jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1CardCounts.cpp@1f1d373cd044 (annotated)

src/share/vm/gc_implementation/g1/g1CardCounts.cpp@1f1d373cd044 (annotated)

src/share/vm/gc_implementation/g1/g1CardCounts.cpp

Thu, 21 Aug 2014 11:47:10 +0200

author: tschatzl
date: Thu, 21 Aug 2014 11:47:10 +0200
changeset 7051: 1f1d373cd044
parent 6680: 78bbf4d43a14
child 7257: e7d0505c8a30
permissions: -rw-r--r--

8038423: G1: Decommit memory within heap
Summary: Allow G1 to decommit memory of arbitrary regions within the heap and their associated auxiliary data structures card table, BOT, hot card cache, and mark bitmaps.
Reviewed-by: mgerdin, brutisso, jwilhelm

 /*
  * Copyright (c) 2013, 2014, 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_implementation/g1/g1CardCounts.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
 #include "memory/cardTableModRefBS.hpp"
 #include "services/memTracker.hpp"
 #include "utilities/copy.hpp"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 void G1CardCountsMappingChangedListener::on_commit(uint start_idx, size_t num_regions) {
   MemRegion mr(G1CollectedHeap::heap()->bottom_addr_for_region(start_idx), num_regions * HeapRegion::GrainWords);
   _counts->clear_range(mr);
 }
 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);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1CardCounts.cpp@1f1d373cd044 (annotated)

src/share/vm/gc_implementation/g1/g1CardCounts.cpp