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51 řádky
983 B
51 řádky
983 B
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typedef struct Memory_Arena
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{
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void *memory;
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size_t size;
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size_t allocation_offset;
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} Memory_Arena;
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_Static_assert(sizeof(size_t) == sizeof(void*),
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"The Memory_Arena implementation assumes that size_t and pointers are of the same size.");
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void *memory_arena_allocate(
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Memory_Arena *arena,
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size_t size,
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size_t alignment)
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{
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#if 0
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printf(
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"%s: arena: {.memory=%p, .size=%zu, .allocation_offset=%zu}\n"
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"size: %zu, alignment: %zu\n"
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, __func__
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, arena->memory, arena->size, arena->allocation_offset
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, size, alignment
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);
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#endif
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size_t allocation_offset = arena->allocation_offset;
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allocation_offset = ((allocation_offset + alignment - 1) / alignment) * alignment;
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if(allocation_offset + size > arena->size)
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{
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return NULL;
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}
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void *allocation = ((char*)arena->memory) + allocation_offset;
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arena->allocation_offset = allocation_offset + size;
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return allocation;
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}
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void memory_arena_reset(
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Memory_Arena *arena)
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{
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arena->allocation_offset = 0;
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}
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