1 /*
2 * Copyright (c) 2015, 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/g1CollectorPolicy.hpp"
28 #include "gc/g1/heapRegion.hpp"
29 #include "gc/g1/heapRegion.inline.hpp"
30 #include "gc/g1/heapRegionRemSet.hpp"
31 #include "gc/g1/youngList.hpp"
32 #include "logging/log.hpp"
33 #include "utilities/ostream.hpp"
34
35 YoungList::YoungList(G1CollectedHeap* g1h) :
36 _g1h(g1h), _head(NULL), _length(0),
37 _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0) {
38 guarantee(check_list_empty(), "just making sure...");
39 }
40
41 void YoungList::push_region(HeapRegion *hr) {
42 assert(!hr->is_young(), "should not already be young");
43 assert(hr->get_next_young_region() == NULL, "cause it should!");
44
45 hr->set_next_young_region(_head);
46 _head = hr;
47
48 _g1h->g1_policy()->set_region_eden(hr, (int) _length);
49 ++_length;
50 }
51
52 void YoungList::add_survivor_region(HeapRegion* hr) {
53 assert(hr->is_survivor(), "should be flagged as survivor region");
54 assert(hr->get_next_young_region() == NULL, "cause it should!");
55
56 hr->set_next_young_region(_survivor_head);
57 if (_survivor_head == NULL) {
58 _survivor_tail = hr;
59 }
60 _survivor_head = hr;
61 ++_survivor_length;
62 }
63
64 void YoungList::empty_list(HeapRegion* list) {
65 while (list != NULL) {
66 HeapRegion* next = list->get_next_young_region();
67 list->set_next_young_region(NULL);
68 list->uninstall_surv_rate_group();
69 // This is called before a Full GC and all the non-empty /
70 // non-humongous regions at the end of the Full GC will end up as
71 // old anyway.
72 list->set_old();
73 list = next;
74 }
75 }
76
77 void YoungList::empty_list() {
78 assert(check_list_well_formed(), "young list should be well formed");
79
80 empty_list(_head);
81 _head = NULL;
82 _length = 0;
83
84 empty_list(_survivor_head);
85 _survivor_head = NULL;
86 _survivor_tail = NULL;
87 _survivor_length = 0;
88
89 assert(check_list_empty(), "just making sure...");
90 }
91
92 bool YoungList::check_list_well_formed() {
93 bool ret = true;
94
95 uint length = 0;
96 HeapRegion* curr = _head;
97 HeapRegion* last = NULL;
98 while (curr != NULL) {
99 if (!curr->is_young()) {
100 log_error(gc, verify)("### YOUNG REGION " PTR_FORMAT "-" PTR_FORMAT " "
101 "incorrectly tagged (y: %d, surv: %d)",
102 p2i(curr->bottom()), p2i(curr->end()),
103 curr->is_young(), curr->is_survivor());
104 ret = false;
105 }
106 ++length;
107 last = curr;
108 curr = curr->get_next_young_region();
109 }
110 ret = ret && (length == _length);
111
112 if (!ret) {
113 log_error(gc, verify)("### YOUNG LIST seems not well formed!");
114 log_error(gc, verify)("### list has %u entries, _length is %u", length, _length);
115 }
116
117 return ret;
118 }
119
120 bool YoungList::check_list_empty() {
121 bool ret = true;
122
123 if (_length != 0) {
124 log_error(gc, verify)("### YOUNG LIST should have 0 length, not %u", _length);
125 ret = false;
126 }
127 if (_head != NULL) {
128 log_error(gc, verify)("### YOUNG LIST does not have a NULL head");
129 ret = false;
130 }
131 if (!ret) {
132 log_error(gc, verify)("### YOUNG LIST does not seem empty");
133 }
134
135 return ret;
136 }
137
138 void
139 YoungList::reset_auxilary_lists() {
140 guarantee( is_empty(), "young list should be empty" );
141 assert(check_list_well_formed(), "young list should be well formed");
142
143 // Add survivor regions to SurvRateGroup.
144 _g1h->g1_policy()->note_start_adding_survivor_regions();
145 _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
146
147 int young_index_in_cset = 0;
148 for (HeapRegion* curr = _survivor_head;
149 curr != NULL;
150 curr = curr->get_next_young_region()) {
151 _g1h->g1_policy()->set_region_survivor(curr, young_index_in_cset);
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->g1_policy()->add_region_to_incremental_cset_rhs(curr);
157 young_index_in_cset += 1;
158 }
159 assert((uint) young_index_in_cset == _survivor_length, "post-condition");
160 _g1h->g1_policy()->note_stop_adding_survivor_regions();
161
162 _head = _survivor_head;
163 _length = _survivor_length;
164 if (_survivor_head != NULL) {
165 assert(_survivor_tail != NULL, "cause it shouldn't be");
166 assert(_survivor_length > 0, "invariant");
167 _survivor_tail->set_next_young_region(NULL);
168 }
169
170 // Don't clear the survivor list handles until the start of
171 // the next evacuation pause - we need it in order to re-tag
172 // the survivor regions from this evacuation pause as 'young'
173 // at the start of the next.
174
175 _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
176
177 assert(check_list_well_formed(), "young list should be well formed");
178 }
179
180 void YoungList::print() {
181 HeapRegion* lists[] = {_head, _survivor_head};
182 const char* names[] = {"YOUNG", "SURVIVOR"};
183
184 for (uint list = 0; list < ARRAY_SIZE(lists); ++list) {
185 tty->print_cr("%s LIST CONTENTS", names[list]);
186 HeapRegion *curr = lists[list];
187 if (curr == NULL) {
188 tty->print_cr(" empty");
189 }
190 while (curr != NULL) {
191 tty->print_cr(" " HR_FORMAT ", P: " PTR_FORMAT ", N: " PTR_FORMAT ", age: %4d",
192 HR_FORMAT_PARAMS(curr),
193 p2i(curr->prev_top_at_mark_start()),
194 p2i(curr->next_top_at_mark_start()),
195 curr->age_in_surv_rate_group_cond());
196 curr = curr->get_next_young_region();
197 }
198 }
199
200 tty->cr();
201 }