johnc@5078: /*
johnc@5078:  * Copyright (c) 2013, 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: 
johnc@5078: void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
johnc@5078:   if (has_count_table()) {
shade@5709:     assert(from_card_num >= 0 && from_card_num < _committed_max_card_num,
shade@5709:            err_msg("from card num out of range: "SIZE_FORMAT, from_card_num));
johnc@5078:     assert(from_card_num < to_card_num,
johnc@5078:            err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT,
johnc@5078:                    from_card_num, to_card_num));
johnc@5078:     assert(to_card_num <= _committed_max_card_num,
johnc@5078:            err_msg("to card num out of range: "
johnc@5078:                    "to: "SIZE_FORMAT ", "
johnc@5078:                    "max: "SIZE_FORMAT,
johnc@5078:                    to_card_num, _committed_max_card_num));
johnc@5078: 
johnc@5078:     to_card_num = MIN2(_committed_max_card_num, to_card_num);
johnc@5078: 
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):
johnc@5078:   _g1h(g1h), _card_counts(NULL),
johnc@5078:   _reserved_max_card_num(0), _committed_max_card_num(0),
johnc@5078:   _committed_size(0) {}
johnc@5078: 
johnc@5078: void G1CardCounts::initialize() {
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: 
johnc@5078:     // Allocate/Reserve the counts table
johnc@5078:     size_t reserved_bytes = _g1h->max_capacity();
johnc@5078:     _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift;
johnc@5078: 
johnc@5078:     size_t reserved_size = _reserved_max_card_num * sizeof(jbyte);
johnc@5078:     ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size));
johnc@5078:     if (!rs.is_reserved()) {
johnc@5078:       warning("Could not reserve enough space for the card counts table");
johnc@5078:       guarantee(!has_reserved_count_table(), "should be NULL");
johnc@5078:       return;
johnc@5078:     }
johnc@5078: 
johnc@5078:     MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);
johnc@5078: 
johnc@5078:     _card_counts_storage.initialize(rs, 0);
johnc@5078:     _card_counts = (jubyte*) _card_counts_storage.low();
johnc@5078:   }
johnc@5078: }
johnc@5078: 
johnc@5078: void G1CardCounts::resize(size_t heap_capacity) {
johnc@5078:   // Expand the card counts table to handle a heap with the given capacity.
johnc@5078: 
johnc@5078:   if (!has_reserved_count_table()) {
johnc@5078:     // Don't expand if we failed to reserve the card counts table.
johnc@5078:     return;
johnc@5078:   }
johnc@5078: 
johnc@5078:   assert(_committed_size ==
johnc@5078:          ReservedSpace::allocation_align_size_up(_committed_size),
johnc@5078:          err_msg("Unaligned? committed_size: " SIZE_FORMAT, _committed_size));
johnc@5078: 
johnc@5121:   // Verify that the committed space for the card counts matches our
johnc@5121:   // committed max card num. Note for some allocation alignments, the
johnc@5121:   // amount of space actually committed for the counts table will be able
johnc@5121:   // to span more cards than the number spanned by the maximum heap.
johnc@5078:   size_t prev_committed_size = _committed_size;
johnc@5121:   size_t prev_committed_card_num = committed_to_card_num(prev_committed_size);
johnc@5121: 
johnc@5078:   assert(prev_committed_card_num == _committed_max_card_num,
johnc@5078:          err_msg("Card mismatch: "
johnc@5078:                  "prev: " SIZE_FORMAT ", "
johnc@5121:                  "committed: "SIZE_FORMAT", "
johnc@5121:                  "reserved: "SIZE_FORMAT,
johnc@5121:                  prev_committed_card_num, _committed_max_card_num, _reserved_max_card_num));
johnc@5078: 
johnc@5078:   size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte);
johnc@5078:   size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size);
johnc@5121:   size_t new_committed_card_num = committed_to_card_num(new_committed_size);
johnc@5078: 
johnc@5078:   if (_committed_max_card_num < new_committed_card_num) {
johnc@5078:     // we need to expand the backing store for the card counts
johnc@5078:     size_t expand_size = new_committed_size - prev_committed_size;
johnc@5078: 
johnc@5078:     if (!_card_counts_storage.expand_by(expand_size)) {
johnc@5078:       warning("Card counts table backing store commit failure");
johnc@5078:       return;
johnc@5078:     }
johnc@5078:     assert(_card_counts_storage.committed_size() == new_committed_size,
johnc@5078:            "expansion commit failure");
johnc@5078: 
johnc@5078:     _committed_size = new_committed_size;
johnc@5078:     _committed_max_card_num = new_committed_card_num;
johnc@5078: 
johnc@5078:     clear_range(prev_committed_card_num, _committed_max_card_num);
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);
johnc@5078:     if (card_num < _committed_max_card_num) {
johnc@5078:       count = (uint) _card_counts[card_num];
johnc@5078:       if (count < G1ConcRSHotCardLimit) {
johnc@5342:         _card_counts[card_num] =
johnc@5342:           (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
johnc@5078:       }
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) {
johnc@5078:   assert(!hr->isHumongous(), "Should have been cleared");
johnc@5078:   if (has_count_table()) {
johnc@5078:     HeapWord* bottom = hr->bottom();
johnc@5078: 
johnc@5078:     // We use the last address in hr as hr could be the
johnc@5078:     // last region in the heap. In which case trying to find
johnc@5078:     // the card for hr->end() will be an OOB accesss to the
johnc@5078:     // card table.
johnc@5078:     HeapWord* last = hr->end() - 1;
johnc@5078:     assert(_g1h->g1_committed().contains(last),
johnc@5078:            err_msg("last not in committed: "
johnc@5078:                    "last: " PTR_FORMAT ", "
johnc@5078:                    "committed: [" PTR_FORMAT ", " PTR_FORMAT ")",
johnc@5078:                    last,
johnc@5078:                    _g1h->g1_committed().start(),
johnc@5078:                    _g1h->g1_committed().end()));
johnc@5078: 
johnc@5078:     const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom);
johnc@5078:     const jbyte* last_card_ptr = _ct_bs->byte_for_const(last);
johnc@5078: 
johnc@5078: #ifdef ASSERT
johnc@5078:     HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
johnc@5078:     assert(start_addr == hr->bottom(), "alignment");
johnc@5078:     HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
johnc@5078:     assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment");
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: 
johnc@5078: void G1CardCounts::clear_all() {
johnc@5078:   assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
johnc@5078:   clear_range((size_t)0, _committed_max_card_num);
johnc@5078: }
johnc@5078: 
johnc@5078: G1CardCounts::~G1CardCounts() {
johnc@5078:   if (has_reserved_count_table()) {
johnc@5078:     _card_counts_storage.release();
johnc@5078:   }
johnc@5078: }
johnc@5078: