atomicops_internals_x86_msvc.h

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// Copyright 2010 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
// This file is an internal atomic implementation, use atomicops.h instead.
 
#ifndef V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_
#define V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_
 
#include "src/base/macros.h"
#include "src/base/win32-headers.h"
 
#if defined(V8_HOST_ARCH_64_BIT)
// windows.h #defines this (only on x64). This causes problems because the
// public API also uses MemoryBarrier at the public name for this fence. So, on
// X64, undef it, and call its documented
// (http://msdn.microsoft.com/en-us/library/windows/desktop/ms684208.aspx)
// implementation directly.
#undef MemoryBarrier
#endif
 
namespace v8 {
namespace base {
 
inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
                                         Atomic32 old_value,
                                         Atomic32 new_value) {
  LONG result = InterlockedCompareExchange(
      reinterpret_cast<volatile LONG*>(ptr),
      static_cast<LONG>(new_value),
      static_cast<LONG>(old_value));
  return static_cast<Atomic32>(result);
}
 
inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
                                         Atomic32 new_value) {
  LONG result = InterlockedExchange(
      reinterpret_cast<volatile LONG*>(ptr),
      static_cast<LONG>(new_value));
  return static_cast<Atomic32>(result);
}
 
inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
                                        Atomic32 increment) {
  return InterlockedExchangeAdd(
      reinterpret_cast<volatile LONG*>(ptr),
      static_cast<LONG>(increment)) + increment;
}
 
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 void MemoryBarrier() {
#if defined(V8_HOST_ARCH_64_BIT)
  // See #undef and note at the top of this file.
  __faststorefence();
#else
  // We use MemoryBarrier from WinNT.h
  ::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 Atomic8* ptr, Atomic8 value) {
  *ptr = 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 Atomic8 NoBarrier_Load(volatile const Atomic8* ptr) {
  return *ptr;
}
 
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.
 
STATIC_ASSERT(sizeof(Atomic64) == sizeof(PVOID));
 
inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
                                         Atomic64 old_value,
                                         Atomic64 new_value) {
  PVOID result = InterlockedCompareExchangePointer(
    reinterpret_cast<volatile PVOID*>(ptr),
    reinterpret_cast<PVOID>(new_value), reinterpret_cast<PVOID>(old_value));
  return reinterpret_cast<Atomic64>(result);
}
 
inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
                                         Atomic64 new_value) {
  PVOID result = InterlockedExchangePointer(
    reinterpret_cast<volatile PVOID*>(ptr),
    reinterpret_cast<PVOID>(new_value));
  return reinterpret_cast<Atomic64>(result);
}
 
inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
                                        Atomic64 increment) {
  return InterlockedExchangeAdd64(
      reinterpret_cast<volatile LONGLONG*>(ptr),
      static_cast<LONGLONG>(increment)) + increment;
}
 
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 v8::base
 
#endif  // V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_