stan/jdk-24
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This commit is contained in:
Y. Srinivas Ramakrishna 2008-06-17 08:40:48 -07:00
commit c201c739e4
1 changed files with 51 additions and 6 deletions
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57
hotspot/src/share/vm/memory/cardTableModRefBS.cpp
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@ -196,6 +196,8 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
assert(_whole_heap.contains(new_region),
"attempt to cover area not in reserved area");
debug_only(verify_guard();)
// collided is true if the expansion would push into another committed region
debug_only(bool collided = false;)
int const ind = find_covering_region_by_base(new_region.start());
MemRegion const old_region = _covered[ind];
assert(old_region.start() == new_region.start(), "just checking");
@ -211,12 +213,36 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
}
// Align the end up to a page size (starts are already aligned).
jbyte* const new_end = byte_after(new_region.last());
HeapWord* const new_end_aligned =
HeapWord* new_end_aligned =
(HeapWord*) align_size_up((uintptr_t)new_end, _page_size);
assert(new_end_aligned >= (HeapWord*) new_end,
"align up, but less");
int ri = 0;
for (ri = 0; ri < _cur_covered_regions; ri++) {
if (ri != ind) {
if (_committed[ri].contains(new_end_aligned)) {
assert((new_end_aligned >= _committed[ri].start()) &&
(_committed[ri].start() > _committed[ind].start()),
"New end of committed region is inconsistent");
new_end_aligned = _committed[ri].start();
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
for (++ri; ri < _cur_covered_regions; ri++) {
assert(!_committed[ri].contains(new_end_aligned),
"New end of committed region is in a second committed region");
}
#endif
// The guard page is always committed and should not be committed over.
HeapWord* const new_end_for_commit = MIN2(new_end_aligned, _guard_region.start());
HeapWord* const new_end_for_commit = MIN2(new_end_aligned,
_guard_region.start());
if (new_end_for_commit > cur_committed.end()) {
// Must commit new pages.
MemRegion const new_committed =
@ -239,9 +265,11 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
if (!uncommit_region.is_empty()) {
if (!os::uncommit_memory((char*)uncommit_region.start(),
uncommit_region.byte_size())) {
// Do better than this for Merlin
vm_exit_out_of_memory(uncommit_region.byte_size(),
"card table contraction");
assert(false, "Card table contraction failed");
// The call failed so don't change the end of the
// committed region. This is better than taking the
// VM down.
new_end_aligned = _committed[ind].end();
}
}
}
@ -257,8 +285,25 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
}
assert(index_for(new_region.last()) < (int) _guard_index,
"The guard card will be overwritten");
jbyte* const end = byte_after(new_region.last());
// This line commented out cleans the newly expanded region and
// not the aligned up expanded region.
// jbyte* const end = byte_after(new_region.last());
jbyte* const end = (jbyte*) new_end_for_commit;
assert((end >= byte_after(new_region.last())) || collided,
"Expect to be beyond new region unless impacting another region");
// do nothing if we resized downward.
#ifdef ASSERT
for (int ri = 0; ri < _cur_covered_regions; ri++) {
if (ri != ind) {
// The end of the new committed region should not
// be in any existing region unless it matches
// the start of the next region.
assert(!_committed[ri].contains(end) ||
(_committed[ri].start() == (HeapWord*) end),
"Overlapping committed regions");
}
}
#endif
if (entry < end) {
memset(entry, clean_card, pointer_delta(end, entry, sizeof(jbyte)));
}