void* malloc_no_memset(size_t n)
{
if (!mm_initialized) {
if (mm_initializing)
return mm_fake_malloc(n);
mm_legacy_constructor();
}
if (!__malloc_use_mmalloc) {
return mm_real_malloc(n);
}
xbt_mheap_t mdp = GET_HEAP();
if (!mdp)
return NULL;
LOCK(mdp);
void *ret = mmalloc_no_memset(mdp, n);
UNLOCK(mdp);
return ret;
}
void *mrealloc(xbt_mheap_t mdp, void *ptr, size_t size)
{
void *result;
int type;
size_t block, blocks, oldlimit;
/* Only keep real realloc, and reroute hidden malloc and free to the relevant functions */
if (size == 0) {
mfree(mdp, ptr);
return mmalloc(mdp, 0);
} else if (ptr == NULL) {
return mmalloc(mdp, size);
}
//printf("(%s)realloc %p to %d...",xbt_thread_self_name(),ptr,(int)size);
if ((char *) ptr < (char *) mdp->heapbase || BLOCK(ptr) > mdp->heapsize) {
printf
("FIXME. Ouch, this pointer is not mine, refusing to proceed (another solution would be to malloc it instead of reallocing it, see source code)\n");
result = mmalloc(mdp, size);
abort();
return result;
}
size_t requested_size = size; // The amount of memory requested by user, for real
/* Work even if the user was stupid enough to ask a ridicullously small block (even 0-length),
* ie return a valid block that can be realloced and freed.
* glibc malloc does not use this trick but return a constant pointer, but we need to enlist the free fragments later on.
*/
if (size < SMALLEST_POSSIBLE_MALLOC)
size = SMALLEST_POSSIBLE_MALLOC;
block = BLOCK(ptr);
type = mdp->heapinfo[block].type;
switch (type) {
case -1:
fprintf(stderr, "Asked realloc a fragment coming from a *free* block. I'm puzzled.\n");
abort();
break;
case 0:
/* Maybe reallocate a large block to a small fragment. */
if (size <= BLOCKSIZE / 2) { // Full block -> Fragment; no need to optimize for time
result = mmalloc(mdp, size);
if (result != NULL) { // useless (mmalloc never returns NULL), but harmless
memcpy(result, ptr, requested_size);
mfree(mdp, ptr);
return (result);
}
}
/* Full blocks -> Full blocks; see if we can hold it in place. */
blocks = BLOCKIFY(size);
if (blocks < mdp->heapinfo[block].busy_block.size) {
int it;
/* The new size is smaller; return excess memory to the free list. */
//printf("(%s) return excess memory...",xbt_thread_self_name());
for (it= block+blocks; it< mdp->heapinfo[block].busy_block.size ; it++){
mdp->heapinfo[it].type = 0; // FIXME that should be useless, type should already be 0 here
mdp->heapinfo[it].busy_block.ignore = 0;
}
mdp->heapinfo[block + blocks].busy_block.size
= mdp->heapinfo[block].busy_block.size - blocks;
mfree(mdp, ADDRESS(block + blocks));
mdp->heapinfo[block].busy_block.size = blocks;
mdp->heapinfo[block].busy_block.busy_size = requested_size;
mdp->heapinfo[block].busy_block.ignore = 0;
result = ptr;
} else if (blocks == mdp->heapinfo[block].busy_block.size) {
/* No block size change necessary; only update the requested size */
result = ptr;
mdp->heapinfo[block].busy_block.busy_size = requested_size;
mdp->heapinfo[block].busy_block.ignore = 0;
} 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.
This trick mandates using a specific version of mmalloc that does not memset the memory to 0 after
action for obvious reasons. */
blocks = mdp->heapinfo[block].busy_block.size;
/* Prevent free from actually returning memory to the system. */
oldlimit = mdp->heaplimit;
mdp->heaplimit = 0;
mfree(mdp, ptr);
mdp->heaplimit = oldlimit;
result = mmalloc_no_memset(mdp, requested_size);
//fprintf(stderr,"remalloc(%zu)~>%p\n",requested_size,result);
if (ptr != result)
memmove(result, ptr, blocks * BLOCKSIZE);
/* FIXME: we should memset the end of the recently area */
}
break;
default: /* Fragment -> ??; type=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. */
//printf("(%s) new size is same kind of fragment...",xbt_thread_self_name());
result = ptr;
int frag_nb = RESIDUAL(result, BLOCKSIZE) >> type;
mdp->heapinfo[block].busy_frag.frag_size[frag_nb] = requested_size;
mdp->heapinfo[block].busy_frag.ignore[frag_nb] = 0;
} else { /* fragment -> Either other fragment, or block */
