1/*
2 * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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).
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23 */
24
25#ifndef SHARE_GC_PARALLEL_IMMUTABLESPACE_HPP
26#define SHARE_GC_PARALLEL_IMMUTABLESPACE_HPP
27
28#include "memory/iterator.hpp"
29
30// An ImmutableSpace is a viewport into a contiguous range
31// (or subrange) of previously allocated objects.
32
33// Invariant: bottom() and end() are on page_size boundaries and
34// bottom() <= end()
35
36class ImmutableSpace: public CHeapObj<mtGC> {
37 friend class VMStructs;
38 protected:
39 HeapWord* _bottom;
40 HeapWord* _end;
41
42 public:
43 ImmutableSpace() { _bottom = NULL; _end = NULL; }
44 HeapWord* bottom() const { return _bottom; }
45 HeapWord* end() const { return _end; }
46
47 MemRegion region() const { return MemRegion(bottom(), end()); }
48
49 // Initialization
50 void initialize(MemRegion mr);
51
52 bool contains(const void* p) const { return _bottom <= p && p < _end; }
53
54 // Size computations. Sizes are in bytes.
55 size_t capacity_in_bytes() const { return capacity_in_words() * HeapWordSize; }
56
57 // Size computations. Sizes are in heapwords.
58 size_t capacity_in_words() const { return pointer_delta(end(), bottom()); }
59 virtual size_t capacity_in_words(Thread*) const { return capacity_in_words(); }
60
61 // Iteration.
62 virtual void oop_iterate(OopIterateClosure* cl);
63 virtual void object_iterate(ObjectClosure* cl);
64
65 // Debugging
66 virtual void print() const PRODUCT_RETURN;
67 virtual void print_short() const PRODUCT_RETURN;
68 virtual void verify();
69};
70
71#endif // SHARE_GC_PARALLEL_IMMUTABLESPACE_HPP
72