1 /*
2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2020, Red Hat, Inc. and/or its affiliates.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
27 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
28
29 #include "memory/memRegion.hpp"
30 #include "runtime/atomic.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33 class ShenandoahMarkBitMap {
34 public:
35 typedef size_t idx_t; // Type used for bit and word indices.
36 typedef uintptr_t bm_word_t; // Element type of array that represents the
37 // bitmap, with BitsPerWord bits per element.
38
39 private:
40 // Values for get_next_bit_impl flip parameter.
41 static const bm_word_t find_ones_flip = 0;
42 static const bm_word_t find_zeros_flip = ~(bm_word_t)0;
43
44 int const _shift;
45 MemRegion _covered;
46
47 bm_word_t* _map; // First word in bitmap
142 ShenandoahMarkBitMap(MemRegion heap, MemRegion storage);
143
144 // Mark word as 'strong' if it hasn't been marked strong yet.
145 // Return true if the word has been marked strong, false if it has already been
146 // marked strong or if another thread has beat us by marking it
147 // strong.
148 // Words that have been marked final before or by a concurrent thread will be
149 // upgraded to strong. In this case, this method also returns true.
150 inline bool mark_strong(HeapWord* w, bool& was_upgraded);
151
152 // Mark word as 'weak' if it hasn't been marked weak or strong yet.
153 // Return true if the word has been marked weak, false if it has already been
154 // marked strong or weak or if another thread has beat us by marking it
155 // strong or weak.
156 inline bool mark_weak(HeapWord* heap_addr);
157
158 inline bool is_marked(HeapWord* addr) const;
159 inline bool is_marked_strong(HeapWord* w) const;
160 inline bool is_marked_weak(HeapWord* addr) const;
161
162 // Return the address corresponding to the next marked bit at or after
163 // "addr", and before "limit", if "limit" is non-null. If there is no
164 // such bit, returns "limit" if that is non-null, or else "endWord()".
165 HeapWord* get_next_marked_addr(const HeapWord* addr,
166 const HeapWord* limit) const;
167
168 bm_word_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const;
169 void clear_range_within_word (idx_t beg, idx_t end);
170 void clear_range (idx_t beg, idx_t end);
171 void clear_range_large(MemRegion mr);
172
173 void clear_range_of_words(idx_t beg, idx_t end);
174 void clear_large_range_of_words(idx_t beg, idx_t end);
175 static void clear_range_of_words(bm_word_t* map, idx_t beg, idx_t end);
176
177 };
178
179 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
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1 /*
2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2020, Red Hat, Inc. and/or its affiliates.
4 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
27 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
28 #define SHARE_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
29
30 #include "memory/memRegion.hpp"
31 #include "runtime/atomic.hpp"
32 #include "utilities/globalDefinitions.hpp"
33
34 class ShenandoahMarkBitMap {
35 public:
36 typedef size_t idx_t; // Type used for bit and word indices.
37 typedef uintptr_t bm_word_t; // Element type of array that represents the
38 // bitmap, with BitsPerWord bits per element.
39
40 private:
41 // Values for get_next_bit_impl flip parameter.
42 static const bm_word_t find_ones_flip = 0;
43 static const bm_word_t find_zeros_flip = ~(bm_word_t)0;
44
45 int const _shift;
46 MemRegion _covered;
47
48 bm_word_t* _map; // First word in bitmap
143 ShenandoahMarkBitMap(MemRegion heap, MemRegion storage);
144
145 // Mark word as 'strong' if it hasn't been marked strong yet.
146 // Return true if the word has been marked strong, false if it has already been
147 // marked strong or if another thread has beat us by marking it
148 // strong.
149 // Words that have been marked final before or by a concurrent thread will be
150 // upgraded to strong. In this case, this method also returns true.
151 inline bool mark_strong(HeapWord* w, bool& was_upgraded);
152
153 // Mark word as 'weak' if it hasn't been marked weak or strong yet.
154 // Return true if the word has been marked weak, false if it has already been
155 // marked strong or weak or if another thread has beat us by marking it
156 // strong or weak.
157 inline bool mark_weak(HeapWord* heap_addr);
158
159 inline bool is_marked(HeapWord* addr) const;
160 inline bool is_marked_strong(HeapWord* w) const;
161 inline bool is_marked_weak(HeapWord* addr) const;
162
163 bool is_bitmap_clear_range(const HeapWord* start, const HeapWord* end) const;
164
165 // Return the address corresponding to the next marked bit at or after
166 // "addr", and before "limit", if "limit" is non-null. If there is no
167 // such bit, returns "limit" if that is non-null, or else "endWord()".
168 HeapWord* get_next_marked_addr(const HeapWord* addr,
169 const HeapWord* limit) const;
170
171 bm_word_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const;
172 void clear_range_within_word (idx_t beg, idx_t end);
173 void clear_range (idx_t beg, idx_t end);
174 void clear_range_large(MemRegion mr);
175
176 void clear_range_of_words(idx_t beg, idx_t end);
177 void clear_large_range_of_words(idx_t beg, idx_t end);
178 static void clear_range_of_words(bm_word_t* map, idx_t beg, idx_t end);
179
180 };
181
182 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHMARKBITMAP_HPP
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