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 #include "utilities/defaultStream.hpp"
36
37 #ifdef DTRACE_ENABLED
38
39 // Only bother with this argument setup if dtrace is available
40
41 #define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED
42 #define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED
43 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared) \
44 { \
45 char* data = NULL; \
46 int len = 0; \
47 Symbol* name = (clss)->name(); \
48 if (name != NULL) { \
49 data = (char*)name->bytes(); \
50 len = name->utf8_length(); \
51 } \
52 HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \
53 data, len, (clss)->class_loader(), (shared)); \
54 }
55
56 #else // ndef DTRACE_ENABLED
57
58 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
59
60 #endif
61
62 #if INCLUDE_MANAGEMENT
63 // counters for classes loaded from class files
64 PerfCounter* ClassLoadingService::_classes_loaded_count = NULL;
65 PerfCounter* ClassLoadingService::_classes_unloaded_count = NULL;
66 PerfCounter* ClassLoadingService::_classbytes_loaded = NULL;
67 PerfCounter* ClassLoadingService::_classbytes_unloaded = NULL;
68
69 // counters for classes loaded from shared archive
70 PerfCounter* ClassLoadingService::_shared_classes_loaded_count = NULL;
71 PerfCounter* ClassLoadingService::_shared_classes_unloaded_count = NULL;
72 PerfCounter* ClassLoadingService::_shared_classbytes_loaded = NULL;
73 PerfCounter* ClassLoadingService::_shared_classbytes_unloaded = NULL;
74 PerfVariable* ClassLoadingService::_class_methods_size = NULL;
75
76 void ClassLoadingService::init() {
77 EXCEPTION_MARK;
78
79 // These counters are for java.lang.management API support.
80 // They are created even if -XX:-UsePerfData is set and in
81 // that case, they will be allocated on C heap.
82 _classes_loaded_count =
83 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
84 PerfData::U_Events, CHECK);
85
86 _classes_unloaded_count =
87 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
88 PerfData::U_Events, CHECK);
89
90 _shared_classes_loaded_count =
91 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
92 PerfData::U_Events, CHECK);
93
94 _shared_classes_unloaded_count =
95 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
96 PerfData::U_Events, CHECK);
97
98 if (UsePerfData) {
99 _classbytes_loaded =
100 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
101 PerfData::U_Bytes, CHECK);
102
103 _classbytes_unloaded =
104 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
105 PerfData::U_Bytes, CHECK);
106 _shared_classbytes_loaded =
107 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
108 PerfData::U_Bytes, CHECK);
109
110 _shared_classbytes_unloaded =
111 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
112 PerfData::U_Bytes, CHECK);
113 _class_methods_size =
114 PerfDataManager::create_variable(SUN_CLS, "methodBytes",
115 PerfData::U_Bytes, CHECK);
116 }
117 }
118
119 void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {
120 DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
121 // Classes that can be unloaded must be non-shared
122 _classes_unloaded_count->inc();
123
124 if (UsePerfData) {
125 // add the class size
126 size_t size = compute_class_size(k);
127 _classbytes_unloaded->inc(size);
128
129 // Compute method size & subtract from running total.
130 // We are called during phase 1 of mark sweep, so it's
131 // still ok to iterate through Method*s here.
132 Array<Method*>* methods = k->methods();
133 for (int i = 0; i < methods->length(); i++) {
134 _class_methods_size->inc(-methods->at(i)->size());
135 }
136 }
137
138 if (TraceClassUnloading) {
139 ResourceMark rm;
140 tty->print_cr("[Unloading class %s " INTPTR_FORMAT "]", k->external_name(), p2i(k));
141 }
142 }
143
144 void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {
145 DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
146 PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
147 : _classes_loaded_count);
148 // increment the count
149 classes_counter->inc();
150
151 if (UsePerfData) {
152 PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
153 : _classbytes_loaded);
154 // add the class size
155 size_t size = compute_class_size(k);
156 classbytes_counter->inc(size);
157 }
158 }
159
160 size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {
161 // lifted from ClassStatistics.do_class(Klass* k)
162
163 size_t class_size = 0;
164
165 class_size += k->size();
166
167 if (k->is_instance_klass()) {
168 class_size += k->methods()->size();
169 // FIXME: Need to count the contents of methods
170 class_size += k->constants()->size();
171 class_size += k->local_interfaces()->size();
172 class_size += k->transitive_interfaces()->size();
173 // We do not have to count implementors, since we only store one!
174 // FIXME: How should these be accounted for, now when they have moved.
175 //class_size += k->fields()->size();
176 }
177 return class_size * oopSize;
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 Flag::Error error = CommandLineFlags::boolAtPut("TraceClassLoading", &verbose, Flag::MANAGEMENT);
185 assert(error==Flag::SUCCESS, "Setting TraceClassLoading flag failed with error %s", Flag::flag_error_str(error));
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 Flag::Error error = CommandLineFlags::boolAtPut("TraceClassUnloading", &value, Flag::MANAGEMENT);
196 assert(error==Flag::SUCCESS, "Setting TraceClassUnLoading flag failed with error %s", Flag::flag_error_str(error));
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