/tools/simulator/libsimulator/lib/protobuf-lite/google/protobuf/stubs/atomicops_internals_arm_gcc.h
https://github.com/dumganhar/cocos2d-x · C Header · 151 lines · 90 code · 21 blank · 40 comment · 7 complexity · b0c7e44eefe09435614b26ade2b43781 MD5 · raw file
- // Protocol Buffers - Google's data interchange format
- // Copyright 2012 Google Inc. All rights reserved.
- // http://code.google.com/p/protobuf/
- //
- // 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 atomicops.h instead.
- //
- // LinuxKernelCmpxchg and Barrier_AtomicIncrement are from Google Gears.
- #ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_
- #define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_
- namespace google {
- namespace protobuf {
- namespace internal {
- // 0xffff0fc0 is the hard coded address of a function provided by
- // the kernel which implements an atomic compare-exchange. On older
- // ARM architecture revisions (pre-v6) this may be implemented using
- // a syscall. This address is stable, and in active use (hard coded)
- // by at least glibc-2.7 and the Android C library.
- typedef Atomic32 (*LinuxKernelCmpxchgFunc)(Atomic32 old_value,
- Atomic32 new_value,
- volatile Atomic32* ptr);
- LinuxKernelCmpxchgFunc pLinuxKernelCmpxchg __attribute__((weak)) =
- (LinuxKernelCmpxchgFunc) 0xffff0fc0;
- typedef void (*LinuxKernelMemoryBarrierFunc)(void);
- LinuxKernelMemoryBarrierFunc pLinuxKernelMemoryBarrier __attribute__((weak)) =
- (LinuxKernelMemoryBarrierFunc) 0xffff0fa0;
- inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- Atomic32 prev_value = *ptr;
- do {
- if (!pLinuxKernelCmpxchg(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 (pLinuxKernelCmpxchg(old_value, new_value,
- const_cast<Atomic32*>(ptr)));
- return old_value;
- }
- inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
- Atomic32 increment) {
- return Barrier_AtomicIncrement(ptr, increment);
- }
- 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 (pLinuxKernelCmpxchg(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.
- }
- }
- inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
- }
- inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
- }
- inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
- *ptr = value;
- }
- inline void MemoryBarrier() {
- pLinuxKernelMemoryBarrier();
- }
- 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;
- }
- } // namespace internal
- } // namespace protobuf
- } // namespace google
- #endif // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_ARM_GCC_H_