/*

 * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#include "precompiled.hpp"

#include "classfile/systemDictionary.hpp"

#include "memory/allocation.hpp"

#include "memory/universe.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/mutexLocker.hpp"

#include "services/classLoadingService.hpp"

#include "services/memoryService.hpp"

#include "utilities/dtrace.hpp"

#ifdef DTRACE_ENABLED

// Only bother with this argument setup if dtrace is available

#ifndef USDT2

HS_DTRACE_PROBE_DECL4(hotspot, class__loaded, char*, int, oop, bool);

HS_DTRACE_PROBE_DECL4(hotspot, class__unloaded, char*, int, oop, bool);

#define DTRACE_CLASSLOAD_PROBE(type, clss, shared)  \

  {                                                 \

    char* data = NULL;                              \

    int len = 0;                                    \

    Symbol* name = (clss)->name();                  \

    if (name != NULL) {                             \

      data = (char*)name->bytes();                  \

      len = name->utf8_length();                    \

    }                                               \

    HS_DTRACE_PROBE4(hotspot, class__##type,        \

      data, len, (clss)->class_loader(), (shared)); \

  }

#else /* USDT2 */

#define HOTSPOT_CLASS_unloaded HOTSPOT_CLASS_UNLOADED

#define HOTSPOT_CLASS_loaded HOTSPOT_CLASS_LOADED

#define DTRACE_CLASSLOAD_PROBE(type, clss, shared)  \

  {                                                 \

    char* data = NULL;                              \

    int len = 0;                                    \

    Symbol* name = (clss)->name();                  \

    if (name != NULL) {                             \

      data = (char*)name->bytes();                  \

      len = name->utf8_length();                    \

    }                                               \

    HOTSPOT_CLASS_##type( /* type = unloaded, loaded */ \

      data, len, (clss)->class_loader(), (shared)); \

  }

#endif /* USDT2 */

#else //  ndef DTRACE_ENABLED

#define DTRACE_CLASSLOAD_PROBE(type, clss, shared)

#endif

// counters for classes loaded from class files

PerfCounter*    ClassLoadingService::_classes_loaded_count = NULL;

PerfCounter*    ClassLoadingService::_classes_unloaded_count = NULL;

PerfCounter*    ClassLoadingService::_classbytes_loaded = NULL;

PerfCounter*    ClassLoadingService::_classbytes_unloaded = NULL;

// counters for classes loaded from shared archive

PerfCounter*    ClassLoadingService::_shared_classes_loaded_count = NULL;

PerfCounter*    ClassLoadingService::_shared_classes_unloaded_count = NULL;

PerfCounter*    ClassLoadingService::_shared_classbytes_loaded = NULL;

PerfCounter*    ClassLoadingService::_shared_classbytes_unloaded = NULL;

PerfVariable*   ClassLoadingService::_class_methods_size = NULL;

void ClassLoadingService::init() {

  EXCEPTION_MARK;

  // These counters are for java.lang.management API support.

  // They are created even if -XX:-UsePerfData is set and in

  // that case, they will be allocated on C heap.

  _classes_loaded_count =

                 PerfDataManager::create_counter(JAVA_CLS, "loadedClasses",

                                                 PerfData::U_Events, CHECK);

  _classes_unloaded_count =

                 PerfDataManager::create_counter(JAVA_CLS, "unloadedClasses",

                                                 PerfData::U_Events, CHECK);

  _shared_classes_loaded_count =

                 PerfDataManager::create_counter(JAVA_CLS, "sharedLoadedClasses",

                                                 PerfData::U_Events, CHECK);

  _shared_classes_unloaded_count =

                 PerfDataManager::create_counter(JAVA_CLS, "sharedUnloadedClasses",

                                                 PerfData::U_Events, CHECK);

  if (UsePerfData) {

    _classbytes_loaded =

                 PerfDataManager::create_counter(SUN_CLS, "loadedBytes",

                                                 PerfData::U_Bytes, CHECK);

    _classbytes_unloaded =

                 PerfDataManager::create_counter(SUN_CLS, "unloadedBytes",

                                                 PerfData::U_Bytes, CHECK);

    _shared_classbytes_loaded =

                 PerfDataManager::create_counter(SUN_CLS, "sharedLoadedBytes",

                                                 PerfData::U_Bytes, CHECK);

    _shared_classbytes_unloaded =

                 PerfDataManager::create_counter(SUN_CLS, "sharedUnloadedBytes",

                                                 PerfData::U_Bytes, CHECK);

    _class_methods_size =

                 PerfDataManager::create_variable(SUN_CLS, "methodBytes",

                                                  PerfData::U_Bytes, CHECK);

  }

}

void ClassLoadingService::notify_class_unloaded(InstanceKlass* k) {

  DTRACE_CLASSLOAD_PROBE(unloaded, k, false);

  // Classes that can be unloaded must be non-shared

  _classes_unloaded_count->inc();

  if (UsePerfData) {

    // add the class size

    size_t size = compute_class_size(k);

    _classbytes_unloaded->inc(size);

    // Compute method size & subtract from running total.

    // We are called during phase 1 of mark sweep, so it's

    // still ok to iterate through Method*s here.

    Array<Method*>* methods = k->methods();

    for (int i = 0; i < methods->length(); i++) {

      _class_methods_size->inc(-methods->at(i)->size());

    }

  }

  if (TraceClassUnloading) {

    ResourceMark rm;

    tty->print_cr("[Unloading class %s " INTPTR_FORMAT "]", k->external_name(), k);

  }

}

void ClassLoadingService::notify_class_loaded(InstanceKlass* k, bool shared_class) {

  DTRACE_CLASSLOAD_PROBE(loaded, k, shared_class);

  PerfCounter* classes_counter = (shared_class ? _shared_classes_loaded_count

                                               : _classes_loaded_count);

  // increment the count

  classes_counter->inc();

  if (UsePerfData) {

    PerfCounter* classbytes_counter = (shared_class ? _shared_classbytes_loaded

                                                    : _classbytes_loaded);

    // add the class size

    size_t size = compute_class_size(k);

    classbytes_counter->inc(size);

  }

}

size_t ClassLoadingService::compute_class_size(InstanceKlass* k) {

  // lifted from ClassStatistics.do_class(Klass* k)

  size_t class_size = 0;

  class_size += k->size();

  if (k->oop_is_instance()) {

    class_size += k->methods()->size();

    // FIXME: Need to count the contents of methods

    class_size += k->constants()->size();

    class_size += k->local_interfaces()->size();

    class_size += k->transitive_interfaces()->size();

    // We do not have to count implementors, since we only store one!

    // FIXME: How should these be accounted for, now when they have moved.

    //class_size += k->fields()->size();

  }

  return class_size * oopSize;

}

bool ClassLoadingService::set_verbose(bool verbose) {

  MutexLocker m(Management_lock);

  // verbose will be set to the previous value

  bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassLoading", &verbose, MANAGEMENT);

  assert(succeed, "Setting TraceClassLoading flag fails");

  reset_trace_class_unloading();

  return verbose;

}

// Caller to this function must own Management_lock

void ClassLoadingService::reset_trace_class_unloading() {

  assert(Management_lock->owned_by_self(), "Must own the Management_lock");

  bool value = MemoryService::get_verbose() || ClassLoadingService::get_verbose();

  bool succeed = CommandLineFlags::boolAtPut((char*)"TraceClassUnloading", &value, MANAGEMENT);

  assert(succeed, "Setting TraceClassUnLoading flag fails");

}

GrowableArray<KlassHandle>* LoadedClassesEnumerator::_loaded_classes = NULL;

Thread* LoadedClassesEnumerator::_current_thread = NULL;

LoadedClassesEnumerator::LoadedClassesEnumerator(Thread* cur_thread) {

  assert(cur_thread == Thread::current(), "Check current thread");

  int init_size = ClassLoadingService::loaded_class_count();

  _klass_handle_array = new GrowableArray<KlassHandle>(init_size);

  // For consistency of the loaded classes, grab the SystemDictionary lock

  MutexLocker sd_mutex(SystemDictionary_lock);

  // Set _loaded_classes and _current_thread and begin enumerating all classes.

  // Only one thread will do the enumeration at a time.

  // These static variables are needed and they are used by the static method

  // add_loaded_class called from classes_do().

  _loaded_classes = _klass_handle_array;

  _current_thread = cur_thread;

  SystemDictionary::classes_do(&add_loaded_class);

  // FIXME: Exclude array klasses for now

  // Universe::basic_type_classes_do(&add_loaded_class);

}