Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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, 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);

 }

 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);

 }