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 */