15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Protocol Buffers - Google's data interchange format 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright 2012 Google Inc. All rights reserved. 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// http://code.google.com/p/protobuf/ 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Redistribution and use in source and binary forms, with or without 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// modification, are permitted provided that the following conditions are 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// met: 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions of source code must retain the above copyright 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// notice, this list of conditions and the following disclaimer. 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Redistributions in binary form must reproduce the above 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// copyright notice, this list of conditions and the following disclaimer 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// in the documentation and/or other materials provided with the 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// distribution. 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// * Neither the name of Google Inc. nor the names of its 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// contributors may be used to endorse or promote products derived from 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// this software without specific prior written permission. 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file is an internal atomic implementation, use atomicops.h instead. 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// LinuxKernelCmpxchg and Barrier_AtomicIncrement are from Google Gears. 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_ 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_ 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace google { 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace protobuf { 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace internal { 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 0xffff0fc0 is the hard coded address of a function provided by 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the kernel which implements an atomic compare-exchange. On older 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// ARM architecture revisions (pre-v6) this may be implemented using 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// a syscall. This address is stable, and in active use (hard coded) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// by at least glibc-2.7 and the Android C library. 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)typedef Atomic32 (*LinuxKernelCmpxchgFunc)(Atomic32 old_value, 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value, 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) volatile Atomic32* ptr); 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)LinuxKernelCmpxchgFunc pLinuxKernelCmpxchg __attribute__((weak)) = 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (LinuxKernelCmpxchgFunc) 0xffff0fc0; 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)typedef void (*LinuxKernelMemoryBarrierFunc)(void); 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)LinuxKernelMemoryBarrierFunc pLinuxKernelMemoryBarrier __attribute__((weak)) = 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) (LinuxKernelMemoryBarrierFunc) 0xffff0fa0; 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr, 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 old_value, 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value) { 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 prev_value = *ptr; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) do { 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!pLinuxKernelCmpxchg(old_value, new_value, 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const_cast<Atomic32*>(ptr))) { 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return old_value; 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) prev_value = *ptr; 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } while (prev_value == old_value); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return prev_value; 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr, 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value) { 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 old_value; 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) do { 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) old_value = *ptr; 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } while (pLinuxKernelCmpxchg(old_value, new_value, 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const_cast<Atomic32*>(ptr))); 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return old_value; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr, 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 increment) { 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return Barrier_AtomicIncrement(ptr, increment); 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr, 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 increment) { 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (;;) { 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Atomic exchange the old value with an incremented one. 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 old_value = *ptr; 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value = old_value + increment; 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (pLinuxKernelCmpxchg(old_value, new_value, 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const_cast<Atomic32*>(ptr)) == 0) { 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The exchange took place as expected. 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return new_value; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Otherwise, *ptr changed mid-loop and we need to retry. 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr, 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 old_value, 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value) { 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return NoBarrier_CompareAndSwap(ptr, old_value, new_value); 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr, 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 old_value, 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 new_value) { 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return NoBarrier_CompareAndSwap(ptr, old_value, new_value); 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) { 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *ptr = value; 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline void MemoryBarrier() { 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pLinuxKernelMemoryBarrier(); 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) { 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *ptr = value; 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MemoryBarrier(); 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) { 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MemoryBarrier(); 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) *ptr = value; 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) { 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return *ptr; 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) { 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Atomic32 value = *ptr; 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MemoryBarrier(); 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return value; 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)inline Atomic32 Release_Load(volatile const Atomic32* ptr) { 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MemoryBarrier(); 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return *ptr; 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace internal 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace protobuf 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace google 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_ 152