1 /*
   2  * Copyright (c) 2003, 2016, 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 #include "logging/log.hpp"
  37 #include "logging/logConfiguration.hpp"
  38 
  39 #ifdef DTRACE_ENABLED
  40 
  41 // Only bother with this argument setup if dtrace is available
  42 
  43 #define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED
  44 #define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED
  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     HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \
  55       data, len, (clss)->class_loader(), (shared)); \
  56   }
  57 
  58 #else //  ndef DTRACE_ENABLED
  59 
  60 #define DTRACE_CLASSLOAD_PROBE(type, clss, shared)
  61 
  62 #endif
  63 
  64 #if INCLUDE_MANAGEMENT
  65 // counters for classes loaded from class files
  66 PerfCounter*    ClassLoadingService::_classes_loaded_count = NULL;
  67 PerfCounter*    ClassLoadingService::_classes_unloaded_count = NULL;
  68 PerfCounter*    ClassLoadingService::_classbytes_loaded = NULL;
  69 PerfCounter*    ClassLoadingService::_classbytes_unloaded = NULL;
  70 
  71 // counters for classes loaded from shared archive
  72 PerfCounter*    ClassLoadingService::_shared_classes_loaded_count = NULL;
  73 PerfCounter*    ClassLoadingService::_shared_classes_unloaded_count = NULL;
  74 PerfCounter*    ClassLoadingService::_shared_classbytes_loaded = NULL;
  75 PerfCounter*    ClassLoadingService::_shared_classbytes_unloaded = NULL;
  76 PerfVariable*   ClassLoadingService::_class_methods_size = NULL;
  77 
  78 void ClassLoadingService::init() {
  79   EXCEPTION_MARK;
  80 
  81   // These counters are for java.lang.management API support.
  82   // They are created even if -XX:-UsePerfData is set and in
  83   // that case, they will be allocated on C heap.
  84   _classes_loaded_count =
  85                  PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",
  86                                                  PerfData::U_Events, CHECK);
  87 
  88   _classes_unloaded_count =
  89                  PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",
  90                                                  PerfData::U_Events, CHECK);
  91 
  92   _shared_classes_loaded_count =
  93                  PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",
  94                                                  PerfData::U_Events, CHECK);
  95 
  96   _shared_classes_unloaded_count =
  97                  PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",
  98                                                  PerfData::U_Events, CHECK);
  99 
 100   if (UsePerfData) {
 101     _classbytes_loaded =
 102                  PerfDataManager::create_counter(SUN_CLS, "loadedBytes",
 103                                                  PerfData::U_Bytes, CHECK);
 104 
 105     _classbytes_unloaded =
 106                  PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",
 107                                                  PerfData::U_Bytes, CHECK);
 108     _shared_classbytes_loaded =
 109                  PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",
 110                                                  PerfData::U_Bytes, CHECK);
 111 
 112     _shared_classbytes_unloaded =
 113                  PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",
 114                                                  PerfData::U_Bytes, CHECK);
 115     _class_methods_size =
 116                  PerfDataManager::create_variable(SUN_CLS, "methodBytes",
 117                                                   PerfData::U_Bytes, CHECK);
 118   }
 119 }
 120 
 121 void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {
 122   DTRACE_CLASSLOAD_PROBE(unloaded, k, false);
 123   // Classes that can be unloaded must be non-shared
 124   _classes_unloaded_count->inc();
 125 
 126   if (UsePerfData) {
 127     // add the class size
 128     size_t size = compute_class_size(k);
 129     _classbytes_unloaded->inc(size);
 130 
 131     // Compute method size & subtract from running total.
 132     // We are called during phase 1 of mark sweep, so it's
 133     // still ok to iterate through Method*s here.
 134     Array<Method*>* methods = k->methods();
 135     for (int i = 0; i < methods->length(); i++) {
 136       _class_methods_size->inc(-methods->at(i)->size());
 137     }
 138   }
 139 
 140   if (log_is_enabled(Info, classunload)) {
 141     ResourceMark rm;
 142     log_info(classunload)("unloading class %s " INTPTR_FORMAT , k->external_name(), p2i(k));
 143   }
 144 }
 145 
 146 void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {
 147   DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);
 148   PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count
 149                                                : _classes_loaded_count);
 150   // increment the count
 151   classes_counter->inc();
 152 
 153   if (UsePerfData) {
 154     PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded
 155                                                     : _classbytes_loaded);
 156     // add the class size
 157     size_t size = compute_class_size(k);
 158     classbytes_counter->inc(size);
 159   }
 160 }
 161 
 162 size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {
 163   // lifted from ClassStatistics.do_class(Klass* k)
 164 
 165   size_t class_size = 0;
 166 
 167   class_size += k->size();
 168 
 169   if (k->is_instance_klass()) {
 170     class_size += k->methods()->size();
 171     // FIXME: Need to count the contents of methods
 172     class_size += k->constants()->size();
 173     class_size += k->local_interfaces()->size();
 174     class_size += k->transitive_interfaces()->size();
 175     // We do not have to count implementors, since we only store one!
 176     // FIXME: How should these be accounted for, now when they have moved.
 177     //class_size += k->fields()->size();
 178   }
 179   return class_size * oopSize;
 180 }
 181 
 182 bool ClassLoadingService::set_verbose(bool verbose) {
 183   MutexLocker m(Management_lock);
 184   // verbose will be set to the previous value
 185   if (verbose) {
 186     LogConfiguration::parse_log_arguments("stdout", "classload=info", NULL, NULL, NULL);
 187   } else {
 188     LogConfiguration::parse_log_arguments("stdout", "classload=off", NULL, NULL, NULL);
 189   }
 190   reset_trace_class_unloading();
 191   return verbose;
 192 }
 193 
 194 // Caller to this function must own Management_lock
 195 void ClassLoadingService::reset_trace_class_unloading() {
 196   assert(Management_lock->owned_by_self(), "Must own the Management_lock");
 197   bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();
 198   if (value) {
 199     LogConfiguration::parse_log_arguments("stdout", "classunload=info", NULL, NULL, NULL);
 200   } else {
 201     LogConfiguration::parse_log_arguments("stdout", "classunload=off", NULL, NULL, NULL);
 202   }
 203 }
 204 
 205 GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;
 206 Thread* LoadedClassesEnumerator::_current_thread = NULL;
 207 
 208 LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {
 209   assert(cur_thread == Thread::current(), "Check current thread");
 210 
 211   int init_size = ClassLoadingService::loaded_class_count();
 212   _klass_handle_array = new GrowableArray<KlassHandle>(init_size);
 213 
 214   // For consistency of the loaded classes, grab the SystemDictionary lock
 215   MutexLocker sd_mutex(SystemDictionary_lock);
 216 
 217   // Set _loaded_classes and _current_thread and begin enumerating all classes.
 218   // Only one thread will do the enumeration at a time.
 219   // These static variables are needed and they are used by the static method
 220   // add_loaded_class called from classes_do().
 221   _loaded_classes = _klass_handle_array;
 222   _current_thread = cur_thread;
 223 
 224   SystemDictionary::classes_do(&add_loaded_class);
 225 
 226   // FIXME: Exclude array klasses for now
 227   // Universe::basic_type_classes_do(&add_loaded_class);
 228 }
 229 
 230 #endif // INCLUDE_MANAGEMENT
--- EOF ---