedIncrement(reinterpret_cast<long*>(addr)) - 1; |
+} |
+ |
+static inline int32_t sk_atomic_add(int32_t* addr, int32_t inc) { |
+ return _InterlockedExchangeAdd(reinterpret_cast<long*>(addr), static_cast<long>(inc)); |
+} |
+ |
+static inline int32_t sk_atomic_dec(int32_t* addr) { |
+ // InterlockedDecrement returns the new value, we want to return the old. |
+ return _InterlockedDecrement(reinterpret_cast<long*>(addr)) + 1; |
+} |
+ |
+static inline void sk_membar_acquire__after_atomic_dec() { } |
+ |
+static inline int32_t sk_atomic_conditional_inc(int32_t* addr) { |
+ long value = *addr; |
+ while (true) { |
+ if (value == 0) { |
+ return 0; |
+ } |
+ |
+ long before = _InterlockedCompareExchange(reinterpret_cast<long*>(addr), value + 1, value); |
+ |
+ if (before == value) { |
+ return value; |
+ } else { |
+ value = before; |
+ } |
+ } |
+} |
+ |
+static inline void sk_membar_acquire__after_atomic_conditional_inc() { } |
+ |
+#endif |