1// Protocol Buffers - Google's data interchange format 2// Copyright 2012 Google Inc. All rights reserved. 3// http://code.google.com/p/protobuf/ 4// 5// Redistribution and use in source and binary forms, with or without 6// modification, are permitted provided that the following conditions are 7// met: 8// 9// * Redistributions of source code must retain the above copyright 10// notice, this list of conditions and the following disclaimer. 11// * Redistributions in binary form must reproduce the above 12// copyright notice, this list of conditions and the following disclaimer 13// in the documentation and/or other materials provided with the 14// distribution. 15// * Neither the name of Google Inc. nor the names of its 16// contributors may be used to endorse or promote products derived from 17// this software without specific prior written permission. 18// 19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31// This file is an internal atomic implementation, use atomicops.h instead. 32 33#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_ 34#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_ 35 36// For _smp_cmpxchg() 37#include <pthread.h> 38 39namespace google { 40namespace protobuf { 41namespace internal { 42 43inline Atomic32 QNXCmpxchg(Atomic32 old_value, 44 Atomic32 new_value, 45 volatile Atomic32* ptr) { 46 return static_cast<Atomic32>( 47 _smp_cmpxchg((volatile unsigned *)ptr, 48 (unsigned)old_value, 49 (unsigned)new_value)); 50} 51 52 53inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr, 54 Atomic32 old_value, 55 Atomic32 new_value) { 56 Atomic32 prev_value = *ptr; 57 do { 58 if (!QNXCmpxchg(old_value, new_value, 59 const_cast<Atomic32*>(ptr))) { 60 return old_value; 61 } 62 prev_value = *ptr; 63 } while (prev_value == old_value); 64 return prev_value; 65} 66 67inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr, 68 Atomic32 new_value) { 69 Atomic32 old_value; 70 do { 71 old_value = *ptr; 72 } while (QNXCmpxchg(old_value, new_value, 73 const_cast<Atomic32*>(ptr))); 74 return old_value; 75} 76 77inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr, 78 Atomic32 increment) { 79 return Barrier_AtomicIncrement(ptr, increment); 80} 81 82inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr, 83 Atomic32 increment) { 84 for (;;) { 85 // Atomic exchange the old value with an incremented one. 86 Atomic32 old_value = *ptr; 87 Atomic32 new_value = old_value + increment; 88 if (QNXCmpxchg(old_value, new_value, 89 const_cast<Atomic32*>(ptr)) == 0) { 90 // The exchange took place as expected. 91 return new_value; 92 } 93 // Otherwise, *ptr changed mid-loop and we need to retry. 94 } 95} 96 97inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, 98 Atomic32 old_value, 99 Atomic32 new_value) { 100 return NoBarrier_CompareAndSwap(ptr, old_value, new_value); 101} 102 103inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, 104 Atomic32 old_value, 105 Atomic32 new_value) { 106 return NoBarrier_CompareAndSwap(ptr, old_value, new_value); 107} 108 109inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) { 110 *ptr = value; 111} 112 113inline void MemoryBarrier() { 114 __sync_synchronize(); 115} 116 117inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) { 118 *ptr = value; 119 MemoryBarrier(); 120} 121 122inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) { 123 MemoryBarrier(); 124 *ptr = value; 125} 126 127inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) { 128 return *ptr; 129} 130 131inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) { 132 Atomic32 value = *ptr; 133 MemoryBarrier(); 134 return value; 135} 136 137inline Atomic32 Release_Load(volatile const Atomic32* ptr) { 138 MemoryBarrier(); 139 return *ptr; 140} 141 142} // namespace internal 143} // namespace protobuf 144} // namespace google 145 146#endif // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_QNX_H_ 147