classLoadingService.cpp revision 8569:5bbf25472731 
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.
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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
64PerfCounter*    ClassLoadingService::_classes_loaded_count = NULL;
65PerfCounter*    ClassLoadingService::_classes_unloaded_count = NULL;
66PerfCounter*    ClassLoadingService::_classbytes_loaded = NULL;
67PerfCounter*    ClassLoadingService::_classbytes_unloaded = NULL;
68
69// counters for classes loaded from shared archive
70PerfCounter*    ClassLoadingService::_shared_classes_loaded_count = NULL;
71PerfCounter*    ClassLoadingService::_shared_classes_unloaded_count = NULL;
72PerfCounter*    ClassLoadingService::_shared_classbytes_loaded = NULL;
73PerfCounter*    ClassLoadingService::_shared_classbytes_unloaded = NULL;
74PerfVariable*   ClassLoadingService::_class_methods_size = NULL;
75
76void 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
119void 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
144void 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
160size_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->oop_is_instance()) {
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
180bool 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, err_msg("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
192void 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, err_msg("Setting TraceClassUnLoading flag failed with error %s", Flag::flag_error_str(error)));
197}
198
199GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
200Thread* LoadedClassesEnumerator::_current_thread = NULL;
201
202LoadedClassesEnumerator::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
225