--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1CardCounts.cpp Wed May 13 15:16:06 2015 +0200
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1CardCounts.hpp"
+#include "gc/g1/g1CollectedHeap.inline.hpp"
+#include "gc/g1/g1CollectorPolicy.hpp"
+#include "gc/g1/g1GCPhaseTimes.hpp"
+#include "gc/shared/cardTableModRefBS.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/copy.hpp"
+
+void G1CardCountsMappingChangedListener::on_commit(uint start_idx, size_t num_regions, bool zero_filled) {
+ if (zero_filled) {
+ return;
+ }
+ MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
+ _counts->clear_range(mr);
+}
+
+size_t G1CardCounts::compute_size(size_t mem_region_size_in_words) {
+ // We keep card counts for every card, so the size of the card counts table must
+ // be the same as the card table.
+ return G1SATBCardTableLoggingModRefBS::compute_size(mem_region_size_in_words);
+}
+
+size_t G1CardCounts::heap_map_factor() {
+ // See G1CardCounts::compute_size() why we reuse the card table value.
+ return G1SATBCardTableLoggingModRefBS::heap_map_factor();
+}
+
+void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {
+ if (has_count_table()) {
+ assert(from_card_num < to_card_num,
+ err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT,
+ from_card_num, to_card_num));
+ Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num));
+ }
+}
+
+G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):
+ _listener(), _g1h(g1h), _card_counts(NULL), _reserved_max_card_num(0) {
+ _listener.set_cardcounts(this);
+}
+
+void G1CardCounts::initialize(G1RegionToSpaceMapper* mapper) {
+ assert(_g1h->max_capacity() > 0, "initialization order");
+ assert(_g1h->capacity() == 0, "initialization order");
+
+ if (G1ConcRSHotCardLimit > 0) {
+ // The max value we can store in the counts table is
+ // max_jubyte. Guarantee the value of the hot
+ // threshold limit is no more than this.
+ guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity");
+
+ _ct_bs = _g1h->g1_barrier_set();
+ _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());
+
+ _card_counts = (jubyte*) mapper->reserved().start();
+ _reserved_max_card_num = mapper->reserved().byte_size();
+ mapper->set_mapping_changed_listener(&_listener);
+ }
+}
+
+uint G1CardCounts::add_card_count(jbyte* card_ptr) {
+ // Returns the number of times the card has been refined.
+ // If we failed to reserve/commit the counts table, return 0.
+ // If card_ptr is beyond the committed end of the counts table,
+ // return 0.
+ // Otherwise return the actual count.
+ // Unless G1ConcRSHotCardLimit has been set appropriately,
+ // returning 0 will result in the card being considered
+ // cold and will be refined immediately.
+ uint count = 0;
+ if (has_count_table()) {
+ size_t card_num = ptr_2_card_num(card_ptr);
+ assert(card_num < _reserved_max_card_num,
+ err_msg("Card "SIZE_FORMAT" outside of card counts table (max size "SIZE_FORMAT")",
+ card_num, _reserved_max_card_num));
+ count = (uint) _card_counts[card_num];
+ if (count < G1ConcRSHotCardLimit) {
+ _card_counts[card_num] =
+ (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));
+ }
+ }
+ return count;
+}
+
+bool G1CardCounts::is_hot(uint count) {
+ return (count >= G1ConcRSHotCardLimit);
+}
+
+void G1CardCounts::clear_region(HeapRegion* hr) {
+ MemRegion mr(hr->bottom(), hr->end());
+ clear_range(mr);
+}
+
+void G1CardCounts::clear_range(MemRegion mr) {
+ if (has_count_table()) {
+ const jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
+ // We use the last address in the range as the range could represent the
+ // last region in the heap. In which case trying to find the card will be an
+ // OOB access to the card table.
+ const jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
+
+#ifdef ASSERT
+ HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
+ assert(start_addr == mr.start(), "MemRegion start must be aligned to a card.");
+ HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
+ assert((last_addr + CardTableModRefBS::card_size_in_words) == mr.end(), "MemRegion end must be aligned to a card.");
+#endif // ASSERT
+
+ // Clear the counts for the (exclusive) card range.
+ size_t from_card_num = ptr_2_card_num(from_card_ptr);
+ size_t to_card_num = ptr_2_card_num(last_card_ptr) + 1;
+ clear_range(from_card_num, to_card_num);
+ }
+}
+
+class G1CardCountsClearClosure : public HeapRegionClosure {
+ private:
+ G1CardCounts* _card_counts;
+ public:
+ G1CardCountsClearClosure(G1CardCounts* card_counts) :
+ HeapRegionClosure(), _card_counts(card_counts) { }
+
+
+ virtual bool doHeapRegion(HeapRegion* r) {
+ _card_counts->clear_region(r);
+ return false;
+ }
+};
+
+void G1CardCounts::clear_all() {
+ assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");
+ G1CardCountsClearClosure cl(this);
+ _g1h->heap_region_iterate(&cl);
+}