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