1 /*
2 * Copyright (c) 2014, 2025, 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 "classfile/classLoaderData.inline.hpp"
26 #include "classfile/classLoaderDataGraph.hpp"
27 #include "classfile/classLoaderStats.hpp"
28 #include "memory/classLoaderMetaspace.hpp"
29 #include "oops/objArrayKlass.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33
34 class ClassStatsClosure : public KlassClosure {
35 public:
36 int _num_classes;
37
38 ClassStatsClosure() :
39 _num_classes(0) {
40 }
41
42 virtual void do_klass(Klass* k) {
43 _num_classes++;
44 }
45 };
46
47 void ClassLoaderStatsClosure::do_cld(ClassLoaderData* cld) {
48 // Class loaders are not kept alive so this closure must only be
49 // used during a safepoint.
50 assert_at_safepoint();
51 oop cl = cld->class_loader_no_keepalive();
52
53 // The hashtable key is the ClassLoader oop since we want to account
54 // for "real" classes and hidden classes together
55 bool added = false;
56 ClassLoaderStats* cls = _stats->put_if_absent(cl, &added);
57 if (added) {
58 cls->_class_loader = cl;
59 _total_loaders++;
60 }
61 assert(cls->_class_loader == cl, "Sanity");
62
63 if (!cld->has_class_mirror_holder()) {
64 cls->_cld = cld;
65 }
66
67 if (cl != nullptr) {
68 cls->_parent = java_lang_ClassLoader::parent_no_keepalive(cl);
69 addEmptyParents(cls->_parent);
70 }
71
72 ClassStatsClosure csc;
73 cld->classes_do(&csc);
74 bool is_hidden = false;
75 if(cld->has_class_mirror_holder()) {
76 // If cld has a class holder then it must be hidden.
77 // Either way, count it as a hidden class.
78 cls->_hidden_classes_count += csc._num_classes;
79 } else {
80 cls->_classes_count = csc._num_classes;
81 }
82 _total_classes += csc._num_classes;
83
84 ClassLoaderMetaspace* ms = cld->metaspace_or_null();
85 if (ms != nullptr) {
86 size_t used_words, capacity_words;
87 ms->usage_numbers(&used_words, nullptr, &capacity_words);
88 size_t used_bytes = used_words * BytesPerWord;
89 size_t capacity_bytes = capacity_words * BytesPerWord;
90 if(cld->has_class_mirror_holder()) {
91 cls->_hidden_chunk_sz += capacity_bytes;
92 cls->_hidden_block_sz += used_bytes;
93 } else {
94 cls->_chunk_sz = capacity_bytes;
95 cls->_block_sz = used_bytes;
96 }
97 _total_chunk_sz += capacity_bytes;
98 _total_block_sz += used_bytes;
99 }
100 }
101
102 // Handles the difference in pointer width on 32 and 64 bit platforms
103 #ifdef _LP64
104 #define SPACE "%8s"
105 #else
106 #define SPACE "%s"
107 #endif
108
109
110 bool ClassLoaderStatsClosure::do_entry(oop const& key, ClassLoaderStats const& cls) {
111 Klass* class_loader_klass = (cls._class_loader == nullptr ? nullptr : cls._class_loader->klass());
112 Klass* parent_klass = (cls._parent == nullptr ? nullptr : cls._parent->klass());
113
114 _out->print(INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT " %6zu %8zu %8zu ",
115 p2i(class_loader_klass), p2i(parent_klass), p2i(cls._cld),
116 cls._classes_count,
117 cls._chunk_sz, cls._block_sz);
118 if (class_loader_klass != nullptr) {
119 _out->print("%s", class_loader_klass->external_name());
120 } else {
121 _out->print("<boot class loader>");
122 }
123 _out->cr();
124 if (cls._hidden_classes_count > 0) {
125 _out->print_cr(SPACE SPACE SPACE " %6zu %8zu %8zu + hidden classes",
126 "", "", "",
127 cls._hidden_classes_count,
128 cls._hidden_chunk_sz, cls._hidden_block_sz);
129 }
130 return true;
131 }
132
133
134 void ClassLoaderStatsClosure::print() {
135 _out->print_cr("ClassLoader" SPACE " Parent" SPACE " CLD*" SPACE " Classes ChunkSz BlockSz Type", "", "", "");
136 _stats->iterate(this);
137 _out->print("Total = %-6zu", _total_loaders);
138 _out->print(SPACE SPACE SPACE " ", "", "", "");
139 _out->print_cr("%6zu %8zu %8zu ",
140 _total_classes,
141 _total_chunk_sz,
142 _total_block_sz);
143 _out->print_cr("ChunkSz: Total size of all allocated metaspace chunks");
144 _out->print_cr("BlockSz: Total size of all allocated metaspace blocks (each chunk has several blocks)");
145 }
146
147
148 void ClassLoaderStatsClosure::addEmptyParents(oop cl) {
149 while (cl != nullptr && java_lang_ClassLoader::loader_data_acquire(cl) == nullptr) {
150 // This classloader has not loaded any classes
151 bool added = false;
152 ClassLoaderStats* cls = _stats->put_if_absent(cl, &added);
153 if (added) {
154 cls->_class_loader = cl;
155 cls->_parent = java_lang_ClassLoader::parent_no_keepalive(cl);
156 _total_loaders++;
157 }
158 assert(cls->_class_loader == cl, "Sanity");
159
160 cl = java_lang_ClassLoader::parent_no_keepalive(cl);
161 }
162 }
163
164
165 void ClassLoaderStatsVMOperation::doit() {
166 ClassLoaderStatsClosure clsc (_out);
167 ClassLoaderDataGraph::loaded_cld_do(&clsc);
168 clsc.print();
169 }
170
171
172 void ClassLoaderStatsDCmd::execute(DCmdSource source, TRAPS) {
173 ClassLoaderStatsVMOperation op(output());
174 VMThread::execute(&op);
175 }