55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
/*
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* malloc.h
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*
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* Internals for the memory allocator
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*/
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#include <stdint.h>
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#include <stddef.h>
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/*
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* This is the minimum chunk size we will ask the kernel for; this should
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* be a multiple of the page size on all architectures.
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*/
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#define MALLOC_CHUNK_SIZE 65536
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#define MALLOC_CHUNK_MASK (MALLOC_CHUNK_SIZE-1)
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/*
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* This structure should be a power of two. This becomes the
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* alignment unit.
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*/
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struct free_arena_header;
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struct arena_header {
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size_t type;
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size_t size; /* Also gives the location of the next entry */
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struct free_arena_header *next, *prev;
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};
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#ifdef DEBUG_MALLOC
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#define ARENA_TYPE_USED 0x64e69c70
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#define ARENA_TYPE_FREE 0x012d610a
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#define ARENA_TYPE_HEAD 0x971676b5
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#define ARENA_TYPE_DEAD 0xeeeeeeee
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#else
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#define ARENA_TYPE_USED 0
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#define ARENA_TYPE_FREE 1
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#define ARENA_TYPE_HEAD 2
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#endif
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#define ARENA_SIZE_MASK (sizeof(struct arena_header)-1)
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#define ARENA_ALIGN_UP(p) ((char *)(((uintptr_t)(p) + ARENA_SIZE_MASK) & ~ARENA_SIZE_MASK))
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#define ARENA_ALIGN_DOWN(p) ((char *)((uintptr_t)(p) & ~ARENA_SIZE_MASK))
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/*
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* This structure should be no more than twice the size of the
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* previous structure.
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*/
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struct free_arena_header {
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struct arena_header a;
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struct free_arena_header *next_free, *prev_free;
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};
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extern struct free_arena_header __malloc_head;
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