Mergul
96bbcb9956
-moved system destroy functionality to System structure "destroy()" function -now arrays are properly destroyed (with destructor calling (__xdtor)) -fixed bug which makes BlockAllocator crashing after freeing it's memory -fixed many smaller memory leaks
100 lines
3.3 KiB
D
100 lines
3.3 KiB
D
/************************************************************************************************************************
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It's internal code.
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Module contain memory allocator.
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Copyright: Copyright © 2018-2019, Dawid Masiukiewicz, Michał Masiukiewicz
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License: BSD 3-clause, see LICENSE file in project root folder.
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*/
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module bubel.ecs.block_allocator;
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import bubel.ecs.manager;
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import bubel.ecs.std;
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/************************************************************************************************************************
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Allocator allocate large blocks and return smaller blocks. When there is no more blocks then next large block is allocated.
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By default freeing memory only returns it to allocator. To free large memory chunks freeMemory function is used.
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freeMemory function return to system memory even if chunk blocks wasn't freed.
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*/
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struct BlockAllocator
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{
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/************************************************************************************************************************
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Get new block. Allocator automatically allocate next memory chunk if needed.
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*/
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void* getBlock() nothrow @nogc
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{
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if (next_block is null)
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allocBlock();
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void* ret = next_block;
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next_block = *cast(void**) next_block;
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return ret;
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}
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/************************************************************************************************************************
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Return block to allocator for further use.
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*/
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void freeBlock(void* block) nothrow @nogc
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{
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*cast(void**) block = next_block;
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next_block = block;
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}
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/************************************************************************************************************************
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Free whole used memory. This function return to system all memory chunks even if not every black was freed.
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*/
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void freeMemory() nothrow @nogc
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{
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while (pointers)
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{
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foreach (i; 0 .. pointers.numberof)
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{
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Mallocator.alignDispose(pointers.blocks[i]);
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}
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BlockPointers* next_pointers = pointers.next_pointers;
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Mallocator.dispose(pointers);
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pointers = next_pointers;
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}
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next_block = null;
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}
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private:
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void allocBlock() nothrow @nogc
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{
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next_block = cast(void*) Mallocator.alignAlloc(block_size * blocks_in_allocation,
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block_size);
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if (next_block is null)
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assert(0);
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if (pointers is null)
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pointers = Mallocator.make!BlockPointers;
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if (pointers.numberof >= 32)
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{
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BlockPointers* new_pointers = Mallocator.make!BlockPointers;
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new_pointers.next_pointers = pointers;
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pointers = new_pointers;
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}
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pointers.blocks[pointers.numberof++] = next_block;
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foreach (i; 0 .. blocks_in_allocation - 1)
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{
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void** pointer = cast(void**)(next_block + i * block_size);
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*pointer = next_block + (i + 1) * block_size;
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}
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void** pointer = cast(void**)(next_block + (blocks_in_allocation - 1) * block_size);
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*pointer = null;
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}
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struct BlockPointers
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{
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void*[32] blocks;
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uint numberof = 0;
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BlockPointers* next_pointers = null;
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}
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uint block_size;
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uint blocks_in_allocation;
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void* next_block = null;
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BlockPointers* pointers = null;
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}
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