1 /*
2 * Copyright (c) 2003, 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 "classfile/systemDictionary.hpp"
27 #include "memory/allocation.hpp"
28 #include "memory/universe.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/mutexLocker.hpp"
31 #include "services/classLoadingService.hpp"
32 #include "services/memoryService.hpp"
33 #include "utilities/dtrace.hpp"
34
35 #ifdef DTRACE_ENABLED
36
37 // Only bother with this argument setup if dtrace is available
38
39 HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
40 HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);
41
42 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
43 { \
44 char* data = NULL; \
45 int len = 0; \
46 symbolOop name = (clss)->name(); \
47 if (name != NULL) { \
48 data = (char*)name->bytes(); \
49 len = name->utf8_length(); \
50 } \
51 HS_DTRACE_PROBE4(hotspot, class__##type, \
52 data, len, (clss)->class_loader(), (shared)); \
53 }
54
55 #else // ndef DTRACE_ENABLED
56
57 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
58
59 #endif
60
61 // counters for classes loaded from class files
62 PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
63 PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
64 PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
65 PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
66
67 // counters for classes loaded from shared archive
68 PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
69 PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
70 PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
71 PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
72 PerfVariable* ClassLoadingService::_class_methods_size = NULL;
73
74 void ClassLoadingService::init() {
75 EXCEPTION_MARK;
76
77 // These counters are for java.lang.management API support.
78 // They are created even if -XX:-UsePerfData is set and in
79 // that case, they will be allocated on C heap.
80 _classes_loaded_count =
81 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
82 PerfData::U_Events, CHECK);
83
84 _classes_unloaded_count =
85 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
86 PerfData::U_Events, CHECK);
87
88 _shared_classes_loaded_count =
89 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
90 PerfData::U_Events, CHECK);
91
92 _shared_classes_unloaded_count =
93 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
94 PerfData::U_Events, CHECK);
95
96 if (UsePerfData) {
97 _classbytes_loaded =
98 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
99 PerfData::U_Bytes, CHECK);
100
101 _classbytes_unloaded =
102 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
103 PerfData::U_Bytes, CHECK);
104 _shared_classbytes_loaded =
105 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
106 PerfData::U_Bytes, CHECK);
107
108 _shared_classbytes_unloaded =
109 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
110 PerfData::U_Bytes, CHECK);
111 _class_methods_size =
112 PerfDataManager::create_variable(SUN_CLS, "methodBytes",
113 PerfData::U_Bytes, CHECK);
114 }
115 }
116
117 void ClassLoadingService::notify_class_unloaded(instanceKlass* k) {
118 DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
119 // Classes that can be unloaded must be non-shared
120 _classes_unloaded_count->inc();
121
122 if (UsePerfData) {
123 // add the class size
124 size_t size = compute_class_size(k);
125 _classbytes_unloaded->inc(size);
126
127 // Compute method size & subtract from running total.
128 // We are called during phase 1 of mark sweep, so it's
129 // still ok to iterate through methodOops here.
130 objArrayOop methods = k->methods();
131 for (int i = 0; i < methods->length(); i++) {
132 _class_methods_size->inc(-methods->obj_at(i)->size());
133 }
134 }
135
136 if (TraceClassUnloading) {
137 ResourceMark rm;
138 tty->print_cr("[Unloading class %s]", k->external_name());
139 }
140 }
141
142 void ClassLoadingService::notify_class_loaded(instanceKlass* k, bool shared_class) {
143 DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
144 PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
145 : _classes_loaded_count);
146 // increment the count
147 classes_counter->inc();
148
149 if (UsePerfData) {
150 PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
151 : _classbytes_loaded);
152 // add the class size
153 size_t size = compute_class_size(k);
154 classbytes_counter->inc(size);
155 }
156 }
157
158 size_t ClassLoadingService::compute_class_size(instanceKlass* k) {
159 // lifted from ClassStatistics.do_class(klassOop k)
160
161 size_t class_size = 0;
162
163 class_size += k->as_klassOop()->size();
164
165 if (k->oop_is_instance()) {
166 class_size += k->methods()->size();
167 class_size += k->constants()->size();
168 class_size += k->local_interfaces()->size();
169 class_size += k->transitive_interfaces()->size();
170 // We do not have to count implementors, since we only store one!
171 class_size += k->fields()->size();
172 }
173 return class_size * oopSize;
174 }
175
176
177 bool ClassLoadingService::set_verbose(bool verbose) {
178 MutexLocker m(Management_lock);
179
180 // verbose will be set to the previous value
181 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);
182 assert(succeed, "Setting TraceClassLoading flag fails");
183 reset_trace_class_unloading();
184
185 return verbose;
186 }
187
188 // Caller to this function must own Management_lock
189 void ClassLoadingService::reset_trace_class_unloading() {
190 assert(Management_lock->owned_by_self(), "Must own the Management_lock");
191 bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
192 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);
193 assert(succeed, "Setting TraceClassUnLoading flag fails");
194 }
195
196 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
197 Thread* LoadedClassesEnumerator::_current_thread = NULL;
198
199 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
200 assert(cur_thread == Thread::current(), "Check current thread");
201
202 int init_size = ClassLoadingService::loaded_class_count();
203 _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
204
205 // For consistency of the loaded classes, grab the SystemDictionary lock
206 MutexLocker sd_mutex(SystemDictionary_lock);
207
208 // Set _loaded_classes and _current_thread and begin enumerating all classes.
209 // Only one thread will do the enumeration at a time.
210 // These static variables are needed and they are used by the static method
211 // add_loaded_class called from classes_do().
212 _loaded_classes = _klass_handle_array;
213 _current_thread = cur_thread;
214
215 SystemDictionary::classes_do(&add_loaded_class);
216
217 // FIXME: Exclude array klasses for now
218 // Universe::basic_type_classes_do(&add_loaded_class);
219 }