view src/share/vm/gc_implementation/g1/vm_operations_g1.hpp @ 1886:72a161e62cc4

6991377: G1: race between concurrent refinement and humongous object allocation Summary: There is a race between the concurrent refinement threads and the humongous object allocation that can cause the concurrent refinement threads to corrupt the part of the BOT that it is being initialized by the humongous object allocation operation. The solution is to do the humongous object allocation in careful steps to ensure that the concurrent refinement threads always have a consistent view over the BOT, region contents, and top. The fix includes some very minor tidying up in sparsePRT. Reviewed-by: jcoomes, johnc, ysr
author tonyp
date Sat, 16 Oct 2010 17:12:19 -0400
parents 4e5661ba9d98
children f95d63e2154a
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/*
 * Copyright (c) 2001, 2009, 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.
 *
 */

// VM_operations for the G1 collector.
// VM_GC_Operation:
//   - VM_CGC_Operation
//   - VM_G1CollectFull
//   - VM_G1CollectForAllocation
//   - VM_G1IncCollectionPause
//   - VM_G1PopRegionCollectionPause

class VM_G1CollectFull: public VM_GC_Operation {
 public:
  VM_G1CollectFull(unsigned int gc_count_before,
                   unsigned int full_gc_count_before,
                   GCCause::Cause cause)
    : VM_GC_Operation(gc_count_before, full_gc_count_before) {
    _gc_cause = cause;
  }
  ~VM_G1CollectFull() {}
  virtual VMOp_Type type() const { return VMOp_G1CollectFull; }
  virtual void doit();
  virtual const char* name() const {
    return "full garbage-first collection";
  }
};

class VM_G1CollectForAllocation: public VM_GC_Operation {
 private:
  HeapWord*   _res;
  size_t      _size;                       // size of object to be allocated
 public:
  VM_G1CollectForAllocation(size_t size, int gc_count_before)
    : VM_GC_Operation(gc_count_before) {
    _size        = size;
    _res         = NULL;
  }
  ~VM_G1CollectForAllocation()        {}
  virtual VMOp_Type type() const { return VMOp_G1CollectForAllocation; }
  virtual void doit();
  virtual const char* name() const {
    return "garbage-first collection to satisfy allocation";
  }
  HeapWord* result() { return _res; }
};

class VM_G1IncCollectionPause: public VM_GC_Operation {
private:
  bool _should_initiate_conc_mark;
  double _target_pause_time_ms;
  unsigned int _full_collections_completed_before;
public:
  VM_G1IncCollectionPause(unsigned int   gc_count_before,
                          bool           should_initiate_conc_mark,
                          double         target_pause_time_ms,
                          GCCause::Cause cause)
    : VM_GC_Operation(gc_count_before),
      _full_collections_completed_before(0),
      _should_initiate_conc_mark(should_initiate_conc_mark),
      _target_pause_time_ms(target_pause_time_ms) {
    guarantee(target_pause_time_ms > 0.0,
              err_msg("target_pause_time_ms = %1.6lf should be positive",
                      target_pause_time_ms));

    _gc_cause = cause;
  }
  virtual VMOp_Type type() const { return VMOp_G1IncCollectionPause; }
  virtual void doit();
  virtual void doit_epilogue();
  virtual const char* name() const {
    return "garbage-first incremental collection pause";
  }
};

// Concurrent GC stop-the-world operations such as initial and final mark;
// consider sharing these with CMS's counterparts.
class VM_CGC_Operation: public VM_Operation {
  VoidClosure* _cl;
  const char* _printGCMessage;
 public:
  VM_CGC_Operation(VoidClosure* cl, const char *printGCMsg) :
    _cl(cl),
    _printGCMessage(printGCMsg)
    {}

  ~VM_CGC_Operation() {}

  virtual VMOp_Type type() const { return VMOp_CGC_Operation; }
  virtual void doit();
  virtual bool doit_prologue();
  virtual void doit_epilogue();
  virtual const char* name() const {
    return "concurrent gc";
  }
};