diff --git a/gnu/lib/libmalloc/Makefile b/gnu/lib/libmalloc/Makefile index b5aeb2606f31..463927d29b6b 100644 --- a/gnu/lib/libmalloc/Makefile +++ b/gnu/lib/libmalloc/Makefile @@ -1,9 +1,9 @@ -# $Id: Makefile,v 1.1 1993/09/23 21:10:40 cgd Exp $ +# $Id: Makefile,v 1.1 1993/09/24 13:03:14 rgrimes Exp $ CFLAGS+= -I${.CURDIR} LIB= gnumalloc -SRCS+= malloc.c free.c cfree.c realloc.c calloc.c morecore.c +SRCS+= malloc.c cfree.c calloc.c morecore.c SRCS+= memalign.c valloc.c mcheck.c mtrace.c mstats.c vm-limit.c SRCS+= ralloc.c NOMAN= noman diff --git a/gnu/lib/libmalloc/malloc.c b/gnu/lib/libmalloc/malloc.c index 47a6b8d46e54..3c1ee9943d57 100644 --- a/gnu/lib/libmalloc/malloc.c +++ b/gnu/lib/libmalloc/malloc.c @@ -316,3 +316,307 @@ malloc (size) return result; } + +#define min(A, B) ((A) < (B) ? (A) : (B)) + +/* Debugging hook for realloc. */ +__ptr_t (*__realloc_hook) __P ((__ptr_t __ptr, size_t __size)); + +/* Resize the given region to the new size, returning a pointer + to the (possibly moved) region. This is optimized for speed; + some benchmarks seem to indicate that greater compactness is + achieved by unconditionally allocating and copying to a + new region. This module has incestuous knowledge of the + internals of both free and malloc. */ +__ptr_t +realloc (ptr, size) + __ptr_t ptr; + size_t size; +{ + __ptr_t result; + int type; + size_t block, blocks, oldlimit; + + if (size == 0) + { + free (ptr); + return malloc (0); + } + else if (ptr == NULL) + return malloc (size); + + if (__realloc_hook != NULL) + return (*__realloc_hook) (ptr, size); + + block = BLOCK (ptr); + + type = _heapinfo[block].busy.type; + switch (type) + { + case 0: + /* Maybe reallocate a large block to a small fragment. */ + if (size <= BLOCKSIZE / 2) + { + result = malloc (size); + if (result != NULL) + { + memcpy (result, ptr, size); + free (ptr); + return result; + } + } + + /* The new size is a large allocation as well; + see if we can hold it in place. */ + blocks = BLOCKIFY (size); + if (blocks < _heapinfo[block].busy.info.size) + { + /* The new size is smaller; return + excess memory to the free list. */ + _heapinfo[block + blocks].busy.type = 0; + _heapinfo[block + blocks].busy.info.size + = _heapinfo[block].busy.info.size - blocks; + _heapinfo[block].busy.info.size = blocks; + free (ADDRESS (block + blocks)); + result = ptr; + } + else if (blocks == _heapinfo[block].busy.info.size) + /* No size change necessary. */ + result = ptr; + else + { + /* Won't fit, so allocate a new region that will. + Free the old region first in case there is sufficient + adjacent free space to grow without moving. */ + blocks = _heapinfo[block].busy.info.size; + /* Prevent free from actually returning memory to the system. */ + oldlimit = _heaplimit; + _heaplimit = 0; + free (ptr); + _heaplimit = oldlimit; + result = malloc (size); + if (result == NULL) + { + /* Now we're really in trouble. We have to unfree + the thing we just freed. Unfortunately it might + have been coalesced with its neighbors. */ + if (_heapindex == block) + (void) malloc (blocks * BLOCKSIZE); + else + { + __ptr_t previous = malloc ((block - _heapindex) * BLOCKSIZE); + (void) malloc (blocks * BLOCKSIZE); + free (previous); + } + return NULL; + } + if (ptr != result) + memmove (result, ptr, blocks * BLOCKSIZE); + } + break; + + default: + /* Old size is a fragment; type is logarithm + to base two of the fragment size. */ + if (size > (size_t) (1 << (type - 1)) && size <= (size_t) (1 << type)) + /* The new size is the same kind of fragment. */ + result = ptr; + else + { + /* The new size is different; allocate a new space, + and copy the lesser of the new size and the old. */ + result = malloc (size); + if (result == NULL) + return NULL; + memcpy (result, ptr, min (size, (size_t) 1 << type)); + free (ptr); + } + break; + } + + return result; +} + +/* Debugging hook for free. */ +void (*__free_hook) __P ((__ptr_t __ptr)); + +/* List of blocks allocated by memalign. */ +struct alignlist *_aligned_blocks = NULL; + +/* Return memory to the heap. + Like `free' but don't call a __free_hook if there is one. */ +void +_free_internal (ptr) + __ptr_t ptr; +{ + int type; + size_t block, blocks; + register size_t i; + struct list *prev, *next; + + block = BLOCK (ptr); + + type = _heapinfo[block].busy.type; + switch (type) + { + case 0: + /* Get as many statistics as early as we can. */ + --_chunks_used; + _bytes_used -= _heapinfo[block].busy.info.size * BLOCKSIZE; + _bytes_free += _heapinfo[block].busy.info.size * BLOCKSIZE; + + /* Find the free cluster previous to this one in the free list. + Start searching at the last block referenced; this may benefit + programs with locality of allocation. */ + i = _heapindex; + if (i > block) + while (i > block) + i = _heapinfo[i].free.prev; + else + { + do + i = _heapinfo[i].free.next; + while (i > 0 && i < block); + i = _heapinfo[i].free.prev; + } + + /* Determine how to link this block into the free list. */ + if (block == i + _heapinfo[i].free.size) + { + /* Coalesce this block with its predecessor. */ + _heapinfo[i].free.size += _heapinfo[block].busy.info.size; + block = i; + } + else + { + /* Really link this block back into the free list. */ + _heapinfo[block].free.size = _heapinfo[block].busy.info.size; + _heapinfo[block].free.next = _heapinfo[i].free.next; + _heapinfo[block].free.prev = i; + _heapinfo[i].free.next = block; + _heapinfo[_heapinfo[block].free.next].free.prev = block; + ++_chunks_free; + } + + /* Now that the block is linked in, see if we can coalesce it + with its successor (by deleting its successor from the list + and adding in its size). */ + if (block + _heapinfo[block].free.size == _heapinfo[block].free.next) + { + _heapinfo[block].free.size + += _heapinfo[_heapinfo[block].free.next].free.size; + _heapinfo[block].free.next + = _heapinfo[_heapinfo[block].free.next].free.next; + _heapinfo[_heapinfo[block].free.next].free.prev = block; + --_chunks_free; + } + + /* Now see if we can return stuff to the system. */ + blocks = _heapinfo[block].free.size; + if (blocks >= FINAL_FREE_BLOCKS && block + blocks == _heaplimit + && (*__morecore) (0) == ADDRESS (block + blocks)) + { + register size_t bytes = blocks * BLOCKSIZE; + _heaplimit -= blocks; + (*__morecore) (-bytes); + _heapinfo[_heapinfo[block].free.prev].free.next + = _heapinfo[block].free.next; + _heapinfo[_heapinfo[block].free.next].free.prev + = _heapinfo[block].free.prev; + block = _heapinfo[block].free.prev; + --_chunks_free; + _bytes_free -= bytes; + } + + /* Set the next search to begin at this block. */ + _heapindex = block; + break; + + default: + /* Do some of the statistics. */ + --_chunks_used; + _bytes_used -= 1 << type; + ++_chunks_free; + _bytes_free += 1 << type; + + /* Get the address of the first free fragment in this block. */ + prev = (struct list *) ((char *) ADDRESS (block) + + (_heapinfo[block].busy.info.frag.first << type)); + + if (_heapinfo[block].busy.info.frag.nfree == (BLOCKSIZE >> type) - 1) + { + /* If all fragments of this block are free, remove them + from the fragment list and free the whole block. */ + next = prev; + for (i = 1; i < (size_t) (BLOCKSIZE >> type); ++i) + next = next->next; + prev->prev->next = next; + if (next != NULL) + next->prev = prev->prev; + _heapinfo[block].busy.type = 0; + _heapinfo[block].busy.info.size = 1; + + /* Keep the statistics accurate. */ + ++_chunks_used; + _bytes_used += BLOCKSIZE; + _chunks_free -= BLOCKSIZE >> type; + _bytes_free -= BLOCKSIZE; + + free (ADDRESS (block)); + } + else if (_heapinfo[block].busy.info.frag.nfree != 0) + { + /* If some fragments of this block are free, link this + fragment into the fragment list after the first free + fragment of this block. */ + next = (struct list *) ptr; + next->next = prev->next; + next->prev = prev; + prev->next = next; + if (next->next != NULL) + next->next->prev = next; + ++_heapinfo[block].busy.info.frag.nfree; + } + else + { + /* No fragments of this block are free, so link this + fragment into the fragment list and announce that + it is the first free fragment of this block. */ + prev = (struct list *) ptr; + _heapinfo[block].busy.info.frag.nfree = 1; + _heapinfo[block].busy.info.frag.first = (unsigned long int) + ((unsigned long int) ((char *) ptr - (char *) NULL) + % BLOCKSIZE >> type); + prev->next = _fraghead[type].next; + prev->prev = &_fraghead[type]; + prev->prev->next = prev; + if (prev->next != NULL) + prev->next->prev = prev; + } + break; + } +} + +/* Return memory to the heap. */ +void +free (ptr) + __ptr_t ptr; +{ + register struct alignlist *l; + + if (ptr == NULL) + return; + + for (l = _aligned_blocks; l != NULL; l = l->next) + if (l->aligned == ptr) + { + l->aligned = NULL; /* Mark the slot in the list as free. */ + ptr = l->exact; + break; + } + + if (__free_hook != NULL) + (*__free_hook) (ptr); + else + _free_internal (ptr); +}