1 /*
   2  * Copyright (c) 2003, 2014, 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);
 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);
 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
--- EOF ---