8059066: CardTableModRefBS might commit the same page twice

Reviewed-by: tschatzl, kbarrett, jmasa
This commit is contained in:
Erik Helin 2014-12-02 09:53:30 +01:00
parent 902d2139f6
commit cbe8efabfe
2 changed files with 69 additions and 23 deletions

View file

@ -275,29 +275,26 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
// the new_end_aligned does not intrude onto the committed
// space of another region.
int ri = 0;
for (ri = 0; ri < _cur_covered_regions; ri++) {
if (ri != ind) {
if (_committed[ri].contains(new_end_aligned)) {
// The prior check included in the assert
// (new_end_aligned >= _committed[ri].start())
// is redundant with the "contains" test.
// Any region containing the new end
// should start at or beyond the region found (ind)
// for the new end (committed regions are not expected to
// be proper subsets of other committed regions).
assert(_committed[ri].start() >= _committed[ind].start(),
"New end of committed region is inconsistent");
new_end_aligned = _committed[ri].start();
// new_end_aligned can be equal to the start of its
// committed region (i.e., of "ind") if a second
// region following "ind" also start at the same location
// as "ind".
assert(new_end_aligned >= _committed[ind].start(),
"New end of committed region is before start");
debug_only(collided = true;)
// Should only collide with 1 region
break;
}
for (ri = ind + 1; ri < _cur_covered_regions; ri++) {
if (new_end_aligned > _committed[ri].start()) {
assert(new_end_aligned <= _committed[ri].end(),
"An earlier committed region can't cover a later committed region");
// Any region containing the new end
// should start at or beyond the region found (ind)
// for the new end (committed regions are not expected to
// be proper subsets of other committed regions).
assert(_committed[ri].start() >= _committed[ind].start(),
"New end of committed region is inconsistent");
new_end_aligned = _committed[ri].start();
// new_end_aligned can be equal to the start of its
// committed region (i.e., of "ind") if a second
// region following "ind" also start at the same location
// as "ind".
assert(new_end_aligned >= _committed[ind].start(),
"New end of committed region is before start");
debug_only(collided = true;)
// Should only collide with 1 region
break;
}
}
#ifdef ASSERT