1 /*
2 * Copyright (c) 1997, 2011, 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_implementation/shared/markSweep.inline.hpp"
27 #include "gc_interface/collectedHeap.hpp"
28 #include "gc_interface/collectedHeap.inline.hpp"
29 #include "memory/oopFactory.hpp"
30 #include "memory/permGen.hpp"
31 #include "oops/constantPoolKlass.hpp"
32 #include "oops/instanceKlass.hpp"
33 #include "oops/instanceOop.hpp"
34 #include "oops/klassKlass.hpp"
35 #include "oops/klassOop.hpp"
36 #include "oops/methodKlass.hpp"
37 #include "oops/objArrayKlass.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "oops/oop.inline2.hpp"
40 #include "oops/symbol.hpp"
41 #include "oops/typeArrayKlass.hpp"
42 #include "runtime/handles.inline.hpp"
43 #ifndef SERIALGC
44 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
45 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
46 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
47 #include "memory/cardTableRS.hpp"
48 #include "oops/oop.pcgc.inline.hpp"
49 #endif
50
51 int klassKlass::oop_size(oop obj) const {
52 assert (obj->is_klass(), "must be a klassOop");
53 return klassOop(obj)->klass_part()->klass_oop_size();
54 }
55
56 klassOop klassKlass::create_klass(TRAPS) {
57 KlassHandle h_this_klass;
58 klassKlass o;
59 // for bootstrapping, handles may not be available yet.
60 klassOop k = base_create_klass_oop(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL);
61 k->set_klass(k); // point to thyself
62 // Do not try to allocate mirror, java.lang.Class not loaded at this point.
63 // See Universe::fixup_mirrors()
64 return k;
65 }
66
67 void klassKlass::oop_follow_contents(oop obj) {
68 Klass* k = Klass::cast(klassOop(obj));
69 // If we are alive it is valid to keep our superclass and subtype caches alive
70 MarkSweep::mark_and_push(k->adr_super());
71 for (juint i = 0; i < Klass::primary_super_limit(); i++)
72 MarkSweep::mark_and_push(k->adr_primary_supers()+i);
73 MarkSweep::mark_and_push(k->adr_secondary_super_cache());
74 MarkSweep::mark_and_push(k->adr_secondary_supers());
75 MarkSweep::mark_and_push(k->adr_java_mirror());
76 // We follow the subklass and sibling links at the end of the
77 // marking phase, since otherwise following them will prevent
78 // class unloading (all classes are transitively linked from
79 // java.lang.Object).
80 MarkSweep::revisit_weak_klass_link(k);
81 obj->follow_header();
82 }
83
84 #ifndef SERIALGC
85 void klassKlass::oop_follow_contents(ParCompactionManager* cm,
86 oop obj) {
87 Klass* k = Klass::cast(klassOop(obj));
88 // If we are alive it is valid to keep our superclass and subtype caches alive
89 PSParallelCompact::mark_and_push(cm, k->adr_super());
90 for (juint i = 0; i < Klass::primary_super_limit(); i++)
91 PSParallelCompact::mark_and_push(cm, k->adr_primary_supers()+i);
92 PSParallelCompact::mark_and_push(cm, k->adr_secondary_super_cache());
93 PSParallelCompact::mark_and_push(cm, k->adr_secondary_supers());
94 PSParallelCompact::mark_and_push(cm, k->adr_java_mirror());
95 // We follow the subklass and sibling links at the end of the
96 // marking phase, since otherwise following them will prevent
97 // class unloading (all classes are transitively linked from
98 // java.lang.Object).
99 PSParallelCompact::revisit_weak_klass_link(cm, k);
100 obj->follow_header(cm);
101 }
102 #endif // SERIALGC
103
104 int klassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
105 // Get size before changing pointers
106 int size = oop_size(obj);
107 Klass* k = Klass::cast(klassOop(obj));
108 blk->do_oop(k->adr_super());
109 for (juint i = 0; i < Klass::primary_super_limit(); i++)
110 blk->do_oop(k->adr_primary_supers()+i);
111 blk->do_oop(k->adr_secondary_super_cache());
112 blk->do_oop(k->adr_secondary_supers());
113 blk->do_oop(k->adr_java_mirror());
114 // The following are in the perm gen and are treated
115 // specially in a later phase of a perm gen collection; ...
116 assert(oop(k)->is_perm(), "should be in perm");
117 assert(oop(k->subklass())->is_perm_or_null(), "should be in perm");
118 assert(oop(k->next_sibling())->is_perm_or_null(), "should be in perm");
119 // ... don't scan them normally, but remember this klassKlass
120 // for later (see, for instance, oop_follow_contents above
121 // for what MarkSweep does with it.
122 if (blk->should_remember_klasses()) {
123 blk->remember_klass(k);
124 }
125 obj->oop_iterate_header(blk);
126 return size;
127 }
128
129
130 int klassKlass::oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) {
131 // Get size before changing pointers
132 int size = oop_size(obj);
133 Klass* k = Klass::cast(klassOop(obj));
134 oop* adr;
135 adr = k->adr_super();
136 if (mr.contains(adr)) blk->do_oop(adr);
137 for (juint i = 0; i < Klass::primary_super_limit(); i++) {
138 adr = k->adr_primary_supers()+i;
139 if (mr.contains(adr)) blk->do_oop(adr);
140 }
141 adr = k->adr_secondary_super_cache();
142 if (mr.contains(adr)) blk->do_oop(adr);
143 adr = k->adr_secondary_supers();
144 if (mr.contains(adr)) blk->do_oop(adr);
145 adr = k->adr_java_mirror();
146 if (mr.contains(adr)) blk->do_oop(adr);
147 // The following are "weak links" in the perm gen and are
148 // treated specially in a later phase of a perm gen collection.
149 assert(oop(k)->is_perm(), "should be in perm");
150 assert(oop(k->adr_subklass())->is_perm(), "should be in perm");
151 assert(oop(k->adr_next_sibling())->is_perm(), "should be in perm");
152 if (blk->should_remember_klasses()
153 && (mr.contains(k->adr_subklass())
154 || mr.contains(k->adr_next_sibling()))) {
155 blk->remember_klass(k);
156 }
157 obj->oop_iterate_header(blk, mr);
158 return size;
159 }
160
161
162 int klassKlass::oop_adjust_pointers(oop obj) {
163 // Get size before changing pointers
164 int size = oop_size(obj);
165 obj->adjust_header();
166
167 Klass* k = Klass::cast(klassOop(obj));
168
169 MarkSweep::adjust_pointer(k->adr_super());
170 for (juint i = 0; i < Klass::primary_super_limit(); i++)
171 MarkSweep::adjust_pointer(k->adr_primary_supers()+i);
172 MarkSweep::adjust_pointer(k->adr_secondary_super_cache());
173 MarkSweep::adjust_pointer(k->adr_secondary_supers());
174 MarkSweep::adjust_pointer(k->adr_java_mirror());
175 MarkSweep::adjust_pointer(k->adr_subklass());
176 MarkSweep::adjust_pointer(k->adr_next_sibling());
177 return size;
178 }
179
180 #ifndef SERIALGC
181 void klassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
182 Klass* k = Klass::cast(klassOop(obj));
183
184 oop* p = k->adr_java_mirror();
185 if (PSScavenge::should_scavenge(p)) {
186 pm->claim_or_forward_depth(p);
187 }
188 }
189
190 int klassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
191 Klass* k = Klass::cast(klassOop(obj));
192
193 oop* const beg_oop = k->oop_block_beg();
194 oop* const end_oop = k->oop_block_end();
195 for (oop* cur_oop = beg_oop; cur_oop < end_oop; ++cur_oop) {
196 PSParallelCompact::adjust_pointer(cur_oop);
197 }
198
199 return oop_size(obj);
200 }
201 #endif // SERIALGC
202
203
204 // Printing
205
206 void klassKlass::oop_print_on(oop obj, outputStream* st) {
207 Klass::oop_print_on(obj, st);
208 }
209
210 void klassKlass::oop_print_value_on(oop obj, outputStream* st) {
211 Klass::oop_print_value_on(obj, st);
212 }
213
214 const char* klassKlass::internal_name() const {
215 return "{other class}";
216 }
217
218
219 // Verification
220
221 void klassKlass::oop_verify_on(oop obj, outputStream* st) {
222 Klass::oop_verify_on(obj, st);
223 guarantee(obj->is_perm(), "should be in permspace");
224 guarantee(obj->is_klass(), "should be klass");
225
226 Klass* k = Klass::cast(klassOop(obj));
227 if (k->super() != NULL) {
228 guarantee(k->super()->is_perm(), "should be in permspace");
229 guarantee(k->super()->is_klass(), "should be klass");
230 }
231 klassOop ko = k->secondary_super_cache();
232 if( ko != NULL ) {
233 guarantee(ko->is_perm(), "should be in permspace");
234 guarantee(ko->is_klass(), "should be klass");
235 }
236 for( uint i = 0; i < primary_super_limit(); i++ ) {
237 oop ko = k->adr_primary_supers()[i]; // Cannot use normal accessor because it asserts
238 if( ko != NULL ) {
239 guarantee(ko->is_perm(), "should be in permspace");
240 guarantee(ko->is_klass(), "should be klass");
241 }
242 }
243
244 if (k->java_mirror() != NULL || (k->oop_is_instance() && instanceKlass::cast(klassOop(obj))->is_loaded())) {
245 guarantee(k->java_mirror() != NULL, "should be allocated");
246 guarantee(k->java_mirror()->is_perm() || !JavaObjectsInPerm, "should be in permspace");
247 guarantee(k->java_mirror()->is_instance(), "should be instance");
248 }
249 }