Boost C++ Libraries

boost/fiber/stack_allocator_wrapper.hpp

#ifndef BOOST_FIBERS_STACK_ALLOCATOR_WRAPPER_H
#define BOOST_FIBERS_STACK_ALLOCATOR_WRAPPER_H

#include <memory>

#include <boost/fiber/detail/config.hpp>
#include <boost/context/stack_context.hpp>
#include <boost/fiber/fixedsize_stack.hpp>
#include <boost/fiber/segmented_stack.hpp>

namespace boost {
namespace fibers {
namespace detail {
class BOOST_FIBERS_DECL polymorphic_stack_allocator_base {
public:
    polymorphic_stack_allocator_base() = default;

    virtual ~polymorphic_stack_allocator_base() = default;

    polymorphic_stack_allocator_base(const polymorphic_stack_allocator_base&) = delete;
    polymorphic_stack_allocator_base& operator=(const polymorphic_stack_allocator_base&) = delete;

    polymorphic_stack_allocator_base(polymorphic_stack_allocator_base&&) = delete;
    polymorphic_stack_allocator_base& operator=(polymorphic_stack_allocator_base&&) = delete;

    virtual boost::context::stack_context allocate() = 0;

    virtual void deallocate(boost::context::stack_context& sctx) = 0;
};

template< typename StackAllocator >
class BOOST_FIBERS_DECL polymorphic_stack_allocator_impl final : public polymorphic_stack_allocator_base {
public:
    template<typename ... Args >
    polymorphic_stack_allocator_impl( Args && ... args )
        :_allocator(std::forward< Args >( args) ... )
    {}

    ~polymorphic_stack_allocator_impl() = default;

    boost::context::stack_context allocate() override
    {
        return _allocator.allocate();
    }

    void deallocate(boost::context::stack_context& sctx) override
    {
        _allocator.deallocate(sctx);
    }

private:
    StackAllocator _allocator;
};
}

class BOOST_FIBERS_DECL stack_allocator_wrapper final {
public:
    stack_allocator_wrapper(std::unique_ptr<detail::polymorphic_stack_allocator_base> allocator)
        :_allocator(std::move(allocator))
    {}

    ~stack_allocator_wrapper() = default;

    stack_allocator_wrapper(const stack_allocator_wrapper&) = delete;
    stack_allocator_wrapper& operator=(const stack_allocator_wrapper&) = delete;

    stack_allocator_wrapper(stack_allocator_wrapper&&) = default;
    stack_allocator_wrapper& operator=(stack_allocator_wrapper&&) = default;

    boost::context::stack_context allocate()
    {
        return _allocator->allocate();
    }

    void deallocate(boost::context::stack_context& sctx)
    {
        _allocator->deallocate(sctx);
    }

private:
    std::unique_ptr<detail::polymorphic_stack_allocator_base> _allocator;
};

template <typename StackAllocator, typename ... Args>
BOOST_FIBERS_DECL stack_allocator_wrapper make_stack_allocator_wrapper(Args && ... args)
{
    return stack_allocator_wrapper(
            std::unique_ptr<detail::polymorphic_stack_allocator_base>(
                new detail::polymorphic_stack_allocator_impl<StackAllocator>(std::forward< Args >( args) ... )));
}
}
}

#endif