On Wed, Apr 01, 2009 at 07:59:56PM +0000, Martin Kersten wrote:
> Update of /cvsroot/monetdb/MonetDB5/src/modules/mal
> In directory 23jxhf1.ch3.sourceforge.com:/tmp/cvs-serv25709
>
> Modified Files:
> mat.mx
> Log Message:
> Packing of BATs should avoid falling into the BATextend trap.
> Preclaim enough space. Don't bother about the properties of the
> result. That should be decided later.
>
This checking removes the only initialization of the pointer variable
int *ret;
which is then later dereferenced for assginment --- this might/will result
in a segfault or other non-deterministic behavior. See details below.
Stefan
>
> U mat.mx
> Index: mat.mx
> ===================================================================
> RCS file: /cvsroot/monetdb/MonetDB5/src/modules/mal/mat.mx,v
> retrieving revision 1.25
> retrieving revision 1.26
> diff -u -d -r1.25 -r1.26
> --- mat.mx 7 Jan 2009 14:15:13 -0000 1.25
> +++ mat.mx 1 Apr 2009 19:59:50 -0000 1.26
> @@ -134,22 +134,31 @@
> The pack operation could be quite expensive, because it
> may create a really large BAT.
> For the experiments we materialize the BAT in the first
> -component.
> +component. It should be extended upfront to accomodate
> +all elements.
> @c
> str
> MATpackInternal(MalStkPtr stk, InstrPtr p,int first)
> {
> int i,*ret;
^^^^
> BAT *b, *bn;
> + BUN cap=0;
>
> bn= BATdescriptor(stk->stk[getArg(p,first)].val.ival);
> - if( bn == NULL)
> - throw(MAL, "mat.pack","Could access BAT");
> - if (BAThrestricted(bn) || BATtrestricted(bn)) {
> + if (bn && (BAThrestricted(bn) || BATtrestricted(bn)) ){
> b = BATcopy(bn, bn->htype, bn->ttype, TRUE);
> BBPunfix(bn->batCacheid);
> bn = b;
> }
> + if( bn == NULL)
> + throw(MAL, "mat.pack","Could not access BAT");
> +
> + for(i=first; i<p->argc; i++){
> + b= BATdescriptor(stk->stk[getArg(p,i)].val.ival);
> + cap += BATcount(b);
> + BBPunfix(b->batCacheid);
> + }
> + bn = BATextend(bn, cap);
> for(i=first+1; i<p->argc; i++){
> b= BATdescriptor(stk->stk[getArg(p,i)].val.ival);
> if( b == NULL)
> @@ -158,12 +167,6 @@
> BATins(bn,b,FALSE);
> BBPunfix(b->batCacheid);
> }
> - if (bn->htype == TYPE_oid && !BAThordered(bn)) {
> - BAT *b = BATsort(bn);
> - BBPunfix(bn->batCacheid);
> - bn = b;
> - }
> - ret= (int*) getArgReference(stk,p,0);
^ ^^^^
> BBPkeepref(*ret = bn->batCacheid);
^^^^
> return MAL_SUCCEED;
> }
>
>
> ------------------------------------------------------------------------------
> _______________________________________________
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> [email protected]
> https://lists.sourceforge.net/lists/listinfo/monetdb-checkins
--
| Dr. Stefan Manegold | mailto:[email protected] |
| CWI, P.O.Box 94079 | http://www.cwi.nl/~manegold/ |
| 1090 GB Amsterdam | Tel.: +31 (20) 592-4212 |
| The Netherlands | Fax : +31 (20) 592-4312 |
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