Add AMTL files

public/amtl/am-atomics.h

@@ -0,0 +1,102 @@
+// vim: set sts=8 ts=2 sw=2 tw=99 et:
+//
+// Copyright (C) 2013, David Anderson and AlliedModders LLC
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+// 
+//  * Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+//  * Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//  * Neither the name of AlliedModders LLC nor the names of its contributors
+//    may be used to endorse or promote products derived from this software
+//    without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef _include_amtl_atomics_h_
+#define _include_amtl_atomics_h_
+
+#include <am-utility.h>
+
+namespace ke {
+
+#if defined(_MSC_VER)
+extern "C" {
+  long __cdecl _InterlockedIncrement(long volatile *dest);
+  long __cdecl _InterlockedDecrement(long volatile *dest);
+}
+# pragma intrinsic(_InterlockedIncrement)
+# pragma intrinsic(_InterlockedDecrement)
+#endif
+
+template <size_t Width>
+struct AtomicOps;
+
+template <>
+struct AtomicOps<4>
+{
+#if defined(_MSC_VER)
+  typedef long Type;
+
+  static Type Increment(Type *ptr) {
+    return _InterlockedIncrement(ptr);
+  }
+  static Type Decrement(Type *ptr) {
+    return _InterlockedDecrement(ptr);
+  };
+#elif defined(__GNUC__)
+  typedef int Type;
+
+  // x86/x64 notes: When using GCC < 4.8, this will compile to a spinlock.
+  // On 4.8+, or when using Clang, we'll get the more optimal "lock addl"
+  // variant.
+  static Type Increment(Type *ptr) {
+    return __sync_add_and_fetch(ptr, 1);
+  }
+  static Type Decrement(Type *ptr) {
+    return __sync_sub_and_fetch(ptr, 1);
+  }
+#endif
+};
+
+class AtomicRefCount
+{
+  typedef AtomicOps<sizeof(uintptr_t)> Ops;
+
+ public:
+  AtomicRefCount(uintptr_t value)
+   : value_(value)
+  {
+  }
+
+  void increment() {
+    Ops::Increment(&value_);
+  }
+
+  // Return false if all references are gone.
+  bool decrement() {
+    return Ops::Decrement(&value_) != 0;
+  }
+
+ private:
+  Ops::Type value_;
+};
+
+}
+
+#endif // _include_amtl_atomics_h_
+