Pull new version of protobuf sources.

third_party/protobuf/src/google/protobuf/stubs/atomicops_internals_generic_gcc.h

-// Protocol Buffers - Google's data interchange format
-// Copyright 2012 Google Inc.  All rights reserved.
-// http://code.google.com/p/protobuf/
+// Copyright 2013 Red Hat 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
+//     * Neither the name of Red Hat 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 atomicops.h instead.
 
-#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_
-#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_
-
-// For _smp_cmpxchg()
-#include <pthread.h>
+#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_GENERIC_GCC_H_
+#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_GENERIC_GCC_H_
 
 namespace google {
 namespace protobuf {
 namespace internal {
 
-inline Atomic32 QNXCmpxchg(Atomic32 old_value,
-                           Atomic32 new_value,
-                           volatile Atomic32* ptr) {
-  return static_cast<Atomic32>(
-      _smp_cmpxchg((volatile unsigned *)ptr,
-                   (unsigned)old_value,
-                   (unsigned)new_value));
-}
-
-
 inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
                                          Atomic32 old_value,
                                          Atomic32 new_value) {
-  Atomic32 prev_value = *ptr;
-  do {
-    if (!QNXCmpxchg(old_value, new_value,
-                    const_cast<Atomic32*>(ptr))) {
-      return old_value;
-    }
-    prev_value = *ptr;
-  } while (prev_value == old_value);
-  return prev_value;
+  __atomic_compare_exchange_n(ptr, &old_value, new_value, true,
+                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);
+  return old_value;
 }
 
 inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
                                          Atomic32 new_value) {
-  Atomic32 old_value;
-  do {
-    old_value = *ptr;
-  } while (QNXCmpxchg(old_value, new_value,
-                      const_cast<Atomic32*>(ptr)));
-  return old_value;
+  return __atomic_exchange_n(ptr, new_value, __ATOMIC_RELAXED);
 }
 
 inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
                                           Atomic32 increment) {
-  return Barrier_AtomicIncrement(ptr, increment);
+  return __atomic_add_fetch(ptr, increment, __ATOMIC_RELAXED);
 }
 
 inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
                                         Atomic32 increment) {
-  for (;;) {
-    // Atomic exchange the old value with an incremented one.
-    Atomic32 old_value = *ptr;
-    Atomic32 new_value = old_value + increment;
-    if (QNXCmpxchg(old_value, new_value,
-                   const_cast<Atomic32*>(ptr)) == 0) {
-      // The exchange took place as expected.
-      return new_value;
-    }
-    // Otherwise, *ptr changed mid-loop and we need to retry.
-  }
+  return __atomic_add_fetch(ptr, increment, __ATOMIC_SEQ_CST);
 }
 
 inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
                                        Atomic32 old_value,
                                        Atomic32 new_value) {
-  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  __atomic_compare_exchange_n(ptr, &old_value, new_value, true,
+                              __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
+  return old_value;
 }
 
 inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
                                        Atomic32 old_value,
                                        Atomic32 new_value) {
-  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
+  __atomic_compare_exchange_n(ptr, &old_value, new_value, true,
+                              __ATOMIC_RELEASE, __ATOMIC_ACQUIRE);
+  return old_value;
 }
 
 inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
-  *ptr = value;
+  __atomic_store_n(ptr, value, __ATOMIC_RELAXED);
 }
 
 inline void MemoryBarrier() {
   __sync_synchronize();
 }
 
 inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
-  *ptr = value;
-  MemoryBarrier();
+  __atomic_store_n(ptr, value, __ATOMIC_SEQ_CST);
 }
 
 inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
-  MemoryBarrier();
-  *ptr = value;
+  __atomic_store_n(ptr, value, __ATOMIC_RELEASE);
 }
 
 inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
-  return *ptr;
+  return __atomic_load_n(ptr, __ATOMIC_RELAXED);
 }
 
 inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
-  Atomic32 value = *ptr;
-  MemoryBarrier();
-  return value;
+  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
 }
 
 inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
-  MemoryBarrier();
-  return *ptr;
+  return __atomic_load_n(ptr, __ATOMIC_SEQ_CST);
 }
 
+#ifdef __LP64__
+
+inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
+  __atomic_store_n(ptr, value, __ATOMIC_RELEASE);
+}
+
+inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
+  return __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
+}
+
+inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
+                                       Atomic64 old_value,
+                                       Atomic64 new_value) {
+  __atomic_compare_exchange_n(ptr, &old_value, new_value, true,
+                              __ATOMIC_ACQUIRE, __ATOMIC_ACQUIRE);
+  return old_value;
+}
+
+inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
+                                         Atomic64 old_value,
+                                         Atomic64 new_value) {
+  __atomic_compare_exchange_n(ptr, &old_value, new_value, true,
+                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);
+  return old_value;
+}
+
+#endif // defined(__LP64__)
+
 }  // namespace internal
 }  // namespace protobuf
 }  // namespace google
 
-#endif  // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_
+#endif  // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_GENERIC_GCC_H_