/* Prototypes for local functions */
-static int initialize(xbt_mheap_t mdp);
+static void initialize(xbt_mheap_t mdp);
static void *register_morecore(xbt_mheap_t mdp, size_t size);
static void *align(xbt_mheap_t mdp, size_t size);
-/* Allocation aligned on block boundary */
+/* Allocation aligned on block boundary.
+ *
+ * It never returns NULL, but dies verbosely on error.
+ */
static void *align(struct mdesc *mdp, size_t size)
{
void *result;
/* Finish the initialization of the mheap. If we want to inline it
* properly, we need to make the align function publicly visible, too */
-static int initialize(xbt_mheap_t mdp)
+static void initialize(xbt_mheap_t mdp)
{
mdp->heapsize = HEAP / BLOCKSIZE;
mdp->heapinfo = (malloc_info *)
align(mdp, mdp->heapsize * sizeof(malloc_info));
- if (mdp->heapinfo == NULL) {
- return (0);
- }
+
memset((void *) mdp->heapinfo, 0, mdp->heapsize * sizeof(malloc_info));
+ mdp->heapinfo[0].type=-1;
mdp->heapinfo[0].free_block.size = 0;
mdp->heapinfo[0].free_block.next = mdp->heapinfo[0].free_block.prev = 0;
mdp->heapindex = 0;
mdp->heapbase = (void *) mdp->heapinfo;
mdp->flags |= MMALLOC_INITIALIZED;
- return (1);
}
/* Get neatly aligned memory from the low level layers, and register it
malloc_info *newinfo, *oldinfo;
size_t newsize;
- result = align(mdp, size);
- if (result == NULL) {
- return (NULL);
- }
+ result = align(mdp, size); // Never returns NULL
/* Check if we need to grow the info table (in a multiplicative manner) */
if ((size_t) BLOCK((char *) result + size) > mdp->heapsize) {
+ int it;
newsize = mdp->heapsize;
while ((size_t) BLOCK((char *) result + size) > newsize)
/* mark the space previously occupied by the block info as free by first marking it
* as occupied in the regular way, and then freing it */
- newinfo[BLOCK(oldinfo)].type = 0;
+ for (it=0; it<BLOCKIFY(mdp->heapsize * sizeof(malloc_info)); it++)
+ newinfo[BLOCK(oldinfo)+it].type = 0;
+
newinfo[BLOCK(oldinfo)].busy_block.size = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
newinfo[BLOCK(oldinfo)].busy_block.busy_size = size;
- __mmalloc_free(mdp, (void *) oldinfo);
+ mfree(mdp, (void *) oldinfo);
mdp->heapsize = newsize;
}
register size_t i;
struct list *next;
register size_t log;
+ int it;
+
+ 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 0-byte block, ie return a valid block that can be realloced or freed
- * glibc malloc does not use this trick but return a constant pointer, but my hack is quicker to implement ;)
+ /* 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 == 0)
- size = 1;
+ if (size < SMALLEST_POSSIBLE_MALLOC)
+ size = SMALLEST_POSSIBLE_MALLOC;
// printf("(%s) Mallocing %d bytes on %p (default: %p)...",xbt_thread_self_name(),size,mdp,__mmalloc_default_mdp);fflush(stdout);
- if (!(mdp->flags & MMALLOC_INITIALIZED)) {
- if (!initialize(mdp)) {
- return (NULL);
- }
- }
-
- if (size < sizeof(struct list)) {
- size = sizeof(struct list);
- }
+ if (!(mdp->flags & MMALLOC_INITIALIZED))
+ initialize(mdp);
/* Determine the allocation policy based on the request size. */
if (size <= BLOCKSIZE / 2) {
/* There are free fragments of this size.
Pop a fragment out of the fragment list and return it.
Update the block's nfree and first counters. */
+ int frag_nb;
result = (void *) next;
+ block = BLOCK(result);
+
+ frag_nb = RESIDUAL(result, BLOCKSIZE) >> log;
+ mdp->heapinfo[block].busy_frag.frag_size[frag_nb] = requested_size;
+ //FIXME setup backtrace
+
next->prev->next = next->next;
if (next->next != NULL) {
next->next->prev = next->prev;
}
- block = BLOCK(result);
if (--mdp->heapinfo[block].busy_frag.nfree != 0) {
mdp->heapinfo[block].busy_frag.first =
RESIDUAL(next->next, BLOCKSIZE) >> log;
/* No free fragments of the desired size, so get a new block
and break it into fragments, returning the first. */
//printf("(%s) No free fragment...",xbt_thread_self_name());
- result = mmalloc(mdp, BLOCKSIZE);
- //printf("(%s) Fragment: %p...",xbt_thread_self_name(),result);
- if (result == NULL) {
- return (NULL);
- }
- /* Link all fragments but the first into the free list. */
+ result = mmalloc(mdp, BLOCKSIZE); // does not return NULL
+
+ /* Link all fragments but the first into the free list, and mark their requested size to 0. */
+ block = BLOCK(result);
for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i) {
+ mdp->heapinfo[block].busy_frag.frag_size[i] = 0;
next = (struct list *) ((char *) result + (i << log));
next->next = mdp->fraghead[log].next;
next->prev = &mdp->fraghead[log];
next->next->prev = next;
}
}
+ mdp->heapinfo[block].busy_frag.frag_size[0] = requested_size;
+ // FIXME: setup backtrace
/* Initialize the nfree and first counters for this block. */
- block = BLOCK(result);
mdp->heapinfo[block].type = log;
mdp->heapinfo[block].busy_frag.nfree = i - 1;
mdp->heapinfo[block].busy_frag.first = i - 1;
blocks = BLOCKIFY(size);
start = block = MALLOC_SEARCH_START;
while (mdp->heapinfo[block].free_block.size < blocks) {
+ if (mdp->heapinfo[block].type >=0) { // Don't trust xbt_die and friends in malloc-level library, you fool!
+ fprintf(stderr,"Internal error: found a free block not marked as such (block=%lu type=%lu). Please report this bug.\n",(unsigned long)block,(unsigned long)mdp->heapinfo[block].type);
+ abort();
+ }
+
block = mdp->heapinfo[block].free_block.next;
if (block == start) {
/* Need to get more from the system. Check to see if
continue;
}
result = register_morecore(mdp, blocks * BLOCKSIZE);
- if (result == NULL) {
- return (NULL);
- }
+
block = BLOCK(result);
- mdp->heapinfo[block].type = 0;
+ for (it=0;it<blocks;it++)
+ mdp->heapinfo[block+it].type = 0;
mdp->heapinfo[block].busy_block.size = blocks;
- mdp->heapinfo[block].busy_block.busy_size = size;
- return (result);
+ mdp->heapinfo[block].busy_block.busy_size = requested_size;
+ // FIXME: setup backtrace
+
+ return result;
}
+ /* Need large block(s), but found some in the existing heap */
}
/* At this point we have found a suitable free list entry.
= mdp->heapindex = mdp->heapinfo[block].free_block.next;
}
- mdp->heapinfo[block].type = 0;
+ for (it=0;it<blocks;it++)
+ mdp->heapinfo[block+it].type = 0;
mdp->heapinfo[block].busy_block.size = blocks;
- mdp->heapinfo[block].busy_block.busy_size = size;
+ mdp->heapinfo[block].busy_block.busy_size = requested_size;
}
//printf("(%s) Done mallocing. Result is %p\n",xbt_thread_self_name(),result);fflush(stdout);
return (result);
