/*

 * Copyright 2005-2007 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.

 *

 */

// Tasks for parallel compaction of the old generation

//

// Tasks are created and enqueued on a task queue. The

// tasks for parallel old collector for marking objects

// are MarkFromRootsTask and ThreadRootsMarkingTask.

//

// MarkFromRootsTask's are created

// with a root group (e.g., jni_handles) and when the do_it()

// method of a MarkFromRootsTask is executed, it starts marking

// form it's root group.

//

// ThreadRootsMarkingTask's are created for each Java thread.  When

// the do_it() method of a ThreadRootsMarkingTask is executed, it

// starts marking from the thread's roots.

//

// The enqueuing of the MarkFromRootsTask and ThreadRootsMarkingTask

// do little more than create the task and put it on a queue.  The

// queue is a GCTaskQueue and threads steal tasks from this GCTaskQueue.

//

// In addition to the MarkFromRootsTask and ThreadRootsMarkingTask

// tasks there are StealMarkingTask tasks.  The StealMarkingTask's

// steal a reference from the marking stack of another

// thread and transitively marks the object of the reference

// and internal references.  After successfully stealing a reference

// and marking it, the StealMarkingTask drains its marking stack

// stack before attempting another steal.

//

// ThreadRootsMarkingTask

//

// This task marks from the roots of a single thread. This task

// enables marking of thread roots in parallel.

//

class ParallelTaskTerminator;

class ThreadRootsMarkingTask : public GCTask {

 private:

  JavaThread* _java_thread;

  VMThread* _vm_thread;

 public:

  ThreadRootsMarkingTask(JavaThread* root) : _java_thread(root), _vm_thread(NULL) {}

  ThreadRootsMarkingTask(VMThread* root) : _java_thread(NULL), _vm_thread(root) {}

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

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

};

//

// MarkFromRootsTask

//

// This task marks from all the roots to all live

// objects.

//

//

class MarkFromRootsTask : public GCTask {

 public:

  enum RootType {

    universe              = 1,

    jni_handles           = 2,

    threads               = 3,

    object_synchronizer   = 4,

    flat_profiler         = 5,

    management            = 6,

    jvmti                 = 7,

    system_dictionary     = 8,

    vm_symbols            = 9,

    reference_processing  = 10

  };

 private:

  RootType _root_type;

 public:

  MarkFromRootsTask(RootType value) : _root_type(value) {}

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

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

};

//

// RefProcTaskProxy

//

// This task is used as a proxy to parallel reference processing tasks .

//

class RefProcTaskProxy : public GCTask {

  typedef AbstractRefProcTaskExecutor::ProcessTask ProcessTask;

  ProcessTask & _rp_task;

  uint          _work_id;

public:

  RefProcTaskProxy(ProcessTask & rp_task, uint work_id)

    : _rp_task(rp_task),

      _work_id(work_id)

  { }

private:

  virtual char* name() { return (char *)"Process referents by policy in parallel"; }

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

};

//

// RefEnqueueTaskProxy

//

// This task is used as a proxy to parallel reference processing tasks .

//

class RefEnqueueTaskProxy: public GCTask {

  typedef AbstractRefProcTaskExecutor::EnqueueTask EnqueueTask;

  EnqueueTask& _enq_task;

  uint         _work_id;

public:

  RefEnqueueTaskProxy(EnqueueTask& enq_task, uint work_id)

    : _enq_task(enq_task),

      _work_id(work_id)

  { }

  virtual char* name() { return (char *)"Enqueue reference objects in parallel"; }

  virtual void do_it(GCTaskManager* manager, uint which)

  {

    _enq_task.work(_work_id);

  }

};

//

// RefProcTaskExecutor

//

// Task executor is an interface for the reference processor to run

// tasks using GCTaskManager.

//

class RefProcTaskExecutor: public AbstractRefProcTaskExecutor {

  virtual void execute(ProcessTask& task);

  virtual void execute(EnqueueTask& task);

};

//

// StealMarkingTask

//

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

//

class StealMarkingTask : public GCTask {

 private:

   ParallelTaskTerminator* const _terminator;

 private:

 public:

  char* name() { return (char *)"steal-marking-task"; }

  StealMarkingTask(ParallelTaskTerminator* t);

  ParallelTaskTerminator* terminator() { return _terminator; }

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

};

//

// StealChunkCompactionTask

//

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

//

class StealChunkCompactionTask : public GCTask {

 private:

   ParallelTaskTerminator* const _terminator;

 public:

  StealChunkCompactionTask(ParallelTaskTerminator* t);

  char* name() { return (char *)"steal-chunk-task"; }

  ParallelTaskTerminator* terminator() { return _terminator; }

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

};

//

// UpdateDensePrefixTask

//

// This task is used to update the dense prefix

// of a space.

//

class UpdateDensePrefixTask : public GCTask {

 private:

  PSParallelCompact::SpaceId _space_id;

  size_t _chunk_index_start;

  size_t _chunk_index_end;

 public:

  char* name() { return (char *)"update-dense_prefix-task"; }

  UpdateDensePrefixTask(PSParallelCompact::SpaceId space_id,

                        size_t chunk_index_start,

                        size_t chunk_index_end);

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

};

//

// DrainStacksCompactionTask

//

// This task processes chunks that have been added to the stacks of each

// compaction manager.

//

// Trying to use one draining thread does not work because there are no

// guarantees about which task will be picked up by which thread.  For example,

// if thread A gets all the preloaded chunks, thread A may not get a draining

// task (they may all be done by other threads).

//

class DrainStacksCompactionTask : public GCTask {

 public:

  char* name() { return (char *)"drain-chunk-task"; }

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

};