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/growableArray.hpp"
35 #include "utilities/ostream.hpp"
36
37 YoungList::YoungList(G1CollectedHeap* g1h) :
38 _g1h(g1h),
39 _survivor_regions(new (ResourceObj::C_HEAP, mtGC) GrowableArray<HeapRegion*>(8, true, mtGC)),
40 _head(NULL),
41 _length(0) {
42 guarantee(check_list_empty(), "just making sure...");
43 }
44
45 void YoungList::push_region(HeapRegion *hr) {
46 assert(!hr->is_young(), "should not already be young");
47 assert(hr->get_next_young_region() == NULL, "cause it should!");
48
49 hr->set_next_young_region(_head);
50 _head = hr;
51
52 _g1h->g1_policy()->set_region_eden(hr);
53 ++_length;
54 }
55
56 void YoungList::add_survivor_region(HeapRegion* hr) {
57 assert(hr->is_survivor(), "should be flagged as survivor region");
58 assert(hr->get_next_young_region() == NULL, "cause it should!");
59
60 _survivor_regions->append(hr);
61 }
62
63 void YoungList::empty_list(HeapRegion* list) {
64 while (list != NULL) {
65 HeapRegion* next = list->get_next_young_region();
66 list->set_next_young_region(NULL);
67 list->uninstall_surv_rate_group();
68 // This is called before a Full GC and all the non-empty /
69 // non-humongous regions at the end of the Full GC will end up as
70 // old anyway.
71 list->set_old();
72 list = next;
73 }
74 }
75
76 void YoungList::empty_list() {
77 assert(check_list_well_formed(), "young list should be well formed");
78
79 empty_list(_head);
80 _head = NULL;
81 _length = 0;
82
83 if (survivor_length() > 0) {
84 empty_list(_survivor_regions->last());
85 }
86 _survivor_regions->clear();
87
88 assert(check_list_empty(), "just making sure...");
89 }
90
91 uint YoungList::survivor_length() {
92 return _survivor_regions->length();
93 }
94
95 bool YoungList::check_list_well_formed() {
96 bool ret = true;
97
98 uint length = 0;
99 HeapRegion* curr = _head;
100 HeapRegion* last = NULL;
101 while (curr != NULL) {
102 if (!curr->is_young()) {
103 log_error(gc, verify)("### YOUNG REGION " PTR_FORMAT "-" PTR_FORMAT " "
104 "incorrectly tagged (y: %d, surv: %d)",
105 p2i(curr->bottom()), p2i(curr->end()),
106 curr->is_young(), curr->is_survivor());
107 ret = false;
108 }
109 ++length;
110 last = curr;
111 curr = curr->get_next_young_region();
112 }
113 ret = ret && (length == _length);
114
115 if (!ret) {
116 log_error(gc, verify)("### YOUNG LIST seems not well formed!");
117 log_error(gc, verify)("### list has %u entries, _length is %u", length, _length);
118 }
119
120 return ret;
121 }
122
123 bool YoungList::check_list_empty() {
124 bool ret = true;
125
126 if (_length != 0) {
127 log_error(gc, verify)("### YOUNG LIST should have 0 length, not %u", _length);
128 ret = false;
129 }
130 if (_head != NULL) {
131 log_error(gc, verify)("### YOUNG LIST does not have a NULL head");
132 ret = false;
133 }
134 if (!ret) {
135 log_error(gc, verify)("### YOUNG LIST does not seem empty");
136 }
137
138 return ret;
139 }
140
141 void
142 YoungList::reset_auxilary_lists() {
143 guarantee( is_empty(), "young list should be empty" );
144 assert(check_list_well_formed(), "young list should be well formed");
145
146 // Add survivor regions to SurvRateGroup.
147 _g1h->g1_policy()->note_start_adding_survivor_regions();
148 _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
149
150 HeapRegion* last = NULL;
151 for (GrowableArrayIterator<HeapRegion*> it = _survivor_regions->begin();
152 it != _survivor_regions->end();
153 ++it) {
154 HeapRegion* curr = *it;
155 _g1h->g1_policy()->set_region_survivor(curr);
156
157 // The region is a non-empty survivor so let's add it to
158 // the incremental collection set for the next evacuation
159 // pause.
160 _g1h->collection_set()->add_survivor_regions(curr);
161
162 curr->set_next_young_region(last);
163 last = curr;
164 }
165 _g1h->g1_policy()->note_stop_adding_survivor_regions();
166
167 _head = last;
168 _length = _survivor_regions->length();
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 }