1 /*
2 * Copyright (c) 2003, 2015, 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 #include "utilities/macros.hpp"
35
36 #ifdef DTRACE_ENABLED
37
38 // Only bother with this argument setup if dtrace is available
39
40 #define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED
41 #define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED
42 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
43 { \
44 char* data = NULL; \
45 int len = 0; \
46 Symbol* name = (clss)->name(); \
47 if (name != NULL) { \
48 data = (char*)name->bytes(); \
49 len = name->utf8_length(); \
50 } \
51 HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \
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 #if INCLUDE_MANAGEMENT
62 // counters for classes loaded from class files
63 PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
64 PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
65 PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
66 PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
67
68 // counters for classes loaded from shared archive
69 PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
70 PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
71 PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
72 PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
73 PerfVariable* ClassLoadingService::_class_methods_size = NULL;
74
75 void ClassLoadingService::init() {
76 EXCEPTION_MARK;
77
78 // These counters are for java.lang.management API support.
79 // They are created even if -XX:-UsePerfData is set and in
80 // that case, they will be allocated on C heap.
81 _classes_loaded_count =
82 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
83 PerfData::U_Events, CHECK);
84
85 _classes_unloaded_count =
86 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
87 PerfData::U_Events, CHECK);
88
89 _shared_classes_loaded_count =
90 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
91 PerfData::U_Events, CHECK);
92
93 _shared_classes_unloaded_count =
94 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
95 PerfData::U_Events, CHECK);
96
97 if (UsePerfData) {
98 _classbytes_loaded =
99 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
100 PerfData::U_Bytes, CHECK);
101
102 _classbytes_unloaded =
103 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
104 PerfData::U_Bytes, CHECK);
105 _shared_classbytes_loaded =
106 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
107 PerfData::U_Bytes, CHECK);
108
109 _shared_classbytes_unloaded =
110 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
111 PerfData::U_Bytes, CHECK);
112 _class_methods_size =
113 PerfDataManager::create_variable(SUN_CLS, "methodBytes",
114 PerfData::U_Bytes, CHECK);
115 }
116 }
117
118 void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {
119 DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
120 // Classes that can be unloaded must be non-shared
121 _classes_unloaded_count->inc();
122
123 if (UsePerfData) {
124 // add the class size
125 size_t size = compute_class_size(k);
126 _classbytes_unloaded->inc(size);
127
128 // Compute method size & subtract from running total.
129 // We are called during phase 1 of mark sweep, so it's
130 // still ok to iterate through Method*s here.
131 Array<Method*>* methods = k->methods();
132 for (int i = 0; i < methods->length(); i++) {
133 _class_methods_size->inc(-methods->at(i)->size());
134 }
135 }
136
137 if (TraceClassUnloading) {
138 ResourceMark rm;
139 tty->print_cr("[Unloading class %s " INTPTR_FORMAT "]", k->external_name(), p2i(k));
140 }
141 }
142
143 void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {
144 DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
145 PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
146 : _classes_loaded_count);
147 // increment the count
148 classes_counter->inc();
149
150 if (UsePerfData) {
151 PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
152 : _classbytes_loaded);
153 // add the class size
154 size_t size = compute_class_size(k);
155 classbytes_counter->inc(size);
156 }
157 }
158
159 size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {
160 // lifted from ClassStatistics.do_class(Klass* k)
161
162 size_t class_size = 0;
163
164 class_size += k->size();
165
166 if (k->oop_is_instance()) {
167 class_size += k->methods()->size();
168 // FIXME: Need to count the contents of methods
169 class_size += k->constants()->size();
170 class_size += k->local_interfaces()->size();
171 class_size += k->transitive_interfaces()->size();
172 // We do not have to count implementors, since we only store one!
173 // FIXME: How should these be accounted for, now when they have moved.
174 //class_size += k->fields()->size();
175 }
176 return class_size * oopSize;
177 }
178
179
180 bool ClassLoadingService::set_verbose(bool verbose) {
181 MutexLocker m(Management_lock);
182
183 // verbose will be set to the previous value
184 bool succeed = (CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, Flag::MANAGEMENT) == Flag::SUCCESS);
185 assert(succeed, "Setting TraceClassLoading flag fails");
186 reset_trace_class_unloading();
187
188 return verbose;
189 }
190
191 // Caller to this function must own Management_lock
192 void ClassLoadingService::reset_trace_class_unloading() {
193 assert(Management_lock->owned_by_self(), "Must own the Management_lock");
194 bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
195 bool succeed = (CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, Flag::MANAGEMENT) == Flag::SUCCESS);
196 assert(succeed, "Setting TraceClassUnLoading flag fails");
197 }
198
199 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
200 Thread* LoadedClassesEnumerator::_current_thread = NULL;
201
202 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
203 assert(cur_thread == Thread::current(), "Check current thread");
204
205 int init_size = ClassLoadingService::loaded_class_count();
206 _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
207
208 // For consistency of the loaded classes, grab the SystemDictionary lock
209 MutexLocker sd_mutex(SystemDictionary_lock);
210
211 // Set _loaded_classes and _current_thread and begin enumerating all classes.
212 // Only one thread will do the enumeration at a time.
213 // These static variables are needed and they are used by the static method
214 // add_loaded_class called from classes_do().
215 _loaded_classes = _klass_handle_array;
216 _current_thread = cur_thread;
217
218 SystemDictionary::classes_do(&add_loaded_class);
219
220 // FIXME: Exclude array klasses for now
221 // Universe::basic_type_classes_do(&add_loaded_class);
222 }
223
224 #endif // INCLUDE_MANAGEMENT