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This commit is contained in:
Erik Trimble 2009-03-12 18:16:36 -07:00
commit 8d6035660e
223 changed files with 5079 additions and 2219 deletions
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71
hotspot/src/share/vm/memory/cardTableModRefBS.cpp
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@ -217,15 +217,28 @@ void CardTableModRefBS::resize_covered_region(MemRegion new_region) {
(HeapWord*) align_size_up((uintptr_t)new_end, _page_size);
assert(new_end_aligned >= (HeapWord*) new_end,
"align up, but less");
// Check the other regions (excludes "ind") to ensure that
// 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)) {
assert((new_end_aligned >= _committed[ri].start()) &&
(_committed[ri].start() > _committed[ind].start()),
// 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();
assert(new_end_aligned > _committed[ind].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
@ -343,18 +356,62 @@ void CardTableModRefBS::write_ref_field_work(void* field, oop newVal) {
inline_write_ref_field(field, newVal);
}
/*
Claimed and deferred bits are used together in G1 during the evacuation
pause. These bits can have the following state transitions:
1. The claimed bit can be put over any other card state. Except that
the "dirty -> dirty and claimed" transition is checked for in
G1 code and is not used.
2. Deferred bit can be set only if the previous state of the card
was either clean or claimed. mark_card_deferred() is wait-free.
We do not care if the operation is be successful because if
it does not it will only result in duplicate entry in the update
buffer because of the "cache-miss". So it's not worth spinning.
*/
bool CardTableModRefBS::claim_card(size_t card_index) {
jbyte val = _byte_map[card_index];
if (val != claimed_card_val()) {
jbyte res = Atomic::cmpxchg((jbyte) claimed_card_val(), &_byte_map[card_index], val);
if (res == val)
assert(val != dirty_card_val(), "Shouldn't claim a dirty card");
while (val == clean_card_val() ||
(val & (clean_card_mask_val() | claimed_card_val())) != claimed_card_val()) {
jbyte new_val = val;
if (val == clean_card_val()) {
new_val = (jbyte)claimed_card_val();
} else {
new_val = val | (jbyte)claimed_card_val();
}
jbyte res = Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
if (res == val) {
return true;
else return false;
}
val = res;
}
return false;
}
bool CardTableModRefBS::mark_card_deferred(size_t card_index) {
jbyte val = _byte_map[card_index];
// It's already processed
if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
return false;
}
// Cached bit can be installed either on a clean card or on a claimed card.
jbyte new_val = val;
if (val == clean_card_val()) {
new_val = (jbyte)deferred_card_val();
} else {
if (val & claimed_card_val()) {
new_val = val | (jbyte)deferred_card_val();
}
}
if (new_val != val) {
Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
}
return true;
}
void CardTableModRefBS::non_clean_card_iterate(Space* sp,
MemRegion mr,
DirtyCardToOopClosure* dcto_cl,