void HeapRegion::hr_clear(bool par, bool clear_space) {
_humongous_type = NotHumongous;
_humongous_start_region = NULL;
_in_collection_set = false;
_is_gc_alloc_region = false;
// Age stuff (if parallel, this will be done separately, since it needs
// to be sequential).
G1CollectedHeap* g1h = G1CollectedHeap::heap();
set_young_index_in_cset(-1);
uninstall_surv_rate_group();
set_young_type(NotYoung);
// In case it had been the start of a humongous sequence, reset its end.
set_end(_orig_end);
if (!par) {
// If this is parallel, this will be done later.
HeapRegionRemSet* hrrs = rem_set();
if (hrrs != NULL) hrrs->clear();
_claimed = InitialClaimValue;
}
zero_marked_bytes();
set_sort_index(-1);
_offsets.resize(HeapRegion::GrainWords);
init_top_at_mark_start();
if (clear_space) clear(SpaceDecorator::Mangle);
}
void HeapRegion::hr_clear(bool par, bool clear_space, bool locked) {
assert(_humongous_type == NotHumongous,
"we should have already filtered out humongous regions");
assert(_humongous_start_region == NULL,
"we should have already filtered out humongous regions");
assert(_end == _orig_end,
"we should have already filtered out humongous regions");
_in_collection_set = false;
set_young_index_in_cset(-1);
uninstall_surv_rate_group();
set_young_type(NotYoung);
reset_pre_dummy_top();
if (!par) {
// If this is parallel, this will be done later.
HeapRegionRemSet* hrrs = rem_set();
if (locked) {
hrrs->clear_locked();
} else {
hrrs->clear();
}
_claimed = InitialClaimValue;
}
zero_marked_bytes();
_offsets.resize(HeapRegion::GrainWords);
init_top_at_mark_start();
if (clear_space) clear(SpaceDecorator::Mangle);
}
void HeapRegion::migrate_strong_code_roots() {
assert(in_collection_set(), "only collection set regions");
assert(!isHumongous(),
err_msg("humongous region "HR_FORMAT" should not have been added to collection set",
HR_FORMAT_PARAMS(this)));
HeapRegionRemSet* hrrs = rem_set();
hrrs->migrate_strong_code_roots();
}
void HeapRegion::par_clear() {
assert(used() == 0, "the region should have been already cleared");
assert(capacity() == HeapRegion::GrainBytes, "should be back to normal");
HeapRegionRemSet* hrrs = rem_set();
hrrs->clear();
CardTableModRefBS* ct_bs =
(CardTableModRefBS*)G1CollectedHeap::heap()->barrier_set();
ct_bs->clear(MemRegion(bottom(), end()));
}
void HeapRegion::verify_strong_code_roots(VerifyOption vo, bool* failures) const {
if (!G1VerifyHeapRegionCodeRoots) {
// We're not verifying code roots.
return;
}
if (vo == VerifyOption_G1UseMarkWord) {
// Marking verification during a full GC is performed after class
// unloading, code cache unloading, etc so the strong code roots
// attached to each heap region are in an inconsistent state. They won't
// be consistent until the strong code roots are rebuilt after the
// actual GC. Skip verifying the strong code roots in this particular
// time.
assert(VerifyDuringGC, "only way to get here");
return;
}
HeapRegionRemSet* hrrs = rem_set();
size_t strong_code_roots_length = hrrs->strong_code_roots_list_length();
// if this region is empty then there should be no entries
// on its strong code root list
if (is_empty()) {
if (strong_code_roots_length > 0) {
gclog_or_tty->print_cr("region ["PTR_FORMAT","PTR_FORMAT"] is empty "
"but has "SIZE_FORMAT" code root entries",
bottom(), end(), strong_code_roots_length);
*failures = true;
}
return;
}
if (continuesHumongous()) {
if (strong_code_roots_length > 0) {
gclog_or_tty->print_cr("region "HR_FORMAT" is a continuation of a humongous "
"region but has "SIZE_FORMAT" code root entries",
HR_FORMAT_PARAMS(this), strong_code_roots_length);
*failures = true;
}
return;
}
VerifyStrongCodeRootCodeBlobClosure cb_cl(this);
strong_code_roots_do(&cb_cl);
if (cb_cl.failures()) {
*failures = true;
}
}
bool doHeapRegion(HeapRegion* r) {
HeapRegionRemSet* hrrs = r->rem_set();
_count += (int) hrrs->occupied();
if (hrrs->occupied() == 0) {
gclog_or_tty->print("Heap Region [" PTR_FORMAT ", " PTR_FORMAT ") "
"has no remset entries\n",
r->bottom(), r->end());
} else {
gclog_or_tty->print("Printing rem set for heap region [" PTR_FORMAT ", " PTR_FORMAT ")\n",
r->bottom(), r->end());
r->print();
hrrs->print();
gclog_or_tty->print("\nDone printing rem set\n");
}
return false;
}
bool doHeapRegion(HeapRegion* r) {
assert(r->in_collection_set(), "should only be called on elements of CS.");
HeapRegionRemSet* hrrs = r->rem_set();
if (hrrs->iter_is_complete()) return false; // All done.
if (!_try_claimed && !hrrs->claim_iter()) return false;
_g1h->push_dirty_cards_region(r);
// If we didn't return above, then
// _try_claimed || r->claim_iter()
// is true: either we're supposed to work on claimed-but-not-complete
// regions, or we successfully claimed the region.
HeapRegionRemSetIterator* iter = _g1h->rem_set_iterator(_worker_i);
hrrs->init_iterator(iter);
size_t card_index;
// We claim cards in block so as to recude the contention. The block size is determined by
// the G1RSetScanBlockSize parameter.
size_t jump_to_card = hrrs->iter_claimed_next(_block_size);
for (size_t current_card = 0; iter->has_next(card_index); current_card++) {
if (current_card >= jump_to_card + _block_size) {
jump_to_card = hrrs->iter_claimed_next(_block_size);
}
if (current_card < jump_to_card) continue;
HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index);
#if 0
gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n",
card_start, card_start + CardTableModRefBS::card_size_in_words);
#endif
HeapRegion* card_region = _g1h->heap_region_containing(card_start);
assert(card_region != NULL, "Yielding cards not in the heap?");
_cards++;
if (!card_region->is_on_dirty_cards_region_list()) {
_g1h->push_dirty_cards_region(card_region);
}
// If the card is dirty, then we will scan it during updateRS.
if (!card_region->in_collection_set() && !_ct_bs->is_card_dirty(card_index)) {
// We make the card as "claimed" lazily (so races are possible but they're benign),
// which reduces the number of duplicate scans (the rsets of the regions in the cset
// can intersect).
if (!_ct_bs->is_card_claimed(card_index)) {
_ct_bs->set_card_claimed(card_index);
scanCard(card_index, card_region);
}
}
}
if (!_try_claimed) {
hrrs->set_iter_complete();
}
return false;
}
bool doHeapRegion(HeapRegion* r) {
assert(r->in_collection_set(), "should only be called on elements of CS.");
HeapRegionRemSet* hrrs = r->rem_set();
if (hrrs->iter_is_complete()) return false; // All done.
if (!_try_claimed && !hrrs->claim_iter()) return false;
// If we ever free the collection set concurrently, we should also
// clear the card table concurrently therefore we won't need to
// add regions of the collection set to the dirty cards region.
_g1h->push_dirty_cards_region(r);
// If we didn't return above, then
// _try_claimed || r->claim_iter()
// is true: either we're supposed to work on claimed-but-not-complete
// regions, or we successfully claimed the region.
HeapRegionRemSetIterator iter(hrrs);
size_t card_index;
// We claim cards in block so as to reduce the contention. The block size is determined by
// the G1RSetScanBlockSize parameter.
size_t jump_to_card = hrrs->iter_claimed_next(_block_size);
for (size_t current_card = 0; iter.has_next(card_index); current_card++) {
if (current_card >= jump_to_card + _block_size) {
jump_to_card = hrrs->iter_claimed_next(_block_size);
}
if (current_card < jump_to_card) continue;
HeapWord* card_start = _g1h->bot_shared()->address_for_index(card_index);
#if 0
gclog_or_tty->print("Rem set iteration yielded card [" PTR_FORMAT ", " PTR_FORMAT ").\n",
card_start, card_start + CardTableModRefBS::card_size_in_words);
#endif
HeapRegion* card_region = _g1h->heap_region_containing(card_start);
_cards++;
if (!card_region->is_on_dirty_cards_region_list()) {
_g1h->push_dirty_cards_region(card_region);
}
// If the card is dirty, then we will scan it during updateRS.
if (!card_region->in_collection_set() &&
!_ct_bs->is_card_dirty(card_index)) {
scanCard(card_index, card_region);
}
}
if (!_try_claimed) {
// Scan the strong code root list attached to the current region
scan_strong_code_roots(r);
hrrs->set_iter_complete();
}
return false;
}
void HeapRegion::strong_code_roots_do(CodeBlobClosure* blk) const {
HeapRegionRemSet* hrrs = rem_set();
hrrs->strong_code_roots_do(blk);
}
void HeapRegion::remove_strong_code_root(nmethod* nm) {
HeapRegionRemSet* hrrs = rem_set();
hrrs->remove_strong_code_root(nm);
}
void HeapRegion::add_strong_code_root_locked(nmethod* nm) {
assert_locked_or_safepoint(CodeCache_lock);
HeapRegionRemSet* hrrs = rem_set();
hrrs->add_strong_code_root_locked(nm);
}
bool doHeapRegion(HeapRegion *r) {
HeapRegionRemSet* hrrs = r->rem_set();
hrrs->init_for_par_iteration();
return false;
}
