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