bitcore-node-zcash/deps/boost/atomic/detail/windows.hpp

1670 lines
48 KiB
C++

#ifndef BOOST_ATOMIC_DETAIL_WINDOWS_HPP
#define BOOST_ATOMIC_DETAIL_WINDOWS_HPP
// Copyright (c) 2009 Helge Bahmann
// Copyright (c) 2012 Andrey Semashev
// Copyright (c) 2013 Tim Blechmann, Andrey Semashev
//
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <string.h>
#include <cstddef>
#include <boost/cstdint.hpp>
#include <boost/type_traits/make_signed.hpp>
#include <boost/atomic/detail/config.hpp>
#include <boost/atomic/detail/interlocked.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
#ifdef _MSC_VER
#pragma warning(push)
// 'order' : unreferenced formal parameter
#pragma warning(disable: 4100)
#endif
#if defined(_MSC_VER) && (defined(_M_AMD64) || defined(_M_IX86))
extern "C" void _mm_pause(void);
#pragma intrinsic(_mm_pause)
#define BOOST_ATOMIC_X86_PAUSE() _mm_pause()
#else
#define BOOST_ATOMIC_X86_PAUSE()
#endif
#if defined(_M_IX86) && _M_IX86 >= 500
#define BOOST_ATOMIC_X86_HAS_CMPXCHG8B 1
#endif
// Define hardware barriers
#if defined(_MSC_VER) && (defined(_M_AMD64) || (defined(_M_IX86) && defined(_M_IX86_FP) && _M_IX86_FP >= 2))
extern "C" void _mm_mfence(void);
#pragma intrinsic(_mm_mfence)
#endif
// Define compiler barriers
#if defined(__INTEL_COMPILER)
#define BOOST_ATOMIC_COMPILER_BARRIER() __memory_barrier()
#elif defined(_MSC_VER) && _MSC_VER >= 1310 && !defined(_WIN32_WCE)
extern "C" void _ReadWriteBarrier(void);
#pragma intrinsic(_ReadWriteBarrier)
#define BOOST_ATOMIC_COMPILER_BARRIER() _ReadWriteBarrier()
#endif
#ifndef BOOST_ATOMIC_COMPILER_BARRIER
#define BOOST_ATOMIC_COMPILER_BARRIER()
#endif
namespace boost {
namespace atomics {
namespace detail {
BOOST_FORCEINLINE void hardware_full_fence(void)
{
#if defined(_MSC_VER) && (defined(_M_AMD64) || (defined(_M_IX86) && defined(_M_IX86_FP) && _M_IX86_FP >= 2))
// Use mfence only if SSE2 is available
_mm_mfence();
#else
long tmp;
BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&tmp, 0);
#endif
}
BOOST_FORCEINLINE void
platform_fence_before(memory_order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
}
BOOST_FORCEINLINE void
platform_fence_after(memory_order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
}
BOOST_FORCEINLINE void
platform_fence_before_store(memory_order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
}
BOOST_FORCEINLINE void
platform_fence_after_store(memory_order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
}
BOOST_FORCEINLINE void
platform_fence_after_load(memory_order order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
// On x86 and x86_64 there is no need for a hardware barrier,
// even if seq_cst memory order is requested, because all
// seq_cst writes are implemented with lock-prefixed operations
// or xchg which has implied lock prefix. Therefore normal loads
// are already ordered with seq_cst stores on these architectures.
#if !(defined(_MSC_VER) && (defined(_M_AMD64) || defined(_M_IX86)))
if (order == memory_order_seq_cst)
hardware_full_fence();
#endif
}
} // namespace detail
} // namespace atomics
#define BOOST_ATOMIC_THREAD_FENCE 2
BOOST_FORCEINLINE void
atomic_thread_fence(memory_order order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
if (order == memory_order_seq_cst)
atomics::detail::hardware_full_fence();
}
#define BOOST_ATOMIC_SIGNAL_FENCE 2
BOOST_FORCEINLINE void
atomic_signal_fence(memory_order)
{
BOOST_ATOMIC_COMPILER_BARRIER();
}
#undef BOOST_ATOMIC_COMPILER_BARRIER
class atomic_flag
{
private:
atomic_flag(const atomic_flag &) /* = delete */ ;
atomic_flag & operator=(const atomic_flag &) /* = delete */ ;
uint32_t v_;
public:
BOOST_CONSTEXPR atomic_flag(void) BOOST_NOEXCEPT : v_(0) {}
bool
test_and_set(memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
atomics::detail::platform_fence_before(order);
const uint32_t old = (uint32_t)BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, 1);
atomics::detail::platform_fence_after(order);
return old != 0;
}
void
clear(memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
atomics::detail::platform_fence_before_store(order);
BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, 0);
atomics::detail::platform_fence_after_store(order);
}
};
} // namespace boost
#define BOOST_ATOMIC_FLAG_LOCK_FREE 2
#include <boost/atomic/detail/base.hpp>
#if !defined(BOOST_ATOMIC_FORCE_FALLBACK)
#define BOOST_ATOMIC_CHAR_LOCK_FREE 2
#define BOOST_ATOMIC_SHORT_LOCK_FREE 2
#define BOOST_ATOMIC_INT_LOCK_FREE 2
#define BOOST_ATOMIC_LONG_LOCK_FREE 2
#if defined(BOOST_ATOMIC_X86_HAS_CMPXCHG8B) || defined(_M_AMD64) || defined(_M_IA64)
#define BOOST_ATOMIC_LLONG_LOCK_FREE 2
#else
#define BOOST_ATOMIC_LLONG_LOCK_FREE 0
#endif
#define BOOST_ATOMIC_POINTER_LOCK_FREE 2
#define BOOST_ATOMIC_BOOL_LOCK_FREE 2
namespace boost {
namespace atomics {
namespace detail {
#if defined(_MSC_VER)
#pragma warning(push)
// 'char' : forcing value to bool 'true' or 'false' (performance warning)
#pragma warning(disable: 4800)
#endif
template<typename T, bool Sign>
class base_atomic<T, int, 1, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8
typedef value_type storage_type;
#else
typedef uint32_t storage_type;
#endif
typedef T difference_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
v_ = static_cast< storage_type >(v);
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst) const volatile BOOST_NOEXCEPT
{
value_type v = static_cast< value_type >(v_);
platform_fence_after_load(order);
return v;
}
value_type
fetch_add(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD8
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD8(&v_, v));
#else
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD(&v_, v));
#endif
platform_fence_after(order);
return v;
}
value_type
fetch_sub(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
typedef typename make_signed< value_type >::type signed_value_type;
return fetch_add(static_cast< value_type >(-static_cast< signed_value_type >(v)), order);
}
value_type
exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE8
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE8(&v_, v));
#else
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, v));
#endif
platform_fence_after(order);
return v;
}
bool
compare_exchange_strong(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8(&v_, desired, previous));
#else
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired, previous));
#endif
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
value_type
fetch_and(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_AND8
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND8(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_AND)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp & v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_or(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_OR8
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR8(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_OR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp | v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_xor(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_XOR8
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR8(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_XOR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp ^ v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
bool
is_lock_free(void) const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
#if defined(_MSC_VER)
#pragma warning(pop)
#endif
template<typename T, bool Sign>
class base_atomic<T, int, 2, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16
typedef value_type storage_type;
#else
typedef uint32_t storage_type;
#endif
typedef T difference_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
v_ = static_cast< storage_type >(v);
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst) const volatile BOOST_NOEXCEPT
{
value_type v = static_cast< value_type >(v_);
platform_fence_after_load(order);
return v;
}
value_type
fetch_add(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD16
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD16(&v_, v));
#else
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD(&v_, v));
#endif
platform_fence_after(order);
return v;
}
value_type
fetch_sub(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
typedef typename make_signed< value_type >::type signed_value_type;
return fetch_add(static_cast< value_type >(-static_cast< signed_value_type >(v)), order);
}
value_type
exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE16
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE16(&v_, v));
#else
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, v));
#endif
platform_fence_after(order);
return v;
}
bool
compare_exchange_strong(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16(&v_, desired, previous));
#else
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired, previous));
#endif
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
value_type
fetch_and(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_AND16
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND16(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_AND)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp & v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_or(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_OR16
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR16(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_OR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp | v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_xor(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#ifdef BOOST_ATOMIC_INTERLOCKED_XOR16
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR16(&v_, v));
platform_fence_after(order);
return v;
#elif defined(BOOST_ATOMIC_INTERLOCKED_XOR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp ^ v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
bool
is_lock_free(void) const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
template<typename T, bool Sign>
class base_atomic<T, int, 4, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
typedef value_type storage_type;
typedef T difference_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
v_ = static_cast< storage_type >(v);
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst) const volatile BOOST_NOEXCEPT
{
value_type v = static_cast< value_type >(v_);
platform_fence_after_load(order);
return v;
}
value_type
fetch_add(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD(&v_, v));
platform_fence_after(order);
return v;
}
value_type
fetch_sub(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
typedef typename make_signed< value_type >::type signed_value_type;
return fetch_add(static_cast< value_type >(-static_cast< signed_value_type >(v)), order);
}
value_type
exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, v));
platform_fence_after(order);
return v;
}
bool
compare_exchange_strong(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired, previous));
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
value_type
fetch_and(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_AND)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp & v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_or(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_OR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for(; !compare_exchange_weak(tmp, tmp | v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_xor(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_XOR)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp ^ v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
// MSVC 2012 fails to recognize sizeof(T) as a constant expression in template specializations
enum msvc_sizeof_pointer_workaround { sizeof_pointer = sizeof(void*) };
template<bool Sign>
class base_atomic<void*, void*, sizeof_pointer, Sign>
{
private:
typedef base_atomic this_type;
typedef std::ptrdiff_t difference_type;
typedef void* value_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
const_cast<volatile value_type &>(v_) = v;
} else {
exchange(v, order);
}
}
value_type load(memory_order order = memory_order_seq_cst)const volatile BOOST_NOEXCEPT
{
value_type v = const_cast<const volatile value_type &>(v_);
platform_fence_after_load(order);
return v;
}
value_type exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = (value_type)BOOST_ATOMIC_INTERLOCKED_EXCHANGE_POINTER(&v_, v);
platform_fence_after(order);
return v;
}
bool compare_exchange_strong(value_type & expected, value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
value_type oldval = (value_type)BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&v_, desired, previous);
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool compare_exchange_weak(value_type & expected, value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
value_type
fetch_add(difference_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
value_type res = (value_type)BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD_POINTER(&v_, v);
platform_fence_after(order);
return res;
}
value_type
fetch_sub(difference_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
return fetch_add(-v, order);
}
BOOST_ATOMIC_DECLARE_VOID_POINTER_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
value_type v_;
};
template<typename T, bool Sign>
class base_atomic<T*, void*, sizeof_pointer, Sign>
{
private:
typedef base_atomic this_type;
typedef T* value_type;
typedef std::ptrdiff_t difference_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
const_cast<volatile value_type &>(v_) = v;
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst)const volatile BOOST_NOEXCEPT
{
value_type v = const_cast<const volatile value_type &>(v_);
platform_fence_after_load(order);
return v;
}
value_type
exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = (value_type)BOOST_ATOMIC_INTERLOCKED_EXCHANGE_POINTER(&v_, v);
platform_fence_after(order);
return v;
}
bool
compare_exchange_strong(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
value_type oldval = (value_type)BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&v_, desired, previous);
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
value_type
fetch_add(difference_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
v = v * sizeof(*v_);
platform_fence_before(order);
value_type res = (value_type)BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD_POINTER(&v_, v);
platform_fence_after(order);
return res;
}
value_type
fetch_sub(difference_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
return fetch_add(-v, order);
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_POINTER_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
value_type v_;
};
template<typename T, bool Sign>
class base_atomic<T, void, 1, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8
typedef uint8_t storage_type;
#else
typedef uint32_t storage_type;
#endif
protected:
typedef value_type const& value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8
BOOST_CONSTEXPR explicit base_atomic(value_type const& v) BOOST_NOEXCEPT : v_(reinterpret_cast< storage_type const& >(v))
{
}
#else
explicit base_atomic(value_type const& v) BOOST_NOEXCEPT : v_(0)
{
memcpy(&v_, &v, sizeof(value_type));
}
#endif
void
store(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
const_cast<volatile storage_type &>(v_) = tmp;
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst) const volatile BOOST_NOEXCEPT
{
storage_type tmp = const_cast<volatile storage_type &>(v_);
platform_fence_after_load(order);
value_type v;
memcpy(&v, &tmp, sizeof(value_type));
return v;
}
value_type
exchange(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE8
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE8(&v_, tmp));
#else
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, tmp));
#endif
platform_fence_after(order);
value_type res;
memcpy(&res, &tmp, sizeof(value_type));
return res;
}
bool
compare_exchange_strong(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
storage_type expected_s = 0, desired_s = 0;
memcpy(&expected_s, &expected, sizeof(value_type));
memcpy(&desired_s, &desired, sizeof(value_type));
platform_fence_before(success_order);
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE8(&v_, desired_s, expected_s));
#else
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired_s, expected_s));
#endif
bool success = (oldval == expected_s);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
memcpy(&expected, &oldval, sizeof(value_type));
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
bool
is_lock_free(void) const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_BASE_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
template<typename T, bool Sign>
class base_atomic<T, void, 2, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16
typedef uint16_t storage_type;
#else
typedef uint32_t storage_type;
#endif
protected:
typedef value_type const& value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16
BOOST_CONSTEXPR explicit base_atomic(value_type const& v) BOOST_NOEXCEPT : v_(reinterpret_cast< storage_type const& >(v))
{
}
#else
explicit base_atomic(value_type const& v) BOOST_NOEXCEPT : v_(0)
{
memcpy(&v_, &v, sizeof(value_type));
}
#endif
void
store(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
const_cast<volatile storage_type &>(v_) = tmp;
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst)const volatile BOOST_NOEXCEPT
{
storage_type tmp = const_cast<volatile storage_type &>(v_);
platform_fence_after_load(order);
value_type v;
memcpy(&v, &tmp, sizeof(value_type));
return v;
}
value_type
exchange(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
#ifdef BOOST_ATOMIC_INTERLOCKED_EXCHANGE16
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE16(&v_, tmp));
#else
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, tmp));
#endif
platform_fence_after(order);
value_type res;
memcpy(&res, &tmp, sizeof(value_type));
return res;
}
bool
compare_exchange_strong(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
storage_type expected_s = 0, desired_s = 0;
memcpy(&expected_s, &expected, sizeof(value_type));
memcpy(&desired_s, &desired, sizeof(value_type));
platform_fence_before(success_order);
#ifdef BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE16(&v_, desired_s, expected_s));
#else
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired_s, expected_s));
#endif
bool success = (oldval == expected_s);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
memcpy(&expected, &oldval, sizeof(value_type));
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_BASE_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
template<typename T, bool Sign>
class base_atomic<T, void, 4, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
typedef uint32_t storage_type;
protected:
typedef value_type const& value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
explicit base_atomic(value_type const& v) : v_(0)
{
memcpy(&v_, &v, sizeof(value_type));
}
void
store(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
const_cast<volatile storage_type &>(v_) = tmp;
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst)const volatile BOOST_NOEXCEPT
{
storage_type tmp = const_cast<volatile storage_type &>(v_);
platform_fence_after_load(order);
value_type v;
memcpy(&v, &tmp, sizeof(value_type));
return v;
}
value_type
exchange(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE(&v_, tmp));
platform_fence_after(order);
value_type res;
memcpy(&res, &tmp, sizeof(value_type));
return res;
}
bool
compare_exchange_strong(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
storage_type expected_s = 0, desired_s = 0;
memcpy(&expected_s, &expected, sizeof(value_type));
memcpy(&desired_s, &desired, sizeof(value_type));
platform_fence_before(success_order);
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE(&v_, desired_s, expected_s));
bool success = (oldval == expected_s);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
memcpy(&expected, &oldval, sizeof(value_type));
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
bool
is_lock_free(void) const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_BASE_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
#if defined(_M_AMD64) || defined(_M_IA64)
template<typename T, bool Sign>
class base_atomic<T, int, 8, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
typedef value_type storage_type;
typedef T difference_type;
protected:
typedef value_type value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
BOOST_CONSTEXPR explicit base_atomic(value_type v) BOOST_NOEXCEPT: v_(v) {}
void
store(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
platform_fence_before(order);
v_ = static_cast< storage_type >(v);
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst) const volatile BOOST_NOEXCEPT
{
value_type v = static_cast< value_type >(v_);
platform_fence_after_load(order);
return v;
}
value_type
fetch_add(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE_ADD64(&v_, v));
platform_fence_after(order);
return v;
}
value_type
fetch_sub(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
typedef typename make_signed< value_type >::type signed_value_type;
return fetch_add(static_cast< value_type >(-static_cast< signed_value_type >(v)), order);
}
value_type
exchange(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE64(&v_, v));
platform_fence_after(order);
return v;
}
bool
compare_exchange_strong(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
value_type previous = expected;
platform_fence_before(success_order);
value_type oldval = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE64(&v_, desired, previous));
bool success = (previous == oldval);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
expected = oldval;
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
value_type
fetch_and(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_AND64)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_AND64(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp & v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_or(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_OR64)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_OR64(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp | v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
value_type
fetch_xor(value_type v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_XOR64)
platform_fence_before(order);
v = static_cast< value_type >(BOOST_ATOMIC_INTERLOCKED_XOR64(&v_, v));
platform_fence_after(order);
return v;
#else
value_type tmp = load(memory_order_relaxed);
for (; !compare_exchange_weak(tmp, tmp ^ v, order, memory_order_relaxed);)
{
BOOST_ATOMIC_X86_PAUSE();
}
return tmp;
#endif
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
template<typename T, bool Sign>
class base_atomic<T, void, 8, Sign>
{
private:
typedef base_atomic this_type;
typedef T value_type;
typedef uint64_t storage_type;
protected:
typedef value_type const& value_arg_type;
public:
BOOST_DEFAULTED_FUNCTION(base_atomic(void), {})
explicit base_atomic(value_type const& v) : v_(0)
{
memcpy(&v_, &v, sizeof(value_type));
}
void
store(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
if (order != memory_order_seq_cst) {
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
const_cast<volatile storage_type &>(v_) = tmp;
} else {
exchange(v, order);
}
}
value_type
load(memory_order order = memory_order_seq_cst)const volatile BOOST_NOEXCEPT
{
storage_type tmp = const_cast<volatile storage_type &>(v_);
platform_fence_after_load(order);
value_type v;
memcpy(&v, &tmp, sizeof(value_type));
return v;
}
value_type
exchange(value_type const& v, memory_order order = memory_order_seq_cst) volatile BOOST_NOEXCEPT
{
storage_type tmp = 0;
memcpy(&tmp, &v, sizeof(value_type));
platform_fence_before(order);
tmp = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_EXCHANGE64(&v_, tmp));
platform_fence_after(order);
value_type res;
memcpy(&res, &tmp, sizeof(value_type));
return res;
}
bool
compare_exchange_strong(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
storage_type expected_s = 0, desired_s = 0;
memcpy(&expected_s, &expected, sizeof(value_type));
memcpy(&desired_s, &desired, sizeof(value_type));
platform_fence_before(success_order);
storage_type oldval = static_cast< storage_type >(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE64(&v_, desired_s, expected_s));
bool success = (oldval == expected_s);
if (success)
platform_fence_after(success_order);
else
platform_fence_after(failure_order);
memcpy(&expected, &oldval, sizeof(value_type));
return success;
}
bool
compare_exchange_weak(
value_type & expected,
value_type const& desired,
memory_order success_order,
memory_order failure_order) volatile BOOST_NOEXCEPT
{
return compare_exchange_strong(expected, desired, success_order, failure_order);
}
bool
is_lock_free(void)const volatile BOOST_NOEXCEPT
{
return true;
}
BOOST_ATOMIC_DECLARE_BASE_OPERATORS
BOOST_DELETED_FUNCTION(base_atomic(base_atomic const&))
BOOST_DELETED_FUNCTION(base_atomic& operator=(base_atomic const&))
private:
storage_type v_;
};
#elif defined(BOOST_ATOMIC_X86_HAS_CMPXCHG8B)
template<typename T>
inline bool
platform_cmpxchg64_strong(T & expected, T desired, volatile T * p) BOOST_NOEXCEPT
{
#if defined(BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE64)
const T oldval = BOOST_ATOMIC_INTERLOCKED_COMPARE_EXCHANGE64(p, desired, expected);
const bool result = (oldval == expected);
expected = oldval;
return result;
#else
bool result;
__asm
{
mov edi, p
mov esi, expected
mov ebx, dword ptr [desired]
mov ecx, dword ptr [desired + 4]
mov eax, dword ptr [esi]
mov edx, dword ptr [esi + 4]
lock cmpxchg8b qword ptr [edi]
mov dword ptr [esi], eax
mov dword ptr [esi + 4], edx
sete result
};
return result;
#endif
}
// Intel 64 and IA-32 Architectures Software Developer's Manual, Volume 3A, 8.1.1. Guaranteed Atomic Operations:
//
// The Pentium processor (and newer processors since) guarantees that the following additional memory operations will always be carried out atomically:
// * Reading or writing a quadword aligned on a 64-bit boundary
//
// Luckily, the memory is almost always 8-byte aligned in our case because atomic<> uses 64 bit native types for storage and dynamic memory allocations
// have at least 8 byte alignment. The only unfortunate case is when atomic is placeod on the stack and it is not 8-byte aligned (like on 32 bit Windows).
template<typename T>
inline void
platform_store64(T value, volatile T * p) BOOST_NOEXCEPT
{
if (((uint32_t)p & 0x00000007) == 0)
{
#if defined(_M_IX86_FP) && _M_IX86_FP >= 2
__asm
{
mov edx, p
movq xmm4, value
movq qword ptr [edx], xmm4
};
#else
__asm
{
mov edx, p
fild value
fistp qword ptr [edx]
};
#endif
}
else
{
__asm
{
mov edi, p
mov ebx, dword ptr [value]
mov ecx, dword ptr [value + 4]
mov eax, dword ptr [edi]
mov edx, dword ptr [edi + 4]
align 16
again:
lock cmpxchg8b qword ptr [edi]
jne again
};
}
}
template<typename T>
inline T
platform_load64(const volatile T * p) BOOST_NOEXCEPT
{
T value;
if (((uint32_t)p & 0x00000007) == 0)
{
#if defined(_M_IX86_FP) && _M_IX86_FP >= 2
__asm
{
mov edx, p
movq xmm4, qword ptr [edx]
movq value, xmm4
};
#else
__asm
{
mov edx, p
fild qword ptr [edx]
fistp value
};
#endif
}
else
{
// We don't care for comparison result here; the previous value will be stored into value anyway.
// Also we don't care for ebx and ecx values, they just have to be equal to eax and edx before cmpxchg8b.
__asm
{
mov edi, p
mov eax, ebx
mov edx, ecx
lock cmpxchg8b qword ptr [edi]
mov dword ptr [value], eax
mov dword ptr [value + 4], edx
};
}
return value;
}
#endif
} // namespace detail
} // namespace atomics
} // namespace boost
/* pull in 64-bit atomic type using cmpxchg8b above */
#if defined(BOOST_ATOMIC_X86_HAS_CMPXCHG8B)
#include <boost/atomic/detail/cas64strong.hpp>
#endif
#endif /* !defined(BOOST_ATOMIC_FORCE_FALLBACK) */
#ifdef _MSC_VER
#pragma warning(pop)
#endif
#endif