98 lines
3.2 KiB
C++
98 lines
3.2 KiB
C++
/*
|
|
* 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)
|
|
*
|
|
* Copyright (c) 2020 Andrey Semashev
|
|
*/
|
|
/*!
|
|
* \file atomic/detail/wait_ops_emulated.hpp
|
|
*
|
|
* This header contains emulated (lock-based) implementation of the waiting and notifying atomic operations.
|
|
*/
|
|
|
|
#ifndef BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_
|
|
#define BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_
|
|
|
|
#include <cstddef>
|
|
#include <boost/static_assert.hpp>
|
|
#include <boost/memory_order.hpp>
|
|
#include <boost/atomic/detail/config.hpp>
|
|
#include <boost/atomic/detail/lock_pool.hpp>
|
|
#include <boost/atomic/detail/wait_operations_fwd.hpp>
|
|
#include <boost/atomic/detail/header.hpp>
|
|
|
|
#ifdef BOOST_HAS_PRAGMA_ONCE
|
|
#pragma once
|
|
#endif
|
|
|
|
namespace boost {
|
|
namespace atomics {
|
|
namespace detail {
|
|
|
|
//! Emulated implementation of waiting and notifying operations
|
|
template< typename Base >
|
|
struct wait_operations_emulated :
|
|
public Base
|
|
{
|
|
typedef Base base_type;
|
|
typedef typename base_type::storage_type storage_type;
|
|
typedef lock_pool::scoped_lock< base_type::storage_alignment, true > scoped_lock;
|
|
typedef lock_pool::scoped_wait_state< base_type::storage_alignment > scoped_wait_state;
|
|
|
|
static BOOST_CONSTEXPR_OR_CONST bool always_has_native_wait_notify = false;
|
|
|
|
static BOOST_FORCEINLINE bool has_native_wait_notify(storage_type const volatile&) BOOST_NOEXCEPT
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static
|
|
#if defined(BOOST_MSVC) && BOOST_MSVC < 1500
|
|
// In some cases, when this function is inlined, MSVC-8 (VS2005) x64 generates broken code that returns a bogus value from this function.
|
|
BOOST_NOINLINE
|
|
#endif
|
|
storage_type wait(storage_type const volatile& storage, storage_type old_val, memory_order) BOOST_NOEXCEPT
|
|
{
|
|
BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
|
|
storage_type const& s = const_cast< storage_type const& >(storage);
|
|
scoped_wait_state wait_state(&storage);
|
|
storage_type new_val = s;
|
|
while (new_val == old_val)
|
|
{
|
|
wait_state.wait();
|
|
new_val = s;
|
|
}
|
|
|
|
return new_val;
|
|
}
|
|
|
|
static void notify_one(storage_type volatile& storage) BOOST_NOEXCEPT
|
|
{
|
|
BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
|
|
scoped_lock lock(&storage);
|
|
lock_pool::notify_one(lock.get_lock_state(), &storage);
|
|
}
|
|
|
|
static void notify_all(storage_type volatile& storage) BOOST_NOEXCEPT
|
|
{
|
|
BOOST_STATIC_ASSERT_MSG(!base_type::is_interprocess, "Boost.Atomic: operation invoked on a non-lock-free inter-process atomic object");
|
|
scoped_lock lock(&storage);
|
|
lock_pool::notify_all(lock.get_lock_state(), &storage);
|
|
}
|
|
};
|
|
|
|
template< typename Base, std::size_t Size, bool Interprocess >
|
|
struct wait_operations< Base, Size, false, Interprocess > :
|
|
public wait_operations_emulated< Base >
|
|
{
|
|
};
|
|
|
|
} // namespace detail
|
|
} // namespace atomics
|
|
} // namespace boost
|
|
|
|
#include <boost/atomic/detail/footer.hpp>
|
|
|
|
#endif // BOOST_ATOMIC_DETAIL_WAIT_OPS_EMULATED_HPP_INCLUDED_
|