1 /*
   2  * Copyright (c) 2003, 2012, 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 #ifndef USDT2
  41 
  42 HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);
  43 HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);
  44 
  45 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)  \
  46   {                                                 \
  47     char* data = NULL;                              \
  48     int len = 0;                                    \
  49     Symbol* name = (clss)->name();                  \
  50     if (name != NULL) {                             \
  51       data = (char*)name->bytes();                  \
  52       len = name->utf8_length();                    \
  53     }                                               \
  54     HS_DTRACE_PROBE4(hotspot, class__##type,        \
  55       data, len, (clss)->class_loader(), (shared)); \
  56   }
  57 
  58 #else /* USDT2 */
  59 
  60 #define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED
  61 #define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED
  62 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)  \
  63   {                                                 \
  64     char* data = NULL;                              \
  65     int len = 0;                                    \
  66     Symbol* name = (clss)->name();                  \
  67     if (name != NULL) {                             \
  68       data = (char*)name->bytes();                  \
  69       len = name->utf8_length();                    \
  70     }                                               \
  71     HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \
  72       data, len, (clss)->class_loader(), (shared)); \
  73   }
  74 
  75 #endif /* USDT2 */
  76 #else //  ndef DTRACE_ENABLED
  77 
  78 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
  79 
  80 #endif
  81 
  82 #if INCLUDE_MANAGEMENT
  83 // counters for classes loaded from class files
  84 PerfCounter*    ClassLoadingService::_classes_loaded_count = NULL;
  85 PerfCounter*    ClassLoadingService::_classes_unloaded_count = NULL;
  86 PerfCounter*    ClassLoadingService::_classbytes_loaded = NULL;
  87 PerfCounter*    ClassLoadingService::_classbytes_unloaded = NULL;
  88 
  89 // counters for classes loaded from shared archive
  90 PerfCounter*    ClassLoadingService::_shared_classes_loaded_count = NULL;
  91 PerfCounter*    ClassLoadingService::_shared_classes_unloaded_count = NULL;
  92 PerfCounter*    ClassLoadingService::_shared_classbytes_loaded = NULL;
  93 PerfCounter*    ClassLoadingService::_shared_classbytes_unloaded = NULL;
  94 PerfVariable*   ClassLoadingService::_class_methods_size = NULL;
  95 
  96 void ClassLoadingService::init() {
  97   EXCEPTION_MARK;
  98 
  99   // These counters are for java.lang.management API support.
 100   // They are created even if -XX:-UsePerfData is set and in
 101   // that case, they will be allocated on C heap.
 102   _classes_loaded_count =
 103                  PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
 104                                                  PerfData::U_Events, CHECK);
 105 
 106   _classes_unloaded_count =
 107                  PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
 108                                                  PerfData::U_Events, CHECK);
 109 
 110   _shared_classes_loaded_count =
 111                  PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
 112                                                  PerfData::U_Events, CHECK);
 113 
 114   _shared_classes_unloaded_count =
 115                  PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
 116                                                  PerfData::U_Events, CHECK);
 117 
 118   if (UsePerfData) {
 119     _classbytes_loaded =
 120                  PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
 121                                                  PerfData::U_Bytes, CHECK);
 122 
 123     _classbytes_unloaded =
 124                  PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
 125                                                  PerfData::U_Bytes, CHECK);
 126     _shared_classbytes_loaded =
 127                  PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
 128                                                  PerfData::U_Bytes, CHECK);
 129 
 130     _shared_classbytes_unloaded =
 131                  PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
 132                                                  PerfData::U_Bytes, CHECK);
 133     _class_methods_size =
 134                  PerfDataManager::create_variable(SUN_CLS, "methodBytes",
 135                                                   PerfData::U_Bytes, CHECK);
 136   }
 137 }
 138 
 139 void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {
 140   DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
 141   // Classes that can be unloaded must be non-shared
 142   _classes_unloaded_count->inc();
 143 
 144   if (UsePerfData) {
 145     // add the class size
 146     size_t size = compute_class_size(k);
 147     _classbytes_unloaded->inc(size);
 148 
 149     // Compute method size & subtract from running total.
 150     // We are called during phase 1 of mark sweep, so it's
 151     // still ok to iterate through Method*s here.
 152     Array<Method*>* methods = k->methods();
 153     for (int i = 0; i < methods->length(); i++) {
 154       _class_methods_size->inc(-methods->at(i)->size());
 155     }
 156   }
 157 
 158   if (TraceClassUnloading) {
 159     ResourceMark rm;
 160     tty->print_cr("[Unloading class %s " INTPTR_FORMAT "]", k->external_name(), k);
 161   }
 162 }
 163 
 164 void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {
 165   DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
 166   PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
 167                                                : _classes_loaded_count);
 168   // increment the count
 169   classes_counter->inc();
 170 
 171   if (UsePerfData) {
 172     PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
 173                                                     : _classbytes_loaded);
 174     // add the class size
 175     size_t size = compute_class_size(k);
 176     classbytes_counter->inc(size);
 177   }
 178 }
 179 
 180 size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {
 181   // lifted from ClassStatistics.do_class(Klass* k)
 182 
 183   size_t class_size = 0;
 184 
 185   class_size += k->size();
 186 
 187   if (k->oop_is_instance()) {
 188     class_size += k->methods()->size();
 189     // FIXME: Need to count the contents of methods
 190     class_size += k->constants()->size();
 191     class_size += k->local_interfaces()->size();
 192     class_size += k->transitive_interfaces()->size();
 193     // We do not have to count implementors, since we only store one!
 194     // FIXME: How should these be accounted for, now when they have moved.
 195     //class_size += k->fields()->size();
 196   }
 197   return class_size * oopSize;
 198 }
 199 
 200 
 201 bool ClassLoadingService::set_verbose(bool verbose) {
 202   MutexLocker m(Management_lock);
 203 
 204   // verbose will be set to the previous value
 205   bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);
 206   assert(succeed, "Setting TraceClassLoading flag fails");
 207   reset_trace_class_unloading();
 208 
 209   return verbose;
 210 }
 211 
 212 // Caller to this function must own Management_lock
 213 void ClassLoadingService::reset_trace_class_unloading() {
 214   assert(Management_lock->owned_by_self(), "Must own the Management_lock");
 215   bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
 216   bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);
 217   assert(succeed, "Setting TraceClassUnLoading flag fails");
 218 }
 219 
 220 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
 221 Thread* LoadedClassesEnumerator::_current_thread = NULL;
 222 
 223 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
 224   assert(cur_thread == Thread::current(), "Check current thread");
 225 
 226   int init_size = ClassLoadingService::loaded_class_count();
 227   _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
 228 
 229   // For consistency of the loaded classes, grab the SystemDictionary lock
 230   MutexLocker sd_mutex(SystemDictionary_lock);
 231 
 232   // Set _loaded_classes and _current_thread and begin enumerating all classes.
 233   // Only one thread will do the enumeration at a time.
 234   // These static variables are needed and they are used by the static method
 235   // add_loaded_class called from classes_do().
 236   _loaded_classes = _klass_handle_array;
 237   _current_thread = cur_thread;
 238 
 239   SystemDictionary::classes_do(&add_loaded_class);
 240 
 241   // FIXME: Exclude array klasses for now
 242   // Universe::basic_type_classes_do(&add_loaded_class);
 243 }
 244 
 245 #endif // INCLUDE_MANAGEMENT