bubel-ecs/source/ecs/block_allocator.d
Dawid Masiukiewicz 54a6d5dec2 CI and common update:
-added webpage deploymnet stage
-added separate build stage which build all binaries and generate documentation
-added Emscripten build stage for merge to master only
-added VBO batch rendering (current default, no render mode switch yet)
-fixed camera positioning calculation
-fixed buffer issue with WebGL
-added viewport scalling (at least 300 pixels height). Pixels are scalled if screen is bigger.
-center demos gameplay area
-added fullpage html template for Emscripten build
2020-05-01 19:26:21 +00:00

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D

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