jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp

Tue, 17 Oct 2017 12:58:25 +0800

author: aoqi
date: Tue, 17 Oct 2017 12:58:25 +0800
changeset 7994: 04ff2f6cd0eb
parent 6876: 710a3c8b516e
child 9448: 73d689add964
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 2001, 2013, 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.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP
 #include "gc_implementation/g1/heapRegion.hpp"
 #include "utilities/growableArray.hpp"
 class CollectionSetChooser: public CHeapObj<mtGC> {
   GrowableArray<HeapRegion*> _regions;
   // Unfortunately, GrowableArray uses ints for length and indexes. To
   // avoid excessive casting in the rest of the class the following
   // wrapper methods are provided that use uints.
   uint regions_length()          { return (uint) _regions.length(); }
   HeapRegion* regions_at(uint i) { return _regions.at((int) i);     }
   void regions_at_put(uint i, HeapRegion* hr) {
     _regions.at_put((int) i, hr);
   }
   void regions_at_put_grow(uint i, HeapRegion* hr) {
     _regions.at_put_grow((int) i, hr);
   }
   void regions_trunc_to(uint i)  { _regions.trunc_to((uint) i); }
   // The index of the next candidate old region to be considered for
   // addition to the CSet.
   uint _curr_index;
   // The number of candidate old regions added to the CSet chooser.
   // Note: this is not updated when removing a region using
   // remove_and_move_to_next() below.
   uint _length;
   // Keeps track of the start of the next array chunk to be claimed by
   // parallel GC workers.
   uint _first_par_unreserved_idx;
   // If a region has more live bytes than this threshold, it will not
   // be added to the CSet chooser and will not be a candidate for
   // collection.
   size_t _region_live_threshold_bytes;
   // The sum of reclaimable bytes over all the regions in the CSet chooser.
   size_t _remaining_reclaimable_bytes;
 public:
   // Return the current candidate region to be considered for
   // collection without removing it from the CSet chooser.
   HeapRegion* peek() {
     HeapRegion* res = NULL;
     if (_curr_index < _length) {
       res = regions_at(_curr_index);
       assert(res != NULL,
              err_msg("Unexpected NULL hr in _regions at index %u",
                      _curr_index));
     }
     return res;
   }
   // Remove the given region from the CSet chooser and move to the
   // next one. The given region should be the current candidate region
   // in the CSet chooser.
   void remove_and_move_to_next(HeapRegion* hr) {
     assert(hr != NULL, "pre-condition");
     assert(_curr_index < _length, "pre-condition");
     assert(regions_at(_curr_index) == hr, "pre-condition");
     regions_at_put(_curr_index, NULL);
     assert(hr->reclaimable_bytes() <= _remaining_reclaimable_bytes,
            err_msg("remaining reclaimable bytes inconsistent "
                    "from region: "SIZE_FORMAT" remaining: "SIZE_FORMAT,
                    hr->reclaimable_bytes(), _remaining_reclaimable_bytes));
     _remaining_reclaimable_bytes -= hr->reclaimable_bytes();
     _curr_index += 1;
   }
   CollectionSetChooser();
   void sort_regions();
   // Determine whether to add the given region to the CSet chooser or
   // not. Currently, we skip humongous regions (we never add them to
   // the CSet, we only reclaim them during cleanup) and regions whose
   // live bytes are over the threshold.
   bool should_add(HeapRegion* hr) {
     assert(hr->is_marked(), "pre-condition");
     assert(!hr->is_young(), "should never consider young regions");
     return !hr->isHumongous() &&
             hr->live_bytes() < _region_live_threshold_bytes;
   }
   // Returns the number candidate old regions added
   uint length() { return _length; }
   // Serial version.
   void add_region(HeapRegion *hr);
   // Must be called before calls to claim_array_chunk().
   // n_regions is the number of regions, chunk_size the chunk size.
   void prepare_for_par_region_addition(uint n_regions, uint chunk_size);
   // Returns the first index in a contiguous chunk of chunk_size indexes
   // that the calling thread has reserved.  These must be set by the
   // calling thread using set_region() (to NULL if necessary).
   uint claim_array_chunk(uint chunk_size);
   // Set the marked array entry at index to hr.  Careful to claim the index
   // first if in parallel.
   void set_region(uint index, HeapRegion* hr);
   // Atomically increment the number of added regions by region_num
   // and the amount of reclaimable bytes by reclaimable_bytes.
   void update_totals(uint region_num, size_t reclaimable_bytes);
   void clear();
   // Return the number of candidate regions that remain to be collected.
   uint remaining_regions() { return _length - _curr_index; }
   // Determine whether the CSet chooser has more candidate regions or not.
   bool is_empty() { return remaining_regions() == 0; }
   // Return the reclaimable bytes that remain to be collected on
   // all the candidate regions in the CSet chooser.
   size_t remaining_reclaimable_bytes() { return _remaining_reclaimable_bytes; }
   // Returns true if the used portion of "_regions" is properly
   // sorted, otherwise asserts false.
   void verify() PRODUCT_RETURN;
 };
 class CSetChooserParUpdater : public StackObj {
 private:
   CollectionSetChooser* _chooser;
   bool _parallel;
   uint _chunk_size;
   uint _cur_chunk_idx;
   uint _cur_chunk_end;
   uint _regions_added;
   size_t _reclaimable_bytes_added;
 public:
   CSetChooserParUpdater(CollectionSetChooser* chooser,
                         bool parallel, uint chunk_size) :
     _chooser(chooser), _parallel(parallel), _chunk_size(chunk_size),
     _cur_chunk_idx(0), _cur_chunk_end(0),
     _regions_added(0), _reclaimable_bytes_added(0) { }
   ~CSetChooserParUpdater() {
     if (_parallel && _regions_added > 0) {
       _chooser->update_totals(_regions_added, _reclaimable_bytes_added);
     }
   }
   void add_region(HeapRegion* hr) {
     if (_parallel) {
       if (_cur_chunk_idx == _cur_chunk_end) {
         _cur_chunk_idx = _chooser->claim_array_chunk(_chunk_size);
         _cur_chunk_end = _cur_chunk_idx + _chunk_size;
       }
       assert(_cur_chunk_idx < _cur_chunk_end, "invariant");
       _chooser->set_region(_cur_chunk_idx, hr);
       _cur_chunk_idx += 1;
     } else {
       _chooser->add_region(hr);
     }
     _regions_added += 1;
     _reclaimable_bytes_added += hr->reclaimable_bytes();
   }
   bool should_add(HeapRegion* hr) { return _chooser->should_add(hr); }
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_COLLECTIONSETCHOOSER_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp@04ff2f6cd0eb (annotated)

src/share/vm/gc_implementation/g1/collectionSetChooser.hpp