1 /*
2 * Copyright (c) 2003, 2005, 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 "incls/_precompiled.incl"
26 # include "incls/_classLoadingService.cpp.incl"
27
28 #ifdef DTRACE_ENABLED
29
30 // Only bother with this argument setup if dtrace is available
31
32 HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
33 HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);
34
35 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
36 { \
37 char* data = NULL; \
38 int len = 0; \
39 symbolOop name = (clss)->name(); \
40 if (name != NULL) { \
41 data = (char*)name->bytes(); \
42 len = name->utf8_length(); \
43 } \
44 HS_DTRACE_PROBE4(hotspot, class__##type, \
45 data, len, (clss)->class_loader(), (shared)); \
46 }
47
48 #else // ndef DTRACE_ENABLED
49
50 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
51
52 #endif
53
54 // counters for classes loaded from class files
55 PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
56 PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
57 PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
58 PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
59
60 // counters for classes loaded from shared archive
61 PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
62 PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
63 PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
64 PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
65 PerfVariable* ClassLoadingService::_class_methods_size = NULL;
66
67 void ClassLoadingService::init() {
68 EXCEPTION_MARK;
69
70 // These counters are for java.lang.management API support.
71 // They are created even if -XX:-UsePerfData is set and in
72 // that case, they will be allocated on C heap.
73 _classes_loaded_count =
74 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
75 PerfData::U_Events, CHECK);
76
77 _classes_unloaded_count =
78 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
79 PerfData::U_Events, CHECK);
80
81 _shared_classes_loaded_count =
82 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
83 PerfData::U_Events, CHECK);
84
85 _shared_classes_unloaded_count =
86 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
87 PerfData::U_Events, CHECK);
88
89 if (UsePerfData) {
90 _classbytes_loaded =
91 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
92 PerfData::U_Bytes, CHECK);
93
94 _classbytes_unloaded =
95 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
96 PerfData::U_Bytes, CHECK);
97 _shared_classbytes_loaded =
98 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
99 PerfData::U_Bytes, CHECK);
100
101 _shared_classbytes_unloaded =
102 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
103 PerfData::U_Bytes, CHECK);
104 _class_methods_size =
105 PerfDataManager::create_variable(SUN_CLS, "methodBytes",
106 PerfData::U_Bytes, CHECK);
107 }
108 }
109
110 void ClassLoadingService::notify_class_unloaded(instanceKlass* k) {
111 DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
112 // Classes that can be unloaded must be non-shared
113 _classes_unloaded_count->inc();
114
115 if (UsePerfData) {
116 // add the class size
117 size_t size = compute_class_size(k);
118 _classbytes_unloaded->inc(size);
119
120 // Compute method size & subtract from running total.
121 // We are called during phase 1 of mark sweep, so it's
122 // still ok to iterate through methodOops here.
123 objArrayOop methods = k->methods();
124 for (int i = 0; i < methods->length(); i++) {
125 _class_methods_size->inc(-methods->obj_at(i)->size());
126 }
127 }
128
129 if (TraceClassUnloading) {
130 ResourceMark rm;
131 tty->print_cr("[Unloading class %s]", k->external_name());
132 }
133 }
134
135 void ClassLoadingService::notify_class_loaded(instanceKlass* k, bool shared_class) {
136 DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
137 PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
138 : _classes_loaded_count);
139 // increment the count
140 classes_counter->inc();
141
142 if (UsePerfData) {
143 PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
144 : _classbytes_loaded);
145 // add the class size
146 size_t size = compute_class_size(k);
147 classbytes_counter->inc(size);
148 }
149 }
150
151 size_t ClassLoadingService::compute_class_size(instanceKlass* k) {
152 // lifted from ClassStatistics.do_class(klassOop k)
153
154 size_t class_size = 0;
155
156 class_size += k->as_klassOop()->size();
157
158 if (k->oop_is_instance()) {
159 class_size += k->methods()->size();
160 class_size += k->constants()->size();
161 class_size += k->local_interfaces()->size();
162 class_size += k->transitive_interfaces()->size();
163 // We do not have to count implementors, since we only store one!
164 class_size += k->fields()->size();
165 }
166 return class_size * oopSize;
167 }
168
169
170 bool ClassLoadingService::set_verbose(bool verbose) {
171 MutexLocker m(Management_lock);
172
173 // verbose will be set to the previous value
174 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);
175 assert(succeed, "Setting TraceClassLoading flag fails");
176 reset_trace_class_unloading();
177
178 return verbose;
179 }
180
181 // Caller to this function must own Management_lock
182 void ClassLoadingService::reset_trace_class_unloading() {
183 assert(Management_lock->owned_by_self(), "Must own the Management_lock");
184 bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
185 bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);
186 assert(succeed, "Setting TraceClassUnLoading flag fails");
187 }
188
189 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
190 Thread* LoadedClassesEnumerator::_current_thread = NULL;
191
192 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
193 assert(cur_thread == Thread::current(), "Check current thread");
194
195 int init_size = ClassLoadingService::loaded_class_count();
196 _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
197
198 // For consistency of the loaded classes, grab the SystemDictionary lock
199 MutexLocker sd_mutex(SystemDictionary_lock);
200
201 // Set _loaded_classes and _current_thread and begin enumerating all classes.
202 // Only one thread will do the enumeration at a time.
203 // These static variables are needed and they are used by the static method
204 // add_loaded_class called from classes_do().
205 _loaded_classes = _klass_handle_array;
206 _current_thread = cur_thread;
207
208 SystemDictionary::classes_do(&add_loaded_class);
209
210 // FIXME: Exclude array klasses for now
211 // Universe::basic_type_classes_do(&add_loaded_class);
212 }