1 files changed, 71 insertions, 0 deletions
diff --git a/sfntly/port/atomic.h b/sfntly/port/atomic.h
new file mode 100644
index 0000000..b381a52
--- /dev/null
+++ b/sfntly/port/atomic.h
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2011 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef SFNTLY_CPP_SRC_SFNTLY_PORT_ATOMIC_H_
+#define SFNTLY_CPP_SRC_SFNTLY_PORT_ATOMIC_H_
+
+#if defined (WIN32)
+
+#include <windows.h>
+
+static inline size_t AtomicIncrement(size_t* address) {
+#if defined (_WIN64)
+  return InterlockedIncrement64(reinterpret_cast<LONGLONG*>(address));
+#else
+  return InterlockedIncrement(reinterpret_cast<LONG*>(address));
+#endif
+}
+
+static inline size_t AtomicDecrement(size_t* address) {
+#if defined (_WIN64)
+  return InterlockedDecrement64(reinterpret_cast<LONGLONG*>(address));
+#else
+  return InterlockedDecrement(reinterpret_cast<LONG*>(address));
+#endif
+}
+
+#elif defined (__APPLE__)
+
+#include <libkern/OSAtomic.h>
+
+static inline size_t AtomicIncrement(size_t* address) {
+  return OSAtomicIncrement32Barrier(reinterpret_cast<int32_t*>(address));
+}
+
+static inline size_t AtomicDecrement(size_t* address) {
+  return OSAtomicDecrement32Barrier(reinterpret_cast<int32_t*>(address));
+}
+
+// Originally we check __GCC_HAVE_SYNC_COMPARE_AND_SWAP_4, however, there are
+// issues that clang not carring over this definition.  Therefore we boldly
+// assume it's gcc or gcc-compatible here.  Compilation shall still fail since
+// the intrinsics used are GCC-specific.
+
+#else
+
+#include <stddef.h>
+
+static inline size_t AtomicIncrement(size_t* address) {
+  return __sync_add_and_fetch(address, 1);
+}
+
+static inline size_t AtomicDecrement(size_t* address) {
+  return __sync_sub_and_fetch(address, 1);
+}
+
+#endif  // WIN32
+
+#endif  // SFNTLY_CPP_SRC_SFNTLY_PORT_ATOMIC_H_