Move base to DEPS

base/atomicops.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// For atomic operations on reference counts, see atomic_refcount.h.
-// For atomic operations on sequence numbers, see atomic_sequence_num.h.
-
-// The routines exported by this module are subtle.  If you use them, even if
-// you get the code right, it will depend on careful reasoning about atomicity
-// and memory ordering; it will be less readable, and harder to maintain.  If
-// you plan to use these routines, you should have a good reason, such as solid
-// evidence that performance would otherwise suffer, or there being no
-// alternative.  You should assume only properties explicitly guaranteed by the
-// specifications in this file.  You are almost certainly _not_ writing code
-// just for the x86; if you assume x86 semantics, x86 hardware bugs and
-// implementations on other archtectures will cause your code to break.  If you
-// do not know what you are doing, avoid these routines, and use a Mutex.
-//
-// It is incorrect to make direct assignments to/from an atomic variable.
-// You should use one of the Load or Store routines.  The NoBarrier
-// versions are provided when no barriers are needed:
-//   NoBarrier_Store()
-//   NoBarrier_Load()
-// Although there are currently no compiler enforcement, you are encouraged
-// to use these.
-//
-
-#ifndef BASE_ATOMICOPS_H_
-#define BASE_ATOMICOPS_H_
-
-#include <stdint.h>
-
-// Small C++ header which defines implementation specific macros used to
-// identify the STL implementation.
-// - libc++: captures __config for _LIBCPP_VERSION
-// - libstdc++: captures bits/c++config.h for __GLIBCXX__
-#include <cstddef>
-
-#include "base/base_export.h"
-#include "build/build_config.h"
-
-#if defined(OS_WIN) && defined(ARCH_CPU_64_BITS)
-// 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 base {
-namespace subtle {
-
-typedef int32_t Atomic32;
-#ifdef ARCH_CPU_64_BITS
-// We need to be able to go between Atomic64 and AtomicWord implicitly.  This
-// means Atomic64 and AtomicWord should be the same type on 64-bit.
-#if defined(__ILP32__) || defined(OS_NACL)
-// NaCl's intptr_t is not actually 64-bits on 64-bit!
-// http://code.google.com/p/nativeclient/issues/detail?id=1162
-typedef int64_t Atomic64;
-#else
-typedef intptr_t Atomic64;
-#endif
-#endif
-
-// Use AtomicWord for a machine-sized pointer.  It will use the Atomic32 or
-// Atomic64 routines below, depending on your architecture.
-typedef intptr_t AtomicWord;
-
-// Atomically execute:
-//      result = *ptr;
-//      if (*ptr == old_value)
-//        *ptr = new_value;
-//      return result;
-//
-// I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
-// Always return the old value of "*ptr"
-//
-// This routine implies no memory barriers.
-Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
-                                  Atomic32 old_value,
-                                  Atomic32 new_value);
-
-// Atomically store new_value into *ptr, returning the previous value held in
-// *ptr.  This routine implies no memory barriers.
-Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr, Atomic32 new_value);
-
-// Atomically increment *ptr by "increment".  Returns the new value of
-// *ptr with the increment applied.  This routine implies no memory barriers.
-Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr, Atomic32 increment);
-
-Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
-                                 Atomic32 increment);
-
-// These following lower-level operations are typically useful only to people
-// implementing higher-level synchronization operations like spinlocks,
-// mutexes, and condition-variables.  They combine CompareAndSwap(), a load, or
-// a store with appropriate memory-ordering instructions.  "Acquire" operations
-// ensure that no later memory access can be reordered ahead of the operation.
-// "Release" operations ensure that no previous memory access can be reordered
-// after the operation.  "Barrier" operations have both "Acquire" and "Release"
-// semantics.   A MemoryBarrier() has "Barrier" semantics, but does no memory
-// access.
-Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
-                                Atomic32 old_value,
-                                Atomic32 new_value);
-Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
-                                Atomic32 old_value,
-                                Atomic32 new_value);
-
-void MemoryBarrier();
-void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value);
-void Acquire_Store(volatile Atomic32* ptr, Atomic32 value);
-void Release_Store(volatile Atomic32* ptr, Atomic32 value);
-
-Atomic32 NoBarrier_Load(volatile const Atomic32* ptr);
-Atomic32 Acquire_Load(volatile const Atomic32* ptr);
-Atomic32 Release_Load(volatile const Atomic32* ptr);
-
-// 64-bit atomic operations (only available on 64-bit processors).
-#ifdef ARCH_CPU_64_BITS
-Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
-                                  Atomic64 old_value,
-                                  Atomic64 new_value);
-Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr, Atomic64 new_value);
-Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
-Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr, Atomic64 increment);
-
-Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
-                                Atomic64 old_value,
-                                Atomic64 new_value);
-Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
-                                Atomic64 old_value,
-                                Atomic64 new_value);
-void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value);
-void Acquire_Store(volatile Atomic64* ptr, Atomic64 value);
-void Release_Store(volatile Atomic64* ptr, Atomic64 value);
-Atomic64 NoBarrier_Load(volatile const Atomic64* ptr);
-Atomic64 Acquire_Load(volatile const Atomic64* ptr);
-Atomic64 Release_Load(volatile const Atomic64* ptr);
-#endif  // ARCH_CPU_64_BITS
-
-}  // namespace subtle
-}  // namespace base
-
-// Try to use a portable implementation based on C++11 atomics.
-//
-// Some toolchains support C++11 language features without supporting library
-// features (recent compiler, older STL). Whitelist libstdc++ and libc++ that we
-// know will have <atomic> when compiling C++11.
-#if ((__cplusplus >= 201103L) &&                            \
-     ((defined(__GLIBCXX__) && (__GLIBCXX__ > 20110216)) || \
-      (defined(_LIBCPP_VERSION) && (_LIBCPP_STD_VER >= 11))))
-#  include "base/atomicops_internals_portable.h"
-#else  // Otherwise use a platform specific implementation.
-#  if defined(THREAD_SANITIZER)
-#    error "Thread sanitizer must use the portable atomic operations"
-#  elif (defined(OS_WIN) && defined(COMPILER_MSVC) && \
-         defined(ARCH_CPU_X86_FAMILY))
-#    include "base/atomicops_internals_x86_msvc.h"
-#  elif defined(OS_MACOSX)
-#    include "base/atomicops_internals_mac.h"
-#  else
-#    error "Atomic operations are not supported on your platform"
-#  endif
-#endif   // Portable / non-portable includes.
-
-// On some platforms we need additional declarations to make
-// AtomicWord compatible with our other Atomic* types.
-#if defined(OS_MACOSX) || defined(OS_OPENBSD)
-#include "base/atomicops_internals_atomicword_compat.h"
-#endif
-
-#endif  // BASE_ATOMICOPS_H_