xref: /external/chromium_org/third_party/protobuf/src/google/protobuf/stubs/atomicops_internals_x86_msvc.h

// Protocol Buffers - Google's data interchange format
// Copyright 2012 Google Inc.  All rights reserved.
// http://code.google.com/p/protobuf/
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// This file is an internal atomic implementation, use atomicops.h instead.

#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_X86_MSVC_H_
#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_X86_MSVC_H_

namespace google {
namespace protobuf {
namespace internal {

inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
                                          Atomic32 increment) {
  return Barrier_AtomicIncrement(ptr, increment);
}

#if !(defined(_MSC_VER) && _MSC_VER >= 1400)
#error "We require at least vs2005 for MemoryBarrier"
#endif

inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
                                       Atomic32 old_value,
                                       Atomic32 new_value) {
  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}

inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
                                       Atomic32 old_value,
                                       Atomic32 new_value) {
  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}

inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
  *ptr = value;
}

inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
  NoBarrier_AtomicExchange(ptr, value);
              // acts as a barrier in this implementation
}

inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
  *ptr = value;  // works w/o barrier for current Intel chips as of June 2005
  // See comments in Atomic64 version of Release_Store() below.
}

inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
  return *ptr;
}

inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
  Atomic32 value = *ptr;
  return value;
}

inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
  MemoryBarrier();
  return *ptr;
}

#if defined(_WIN64)

// 64-bit low-level operations on 64-bit platform.

inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
                                          Atomic64 increment) {
  return Barrier_AtomicIncrement(ptr, increment);
}

inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
  *ptr = value;
}

inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
  NoBarrier_AtomicExchange(ptr, value);
              // acts as a barrier in this implementation
}

inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
  *ptr = value;  // works w/o barrier for current Intel chips as of June 2005

  // When new chips come out, check:
  //  IA-32 Intel Architecture Software Developer's Manual, Volume 3:
  //  System Programming Guide, Chatper 7: Multiple-processor management,
  //  Section 7.2, Memory Ordering.
  // Last seen at:
  //   http://developer.intel.com/design/pentium4/manuals/index_new.htm
}

inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
  return *ptr;
}

inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
  Atomic64 value = *ptr;
  return value;
}

inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
  MemoryBarrier();
  return *ptr;
}

inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
                                       Atomic64 old_value,
                                       Atomic64 new_value) {
  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}

inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
                                       Atomic64 old_value,
                                       Atomic64 new_value) {
  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
}

#endif  // defined(_WIN64)

}  // namespace internal
}  // namespace protobuf
}  // namespace google

#endif  // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_X86_MSVC_H_