/*

 * Copyright (c) 2002, 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 "gc_interface/collectedHeap.hpp"

#include "memory/genCollectedHeap.hpp"

#include "memory/heapInspection.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/os.hpp"

#include "utilities/globalDefinitions.hpp"

#include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"

// HeapInspection

int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) {

  if(e1->_instance_words > e2->_instance_words) {

    return -1;

  } else if(e1->_instance_words < e2->_instance_words) {

    return 1;

  }

  return 0;

}

void KlassInfoEntry::print_on(outputStream* st) const {

  ResourceMark rm;

  const char* name;;

  if (_klass->name() != NULL) {

    name = _klass->external_name();

  } else {

    if (_klass == Universe::boolArrayKlassObj())         name = "<boolArrayKlass>";         else

    if (_klass == Universe::charArrayKlassObj())         name = "<charArrayKlass>";         else

    if (_klass == Universe::singleArrayKlassObj())       name = "<singleArrayKlass>";       else

    if (_klass == Universe::doubleArrayKlassObj())       name = "<doubleArrayKlass>";       else

    if (_klass == Universe::byteArrayKlassObj())         name = "<byteArrayKlass>";         else

    if (_klass == Universe::shortArrayKlassObj())        name = "<shortArrayKlass>";        else

    if (_klass == Universe::intArrayKlassObj())          name = "<intArrayKlass>";          else

    if (_klass == Universe::longArrayKlassObj())         name = "<longArrayKlass>";         else

      name = "<no name>";

  }

  // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit

  st->print_cr(INT64_FORMAT_W(13) "  " UINT64_FORMAT_W(13) "  %s",

               (jlong)  _instance_count,

               (julong) _instance_words * HeapWordSize,

               name);

}

KlassInfoEntry* KlassInfoBucket::lookup(Klass* const k) {

  KlassInfoEntry* elt = _list;

  while (elt != NULL) {

    if (elt->is_equal(k)) {

      return elt;

    }

    elt = elt->next();

  }

  elt = new KlassInfoEntry(k, list());

  // We may be out of space to allocate the new entry.

  if (elt != NULL) {

    set_list(elt);

  }

  return elt;

}

void KlassInfoBucket::iterate(KlassInfoClosure* cic) {

  KlassInfoEntry* elt = _list;

  while (elt != NULL) {

    cic->do_cinfo(elt);

    elt = elt->next();

  }

}

void KlassInfoBucket::empty() {

  KlassInfoEntry* elt = _list;

  _list = NULL;

  while (elt != NULL) {

    KlassInfoEntry* next = elt->next();

    delete elt;

    elt = next;

  }

}

KlassInfoTable::KlassInfoTable(int size, HeapWord* ref) {

  _size = 0;

  _ref = ref;

  _buckets = NEW_C_HEAP_ARRAY(KlassInfoBucket, size, mtInternal);

  if (_buckets != NULL) {

    _size = size;

    for (int index = 0; index < _size; index++) {

      _buckets[index].initialize();

    }

  }

}

KlassInfoTable::~KlassInfoTable() {

  if (_buckets != NULL) {

    for (int index = 0; index < _size; index++) {

      _buckets[index].empty();

    }

    FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets, mtInternal);

    _size = 0;

  }

}

uint KlassInfoTable::hash(Klass* p) {

  assert(p->is_metadata(), "all klasses are metadata");

  return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);

}

KlassInfoEntry* KlassInfoTable::lookup(Klass* const k) {

  uint         idx = hash(k) % _size;

  assert(_buckets != NULL, "Allocation failure should have been caught");

  KlassInfoEntry*  e   = _buckets[idx].lookup(k);

  // Lookup may fail if this is a new klass for which we

  // could not allocate space for an new entry.

  assert(e == NULL || k == e->klass(), "must be equal");

  return e;

}

// Return false if the entry could not be recorded on account

// of running out of space required to create a new entry.

bool KlassInfoTable::record_instance(const oop obj) {

  Klass*        k = obj->klass();

  KlassInfoEntry* elt = lookup(k);

  // elt may be NULL if it's a new klass for which we

  // could not allocate space for a new entry in the hashtable.

  if (elt != NULL) {

    elt->set_count(elt->count() + 1);

    elt->set_words(elt->words() + obj->size());

    return true;

  } else {

    return false;

  }

}

void KlassInfoTable::iterate(KlassInfoClosure* cic) {

  assert(_size == 0 || _buckets != NULL, "Allocation failure should have been caught");

  for (int index = 0; index < _size; index++) {

    _buckets[index].iterate(cic);

  }

}

int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {

  return (*e1)->compare(*e1,*e2);

}

KlassInfoHisto::KlassInfoHisto(const char* title, int estimatedCount) :

  _title(title) {

  _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(estimatedCount,true);

}

KlassInfoHisto::~KlassInfoHisto() {

  delete _elements;

}

void KlassInfoHisto::add(KlassInfoEntry* cie) {

  elements()->append(cie);

}

void KlassInfoHisto::sort() {

  elements()->sort(KlassInfoHisto::sort_helper);

}

void KlassInfoHisto::print_elements(outputStream* st) const {

  // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit

  jlong total = 0;

  julong totalw = 0;

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

    st->print("%4d: ", i+1);

    elements()->at(i)->print_on(st);

    total += elements()->at(i)->count();

    totalw += elements()->at(i)->words();

  }

  st->print_cr("Total " INT64_FORMAT_W(13) "  " UINT64_FORMAT_W(13),

               total, totalw * HeapWordSize);

}

void KlassInfoHisto::print_on(outputStream* st) const {

  st->print_cr("%s",title());

  print_elements(st);

}

class HistoClosure : public KlassInfoClosure {

 private:

  KlassInfoHisto* _cih;

 public:

  HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}

  void do_cinfo(KlassInfoEntry* cie) {

    _cih->add(cie);

  }

};

class RecordInstanceClosure : public ObjectClosure {

 private:

  KlassInfoTable* _cit;

  size_t _missed_count;

 public:

  RecordInstanceClosure(KlassInfoTable* cit) :

    _cit(cit), _missed_count(0) {}

  void do_object(oop obj) {

    if (!_cit->record_instance(obj)) {

      _missed_count++;

    }

  }

  size_t missed_count() { return _missed_count; }

};

void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) {

  ResourceMark rm;

  // Get some random number for ref (the hash key)

  HeapWord* ref = (HeapWord*) Universe::boolArrayKlassObj();

  CollectedHeap* heap = Universe::heap();

  bool is_shared_heap = false;

  // Collect klass instance info

  KlassInfoTable cit(KlassInfoTable::cit_size, ref);

  if (!cit.allocation_failed()) {

    // Iterate over objects in the heap

    RecordInstanceClosure ric(&cit);

    Universe::heap()->object_iterate(&ric);

    // Report if certain classes are not counted because of

    // running out of C-heap for the histogram.

    size_t missed_count = ric.missed_count();

    if (missed_count != 0) {

      st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT

                   " total instances in data below",

                   missed_count);

    }

    // Sort and print klass instance info

    KlassInfoHisto histo("\n"

                     " num     #instances         #bytes  class name\n"

                     "----------------------------------------------",

                     KlassInfoHisto::histo_initial_size);

    HistoClosure hc(&histo);

    cit.iterate(&hc);

    histo.sort();

    histo.print_on(st);

  } else {

    st->print_cr("WARNING: Ran out of C-heap; histogram not generated");

  }

  st->flush();

  if (need_prologue && is_shared_heap) {

    SharedHeap* sh = (SharedHeap*)heap;

    sh->gc_epilogue(false /* !full */); // release all acquired locks, etc.

  }

}

class FindInstanceClosure : public ObjectClosure {

 private:

  Klass* _klass;

  GrowableArray<oop>* _result;

 public:

  FindInstanceClosure(Klass* k, GrowableArray<oop>* result) : _klass(k), _result(result) {};

  void do_object(oop obj) {

    if (obj->is_a(_klass)) {

      _result->append(obj);

    }

  }

};

void HeapInspection::find_instances_at_safepoint(Klass* k, GrowableArray<oop>* result) {

  assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");

  assert(Heap_lock->is_locked(), "should have the Heap_lock");

  // Ensure that the heap is parsable

  Universe::heap()->ensure_parsability(false);  // no need to retire TALBs

  // Iterate over objects in the heap

  FindInstanceClosure fic(k, result);

  // If this operation encounters a bad object when using CMS,

  // consider using safe_object_iterate() which avoids metadata

  // objects that may contain bad references.

  Universe::heap()->object_iterate(&fic);

}