Allocator.h

#pragma once
 
/* <editor-fold desc="MIT License">
 
Copyright(c) 2022 Robert Osfield
 
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
</editor-fold> */
 
#include <vsg/core/MemorySlots.h>
 
#include <memory>
#include <mutex>
#include <vector>
 
namespace vsg
{
    enum AllocatorType : uint8_t
    {
        ALLOCATOR_TYPE_NO_DELETE = 0,
        ALLOCATOR_TYPE_NEW_DELETE,
        ALLOCATOR_TYPE_MALLOC_FREE,
        ALLOCATOR_TYPE_VSG_ALLOCATOR
    };
 
    enum AllocatorAffinity : uint32_t
    {
        ALLOCATOR_AFFINITY_OBJECTS,
        ALLOCATOR_AFFINITY_DATA,
        ALLOCATOR_AFFINITY_NODES,
        ALLOCATOR_AFFINITY_LAST = ALLOCATOR_AFFINITY_NODES + 1
    };
 
    class VSG_DECLSPEC Allocator
    {
    public:
        Allocator(std::unique_ptr<Allocator> in_nestedAllocator = {});
 
        virtual ~Allocator();
 
        static std::unique_ptr<Allocator>& instance();
 
        virtual void* allocate(std::size_t size, AllocatorAffinity allocatorAffinity = ALLOCATOR_AFFINITY_OBJECTS);
 
        virtual bool deallocate(void* ptr, std::size_t size);
 
        virtual size_t deleteEmptyMemoryBlocks();
 
        virtual size_t totalAvailableSize() const;
 
        virtual size_t totalReservedSize() const;
 
        virtual size_t totalMemorySize() const;
 
        virtual void report(std::ostream& out) const;
 
        AllocatorType allocatorType = ALLOCATOR_TYPE_VSG_ALLOCATOR;          // use MemoryBlocks by default
        AllocatorType memoryBlocksAllocatorType = ALLOCATOR_TYPE_NEW_DELETE; // Use new/delete within MemoryBlocks by default
        int memoryTracking = MEMORY_TRACKING_DEFAULT;
 
        void setMemoryTracking(int mt);
 
        struct MemoryBlock
        {
            MemoryBlock(size_t blockSize, int memoryTracking, AllocatorType in_allocatorType);
            virtual ~MemoryBlock();
 
            void* allocate(std::size_t size);
            bool deallocate(void* ptr, std::size_t size);
 
            vsg::MemorySlots memorySlots;
            const AllocatorType allocatorType;
            uint8_t* memory = nullptr;
        };
 
        struct MemoryBlocks
        {
            Allocator* parent = nullptr;
            std::string name;
            size_t blockSize = 0;
            std::list<std::unique_ptr<MemoryBlock>> memoryBlocks;
 
            MemoryBlocks(Allocator* in_parent, const std::string& in_name, size_t in_blockSize);
            virtual ~MemoryBlocks();
 
            void* allocate(std::size_t size);
            bool deallocate(void* ptr, std::size_t size);
            size_t deleteEmptyMemoryBlocks();
            size_t totalAvailableSize() const;
            size_t totalReservedSize() const;
            size_t totalMemorySize() const;
        };
 
        MemoryBlocks* getMemoryBlocks(AllocatorAffinity allocatorAffinity);
 
        MemoryBlocks* getOrCreateMemoryBlocks(AllocatorAffinity allocatorAffinity, const std::string& name, size_t blockSize);
 
        void setBlockSize(AllocatorAffinity allocatorAffinity, size_t blockSize);
 
        mutable std::mutex mutex;
 
    protected:
        // if you are assigning a custom allocator you must retain the old allocator to manage the memory it allocated and needs to delete
        std::unique_ptr<Allocator> nestedAllocator;
 
        std::vector<std::unique_ptr<MemoryBlocks>> allocatorMemoryBlocks;
    };
 
    extern VSG_DECLSPEC void* allocate(std::size_t size, AllocatorAffinity allocatorAffinity = ALLOCATOR_AFFINITY_OBJECTS);
 
    extern VSG_DECLSPEC void deallocate(void* ptr, std::size_t size = 0);
 
    template<typename T>
    struct allocator_affinity_nodes
    {
        using value_type = T;
 
        allocator_affinity_nodes() = default;
        template<class U>
        constexpr allocator_affinity_nodes(const allocator_affinity_nodes<U>&) noexcept {}
 
        value_type* allocate(std::size_t n)
        {
            return static_cast<value_type*>(vsg::allocate(n * sizeof(value_type), vsg::ALLOCATOR_AFFINITY_NODES));
        }
 
        void deallocate(value_type* ptr, std::size_t n)
        {
            vsg::deallocate(ptr, n * sizeof(value_type));
        }
    };
 
    template<class T, class U>
    bool operator==(const allocator_affinity_nodes<T>&, const allocator_affinity_nodes<U>&) { return true; }
 
    template<class T, class U>
    bool operator!=(const allocator_affinity_nodes<T>&, const allocator_affinity_nodes<U>&) { return false; }
 
} // namespace vsg