1 /*
2 * Copyright (c) 2003, 2012, 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 #ifndef USDT2
40
41 HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
42 HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);
43
44 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
45 { \
46 char* data = NULL; \
47 int len = 0; \
48 Symbol* name = (clss)->name(); \
49 if (name != NULL) { \
50 data = (char*)name->bytes(); \
51 len = name->utf8_length(); \
52 } \
53 HS_DTRACE_PROBE4(hotspot, class__##type, \
54 data, len, (clss)->class_loader(), (shared)); \
55 }
56
57 #else /* USDT2 */
58
59 #define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED
60 #define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED
61 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
62 { \
63 char* data = NULL; \
64 int len = 0; \
65 Symbol* name = (clss)->name(); \
66 if (name != NULL) { \
67 data = (char*)name->bytes(); \
68 len = name->utf8_length(); \
69 } \
70 HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \
71 data, len, (clss)->class_loader(), (shared)); \
72 }
73
74 #endif /* USDT2 */
75 #else // ndef DTRACE_ENABLED
76
77 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
78
79 #endif
80
81 // counters for classes loaded from class files
82 PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
83 PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
84 PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
85 PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
86
87 // counters for classes loaded from shared archive
88 PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
89 PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
90 PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
91 PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
92 PerfVariable* ClassLoadingService::_class_methods_size = NULL;
93
94 void ClassLoadingService::init() {
95 EXCEPTION_MARK;
96
97 // These counters are for java.lang.management API support.
98 // They are created even if -XX:-UsePerfData is set and in
99 // that case, they will be allocated on C heap.
100 _classes_loaded_count =
101 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
102 PerfData::U_Events, CHECK);
103
104 _classes_unloaded_count =
105 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
106 PerfData::U_Events, CHECK);
107
108 _shared_classes_loaded_count =
109 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
110 PerfData::U_Events, CHECK);
111
112 _shared_classes_unloaded_count =
113 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
114 PerfData::U_Events, CHECK);
115
116 if (UsePerfData) {
117 _classbytes_loaded =
118 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
119 PerfData::U_Bytes, CHECK);
120
121 _classbytes_unloaded =
122 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
123 PerfData::U_Bytes, CHECK);
124 _shared_classbytes_loaded =
125 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
126 PerfData::U_Bytes, CHECK);
127
128 _shared_classbytes_unloaded =
129 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
130 PerfData::U_Bytes, CHECK);
131 _class_methods_size =
132 PerfDataManager::create_variable(SUN_CLS, "methodBytes",
133 PerfData::U_Bytes, CHECK);
134 }
135 }
136
137 void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {
138 DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
139 // Classes that can be unloaded must be non-shared
140 _classes_unloaded_count->inc();
141
142 if (UsePerfData) {
143 // add the class size
144 size_t size = compute_class_size(k);
145 _classbytes_unloaded->inc(size);
146
147 // Compute method size & subtract from running total.
148 // We are called during phase 1 of mark sweep, so it's
149 // still ok to iterate through Method*s here.
150 Array<Method*>* methods = k->methods();
151 for (int i = 0; i < methods->length(); i++) {
152 _class_methods_size->inc(-methods->at(i)->size());
153 }
154 }
155
156 if (TraceClassUnloading) {
157 ResourceMark rm;
158 tty->print_cr("[Unloading class %s " INTPTR_FORMAT "]", k->external_name(), k);
159 }
160 }
161
162 void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {
163 DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
164 PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
165 : _classes_loaded_count);
166 // increment the count
167 classes_counter->inc();
168
169 if (UsePerfData) {
170 PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
171 : _classbytes_loaded);
172 // add the class size
173 size_t size = compute_class_size(k);
174 classbytes_counter->inc(size);
175 }
176 }
177
178 size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {
179 // lifted from ClassStatistics.do_class(Klass* k)
180
181 size_t class_size = 0;
182
183 class_size += k->size();
184
185 if (k->oop_is_instance()) {
186 class_size += k->methods()->size();
187 // FIXME: Need to count the contents of methods
188 class_size += k->constants()->size();
189 class_size += k->local_interfaces()->size();
190 class_size += k->transitive_interfaces()->size();
191 // We do not have to count implementors, since we only store one!
192 // FIXME: How should these be accounted for, now when they have moved.
193 //class_size += k->fields()->size();
194 }
195 return class_size * oopSize;
196 }
197
198
199 bool ClassLoadingService::set_verbose(bool verbose) {
200 MutexLocker m(Management_lock);
201
202 // verbose will be set to the previous value
203 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);
204 assert(succeed, "Setting TraceClassLoading flag fails");
205 reset_trace_class_unloading();
206
207 return verbose;
208 }
209
210 // Caller to this function must own Management_lock
211 void ClassLoadingService::reset_trace_class_unloading() {
212 assert(Management_lock->owned_by_self(), "Must own the Management_lock");
213 bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
214 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);
215 assert(succeed, "Setting TraceClassUnLoading flag fails");
216 }
217
218 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
219 Thread* LoadedClassesEnumerator::_current_thread = NULL;
220
221 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
222 assert(cur_thread == Thread::current(), "Check current thread");
223
224 int init_size = ClassLoadingService::loaded_class_count();
225 _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
226
227 // For consistency of the loaded classes, grab the SystemDictionary lock
228 MutexLocker sd_mutex(SystemDictionary_lock);
229
230 // Set _loaded_classes and _current_thread and begin enumerating all classes.
231 // Only one thread will do the enumeration at a time.
232 // These static variables are needed and they are used by the static method
233 // add_loaded_class called from classes_do().
234 _loaded_classes = _klass_handle_array;
235 _current_thread = cur_thread;
236
237 SystemDictionary::classes_do(&add_loaded_class);
238
239 // FIXME: Exclude array klasses for now
240 // Universe::basic_type_classes_do(&add_loaded_class);
241 }