47 lines
1.1 KiB
C++
47 lines
1.1 KiB
C++
// Copyright (c) Wojciech Figat. All rights reserved.
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#include "ArenaAllocation.h"
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#include "../Math/Math.h"
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void ArenaAllocator::Free()
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{
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// Free all pages
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Page* page = _first;
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while (page)
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{
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Allocator::Free(page->Memory);
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Page* next = page->Next;
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Allocator::Free(page);
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page = next;
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}
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// Unlink
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_first = nullptr;
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}
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void* ArenaAllocator::Allocate(uint64 size, uint64 alignment)
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{
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// Find the first page that has some space left
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Page* page = _first;
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while (page && page->Offset + size + alignment > page->Size)
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page = page->Next;
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// Create a new page if need to
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if (!page)
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{
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uint64 pageSize = Math::Max<uint64>(_pageSize, size);
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page = (Page*)Allocator::Allocate(sizeof(Page));
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page->Memory = Allocator::Allocate(pageSize);
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page->Next = _first;
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page->Offset = 0;
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page->Size = (uint32)pageSize;
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_first = page;
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}
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// Allocate within a page
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page->Offset = Math::AlignUp(page->Offset, (uint32)alignment);
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void* mem = (byte*)page->Memory + page->Offset;
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page->Offset += (uint32)size;
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return mem;
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} |