1 /*
2 * Copyright (c) 2016, 2020, Red Hat, Inc. 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_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/virtualspace.hpp"
30 #include "gc/shenandoah/shenandoahHeap.hpp"
31 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
32 #include "gc/shenandoah/shenandoahPadding.hpp"
33
34 class ShenandoahCollectionSet : public CHeapObj<mtGC> {
35 friend class ShenandoahHeap;
36 private:
37 size_t const _map_size;
38 size_t const _region_size_bytes_shift;
39 ReservedSpace _map_space;
40 char* const _cset_map;
41 // Bias cset map's base address for fast test if an oop is in cset
42 char* const _biased_cset_map;
43
44 ShenandoahHeap* const _heap;
45
46 bool _has_old_regions;
47 size_t _garbage;
48 size_t _used;
49 size_t _live;
50 size_t _region_count;
51 size_t _immediate_trash;
52
53 size_t _young_bytes_to_evacuate;
54 size_t _young_bytes_to_promote;
55 size_t _old_bytes_to_evacuate;
56
57 size_t _young_region_count;
58 size_t _old_region_count;
59
60 size_t _old_garbage; // How many bytes of old garbage are present in a mixed collection set?
61
62 bool* _preselected_regions; // Points to array identifying which tenure-age regions have been preselected
63 // for inclusion in collection set. This field is only valid during brief
64 // spans of time while collection set is being constructed.
65
66 shenandoah_padding(0);
67 volatile size_t _current_index;
68 shenandoah_padding(1);
69
70 public:
71 ShenandoahCollectionSet(ShenandoahHeap* heap, ReservedSpace space, char* heap_base);
72
73 // Add region to collection set
74 void add_region(ShenandoahHeapRegion* r);
75
76 // MT version
77 ShenandoahHeapRegion* claim_next();
78
79 // Single-thread version
80 ShenandoahHeapRegion* next();
81
82 size_t count() const { return _region_count; }
83 bool is_empty() const { return _region_count == 0; }
84
85 void clear_current_index() {
86 _current_index = 0;
87 }
88
89 inline bool is_in(ShenandoahHeapRegion* r) const;
90 inline bool is_in(size_t region_idx) const;
91 inline bool is_in(oop obj) const;
92 inline bool is_in_loc(void* loc) const;
93
94 void print_on(outputStream* out) const;
95
96 inline size_t get_immediate_trash();
97 inline void set_immediate_trash(size_t immediate_trash);
98
99 // This represents total amount of work to be performed by evacuation, including evacuations to young, to old,
100 // and promotions from young to old. This equals get_young_bytes_reserved_for_evacuation() plus
101 // get_old_bytes_reserved_for_evacuation().
102 inline size_t get_bytes_reserved_for_evacuation();
103
104 // It is not known how many of these bytes will be promoted.
105 inline size_t get_young_bytes_reserved_for_evacuation();
106
107 inline size_t get_old_bytes_reserved_for_evacuation();
108
109 inline size_t get_young_bytes_to_be_promoted();
110
111 inline size_t get_old_region_count();
112
113 inline size_t get_young_region_count();
114
115 inline size_t get_old_garbage();
116
117 void establish_preselected(bool *preselected) { _preselected_regions = preselected; }
118 void abandon_preselected() { _preselected_regions = nullptr; }
119 bool is_preselected(size_t region_idx) { return (_preselected_regions != nullptr) && _preselected_regions[region_idx]; }
120
121 bool has_old_regions() const { return _has_old_regions; }
122 size_t used() const { return _used; }
123 size_t live() const { return _live; }
124 size_t garbage() const { return _garbage; }
125
126 void clear();
127
128 private:
129 char* map_address() const {
130 return _cset_map;
131 }
132 char* biased_map_address() const {
133 return _biased_cset_map;
134 }
135 };
136
137 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP