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Diffstat (limited to 'libc/stdlib/malloc-930716/malloc.h')
-rw-r--r-- | libc/stdlib/malloc-930716/malloc.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/libc/stdlib/malloc-930716/malloc.h b/libc/stdlib/malloc-930716/malloc.h new file mode 100644 index 000000000..34458c062 --- /dev/null +++ b/libc/stdlib/malloc-930716/malloc.h @@ -0,0 +1,107 @@ +/* malloc.h - declarations for the allocator. + Copyright (c) 1989, 1993 Michael J. Haertel + You may redistribute this library under the terms of the + GNU Library General Public License (version 2 or any later + version) as published by the Free Software Foundation. + THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY EXPRESS OR IMPLIED + WARRANTY. IN PARTICULAR, THE AUTHOR MAKES NO REPRESENTATION OR + WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS + SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */ + +#include <sys/cdefs.h> + +/* Underlying allocation function; successive calls should return + contiguous pieces of memory. */ +extern void *(*__morecore)(long); + +/* Default value of previous. */ +extern void *__default_morecore_init(long); +extern void *__default_morecore(long); + +/* The allocator divides the heap into blocks of fixed size; large + requests receive one or more whole blocks, and small requests + receive a fragment of a block. Fragment sizes are powers of two, + and all fragments of a block are the same size. When all the + fragments in a block have been freed, the block itself is freed. + WARNING: BLOCKSIZE must be set greater than or equal to the + machine's page size for valloc() to work correctly. The default + definition here is 4096 bytes. */ +#define INT_BIT (CHAR_BIT * sizeof (int)) +#define BLOCKLOG (INT_BIT > 16 ? 12 : 9) +#define BLOCKSIZE (1 << BLOCKLOG) +#define BLOCKIFY(SIZE) (((SIZE) + BLOCKSIZE - 1) / BLOCKSIZE) + +/* Determine the amount of memory spanned by the initial heap table + (not an absolute limit). */ +#define HEAP (INT_BIT > 16 ? 4194304 : 65536) + +/* Number of contiguous free blocks allowed to build up at the end of + memory before they will be returned to the system. */ +#define FINAL_FREE_BLOCKS 8 + +/* Data structure giving per-block information. */ +union info { + struct { + int type; /* Zero for a large block, or positive + giving the logarithm to the base two + of the fragment size. */ + union { + struct { + int nfree; /* Free fragments in a fragmented block. */ + int first; /* First free fragment of the block. */ + } frag; + int size; /* Size (in blocks) of a large cluster. */ + } info; + } busy; + struct { + int size; /* Size (in blocks) of a free cluster. */ + int next; /* Index of next free cluster. */ + int prev; /* Index of previous free cluster. */ + } free; +}; + +/* Pointer to first block of the heap. */ +extern char *_heapbase; + +/* Table indexed by block number giving per-block information. */ +extern union info *_heapinfo; + +/* Address to block number and vice versa. */ +#define BLOCK(A) (((char *) (A) - _heapbase) / BLOCKSIZE + 1) +#define ADDRESS(B) ((void *) (((B) - 1) * BLOCKSIZE + _heapbase)) + +/* Current search index for the heap table. */ +extern int _heapindex; + +/* Limit of valid info table indices. */ +extern int _heaplimit; + +/* Doubly linked lists of free fragments. */ +struct list { + struct list *next; + struct list *prev; +}; + +/* Count of blocks for each fragment size. */ +extern int _fragblocks[]; + +/* Free list headers for each fragment size. */ +extern struct list _fraghead[]; + +/* List of blocks allocated with `memalign' (or `valloc'). */ +struct alignlist +{ + struct alignlist *next; + __ptr_t aligned; /* The address that memaligned returned. */ + __ptr_t exact; /* The address that malloc returned. */ +}; +extern struct alignlist *_aligned_blocks; + +extern void _free_internal __P ((__ptr_t __ptr)); + +extern void free (void *); +extern void * malloc (size_t); +extern void * calloc (size_t, size_t); +extern void * valloc (size_t); +extern void * memalign (size_t, size_t); +extern void * realloc (void *, size_t); |