random crashes in handleQueryRehashHelper
Posted: Sun Jan 31, 2010 4:53 pm
I'm using the latest Chipmunk 5.0 code with Cocos2d for the iphone and I get a crash in this function randomly. It doesn't happen often but it has been happening for over a month and no matter what I do, I can never seem to fix it. I did have it crash once with the debugger up and the pointer for "elt" was bad, it was a small value like 0x343. So it is crashing from a memory access violation but how did "elt" get bad in the first place? "elt" is coming from space->activeShapes->handleSet->table->[1..x]next->elt. Any ideas what I should focus on in my code? Could it be caused by not removing shapes/bodies correctly from activeShapes? I know this might be a very broad question but my hope is someone else has run into the same issue before and remembers how they fixed it. I call cpSpaceStep 120 times a second if that info helps.
Here's the callstack and snippets of the code that match the line number:
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00000004
Thread 0 Crashed:
0 Program 0x00156be8 handleQueryRehashHelper (cpSpaceHash.c:431)
1 Program 0x00153fcc cpHashSetEach (cpHashSet.c:198)
2 Program 0x00156684 cpSpaceHashQueryRehash (cpSpaceHash.c:472)
3 Program 0x001556fc cpSpaceStep (cpSpace.c:659)
Here's the callstack and snippets of the code that match the line number:
Exception Type: EXC_BAD_ACCESS (SIGBUS)
Exception Codes: KERN_PROTECTION_FAILURE at 0x00000004
Thread 0 Crashed:
0 Program 0x00156be8 handleQueryRehashHelper (cpSpaceHash.c:431)
1 Program 0x00153fcc cpHashSetEach (cpHashSet.c:198)
2 Program 0x00156684 cpSpaceHashQueryRehash (cpSpaceHash.c:472)
3 Program 0x001556fc cpSpaceStep (cpSpace.c:659)
Code: Select all
// Hashset iterator func used with cpSpaceHashQueryRehash().
static void
handleQueryRehashHelper(void *elt, void *data)
{
cpHandle *hand = (cpHandle *)elt;
// Unpack the user callback data.
queryRehashPair *pair = (queryRehashPair *)data;
cpSpaceHash *hash = pair->hash;
cpSpaceHashQueryFunc func = pair->func;
cpFloat dim = hash->celldim;
int n = hash->numcells;
void *obj = hand->obj; <******** crashes here
cpBB bb = hash->bbfunc(obj);
---------------
void
cpHashSetEach(cpHashSet *set, cpHashSetIterFunc func, void *data)
{
for(int i=0; i<set->size; i++){
cpHashSetBin *bin = set->table[i];
while(bin){
cpHashSetBin *next = bin->next;
func(bin->elt, data); <******* called from here
bin = next;
}
}
}
---------------
void
cpSpaceHashQueryRehash(cpSpaceHash *hash, cpSpaceHashQueryFunc func, void *data)
{
clearHash(hash);
queryRehashPair pair = {hash, func, data};
cpHashSetEach(hash->handleSet, &handleQueryRehashHelper, &pair); <******* called from here
}
---------------
void
cpSpaceStep(cpSpace *space, cpFloat dt)
{
if(!dt) return; // don't step if the timestep is 0!
cpFloat dt_inv = 1.0f/dt;
cpArray *bodies = space->bodies;
cpArray *constraints = space->constraints;
// Empty the arbiter list.
space->arbiters->num = 0;
// Integrate positions.
for(int i=0; i<bodies->num; i++){
cpBody *body = (cpBody *)bodies->arr[i];
body->position_func(body, dt);
}
// Pre-cache BBoxes and shape data.
cpSpaceHashEach(space->activeShapes, (cpSpaceHashIterator)updateBBCache, NULL);
// Collide!
cpSpaceHashEach(space->activeShapes, (cpSpaceHashIterator)active2staticIter, space);
cpSpaceHashQueryRehash(space->activeShapes, (cpSpaceHashQueryFunc)queryFunc, space); <********called from here
