1 /*
2 * Copyright (c) 2001, 2018, 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.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_GC_CMS_CMSCARDTABLE_HPP
26 #define SHARE_GC_CMS_CMSCARDTABLE_HPP
27
28 #include "gc/shared/cardTableRS.hpp"
29 #include "utilities/globalDefinitions.hpp"
30
31 class DirtyCardToOopClosure;
32 class MemRegion;
33 class OopsInGenClosure;
34 class Space;
35
36 class CMSCardTable : public CardTableRS {
37 private:
38 // Returns the number of chunks necessary to cover "mr".
39 size_t chunks_to_cover(MemRegion mr);
40
41 // Returns the index of the chunk in a stride which
42 // covers the given address.
43 uintptr_t addr_to_chunk_index(const void* addr);
44
45 // Initializes "lowest_non_clean" to point to the array for the region
46 // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk
47 // index of the corresponding to the first element of that array.
48 // Ensures that these arrays are of sufficient size, allocating if necessary.
49 // May be called by several threads concurrently.
50 void get_LNC_array_for_space(Space* sp,
51 jbyte**& lowest_non_clean,
52 uintptr_t& lowest_non_clean_base_chunk_index,
53 size_t& lowest_non_clean_chunk_size);
54
55 // Apply cl, which must either itself apply dcto_cl or be dcto_cl,
56 // to the cards in the stride (of n_strides) within the given space.
57 void process_stride(Space* sp,
58 MemRegion used,
59 jint stride, int n_strides,
60 OopsInGenClosure* cl,
61 CardTableRS* ct,
62 jbyte** lowest_non_clean,
63 uintptr_t lowest_non_clean_base_chunk_index,
64 size_t lowest_non_clean_chunk_size);
65
66 // Makes sure that chunk boundaries are handled appropriately, by
67 // adjusting the min_done of dcto_cl, and by using a special card-table
68 // value to indicate how min_done should be set.
69 void process_chunk_boundaries(Space* sp,
70 DirtyCardToOopClosure* dcto_cl,
71 MemRegion chunk_mr,
72 MemRegion used,
73 jbyte** lowest_non_clean,
74 uintptr_t lowest_non_clean_base_chunk_index,
75 size_t lowest_non_clean_chunk_size);
76
77 virtual void verify_used_region_at_save_marks(Space* sp) const NOT_DEBUG_RETURN;
78
79 protected:
80 // Work method used to implement non_clean_card_iterate_possibly_parallel()
81 // above in the parallel case.
82 virtual void non_clean_card_iterate_parallel_work(Space* sp, MemRegion mr,
83 OopsInGenClosure* cl, CardTableRS* ct,
84 uint n_threads);
85
86 public:
87 CMSCardTable(MemRegion whole_heap);
88 };
89
90 #endif // SHARE_GC_CMS_CMSCARDTABLE_HPP