johnc@5078: /*
drchase@6680:  * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
johnc@5078:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
johnc@5078:  *
johnc@5078:  * This code is free software; you can redistribute it and/or modify it
johnc@5078:  * under the terms of the GNU General Public License version 2 only, as
johnc@5078:  * published by the Free Software Foundation.
johnc@5078:  *
johnc@5078:  * This code is distributed in the hope that it will be useful, but WITHOUT
johnc@5078:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
johnc@5078:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
johnc@5078:  * version 2 for more details (a copy is included in the LICENSE file that
johnc@5078:  * accompanied this code).
johnc@5078:  *
johnc@5078:  * You should have received a copy of the GNU General Public License version
johnc@5078:  * 2 along with this work; if not, write to the Free Software Foundation,
johnc@5078:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
johnc@5078:  *
johnc@5078:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
johnc@5078:  * or visit www.oracle.com if you need additional information or have any
johnc@5078:  * questions.
johnc@5078:  *
johnc@5078:  */
johnc@5078: 
johnc@5078: #include "precompiled.hpp"
johnc@5078: #include "gc_implementation/g1/g1CardCounts.hpp"
johnc@5078: #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
johnc@5078: #include "gc_implementation/g1/g1CollectorPolicy.hpp"
johnc@5078: #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
johnc@5078: #include "memory/cardTableModRefBS.hpp"
johnc@5078: #include "services/memTracker.hpp"
johnc@5078: #include "utilities/copy.hpp"
johnc@5078: 
drchase@6680: PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
drchase@6680: 
tschatzl@7257: void G1CardCountsMappingChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
tschatzl@7257:   if (zero_filled) {
tschatzl@7257:     return;
tschatzl@7257:   }
tschatzl@7051:   MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
tschatzl@7051:   _counts->clear_range(mr);
tschatzl@7051: }
tschatzl@7051: 
johnc@5078: void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
johnc@5078:   if (has_count_table()) {
johnc@5078:     assert(from_card_num < to_card_num,
kevinw@9327:            err_msg("Wrong order? from: " SIZE_FORMAT ", to: " SIZE_FORMAT,
johnc@5078:                    from_card_num, to_card_num));
johnc@5078:     Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num));
johnc@5078:   }
johnc@5078: }
johnc@5078: 
johnc@5078: G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):
tschatzl@7051:   _listener(), _g1h(g1h), _card_counts(NULL), _reserved_max_card_num(0) {
tschatzl@7051:   _listener.set_cardcounts(this);
tschatzl@7051: }
johnc@5078: 
tschatzl@7051: void G1CardCounts::initialize(G1RegionToSpaceMapper* mapper) {
johnc@5078:   assert(_g1h->max_capacity() > 0, "initialization order");
johnc@5078:   assert(_g1h->capacity() == 0, "initialization order");
johnc@5078: 
johnc@5078:   if (G1ConcRSHotCardLimit > 0) {
johnc@5078:     // The max value we can store in the counts table is
johnc@5078:     // max_jubyte. Guarantee the value of the hot
johnc@5078:     // threshold limit is no more than this.
johnc@5078:     guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity");
johnc@5078: 
mgerdin@5811:     _ct_bs = _g1h->g1_barrier_set();
johnc@5078:     _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
johnc@5078: 
tschatzl@7051:     _card_counts = (jubyte*) mapper->reserved().start();
tschatzl@7051:     _reserved_max_card_num = mapper->reserved().byte_size();
tschatzl@7051:     mapper->set_mapping_changed_listener(&_listener);
johnc@5078:   }
johnc@5078: }
johnc@5078: 
johnc@5078: uint G1CardCounts::add_card_count(jbyte* card_ptr) {
johnc@5078:   // Returns the number of times the card has been refined.
johnc@5078:   // If we failed to reserve/commit the counts table, return 0.
johnc@5078:   // If card_ptr is beyond the committed end of the counts table,
johnc@5078:   // return 0.
johnc@5078:   // Otherwise return the actual count.
johnc@5078:   // Unless G1ConcRSHotCardLimit has been set appropriately,
johnc@5078:   // returning 0 will result in the card being considered
johnc@5078:   // cold and will be refined immediately.
johnc@5078:   uint count = 0;
johnc@5078:   if (has_count_table()) {
johnc@5078:     size_t card_num = ptr_2_card_num(card_ptr);
tschatzl@7051:     assert(card_num < _reserved_max_card_num,
kevinw@9327:            err_msg("Card " SIZE_FORMAT " outside of card counts table (max size " SIZE_FORMAT ")",
tschatzl@7051:                    card_num, _reserved_max_card_num));
tschatzl@7051:     count = (uint) _card_counts[card_num];
tschatzl@7051:     if (count < G1ConcRSHotCardLimit) {
tschatzl@7051:       _card_counts[card_num] =
tschatzl@7051:         (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
johnc@5078:     }
johnc@5078:   }
johnc@5078:   return count;
johnc@5078: }
johnc@5078: 
johnc@5078: bool G1CardCounts::is_hot(uint count) {
johnc@5078:   return (count >= G1ConcRSHotCardLimit);
johnc@5078: }
johnc@5078: 
johnc@5078: void G1CardCounts::clear_region(HeapRegion* hr) {
tschatzl@7051:   MemRegion mr(hr->bottom(), hr->end());
tschatzl@7051:   clear_range(mr);
tschatzl@7051: }
tschatzl@7051: 
tschatzl@7051: void G1CardCounts::clear_range(MemRegion mr) {
johnc@5078:   if (has_count_table()) {
tschatzl@7051:     const jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
tschatzl@7051:     // We use the last address in the range as the range could represent the
tschatzl@7051:     // last region in the heap. In which case trying to find the card will be an
tschatzl@7051:     // OOB access to the card table.
tschatzl@7051:     const jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
johnc@5078: 
johnc@5078: #ifdef ASSERT
johnc@5078:     HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
tschatzl@7051:     assert(start_addr == mr.start(), "MemRegion start must be aligned to a card.");
johnc@5078:     HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
tschatzl@7051:     assert((last_addr + CardTableModRefBS::card_size_in_words) == mr.end(), "MemRegion end must be aligned to a card.");
johnc@5078: #endif // ASSERT
johnc@5078: 
johnc@5078:     // Clear the counts for the (exclusive) card range.
johnc@5078:     size_t from_card_num = ptr_2_card_num(from_card_ptr);
johnc@5078:     size_t to_card_num = ptr_2_card_num(last_card_ptr) + 1;
johnc@5078:     clear_range(from_card_num, to_card_num);
johnc@5078:   }
johnc@5078: }
johnc@5078: 
tschatzl@7051: class G1CardCountsClearClosure : public HeapRegionClosure {
tschatzl@7051:  private:
tschatzl@7051:   G1CardCounts* _card_counts;
tschatzl@7051:  public:
tschatzl@7051:   G1CardCountsClearClosure(G1CardCounts* card_counts) :
tschatzl@7051:     HeapRegionClosure(), _card_counts(card_counts) { }
tschatzl@7051: 
tschatzl@7051: 
tschatzl@7051:   virtual bool doHeapRegion(HeapRegion* r) {
tschatzl@7051:     _card_counts->clear_region(r);
tschatzl@7051:     return false;
tschatzl@7051:   }
tschatzl@7051: };
tschatzl@7051: 
johnc@5078: void G1CardCounts::clear_all() {
johnc@5078:   assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
tschatzl@7051:   G1CardCountsClearClosure cl(this);
tschatzl@7051:   _g1h->heap_region_iterate(&cl);
johnc@5078: }