base.hpp

Go to the documentation of this file.

#ifndef BOOST_DETAIL_ATOMIC_BASE_HPP
#define BOOST_DETAIL_ATOMIC_BASE_HPP

//  Copyright (c) 2009 Helge Bahmann
//
//  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)

// Base class definition and fallback implementation.
// To be overridden (through partial specialization) by
// platform implementations.

#include <string.h>

#include <boost/memory_order.hpp>
#include <boost/smart_ptr/detail/spinlock_pool.hpp>

#define BOOST_ATOMIC_DECLARE_BASE_OPERATORS \
        operator value_type(void) volatile const \
        { \
                return load(memory_order_seq_cst); \
        } \
         \
        this_type & \
        operator=(value_type v) volatile \
        { \
                store(v, memory_order_seq_cst); \
                return *const_cast<this_type *>(this); \
        } \
         \
        bool \
        compare_exchange_strong( \
                value_type & expected, \
                value_type desired, \
                memory_order order = memory_order_seq_cst) volatile \
        { \
                return compare_exchange_strong(expected, desired, order, calculate_failure_order(order)); \
        } \
         \
        bool \
        compare_exchange_weak( \
                value_type & expected, \
                value_type desired, \
                memory_order order = memory_order_seq_cst) volatile \
        { \
                return compare_exchange_weak(expected, desired, order, calculate_failure_order(order)); \
        } \
         \

#define BOOST_ATOMIC_DECLARE_ADDITIVE_OPERATORS \
        value_type \
        operator++(int) volatile \
        { \
                return fetch_add(1); \
        } \
         \
        value_type \
        operator++(void) volatile \
        { \
                return fetch_add(1) + 1; \
        } \
         \
        value_type \
        operator--(int) volatile \
        { \
                return fetch_sub(1); \
        } \
         \
        value_type \
        operator--(void) volatile \
        { \
                return fetch_sub(1) - 1; \
        } \
         \
        value_type \
        operator+=(difference_type v) volatile \
        { \
                return fetch_add(v) + v; \
        } \
         \
        value_type \
        operator-=(difference_type v) volatile \
        { \
                return fetch_sub(v) - v; \
        } \

#define BOOST_ATOMIC_DECLARE_BIT_OPERATORS \
        value_type \
        operator&=(difference_type v) volatile \
        { \
                return fetch_and(v) & v; \
        } \
         \
        value_type \
        operator|=(difference_type v) volatile \
        { \
                return fetch_or(v) | v; \
        } \
         \
        value_type \
        operator^=(difference_type v) volatile \
        { \
                return fetch_xor(v) ^ v; \
        } \

#define BOOST_ATOMIC_DECLARE_POINTER_OPERATORS \
        BOOST_ATOMIC_DECLARE_BASE_OPERATORS \
        BOOST_ATOMIC_DECLARE_ADDITIVE_OPERATORS \

#define BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS \
        BOOST_ATOMIC_DECLARE_BASE_OPERATORS \
        BOOST_ATOMIC_DECLARE_ADDITIVE_OPERATORS \
        BOOST_ATOMIC_DECLARE_BIT_OPERATORS \

namespace boost {
namespace detail {
namespace atomic {

static inline memory_order
calculate_failure_order(memory_order order)
{
        switch(order) {
                case memory_order_acq_rel:
                        return memory_order_acquire;
                case memory_order_release:
                        return memory_order_relaxed;
                default:
                        return order;
        }
}

template<typename T, typename C , unsigned int Size, bool Sign>
class base_atomic {
private:
        typedef base_atomic this_type;
        typedef T value_type;
        typedef detail::spinlock_pool<0>::scoped_lock guard_type;
public:
        base_atomic(void) {}
        
        explicit base_atomic(const value_type & v)
        {
                memcpy(&v_, &v, Size);
        }
        
        void
        store(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<char *>(v_));
                
                memcpy(const_cast<char *>(v_), &v, Size);
        }
        
        value_type
        load(memory_order /*order*/ = memory_order_seq_cst) volatile const
        {
                guard_type guard(const_cast<const char *>(v_));
                
                value_type v;
                memcpy(&v, const_cast<const char *>(v_), Size);
                return v;
        }
        
        bool
        compare_exchange_strong(
                value_type & expected,
                value_type desired,
                memory_order /*success_order*/,
                memory_order /*failure_order*/) volatile
        {
                guard_type guard(const_cast<char *>(v_));
                
                if (memcmp(const_cast<char *>(v_), &expected, Size) == 0) {
                        memcpy(const_cast<char *>(v_), &desired, Size);
                        return true;
                } else {
                        memcpy(&expected, const_cast<char *>(v_), Size);
                        return false;
                }
        }
        
        bool
        compare_exchange_weak(
                value_type & expected,
                value_type desired,
                memory_order success_order,
                memory_order failure_order) volatile
        {
                return compare_exchange_strong(expected, desired, success_order, failure_order);
        }
        
        value_type
        exchange(value_type v, memory_order /*order*/=memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<char *>(v_));
                
                value_type tmp;
                memcpy(&tmp, const_cast<char *>(v_), Size);
                
                memcpy(const_cast<char *>(v_), &v, Size);
                return tmp;
        }
        
        bool
        is_lock_free(void) const volatile
        {
                return false;
        }
        
        BOOST_ATOMIC_DECLARE_BASE_OPERATORS
private:
        base_atomic(const base_atomic &) /* = delete */ ;
        void operator=(const base_atomic &) /* = delete */ ;
        
        char v_[Size];
};

template<typename T, unsigned int Size, bool Sign>
class base_atomic<T, int, Size, Sign> {
private:
        typedef base_atomic this_type;
        typedef T value_type;
        typedef T difference_type;
        typedef detail::spinlock_pool<0>::scoped_lock guard_type;
public:
        explicit base_atomic(value_type v) : v_(v) {}
        base_atomic(void) {}
        
        void
        store(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                v_ = v;
        }
        
        value_type
        load(memory_order /*order*/ = memory_order_seq_cst) const volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type v = const_cast<const volatile value_type &>(v_);
                return v;
        }
        
        value_type
        exchange(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ = v;
                return old;
        }
        
        bool
        compare_exchange_strong(value_type & expected, value_type desired,
                memory_order /*success_order*/,
                memory_order /*failure_order*/) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                if (v_ == expected) {
                        v_ = desired;
                        return true;
                } else {
                        expected = v_;
                        return false;
                }
        }
        
        bool
        compare_exchange_weak(value_type & expected, value_type desired,
                memory_order success_order,
                memory_order failure_order) volatile
        {
                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
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ += v;
                return old;
        }
        
        value_type
        fetch_sub(difference_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ -= v;
                return old;
        }
        
        value_type
        fetch_and(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ &= v;
                return old;
        }
        
        value_type
        fetch_or(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ |= v;
                return old;
        }
        
        value_type
        fetch_xor(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ ^= v;
                return old;
        }
        
        bool
        is_lock_free(void) const volatile
        {
                return false;
        }
        
        BOOST_ATOMIC_DECLARE_INTEGRAL_OPERATORS
private:
        base_atomic(const base_atomic &) /* = delete */ ;
        void operator=(const base_atomic &) /* = delete */ ;
        value_type v_;
};

template<typename T, unsigned int Size, bool Sign>
class base_atomic<T *, void *, Size, Sign> {
private:
        typedef base_atomic this_type;
        typedef T * value_type;
        typedef ptrdiff_t difference_type;
        typedef detail::spinlock_pool<0>::scoped_lock guard_type;
public:
        explicit base_atomic(value_type v) : v_(v) {}
        base_atomic(void) {}
        
        void
        store(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                v_ = v;
        }
        
        value_type
        load(memory_order /*order*/ = memory_order_seq_cst) const volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type v = const_cast<const volatile value_type &>(v_);
                return v;
        }
        
        value_type
        exchange(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ = v;
                return old;
        }
        
        bool
        compare_exchange_strong(value_type & expected, value_type desired,
                memory_order /*success_order*/,
                memory_order /*failure_order*/) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                if (v_ == expected) {
                        v_ = desired;
                        return true;
                } else {
                        expected = v_;
                        return false;
                }
        }
        
        bool
        compare_exchange_weak(value_type & expected, value_type desired,
                memory_order success_order,
                memory_order failure_order) volatile
        {
                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
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ += v;
                return old;
        }
        
        value_type fetch_sub(difference_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ -= v;
                return old;
        }
        
        bool
        is_lock_free(void) const volatile
        {
                return false;
        }
        
        BOOST_ATOMIC_DECLARE_POINTER_OPERATORS
private:
        base_atomic(const base_atomic  &) /* = delete */ ;
        void operator=(const base_atomic &) /* = delete */ ;
        value_type v_;
};

template<unsigned int Size, bool Sign>
class base_atomic<void *, void *, Size, Sign> {
private:
        typedef base_atomic this_type;
        typedef void * value_type;
        typedef detail::spinlock_pool<0>::scoped_lock guard_type;
public:
        explicit base_atomic(value_type v) : v_(v) {}
        base_atomic(void) {}
        
        void
        store(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                v_ = v;
        }
        
        value_type
        load(memory_order /*order*/ = memory_order_seq_cst) const volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type v = const_cast<const volatile value_type &>(v_);
                return v;
        }
        
        value_type
        exchange(value_type v, memory_order /*order*/ = memory_order_seq_cst) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                value_type old = v_;
                v_ = v;
                return old;
        }
        
        bool
        compare_exchange_strong(value_type & expected, value_type desired,
                memory_order /*success_order*/,
                memory_order /*failure_order*/) volatile
        {
                guard_type guard(const_cast<value_type *>(&v_));
                
                if (v_ == expected) {
                        v_ = desired;
                        return true;
                } else {
                        expected = v_;
                        return false;
                }
        }
        
        bool
        compare_exchange_weak(value_type & expected, value_type desired,
                memory_order success_order,
                memory_order failure_order) volatile
        {
                return compare_exchange_strong(expected, desired, success_order, failure_order);
        }
        
        bool
        is_lock_free(void) const volatile
        {
                return false;
        }
        
        BOOST_ATOMIC_DECLARE_BASE_OPERATORS
private:
        base_atomic(const base_atomic &) /* = delete */ ;
        void operator=(const base_atomic &) /* = delete */ ;
        value_type v_;
};

}
}
}

#endif