view src/share/vm/gc_implementation/g1/g1SATBCardTableModRefBS.hpp @ 2034:7e37af9d69ef

7011379: G1: overly long concurrent marking cycles Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads. Reviewed-by: johnc, ysr
author tonyp
date Wed, 19 Jan 2011 09:35:17 -0500
parents c18cbe5936b8
children 0ac769a57c64
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/*
 * Copyright (c) 2001, 2010, 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
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP

#include "memory/cardTableModRefBS.hpp"
#include "memory/memRegion.hpp"
#include "oops/oop.inline.hpp"

#ifndef SERIALGC

class DirtyCardQueueSet;

// This barrier is specialized to use a logging barrier to support
// snapshot-at-the-beginning marking.

class G1SATBCardTableModRefBS: public CardTableModRefBSForCTRS {
private:
  // Add "pre_val" to a set of objects that may have been disconnected from the
  // pre-marking object graph.
  static void enqueue(oop pre_val);

public:
  G1SATBCardTableModRefBS(MemRegion whole_heap,
                          int max_covered_regions);

  bool is_a(BarrierSet::Name bsn) {
    return bsn == BarrierSet::G1SATBCT || CardTableModRefBS::is_a(bsn);
  }

  virtual bool has_write_ref_pre_barrier() { return true; }

  // This notes that we don't need to access any BarrierSet data
  // structures, so this can be called from a static context.
  template <class T> static void write_ref_field_pre_static(T* field, oop newVal) {
    T heap_oop = oopDesc::load_heap_oop(field);
    if (!oopDesc::is_null(heap_oop)) {
      enqueue(oopDesc::decode_heap_oop(heap_oop));
    }
  }

  // When we know the current java thread:
  template <class T> static void write_ref_field_pre_static(T* field, oop newVal,
                                                            JavaThread* jt);

  // We export this to make it available in cases where the static
  // type of the barrier set is known.  Note that it is non-virtual.
  template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal) {
    write_ref_field_pre_static(field, newVal);
  }

  // These are the more general virtual versions.
  virtual void write_ref_field_pre_work(oop* field, oop new_val) {
    inline_write_ref_field_pre(field, new_val);
  }
  virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {
    inline_write_ref_field_pre(field, new_val);
  }
  virtual void write_ref_field_pre_work(void* field, oop new_val) {
    guarantee(false, "Not needed");
  }

  template <class T> void write_ref_array_pre_work(T* dst, int count);
  virtual void write_ref_array_pre(oop* dst, int count) {
    write_ref_array_pre_work(dst, count);
  }
  virtual void write_ref_array_pre(narrowOop* dst, int count) {
    write_ref_array_pre_work(dst, count);
  }
};

// Adds card-table logging to the post-barrier.
// Usual invariant: all dirty cards are logged in the DirtyCardQueueSet.
class G1SATBCardTableLoggingModRefBS: public G1SATBCardTableModRefBS {
 private:
  DirtyCardQueueSet& _dcqs;
 public:
  G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
                                 int max_covered_regions);

  bool is_a(BarrierSet::Name bsn) {
    return bsn == BarrierSet::G1SATBCTLogging ||
      G1SATBCardTableModRefBS::is_a(bsn);
  }

  void write_ref_field_work(void* field, oop new_val);

  // Can be called from static contexts.
  static void write_ref_field_static(void* field, oop new_val);

  // NB: if you do a whole-heap invalidation, the "usual invariant" defined
  // above no longer applies.
  void invalidate(MemRegion mr, bool whole_heap = false);

  void write_region_work(MemRegion mr)    { invalidate(mr); }
  void write_ref_array_work(MemRegion mr) { invalidate(mr); }


};


#endif // SERIALGC

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1SATBCARDTABLEMODREFBS_HPP