1/*
2 * Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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23 */
24
25#ifndef SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP
26#define SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP
27
28#include "oops/oopsHierarchy.hpp"
29#include "memory/allocation.hpp"
30
31class G1CMTask;
32
33// Helper class to mark through large objArrays during marking in an efficient way.
34// Instead of pushing large object arrays, we push continuations onto the
35// mark stack. These continuations are identified by having their LSB set.
36// This allows incremental processing of large objects.
37class G1CMObjArrayProcessor VALUE_OBJ_CLASS_SPEC {
38private:
39  // Reference to the task for doing the actual work.
40  G1CMTask* _task;
41
42  // Push the continuation at the given address onto the mark stack.
43  void push_array_slice(HeapWord* addr);
44
45  // Process (apply the closure) on the given continuation of the given objArray.
46  size_t process_array_slice(objArrayOop const obj, HeapWord* start_from, size_t remaining);
47public:
48  static bool should_be_sliced(oop obj);
49
50  G1CMObjArrayProcessor(G1CMTask* task) : _task(task) {
51  }
52
53  // Process the given continuation. Returns the number of words scanned.
54  size_t process_slice(HeapWord* slice);
55  // Start processing the given objArrayOop by scanning the header and pushing its
56  // continuation.
57  size_t process_obj(oop obj);
58};
59
60#endif /* SHARE_VM_GC_G1_G1CONCURRENTMARKOBJARRAYPROCESSOR_HPP */
61