Re: [Monetdb-developers] [Monetdb-checkins] MonetDB5/src/modules/mal tablet.mx, , 1.170, 1.171

On Wed, Sep 10, 2008 at 10:36:27AM +0000, Martin Kersten wrote:

Update of /cvsroot/monetdb/MonetDB5/src/modules/mal In directory sc8-pr-cvs16.sourceforge.net:/tmp/cvs-serv17819

Modified Files: tablet.mx Log Message: More defenses.

U tablet.mx Index: tablet.mx =================================================================== RCS file: /cvsroot/monetdb/MonetDB5/src/modules/mal/tablet.mx,v retrieving revision 1.170 retrieving revision 1.171 diff -u -d -r1.170 -r1.171 --- tablet.mx 10 Sep 2008 09:30:16 -0000 1.170 +++ tablet.mx 10 Sep 2008 10:36:19 -0000 1.171 @@ -1964,10 +1964,12 @@ for( i=0; i< (int)as->nr_attrs; i++) { if (as->format[i].c) { /* prepare enough space */ - BATextend( as->format[i].c, cnt ); + as->format[i].c = BATextend( as->format[i].c, cnt ); + assert(as->format[i].c != NULL);

Assertions are (usually) ment for ensuring consistency of the code and its usage and (hence) to detect situations that may/must ("can") not occur under "normal" circumstances; A BATextend (i.e., a malloc) can very well fail in normal circumstance (e.g., when running out of memory); hence, such a situation should (must?) better be detected and handled by some error handling code, not by an assertion; Recall and be aware that assertions are disabled in the release production version, i.e., in this case a failing BATextend (e.g., due to shortage of memory or address space) will lead to undefined behavor of the code, potentially a segmentation fault. This is IMHO not desired ... Stefan

for (j=0; jformat[i].c); - BATappend(as->format[i].c, partition[j]->format[i].c,TRUE); + as->format[i].c= BATappend(as->format[i].c, partition[j]->format[i].c,TRUE); + assert(as->format[i].c!= NULL); BATsave(as->format[i].c); /* Throw away the temporary bats a.s.a.p. without saveing */ BBPunfix(partition[j]->format[i].c->batCacheid);

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