1 /*
2 * Copyright (c) 1997, 2010, 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/symbolKlass.hpp"
41 #include "oops/symbolOop.hpp"
42 #include "oops/typeArrayKlass.hpp"
43 #include "runtime/handles.inline.hpp"
44 #ifndef SERIALGC
45 #include "oops/oop.pcgc.inline.hpp"
46 #endif
47
48 int klassKlass::oop_size(oop obj) const {
49 assert (obj->is_klass(), "must be a klassOop");
50 return klassOop(obj)->klass_part()->klass_oop_size();
51 }
52
53 klassOop klassKlass::create_klass(TRAPS) {
54 KlassHandle h_this_klass;
55 klassKlass o;
56 // for bootstrapping, handles may not be available yet.
57 klassOop k = base_create_klass_oop(h_this_klass, header_size(), o.vtbl_value(), CHECK_NULL);
58 k->set_klass(k); // point to thyself
59 // Do not try to allocate mirror, java.lang.Class not loaded at this point.
60 // See Universe::fixup_mirrors()
61 return k;
62 }
63
64 void klassKlass::oop_follow_contents(oop obj) {
65 Klass* k = Klass::cast(klassOop(obj));
66 // If we are alive it is valid to keep our superclass and subtype caches alive
67 MarkSweep::mark_and_push(k->adr_super());
68 for (juint i = 0; i < Klass::primary_super_limit(); i++)
69 MarkSweep::mark_and_push(k->adr_primary_supers()+i);
70 MarkSweep::mark_and_push(k->adr_secondary_super_cache());
71 MarkSweep::mark_and_push(k->adr_secondary_supers());
72 MarkSweep::mark_and_push(k->adr_java_mirror());
73 MarkSweep::mark_and_push(k->adr_name());
74 // We follow the subklass and sibling links at the end of the
75 // marking phase, since otherwise following them will prevent
76 // class unloading (all classes are transitively linked from
77 // java.lang.Object).
78 MarkSweep::revisit_weak_klass_link(k);
79 obj->follow_header();
80 }
81
82 #ifndef SERIALGC
83 void klassKlass::oop_follow_contents(ParCompactionManager* cm,
84 oop obj) {
85 Klass* k = Klass::cast(klassOop(obj));
86 // If we are alive it is valid to keep our superclass and subtype caches alive
87 PSParallelCompact::mark_and_push(cm, k->adr_super());
88 for (juint i = 0; i < Klass::primary_super_limit(); i++)
89 PSParallelCompact::mark_and_push(cm, k->adr_primary_supers()+i);
90 PSParallelCompact::mark_and_push(cm, k->adr_secondary_super_cache());
91 PSParallelCompact::mark_and_push(cm, k->adr_secondary_supers());
92 PSParallelCompact::mark_and_push(cm, k->adr_java_mirror());
93 PSParallelCompact::mark_and_push(cm, k->adr_name());
94 // We follow the subklass and sibling links at the end of the
95 // marking phase, since otherwise following them will prevent
96 // class unloading (all classes are transitively linked from
97 // java.lang.Object).
98 PSParallelCompact::revisit_weak_klass_link(cm, k);
99 obj->follow_header(cm);
100 }
101 #endif // SERIALGC
102
103 int klassKlass::oop_oop_iterate(oop obj, OopClosure* blk) {
104 // Get size before changing pointers
105 int size = oop_size(obj);
106 Klass* k = Klass::cast(klassOop(obj));
107 blk->do_oop(k->adr_super());
108 for (juint i = 0; i < Klass::primary_super_limit(); i++)
109 blk->do_oop(k->adr_primary_supers()+i);
110 blk->do_oop(k->adr_secondary_super_cache());
111 blk->do_oop(k->adr_secondary_supers());
112 blk->do_oop(k->adr_java_mirror());
113 blk->do_oop(k->adr_name());
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 adr = k->adr_name();
148 if (mr.contains(adr)) blk->do_oop(adr);
149 // The following are "weak links" in the perm gen and are
150 // treated specially in a later phase of a perm gen collection.
151 assert(oop(k)->is_perm(), "should be in perm");
152 assert(oop(k->adr_subklass())->is_perm(), "should be in perm");
153 assert(oop(k->adr_next_sibling())->is_perm(), "should be in perm");
154 if (blk->should_remember_klasses()
155 && (mr.contains(k->adr_subklass())
156 || mr.contains(k->adr_next_sibling()))) {
157 blk->remember_klass(k);
158 }
159 obj->oop_iterate_header(blk, mr);
160 return size;
161 }
162
163
164 int klassKlass::oop_adjust_pointers(oop obj) {
165 // Get size before changing pointers
166 int size = oop_size(obj);
167 obj->adjust_header();
168
169 Klass* k = Klass::cast(klassOop(obj));
170
171 MarkSweep::adjust_pointer(k->adr_super());
172 for (juint i = 0; i < Klass::primary_super_limit(); i++)
173 MarkSweep::adjust_pointer(k->adr_primary_supers()+i);
174 MarkSweep::adjust_pointer(k->adr_secondary_super_cache());
175 MarkSweep::adjust_pointer(k->adr_secondary_supers());
176 MarkSweep::adjust_pointer(k->adr_java_mirror());
177 MarkSweep::adjust_pointer(k->adr_name());
178 MarkSweep::adjust_pointer(k->adr_subklass());
179 MarkSweep::adjust_pointer(k->adr_next_sibling());
180 return size;
181 }
182
183 #ifndef SERIALGC
184 void klassKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
185 }
186
187 int klassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
188 Klass* k = Klass::cast(klassOop(obj));
189
190 oop* const beg_oop = k->oop_block_beg();
191 oop* const end_oop = k->oop_block_end();
192 for (oop* cur_oop = beg_oop; cur_oop < end_oop; ++cur_oop) {
193 PSParallelCompact::adjust_pointer(cur_oop);
194 }
195
196 return oop_size(obj);
197 }
198
199 int klassKlass::oop_update_pointers(ParCompactionManager* cm, oop obj,
200 HeapWord* beg_addr, HeapWord* end_addr) {
201 Klass* k = Klass::cast(klassOop(obj));
202
203 oop* const beg_oop = MAX2((oop*)beg_addr, k->oop_block_beg());
204 oop* const end_oop = MIN2((oop*)end_addr, k->oop_block_end());
205 for (oop* cur_oop = beg_oop; cur_oop < end_oop; ++cur_oop) {
206 PSParallelCompact::adjust_pointer(cur_oop);
207 }
208
209 return oop_size(obj);
210 }
211 #endif // SERIALGC
212
213
214 // Printing
215
216 void klassKlass::oop_print_on(oop obj, outputStream* st) {
217 Klass::oop_print_on(obj, st);
218 }
219
220 void klassKlass::oop_print_value_on(oop obj, outputStream* st) {
221 Klass::oop_print_value_on(obj, st);
222 }
223
224 const char* klassKlass::internal_name() const {
225 return "{other class}";
226 }
227
228
229 // Verification
230
231 void klassKlass::oop_verify_on(oop obj, outputStream* st) {
232 Klass::oop_verify_on(obj, st);
233 guarantee(obj->is_perm(), "should be in permspace");
234 guarantee(obj->is_klass(), "should be klass");
235
236 Klass* k = Klass::cast(klassOop(obj));
237 if (k->super() != NULL) {
238 guarantee(k->super()->is_perm(), "should be in permspace");
239 guarantee(k->super()->is_klass(), "should be klass");
240 }
241 klassOop ko = k->secondary_super_cache();
242 if( ko != NULL ) {
243 guarantee(ko->is_perm(), "should be in permspace");
244 guarantee(ko->is_klass(), "should be klass");
245 }
246 for( uint i = 0; i < primary_super_limit(); i++ ) {
247 oop ko = k->adr_primary_supers()[i]; // Cannot use normal accessor because it asserts
248 if( ko != NULL ) {
249 guarantee(ko->is_perm(), "should be in permspace");
250 guarantee(ko->is_klass(), "should be klass");
251 }
252 }
253
254 if (k->java_mirror() != NULL || (k->oop_is_instance() && instanceKlass::cast(klassOop(obj))->is_loaded())) {
255 guarantee(k->java_mirror() != NULL, "should be allocated");
256 guarantee(k->java_mirror()->is_perm(), "should be in permspace");
257 guarantee(k->java_mirror()->is_instance(), "should be instance");
258 }
259 if (k->name() != NULL) {
260 guarantee(Universe::heap()->is_in_permanent(k->name()),
261 "should be in permspace");
262 guarantee(k->name()->is_symbol(), "should be symbol");
263 }
264 }