/*

 * 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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 */

#include "gc/cms/concurrentMarkSweepGeneration.hpp"

#include "gc/shared/gcCause.hpp"

#include "gc/shared/gcId.hpp"

#include "gc/shared/gcVMOperations.hpp"

#include "runtime/vmOperations.hpp"

// The VM_CMS_Operation is slightly different from

// a VM_GC_Operation -- and would not have subclassed easily

// to VM_GC_Operation without several changes to VM_GC_Operation.

// To minimize the changes, we have replicated some of the VM_GC_Operation

// functionality here. We will consolidate that back by doing subclassing

// as appropriate in Dolphin.

//

//  VM_Operation

//    VM_CMS_Operation

//    - implements the common portion of work done in support

//      of CMS' stop-world phases (initial mark and remark).

//

//      VM_CMS_Initial_Mark

//      VM_CMS_Final_Mark

//

// Forward decl.

class CMSCollector;

class VM_CMS_Operation: public VM_Operation {

 protected:

  CMSCollector*  _collector;                 // associated collector

  bool           _prologue_succeeded;     // whether doit_prologue succeeded

  uint           _gc_id;

  bool lost_race() const;

 public:

  VM_CMS_Operation(CMSCollector* collector):

    _collector(collector),

    _prologue_succeeded(false),

    _gc_id(GCId::current()) {}

  ~VM_CMS_Operation() {}

  // The legal collector state for executing this CMS op.

  virtual const CMSCollector::CollectorState legal_state() const = 0;

  // Whether the pending list lock needs to be held

  virtual const bool needs_pending_list_lock() const = 0;

  // Execute operations in the context of the caller,

  // prior to execution of the vm operation itself.

  virtual bool doit_prologue();

  // Execute operations in the context of the caller,

  // following completion of the vm operation.

  virtual void doit_epilogue();

  virtual bool evaluate_at_safepoint() const { return true; }

  virtual bool is_cheap_allocated() const { return false; }

  virtual bool allow_nested_vm_operations() const  { return false; }

  bool prologue_succeeded() const { return _prologue_succeeded; }

  void verify_before_gc();

  void verify_after_gc();

};

// VM_CMS_Operation for the initial marking phase of CMS.

class VM_CMS_Initial_Mark: public VM_CMS_Operation {

 public:

  VM_CMS_Initial_Mark(CMSCollector* _collector) :

    VM_CMS_Operation(_collector) {}

  virtual VMOp_Type type() const { return VMOp_CMS_Initial_Mark; }

  virtual void doit();

  virtual const CMSCollector::CollectorState legal_state() const {

    return CMSCollector::InitialMarking;

  }

  virtual const bool needs_pending_list_lock() const {

    return false;

  }

};

// VM_CMS_Operation for the final remark phase of CMS.

class VM_CMS_Final_Remark: public VM_CMS_Operation {

 public:

  VM_CMS_Final_Remark(CMSCollector* _collector) :

    VM_CMS_Operation(_collector) {}

  virtual VMOp_Type type() const { return VMOp_CMS_Final_Remark; }

  virtual void doit();

  virtual const CMSCollector::CollectorState legal_state() const {

    return CMSCollector::FinalMarking;

  }

  virtual const bool needs_pending_list_lock() const {

    return true;

  }

};

// VM operation to invoke a concurrent collection of the heap as a

// GenCollectedHeap heap.

class VM_GenCollectFullConcurrent: public VM_GC_Operation {

 public:

  VM_GenCollectFullConcurrent(uint gc_count_before,

                              uint full_gc_count_before,

                              GCCause::Cause gc_cause)

    : VM_GC_Operation(gc_count_before, gc_cause, full_gc_count_before, true /* full */)

  {

    assert(FullGCCount_lock != NULL, "Error");

  }

  ~VM_GenCollectFullConcurrent() {}

  virtual VMOp_Type type() const { return VMOp_GenCollectFullConcurrent; }

  virtual void doit();

  virtual void doit_epilogue();

  virtual bool is_cheap_allocated() const { return false; }

  virtual bool evaluate_at_safepoint() const;

};