New atomic operation foundation code and interfaces. Based on the atomic operations in google-perftools / tcmalloc.

- Makes atomic operations cross-platform (win/mac/linux).
- Supports 64 bit operations on 64 bit processors.
- Make atomic operations more correct on Windows (barriers).
- Introduces a better / safer interface, and abstracts away most common atomic operations, reference counting and sequence numbers.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@370 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 304 insertions, 0 deletions

diff --git a/base/atomicops_internals_x86_macosx.h b/base/atomicops_internals_x86_macosx.h
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+++ b/base/atomicops_internals_x86_macosx.h
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+// Copyright 2008, Google Inc.
+// 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 Google Inc. 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
+// OWNER 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.
+
+// This file is an internal atomic implementation, use base/atomicops.h instead.
+
+#ifndef BASE_ATOMICOPS_INTERNALS_X86_MACOSX_H_
+#define BASE_ATOMICOPS_INTERNALS_X86_MACOSX_H_
+
+#include <libkern/OSAtomic.h>
+
+namespace base {
+namespace subtle {
+
+inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr,
+                                         Atomic32 old_value,
+                                         Atomic32 new_value) {
+  Atomic32 prev_value;
+  do {
+    if (OSAtomicCompareAndSwap32(old_value, new_value,
+                                 const_cast<Atomic32*>(ptr))) {
+      return old_value;
+    }
+    prev_value = *ptr;
+  } while (prev_value == old_value);
+  return prev_value;
+}
+
+inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr,
+                                         Atomic32 new_value) {
+  Atomic32 old_value;
+  do {
+    old_value = *ptr;
+  } while (!OSAtomicCompareAndSwap32(old_value, new_value,
+                                     const_cast<Atomic32*>(ptr)));
+  return old_value;
+}
+
+inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr,
+                                          Atomic32 increment) {
+  return OSAtomicAdd32(increment, const_cast<Atomic32*>(ptr));
+}
+
+inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr,
+                                          Atomic32 increment) {
+  return OSAtomicAdd32Barrier(increment, const_cast<Atomic32*>(ptr));
+}
+
+inline void MemoryBarrier() {
+  OSMemoryBarrier();
+}
+
+inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  Atomic32 prev_value;
+  do {
+    if (OSAtomicCompareAndSwap32Barrier(old_value, new_value,
+                                        const_cast<Atomic32*>(ptr))) {
+      return old_value;
+    }
+    prev_value = *ptr;
+  } while (prev_value == old_value);
+  return prev_value;
+}
+
+inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr,
+                                       Atomic32 old_value,
+                                       Atomic32 new_value) {
+  return Acquire_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) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
+  return *ptr;
+}
+
+inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) {
+  Atomic32 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic32 Release_Load(volatile const Atomic32 *ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+
+#ifdef __LP64__
+
+// 64-bit implementation on 64-bit platform
+
+inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr,
+                                         Atomic64 old_value,
+                                         Atomic64 new_value) {
+  Atomic64 prev_value;
+  do {
+    if (OSAtomicCompareAndSwap64(old_value, new_value,
+                                 const_cast<Atomic64*>(ptr))) {
+      return old_value;
+    }
+    prev_value = *ptr;
+  } while (prev_value == old_value);
+  return prev_value;
+}
+
+inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr,
+                                         Atomic64 new_value) {
+  Atomic64 old_value;
+  do {
+    old_value = *ptr;
+  } while (!OSAtomicCompareAndSwap64(old_value, new_value,
+                                     const_cast<Atomic64*>(ptr)));
+  return old_value;
+}
+
+inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64 *ptr,
+                                          Atomic64 increment) {
+  return OSAtomicAdd64(increment, const_cast<Atomic64*>(ptr));
+}
+
+inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64 *ptr,
+                                        Atomic64 increment) {
+  return OSAtomicAdd64Barrier(increment, const_cast<Atomic64*>(ptr));
+}
+
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  Atomic64 prev_value;
+  do {
+    if (OSAtomicCompareAndSwap64Barrier(old_value, new_value,
+                                        const_cast<Atomic64*>(ptr))) {
+      return old_value;
+    }
+    prev_value = *ptr;
+  } while (prev_value == old_value);
+  return prev_value;
+}
+
+inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  // The lib kern interface does not distinguish between
+  // Acquire and Release memory barriers; they are equivalent.
+  return Acquire_CompareAndSwap(ptr, old_value, new_value);
+}
+
+inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
+  *ptr = value;
+}
+
+inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
+  *ptr = value;
+  MemoryBarrier();
+}
+
+inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
+  MemoryBarrier();
+  *ptr = value;
+}
+
+inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
+  return *ptr;
+}
+
+inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
+  Atomic64 value = *ptr;
+  MemoryBarrier();
+  return value;
+}
+
+inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
+  MemoryBarrier();
+  return *ptr;
+}
+
+#endif  // defined(__LP64__)
+
+// MacOS uses long for intptr_t, AtomicWord and Atomic32 are always different
+// on the Mac, even when they are the same size.  We need to explicitly cast
+// from AtomicWord to Atomic32/64 to implement the AtomicWord interface.
+#ifdef __LP64__
+#define AtomicWordCastType Atomic64
+#else
+#define AtomicWordCastType Atomic32
+#endif
+
+inline AtomicWord NoBarrier_CompareAndSwap(volatile AtomicWord* ptr,
+                                           AtomicWord old_value,
+                                           AtomicWord new_value) {
+  return NoBarrier_CompareAndSwap(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr),
+      old_value, new_value);
+}
+
+inline AtomicWord NoBarrier_AtomicExchange(volatile AtomicWord* ptr,
+                                           AtomicWord new_value) {
+  return NoBarrier_AtomicExchange(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), new_value);
+}
+
+inline AtomicWord NoBarrier_AtomicIncrement(volatile AtomicWord* ptr,
+                                            AtomicWord increment) {
+  return NoBarrier_AtomicIncrement(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), increment);
+}
+
+inline AtomicWord Barrier_AtomicIncrement(volatile AtomicWord* ptr,
+                                          AtomicWord increment) {
+  return Barrier_AtomicIncrement(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), increment);
+}
+
+inline AtomicWord Acquire_CompareAndSwap(volatile AtomicWord* ptr,
+                                         AtomicWord old_value,
+                                         AtomicWord new_value) {
+  return base::subtle::Acquire_CompareAndSwap(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr),
+      old_value, new_value);
+}
+
+inline AtomicWord Release_CompareAndSwap(volatile AtomicWord* ptr,
+                                         AtomicWord old_value,
+                                         AtomicWord new_value) {
+  return base::subtle::Release_CompareAndSwap(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr),
+      old_value, new_value);
+}
+
+inline void NoBarrier_Store(volatile AtomicWord *ptr, AtomicWord value) {
+  NoBarrier_Store(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), value);
+}
+
+inline void Acquire_Store(volatile AtomicWord* ptr, AtomicWord value) {
+  return base::subtle::Acquire_Store(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), value);
+}
+
+inline void Release_Store(volatile AtomicWord* ptr, AtomicWord value) {
+  return base::subtle::Release_Store(
+      reinterpret_cast<volatile AtomicWordCastType*>(ptr), value);
+}
+
+inline AtomicWord NoBarrier_Load(volatile const AtomicWord *ptr) {
+  return NoBarrier_Load(
+      reinterpret_cast<volatile const AtomicWordCastType*>(ptr));
+}
+
+inline AtomicWord Acquire_Load(volatile const AtomicWord* ptr) {
+  return base::subtle::Acquire_Load(
+      reinterpret_cast<volatile const AtomicWordCastType*>(ptr));
+}
+
+inline AtomicWord Release_Load(volatile const AtomicWord* ptr) {
+  return base::subtle::Release_Load(
+      reinterpret_cast<volatile const AtomicWordCastType*>(ptr));
+}
+
+#undef AtomicWordCastType
+
+}   // namespace base::subtle
+}   // namespace base
+
+#endif  // BASE_ATOMICOPS_INTERNALS_X86_MACOSX_H_