/*

 * Copyright (c) 2016, 2017, 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.

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#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP

#define SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP

#include "oops/oopsHierarchy.hpp"

#include "memory/allocation.hpp"

class G1CMTask;

// Helper class to mark through large objArrays during marking in an efficient way.

// Instead of pushing large object arrays, we push continuations onto the

// mark stack. These continuations are identified by having their LSB set.

// This allows incremental processing of large objects.

class G1CMObjArrayProcessor VALUE_OBJ_CLASS_SPEC {

private:

  // Reference to the task for doing the actual work.

  G1CMTask* _task;

  // Push the continuation at the given address onto the mark stack.

  void push_array_slice(HeapWord* addr);

  // Process (apply the closure) on the given continuation of the given objArray.

  size_t process_array_slice(objArrayOop const obj, HeapWord* start_from, size_t remaining);

public:

  static bool should_be_sliced(oop obj);

  G1CMObjArrayProcessor(G1CMTask* task) : _task(task) {

  }

  // Process the given continuation. Returns the number of words scanned.

  size_t process_slice(HeapWord* slice);

  // Start processing the given objArrayOop by scanning the header and pushing its

  // continuation.

  size_t process_obj(oop obj);

};

#endif /* SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP */