view src/share/vm/gc_implementation/parallelScavenge/psTasks.hpp @ 453:c96030fff130

6684579: SoftReference processing can be made more efficient Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not. Reviewed-by: jmasa
author ysr
date Thu, 20 Nov 2008 16:56:09 -0800
parents a61af66fc99e
children 148e5441d916
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/*
 * Copyright 2002-2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

//
// psTasks.hpp is a collection of GCTasks used by the
// parallelScavenge collector.
//

class GCTask;
class OopClosure;
class OopStack;
class ObjectStartArray;
class ParallelTaskTerminator;
class MutableSpace;
class PSOldGen;
class Thread;
class VMThread;

//
// ScavengeRootsTask
//
// This task scans all the roots of a given type.
//
//

class ScavengeRootsTask : public GCTask {
 public:
  enum RootType {
    universe              = 1,
    jni_handles           = 2,
    threads               = 3,
    object_synchronizer   = 4,
    flat_profiler         = 5,
    system_dictionary     = 6,
    management            = 7,
    jvmti                 = 8
  };
 private:
  RootType _root_type;
 public:
  ScavengeRootsTask(RootType value) : _root_type(value) {}

  char* name() { return (char *)"scavenge-roots-task"; }

  virtual void do_it(GCTaskManager* manager, uint which);
};

//
// ThreadRootsTask
//
// This task scans the roots of a single thread. This task
// enables scanning of thread roots in parallel.
//

class ThreadRootsTask : public GCTask {
 private:
  JavaThread* _java_thread;
  VMThread* _vm_thread;
 public:
  ThreadRootsTask(JavaThread* root) : _java_thread(root), _vm_thread(NULL) {}
  ThreadRootsTask(VMThread* root) : _java_thread(NULL), _vm_thread(root) {}

  char* name() { return (char *)"thread-roots-task"; }

  virtual void do_it(GCTaskManager* manager, uint which);
};

//
// StealTask
//
// This task is used to distribute work to idle threads.
//

class StealTask : public GCTask {
 private:
   ParallelTaskTerminator* const _terminator;
 public:
  char* name() { return (char *)"steal-task"; }

  StealTask(ParallelTaskTerminator* t);

  ParallelTaskTerminator* terminator() { return _terminator; }

  virtual void do_it(GCTaskManager* manager, uint which);
};

//
// SerialOldToYoungRootsTask
//
// This task is used to scan for roots in the perm gen

class SerialOldToYoungRootsTask : public GCTask {
 private:
  PSOldGen* _gen;
  HeapWord* _gen_top;

 public:
  SerialOldToYoungRootsTask(PSOldGen *gen, HeapWord* gen_top) :
    _gen(gen), _gen_top(gen_top) { }

  char* name() { return (char *)"serial-old-to-young-roots-task"; }

  virtual void do_it(GCTaskManager* manager, uint which);
};

//
// OldToYoungRootsTask
//
// This task is used to scan old to young roots in parallel

class OldToYoungRootsTask : public GCTask {
 private:
  PSOldGen* _gen;
  HeapWord* _gen_top;
  uint _stripe_number;

 public:
  OldToYoungRootsTask(PSOldGen *gen, HeapWord* gen_top, uint stripe_number) :
    _gen(gen), _gen_top(gen_top), _stripe_number(stripe_number) { }

  char* name() { return (char *)"old-to-young-roots-task"; }

  virtual void do_it(GCTaskManager* manager, uint which);
};