1 /*
2 * Copyright (c) 2015, 2016, 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 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.hpp"
27 #include "gc/g1/g1CollectionSet.hpp"
28 #include "gc/g1/g1Policy.hpp"
29 #include "gc/g1/heapRegion.hpp"
30 #include "gc/g1/heapRegion.inline.hpp"
31 #include "gc/g1/heapRegionRemSet.hpp"
32 #include "gc/g1/youngList.hpp"
33 #include "logging/log.hpp"
34 #include "utilities/ostream.hpp"
35
36 YoungList::YoungList(G1CollectedHeap* g1h) :
37 _g1h(g1h), _head(NULL), _length(0),
38 _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0) {
39 guarantee(check_list_empty(), "just making sure...");
40 }
41
42 void YoungList::push_region(HeapRegion *hr) {
43 assert(!hr->is_young(), "should not already be young");
44 assert(hr->get_next_young_region() == NULL, "cause it should!");
45
46 hr->set_next_young_region(_head);
47 _head = hr;
48
49 _g1h->g1_policy()->set_region_eden(hr);
50 ++_length;
51 }
52
53 void YoungList::add_survivor_region(HeapRegion* hr) {
54 assert(hr->is_survivor(), "should be flagged as survivor region");
55 assert(hr->get_next_young_region() == NULL, "cause it should!");
56
57 hr->set_next_young_region(_survivor_head);
58 if (_survivor_head == NULL) {
59 _survivor_tail = hr;
60 }
61 _survivor_head = hr;
62 ++_survivor_length;
63 }
64
65 void YoungList::empty_list(HeapRegion* list) {
66 while (list != NULL) {
67 HeapRegion* next = list->get_next_young_region();
68 list->set_next_young_region(NULL);
69 list->uninstall_surv_rate_group();
70 // This is called before a Full GC and all the non-empty /
71 // non-humongous regions at the end of the Full GC will end up as
72 // old anyway.
73 list->set_old();
74 list = next;
75 }
76 }
77
78 void YoungList::empty_list() {
79 assert(check_list_well_formed(), "young list should be well formed");
80
81 empty_list(_head);
82 _head = NULL;
83 _length = 0;
84
85 empty_list(_survivor_head);
86 _survivor_head = NULL;
87 _survivor_tail = NULL;
88 _survivor_length = 0;
89
90 assert(check_list_empty(), "just making sure...");
91 }
92
93 bool YoungList::check_list_well_formed() {
94 bool ret = true;
95
96 uint length = 0;
97 HeapRegion* curr = _head;
98 HeapRegion* last = NULL;
99 while (curr != NULL) {
100 if (!curr->is_young()) {
101 log_error(gc, verify)("### YOUNG REGION " PTR_FORMAT "-" PTR_FORMAT " "
102 "incorrectly tagged (y: %d, surv: %d)",
103 p2i(curr->bottom()), p2i(curr->end()),
104 curr->is_young(), curr->is_survivor());
105 ret = false;
106 }
107 ++length;
108 last = curr;
109 curr = curr->get_next_young_region();
110 }
111 ret = ret && (length == _length);
112
113 if (!ret) {
114 log_error(gc, verify)("### YOUNG LIST seems not well formed!");
115 log_error(gc, verify)("### list has %u entries, _length is %u", length, _length);
116 }
117
118 return ret;
119 }
120
121 bool YoungList::check_list_empty() {
122 bool ret = true;
123
124 if (_length != 0) {
125 log_error(gc, verify)("### YOUNG LIST should have 0 length, not %u", _length);
126 ret = false;
127 }
128 if (_head != NULL) {
129 log_error(gc, verify)("### YOUNG LIST does not have a NULL head");
130 ret = false;
131 }
132 if (!ret) {
133 log_error(gc, verify)("### YOUNG LIST does not seem empty");
134 }
135
136 return ret;
137 }
138
139 void
140 YoungList::reset_auxilary_lists() {
141 guarantee( is_empty(), "young list should be empty" );
142 assert(check_list_well_formed(), "young list should be well formed");
143
144 // Add survivor regions to SurvRateGroup.
145 _g1h->g1_policy()->note_start_adding_survivor_regions();
146 _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
147
148 for (HeapRegion* curr = _survivor_head;
149 curr != NULL;
150 curr = curr->get_next_young_region()) {
151 _g1h->g1_policy()->set_region_survivor(curr);
152
153 // The region is a non-empty survivor so let's add it to
154 // the incremental collection set for the next evacuation
155 // pause.
156 _g1h->collection_set()->add_survivor_regions(curr);
157 }
158 _g1h->g1_policy()->note_stop_adding_survivor_regions();
159
160 _head = _survivor_head;
161 _length = _survivor_length;
162 if (_survivor_head != NULL) {
163 assert(_survivor_tail != NULL, "cause it shouldn't be");
164 assert(_survivor_length > 0, "invariant");
165 _survivor_tail->set_next_young_region(NULL);
166 }
167
168 // Don't clear the survivor list handles until the start of
169 // the next evacuation pause - we need it in order to re-tag
170 // the survivor regions from this evacuation pause as 'young'
171 // at the start of the next.
172
173 _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
174
175 assert(check_list_well_formed(), "young list should be well formed");
176 }
177
178 void YoungList::print() {
179 HeapRegion* lists[] = {_head, _survivor_head};
180 const char* names[] = {"YOUNG", "SURVIVOR"};
181
182 for (uint list = 0; list < ARRAY_SIZE(lists); ++list) {
183 tty->print_cr("%s LIST CONTENTS", names[list]);
184 HeapRegion *curr = lists[list];
185 if (curr == NULL) {
186 tty->print_cr(" empty");
187 }
188 while (curr != NULL) {
189 tty->print_cr(" " HR_FORMAT ", P: " PTR_FORMAT ", N: " PTR_FORMAT ", age: %4d",
190 HR_FORMAT_PARAMS(curr),
191 p2i(curr->prev_top_at_mark_start()),
192 p2i(curr->next_top_at_mark_start()),
193 curr->age_in_surv_rate_group_cond());
194 curr = curr->get_next_young_region();
195 }
196 }
197
198 tty->cr();
199 }