classLoadingService.cpp revision 1472:c18cbe5936b8 
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
32HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
33HS_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
55PerfCounter*    ClassLoadingService::_classes_loaded_count = NULL;
56PerfCounter*    ClassLoadingService::_classes_unloaded_count = NULL;
57PerfCounter*    ClassLoadingService::_classbytes_loaded = NULL;
58PerfCounter*    ClassLoadingService::_classbytes_unloaded = NULL;
59
60// counters for classes loaded from shared archive
61PerfCounter*    ClassLoadingService::_shared_classes_loaded_count = NULL;
62PerfCounter*    ClassLoadingService::_shared_classes_unloaded_count = NULL;
63PerfCounter*    ClassLoadingService::_shared_classbytes_loaded = NULL;
64PerfCounter*    ClassLoadingService::_shared_classbytes_unloaded = NULL;
65PerfVariable*   ClassLoadingService::_class_methods_size = NULL;
66
67void 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
110void 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
135void 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
151size_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
170bool 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
182void 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
189GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
190Thread* LoadedClassesEnumerator::_current_thread = NULL;
191
192LoadedClassesEnumerator::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}
213