for (i = 0; i < NFASTBINS; ++i) {
p = av->fastbins[i];
+ /* The following test can only be performed for the main arena.
+ While mallopt calls malloc_consolidate to get rid of all fast
+ bins (especially those larger than the new maximum) this does
+ only happen for the main arena. Trying to do this for any
+ other arena would mean those arenas have to be locked and
+ malloc_consolidate be called for them. This is excessive. And
+ even if this is acceptable to somebody it still cannot solve
+ the problem completely since if the arena is locked a
+ concurrent malloc call might create a new arena which then
+ could use the newly invalid fast bins. */
+
/* all bins past max_fast are empty */
- if (i > max_fast_bin)
+ if (av == &main_arena && i > max_fast_bin)
assert(p == 0);
while (p != 0) {