1 /*
2 * Copyright (c) 2001, 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.
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_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP
26 #define SHARE_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP
27
28 #include "gc/shared/cardTableModRefBS.hpp"
29
30 class MutableSpace;
31 class ObjectStartArray;
32 class PSPromotionManager;
33 class GCTaskQueue;
34
35 class CardTableExtension : public CardTableModRefBS {
36 private:
37 // Support methods for resizing the card table.
38 // resize_commit_uncommit() returns true if the pages were committed or
39 // uncommitted
40 bool resize_commit_uncommit(int changed_region, MemRegion new_region);
41 void resize_update_card_table_entries(int changed_region,
42 MemRegion new_region);
43 void resize_update_committed_table(int changed_region, MemRegion new_region);
44 void resize_update_covered_table(int changed_region, MemRegion new_region);
45
46 protected:
47
48 static void verify_all_young_refs_precise_helper(MemRegion mr);
49
50 public:
51 enum ExtendedCardValue {
52 youngergen_card = CardTableModRefBS::CT_MR_BS_last_reserved + 1,
53 verify_card = CardTableModRefBS::CT_MR_BS_last_reserved + 5
54 };
55
56 CardTableExtension(MemRegion whole_heap) :
57 CardTableModRefBS(
58 whole_heap,
59 BarrierSet::FakeRtti(BarrierSet::CardTableExtension))
60 { }
61
62 // Scavenge support
63 void scavenge_contents_parallel(ObjectStartArray* start_array,
64 MutableSpace* sp,
65 HeapWord* space_top,
66 PSPromotionManager* pm,
67 uint stripe_number,
68 uint stripe_total);
69
70 // Verification
71 static void verify_all_young_refs_imprecise();
72 static void verify_all_young_refs_precise();
73
74 bool addr_is_marked_imprecise(void *addr);
75 bool addr_is_marked_precise(void *addr);
76
77 void set_card_newgen(void* addr) { jbyte* p = byte_for(addr); *p = verify_card; }
78
79 // Testers for entries
80 static bool card_is_dirty(int value) { return value == dirty_card; }
81 static bool card_is_newgen(int value) { return value == youngergen_card; }
82 static bool card_is_clean(int value) { return value == clean_card; }
83 static bool card_is_verify(int value) { return value == verify_card; }
84
85 // Card marking
86 void inline_write_ref_field_gc(void* field, oop new_val) {
87 jbyte* byte = byte_for(field);
88 *byte = youngergen_card;
89 }
90
91 // Adaptive size policy support
92 // Allows adjustment of the base and size of the covered regions
93 void resize_covered_region(MemRegion new_region);
94 // Finds the covered region to resize based on the start address
95 // of the covered regions.
96 void resize_covered_region_by_start(MemRegion new_region);
97 // Finds the covered region to resize based on the end address
98 // of the covered regions.
99 void resize_covered_region_by_end(int changed_region, MemRegion new_region);
100 // Finds the lowest start address of a covered region that is
101 // previous (i.e., lower index) to the covered region with index "ind".
102 HeapWord* lowest_prev_committed_start(int ind) const;
103
104 #ifdef ASSERT
105
106 bool is_valid_card_address(jbyte* addr) {
107 return (addr >= _byte_map) && (addr < _byte_map + _byte_map_size);
108 }
109
110 #endif // ASSERT
111 };
112
113 template<>
114 struct BarrierSet::GetName<CardTableExtension> {
115 static const BarrierSet::Name value = BarrierSet::CardTableExtension;
116 };
117
118 template<>
119 struct BarrierSet::GetType<BarrierSet::CardTableExtension> {
120 typedef ::CardTableExtension type;
121 };
122
123 #endif // SHARE_VM_GC_PARALLEL_CARDTABLEEXTENSION_HPP