/* Prototypes for local functions */
-static int initialize(struct mdesc *mdp);
-static void *morecore(struct mdesc *mdp, size_t size);
-static void *align(struct mdesc *mdp, size_t size);
-
-/* Aligned allocation. */
-
+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.
+ *
+ * It never returns NULL, but dies verbosely on error.
+ */
static void *align(struct mdesc *mdp, size_t size)
{
void *result;
unsigned long int adj;
- result = mdp->morecore(mdp, size);
+ result = mmorecore(mdp, size);
+
+ /* if this reservation does not fill up the last block of our resa,
+ * complete the reservation by also asking for the full lastest block.
+ *
+ * Also, the returned block is aligned to the end of block (but I've
+ * no fucking idea of why, actually -- http://abstrusegoose.com/432 --
+ * but not doing so seems to lead to issues).
+ */
adj = RESIDUAL(result, BLOCKSIZE);
if (adj != 0) {
adj = BLOCKSIZE - adj;
- mdp->morecore(mdp, adj);
+ mmorecore(mdp, adj);
result = (char *) result + adj;
}
return (result);
}
-/* Set everything up and remember that we have. */
-
-static int initialize(struct mdesc *mdp)
+/* Finish the initialization of the mheap. If we want to inline it
+ * properly, we need to make the align function publicly visible, too */
+static void initialize(xbt_mheap_t mdp)
{
+ int i;
+ malloc_info mi; /* to compute the offset of the swag hook */
+
mdp->heapsize = HEAP / BLOCKSIZE;
mdp->heapinfo = (malloc_info *)
- align(mdp, mdp->heapsize * sizeof(malloc_info));
- if (mdp->heapinfo == NULL) {
- return (0);
- }
+ align(mdp, mdp->heapsize * sizeof(malloc_info));
+
memset((void *) mdp->heapinfo, 0, mdp->heapsize * sizeof(malloc_info));
- mdp->heapinfo[0].free.size = 0;
- mdp->heapinfo[0].free.next = mdp->heapinfo[0].free.prev = 0;
+ 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);
+
+ for (i=0;i<BLOCKLOG;i++) {
+ xbt_swag_init(&(mdp->fraghead[i]),
+ xbt_swag_offset(mi, freehook));
+ }
}
-/* Get neatly aligned memory, initializing or
- growing the heap info table as necessary. */
+#define update_hook(a,offset) do { if (a) { a = ((char*)a +(offset));} }while(0)
-static void *morecore(struct mdesc *mdp, size_t size)
+/* Get neatly aligned memory from the low level layers, and register it
+ * into the heap info table as necessary. */
+static void *register_morecore(struct mdesc *mdp, size_t size)
{
+ int i;
void *result;
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. */
+ /* 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) {
+ while ((size_t) BLOCK((char *) result + size) > newsize)
newsize *= 2;
- }
+
+ /* Copy old info into new location */
+ oldinfo = mdp->heapinfo;
newinfo = (malloc_info *) align(mdp, newsize * sizeof(malloc_info));
- if (newinfo == NULL) {
- mdp->morecore(mdp, -size);
- return (NULL);
+ memset(newinfo, 0, newsize * sizeof(malloc_info));
+ memcpy(newinfo, oldinfo, mdp->heapsize * sizeof(malloc_info));
+
+ /* Update the swag of busy blocks containing free fragments by applying the offset to all swag_hooks. Yeah. My hand is right in the fan and I still type */
+ size_t offset=((char*)newinfo)-((char*)oldinfo);
+
+ for (i=1/*first element of heapinfo describes the mdesc area*/;
+ i<mdp->heaplimit;
+ i++) {
+ update_hook(newinfo[i].freehook.next,offset);
+ update_hook(newinfo[i].freehook.prev,offset);
+ }
+ // also update the starting points of the swag
+ for (i=0;i<BLOCKLOG;i++) {
+ update_hook(mdp->fraghead[i].head,offset);
+ update_hook(mdp->fraghead[i].tail,offset);
}
- memset((void *) newinfo, 0, newsize * sizeof(malloc_info));
- memcpy((void *) newinfo, (void *) mdp->heapinfo,
- mdp->heapsize * sizeof(malloc_info));
- oldinfo = mdp->heapinfo;
- newinfo[BLOCK(oldinfo)].busy.type = 0;
- newinfo[BLOCK(oldinfo)].busy.info.size
- = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
mdp->heapinfo = newinfo;
- __mmalloc_free(mdp, (void *) oldinfo);
+
+ /* 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 */
+ 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;
+ newinfo[BLOCK(oldinfo)].busy_block.bt_size = 0;// FIXME setup the backtrace
+ mfree(mdp, (void *) oldinfo);
mdp->heapsize = newsize;
}
mdp->heaplimit = BLOCK((char *) result + size);
return (result);
}
+#undef update_hook
/* Allocate memory from the heap. */
-
-void *mmalloc(void *md, size_t size)
+void *mmalloc(xbt_mheap_t mdp, size_t size) {
+ void *res= mmalloc_no_memset(mdp,size);
+// fprintf(stderr,"malloc(%zu)~>%p\n",size,res);
+ memset(res,0,size);
+ return res;
+}
+/* Spliting mmalloc this way is mandated by a trick in mrealloc, that gives
+ back the memory of big blocks to the system before reallocating them: we don't
+ want to loose the beginning of the area when this happens */
+void *mmalloc_no_memset(xbt_mheap_t mdp, size_t size)
{
- struct mdesc *mdp;
void *result;
size_t block, blocks, lastblocks, start;
register size_t i;
- struct list *next;
register size_t log;
+ int it;
- /* 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 ;)
+ 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 == 0)
- size = 1;
+ if (size < SMALLEST_POSSIBLE_MALLOC)
+ size = SMALLEST_POSSIBLE_MALLOC;
- mdp = MD_TO_MDP(md);
- LOCK(mdp);
-// printf("(%s) Mallocing %d bytes on %p (default: %p)...",xbt_thread_self_name(),size,mdp,__mmalloc_default_mdp);fflush(stdout);
+ // 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))
+ initialize(mdp);
- if (mdp->mmalloc_hook != NULL) {
- void *res = ((*mdp->mmalloc_hook) (md, size));
- UNLOCK(mdp);
- return res;
- }
-
- if (!(mdp->flags & MMALLOC_INITIALIZED)) {
- if (!initialize(mdp)) {
- UNLOCK(mdp);
- return (NULL);
- }
- }
-
- if (size < sizeof(struct list)) {
- size = sizeof(struct list);
- }
+ mmalloc_paranoia(mdp);
/* Determine the allocation policy based on the request size. */
if (size <= BLOCKSIZE / 2) {
++log;
}
- /* Look in the fragment lists for a
- free fragment of the desired size. */
- next = mdp->fraghead[log].next;
- if (next != NULL) {
- /* 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. */
- result = (void *) next;
- next->prev->next = next->next;
- if (next->next != NULL) {
- next->next->prev = next->prev;
- }
- block = BLOCK(result);
- if (--mdp->heapinfo[block].busy.info.frag.nfree != 0) {
- mdp->heapinfo[block].busy.info.frag.first =
- RESIDUAL(next->next, BLOCKSIZE) >> log;
+ /* Look in the fragment lists for a free fragment of the desired size. */
+ if (xbt_swag_size(&mdp->fraghead[log])>0) {
+ /* There are free fragments of this size; Get one of them and prepare to return it.
+ Update the block's nfree and if no other free fragment, get out of the swag. */
+
+ /* search a fragment that I could return as a result */
+ malloc_info *candidate_info = xbt_swag_getFirst(&mdp->fraghead[log]);
+ size_t candidate_block = (candidate_info - &(mdp->heapinfo[0]));
+ size_t candidate_frag;
+ for (candidate_frag=0;candidate_frag<(size_t) (BLOCKSIZE >> log);candidate_frag++)
+ if (candidate_info->busy_frag.frag_size[candidate_frag] == -1)
+ break;
+ xbt_assert(candidate_frag < (size_t) (BLOCKSIZE >> log),
+ "Block %zu was registered as containing free fragments of type %zu, but I can't find any",candidate_block,log);
+
+ result = (void*) (((char*)ADDRESS(candidate_block)) + (candidate_frag << log));
+
+ /* Remove this fragment from the list of free guys */
+ candidate_info->busy_frag.nfree--;
+ if (candidate_info->busy_frag.nfree == 0) {
+ xbt_swag_remove(candidate_info,&mdp->fraghead[log]);
}
+ /* Update our metadata about this fragment */
+ candidate_info->busy_frag.frag_size[candidate_frag] = requested_size;
+ xbt_backtrace_no_malloc(candidate_info->busy_frag.bt[candidate_frag],XBT_BACKTRACE_SIZE);
+
/* Update the statistics. */
- mdp->heapstats.chunks_used++;
- mdp->heapstats.bytes_used += 1 << log;
- mdp->heapstats.chunks_free--;
- mdp->heapstats.bytes_free -= 1 << log;
+ mdp -> heapstats.chunks_used++;
+ mdp -> heapstats.bytes_used += 1 << log;
+ mdp -> heapstats.chunks_free--;
+ mdp -> heapstats.bytes_free -= 1 << log;
+
} else {
/* No free fragments of the desired size, so get a new block
and break it into fragments, returning the first. */
- UNLOCK(mdp);
- //printf("(%s) No free fragment...",xbt_thread_self_name());
- result = mmalloc(md, BLOCKSIZE);
- //printf("(%s) Fragment: %p...",xbt_thread_self_name(),result);
- LOCK(mdp);
- if (result == NULL) {
- UNLOCK(mdp);
- return (NULL);
- }
-
- /* Link all fragments but the first into the free list. */
- for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i) {
- next = (struct list *) ((char *) result + (i << log));
- next->next = mdp->fraghead[log].next;
- next->prev = &mdp->fraghead[log];
- next->prev->next = next;
- if (next->next != NULL) {
- next->next->prev = next;
- }
- }
- /* Initialize the nfree and first counters for this block. */
+ result = mmalloc(mdp, BLOCKSIZE); // does not return NULL
block = BLOCK(result);
- mdp->heapinfo[block].busy.type = log;
- mdp->heapinfo[block].busy.info.frag.nfree = i - 1;
- mdp->heapinfo[block].busy.info.frag.first = i - 1;
- mdp->heapstats.chunks_free += (BLOCKSIZE >> log) - 1;
- mdp->heapstats.bytes_free += BLOCKSIZE - (1 << log);
- mdp->heapstats.bytes_used -= BLOCKSIZE - (1 << log);
+ mdp->heapinfo[block].type = log;
+ /* Link all fragments but the first as free, and add the block to the swag of blocks containing free frags */
+ for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i) {
+ mdp->heapinfo[block].busy_frag.frag_size[i] = -1;
+ }
+ mdp->heapinfo[block].busy_frag.nfree = i - 1;
+ mdp->heapinfo[block].freehook.prev = NULL;
+ mdp->heapinfo[block].freehook.next = NULL;
+
+ xbt_swag_insert(&mdp->heapinfo[block], &(mdp->fraghead[log]));
+
+ /* mark the fragment returned as busy */
+ mdp->heapinfo[block].busy_frag.frag_size[0] = requested_size;
+ xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_frag.bt[0],XBT_BACKTRACE_SIZE);
+
+ /* update stats */
+ mdp -> heapstats.chunks_free += (BLOCKSIZE >> log) - 1;
+ mdp -> heapstats.bytes_free += BLOCKSIZE - (1 << log);
+ mdp -> heapstats.bytes_used -= BLOCKSIZE - (1 << log);
}
} else {
/* Large allocation to receive one or more blocks.
space we will have to get more memory from the system. */
blocks = BLOCKIFY(size);
start = block = MALLOC_SEARCH_START;
- while (mdp->heapinfo[block].free.size < blocks) {
- block = mdp->heapinfo[block].free.next;
+ 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
the new core will be contiguous with the final free
block; if so we don't need to get as much. */
- block = mdp->heapinfo[0].free.prev;
- lastblocks = mdp->heapinfo[block].free.size;
+ block = mdp->heapinfo[0].free_block.prev;
+ lastblocks = mdp->heapinfo[block].free_block.size;
if (mdp->heaplimit != 0 &&
block + lastblocks == mdp->heaplimit &&
- mdp->morecore(mdp, 0) == ADDRESS(block + lastblocks) &&
- (morecore(mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL) {
+ mmorecore(mdp, 0) == ADDRESS(block + lastblocks) &&
+ (register_morecore(mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL) {
/* Which block we are extending (the `final free
block' referred to above) might have changed, if
it got combined with a freed info table. */
- block = mdp->heapinfo[0].free.prev;
+ block = mdp->heapinfo[0].free_block.prev;
- mdp->heapinfo[block].free.size += (blocks - lastblocks);
- mdp->heapstats.bytes_free += (blocks - lastblocks) * BLOCKSIZE;
+ mdp->heapinfo[block].free_block.size += (blocks - lastblocks);
continue;
}
- result = morecore(mdp, blocks * BLOCKSIZE);
- if (result == NULL) {
- UNLOCK(mdp);
- return (NULL);
- }
+ result = register_morecore(mdp, blocks * BLOCKSIZE);
+
block = BLOCK(result);
- mdp->heapinfo[block].busy.type = 0;
- mdp->heapinfo[block].busy.info.size = blocks;
- mdp->heapstats.chunks_used++;
- mdp->heapstats.bytes_used += blocks * BLOCKSIZE;
- UNLOCK(mdp);
- return (result);
+ 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 = requested_size;
+ mdp->heapinfo[block].busy_block.bt_size=xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_block.bt,XBT_BACKTRACE_SIZE);
+ mdp -> heapstats.chunks_used++;
+ mdp -> heapstats.bytes_used += blocks * BLOCKSIZE;
+
+ return result;
}
+ /* Need large block(s), but found some in the existing heap */
}
/* At this point we have found a suitable free list entry.
Figure out how to remove what we need from the list. */
result = ADDRESS(block);
- if (mdp->heapinfo[block].free.size > blocks) {
+ if (mdp->heapinfo[block].free_block.size > blocks) {
/* The block we found has a bit left over,
so relink the tail end back into the free list. */
- mdp->heapinfo[block + blocks].free.size
- = mdp->heapinfo[block].free.size - blocks;
- mdp->heapinfo[block + blocks].free.next
- = mdp->heapinfo[block].free.next;
- mdp->heapinfo[block + blocks].free.prev
- = mdp->heapinfo[block].free.prev;
- mdp->heapinfo[mdp->heapinfo[block].free.prev].free.next
- = mdp->heapinfo[mdp->heapinfo[block].free.next].free.prev
- = mdp->heapindex = block + blocks;
+ mdp->heapinfo[block + blocks].free_block.size
+ = mdp->heapinfo[block].free_block.size - blocks;
+ mdp->heapinfo[block + blocks].free_block.next
+ = mdp->heapinfo[block].free_block.next;
+ mdp->heapinfo[block + blocks].free_block.prev
+ = mdp->heapinfo[block].free_block.prev;
+ mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
+ = mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
+ = mdp->heapindex = block + blocks;
} else {
/* The block exactly matches our requirements,
so just remove it from the list. */
- mdp->heapinfo[mdp->heapinfo[block].free.next].free.prev
- = mdp->heapinfo[block].free.prev;
- mdp->heapinfo[mdp->heapinfo[block].free.prev].free.next
- = mdp->heapindex = mdp->heapinfo[block].free.next;
- mdp->heapstats.chunks_free--;
+ mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
+ = mdp->heapinfo[block].free_block.prev;
+ mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
+ = mdp->heapindex = mdp->heapinfo[block].free_block.next;
+ }
+
+ 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 = requested_size;
+ //mdp->heapinfo[block].busy_block.bt_size = 0;
+ mdp->heapinfo[block].busy_block.bt_size = xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_block.bt,XBT_BACKTRACE_SIZE);
+
+ mdp -> heapstats.chunks_used++;
+ mdp -> heapstats.bytes_used += blocks * BLOCKSIZE;
+ mdp -> heapstats.bytes_free -= blocks * BLOCKSIZE;
- mdp->heapinfo[block].busy.type = 0;
- mdp->heapinfo[block].busy.info.size = blocks;
- mdp->heapstats.chunks_used++;
- mdp->heapstats.bytes_used += blocks * BLOCKSIZE;
- mdp->heapstats.bytes_free -= blocks * BLOCKSIZE;
}
//printf("(%s) Done mallocing. Result is %p\n",xbt_thread_self_name(),result);fflush(stdout);
- UNLOCK(mdp);
+
return (result);
}
