1 /*
2 * Copyright (c) 2015, 2020, 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.
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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
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23 */
24
25 #ifndef SHARE_OOPS_INSTANCEMIRRORKLASS_INLINE_HPP
26 #define SHARE_OOPS_INSTANCEMIRRORKLASS_INLINE_HPP
27
28 #include "classfile/javaClasses.hpp"
29 #include "oops/instanceKlass.inline.hpp"
30 #include "oops/instanceMirrorKlass.hpp"
31 #include "oops/klass.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "utilities/debug.hpp"
34 #include "utilities/globalDefinitions.hpp"
35 #include "utilities/macros.hpp"
36
37 template <typename T, class OopClosureType>
38 void InstanceMirrorKlass::oop_oop_iterate_statics(oop obj, OopClosureType* closure) {
39 T* p = (T*)start_of_static_fields(obj);
40 T* const end = p + java_lang_Class::static_oop_field_count_raw(obj);
41
42 for (; p < end; ++p) {
43 Devirtualizer::do_oop(closure, p);
44 }
45 }
46
47 template <typename T, class OopClosureType>
48 void InstanceMirrorKlass::oop_oop_iterate(oop obj, OopClosureType* closure) {
49 InstanceKlass::oop_oop_iterate<T>(obj, closure);
50
51 if (Devirtualizer::do_metadata(closure)) {
52 Klass* klass = java_lang_Class::as_Klass_raw(obj);
53 // We'll get NULL for primitive mirrors.
54 if (klass != NULL) {
55 if (klass->class_loader_data() == NULL) {
56 // This is a mirror that belongs to a shared class that has not be loaded yet.
57 // It's only reachable via HeapShared::roots(). All of its fields should be zero
58 // so there's no need to scan.
59 assert(klass->is_shared(), "must be");
60 return;
61 } else if (klass->is_instance_klass() && klass->class_loader_data()->has_class_mirror_holder()) {
62 // A non-strong hidden class or an unsafe anonymous class doesn't have its own class loader,
63 // so when handling the java mirror for the class we need to make sure its class
64 // loader data is claimed, this is done by calling do_cld explicitly.
65 // For non-anonymous classes the call to do_cld is made when the class
66 // loader itself is handled.
67 Devirtualizer::do_cld(closure, klass->class_loader_data());
68 } else {
69 Devirtualizer::do_klass(closure, klass);
70 }
71 } else {
72 // We would like to assert here (as below) that if klass has been NULL, then
73 // this has been a mirror for a primitive type that we do not need to follow
74 // as they are always strong roots.
75 // However, we might get across a klass that just changed during CMS concurrent
76 // marking if allocation occurred in the old generation.
77 // This is benign here, as we keep alive all CLDs that were loaded during the
78 // CMS concurrent phase in the class loading, i.e. they will be iterated over
79 // and kept alive during remark.
80 // assert(java_lang_Class::is_primitive(obj), "Sanity check");
81 }
82 }
83
84 oop_oop_iterate_statics<T>(obj, closure);
85 }
86
87 template <typename T, class OopClosureType>
88 void InstanceMirrorKlass::oop_oop_iterate_reverse(oop obj, OopClosureType* closure) {
89 InstanceKlass::oop_oop_iterate_reverse<T>(obj, closure);
90
91 InstanceMirrorKlass::oop_oop_iterate_statics<T>(obj, closure);
92 }
93
94 template <typename T, class OopClosureType>
95 void InstanceMirrorKlass::oop_oop_iterate_statics_bounded(oop obj,
96 OopClosureType* closure,
97 MemRegion mr) {
98 T* p = (T*)start_of_static_fields(obj);
99 T* end = p + java_lang_Class::static_oop_field_count_raw(obj);
100
101 T* const l = (T*)mr.start();
102 T* const h = (T*)mr.end();
103 assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 &&
104 mask_bits((intptr_t)h, sizeof(T)-1) == 0,
105 "bounded region must be properly aligned");
106
107 if (p < l) {
108 p = l;
109 }
110 if (end > h) {
111 end = h;
112 }
113
114 for (;p < end; ++p) {
115 Devirtualizer::do_oop(closure, p);
116 }
117 }
118
119 template <typename T, class OopClosureType>
120 void InstanceMirrorKlass::oop_oop_iterate_bounded(oop obj, OopClosureType* closure, MemRegion mr) {
121 InstanceKlass::oop_oop_iterate_bounded<T>(obj, closure, mr);
122
123 if (Devirtualizer::do_metadata(closure)) {
124 if (mr.contains(obj)) {
125 Klass* klass = java_lang_Class::as_Klass_raw(obj);
126 // We'll get NULL for primitive mirrors.
127 if (klass != NULL) {
128 Devirtualizer::do_klass(closure, klass);
129 }
130 }
131 }
132
133 oop_oop_iterate_statics_bounded<T>(obj, closure, mr);
134 }
135
136 #endif // SHARE_OOPS_INSTANCEMIRRORKLASS_INLINE_HPP