atomicops_internals_macosx.h

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// This file is an internal atomic implementation, use atomicops.h instead.

#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_MACOSX_H_
#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_MACOSX_H_

#include <libkern/OSAtomic.h>

namespace google {
namespace protobuf {
namespace internal {

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,
 reinterpret_cast<volatile int64_t*>(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,
 reinterpret_cast<volatile int64_t*>(ptr)));
 return old_value;
}

inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
 Atomic64 increment) {
 return OSAtomicAdd64(increment, reinterpret_cast<volatile int64_t*>(ptr));
}

inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
 Atomic64 increment) {
 return OSAtomicAdd64Barrier(increment,
 reinterpret_cast<volatile int64_t*>(ptr));
}

inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
 Atomic64 old_value,
 Atomic64 new_value) {
 Atomic64 prev_value;
 do {
 if (OSAtomicCompareAndSwap64Barrier(
 old_value, new_value, reinterpret_cast<volatile int64_t*>(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__)

} // namespace internal
} // namespace protobuf
} // namespace google

#endif // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_MACOSX_H_