heapInspection.cpp revision 1472:c18cbe5936b8 
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
24
25# include "incls/_precompiled.incl"
26# include "incls/_heapInspection.cpp.incl"
27
28// HeapInspection
29
30int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) {
31  if(e1->_instance_words > e2->_instance_words) {
32    return -1;
33  } else if(e1->_instance_words < e2->_instance_words) {
34    return 1;
35  }
36  return 0;
37}
38
39void KlassInfoEntry::print_on(outputStream* st) const {
40  ResourceMark rm;
41  const char* name;;
42  if (_klass->klass_part()->name() != NULL) {
43    name = _klass->klass_part()->external_name();
44  } else {
45    if (_klass == Universe::klassKlassObj())             name = "<klassKlass>";             else
46    if (_klass == Universe::arrayKlassKlassObj())        name = "<arrayKlassKlass>";        else
47    if (_klass == Universe::objArrayKlassKlassObj())     name = "<objArrayKlassKlass>";     else
48    if (_klass == Universe::instanceKlassKlassObj())     name = "<instanceKlassKlass>";     else
49    if (_klass == Universe::typeArrayKlassKlassObj())    name = "<typeArrayKlassKlass>";    else
50    if (_klass == Universe::symbolKlassObj())            name = "<symbolKlass>";            else
51    if (_klass == Universe::boolArrayKlassObj())         name = "<boolArrayKlass>";         else
52    if (_klass == Universe::charArrayKlassObj())         name = "<charArrayKlass>";         else
53    if (_klass == Universe::singleArrayKlassObj())       name = "<singleArrayKlass>";       else
54    if (_klass == Universe::doubleArrayKlassObj())       name = "<doubleArrayKlass>";       else
55    if (_klass == Universe::byteArrayKlassObj())         name = "<byteArrayKlass>";         else
56    if (_klass == Universe::shortArrayKlassObj())        name = "<shortArrayKlass>";        else
57    if (_klass == Universe::intArrayKlassObj())          name = "<intArrayKlass>";          else
58    if (_klass == Universe::longArrayKlassObj())         name = "<longArrayKlass>";         else
59    if (_klass == Universe::methodKlassObj())            name = "<methodKlass>";            else
60    if (_klass == Universe::constMethodKlassObj())       name = "<constMethodKlass>";       else
61    if (_klass == Universe::methodDataKlassObj())        name = "<methodDataKlass>";        else
62    if (_klass == Universe::constantPoolKlassObj())      name = "<constantPoolKlass>";      else
63    if (_klass == Universe::constantPoolCacheKlassObj()) name = "<constantPoolCacheKlass>"; else
64    if (_klass == Universe::compiledICHolderKlassObj())  name = "<compiledICHolderKlass>";  else
65      name = "<no name>";
66  }
67  // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit
68  st->print_cr(INT64_FORMAT_W(13) "  " UINT64_FORMAT_W(13) "  %s",
69               (jlong)  _instance_count,
70               (julong) _instance_words * HeapWordSize,
71               name);
72}
73
74KlassInfoEntry* KlassInfoBucket::lookup(const klassOop k) {
75  KlassInfoEntry* elt = _list;
76  while (elt != NULL) {
77    if (elt->is_equal(k)) {
78      return elt;
79    }
80    elt = elt->next();
81  }
82  elt = new KlassInfoEntry(k, list());
83  // We may be out of space to allocate the new entry.
84  if (elt != NULL) {
85    set_list(elt);
86  }
87  return elt;
88}
89
90void KlassInfoBucket::iterate(KlassInfoClosure* cic) {
91  KlassInfoEntry* elt = _list;
92  while (elt != NULL) {
93    cic->do_cinfo(elt);
94    elt = elt->next();
95  }
96}
97
98void KlassInfoBucket::empty() {
99  KlassInfoEntry* elt = _list;
100  _list = NULL;
101  while (elt != NULL) {
102    KlassInfoEntry* next = elt->next();
103    delete elt;
104    elt = next;
105  }
106}
107
108KlassInfoTable::KlassInfoTable(int size, HeapWord* ref) {
109  _size = 0;
110  _ref = ref;
111  _buckets = NEW_C_HEAP_ARRAY(KlassInfoBucket, size);
112  if (_buckets != NULL) {
113    _size = size;
114    for (int index = 0; index < _size; index++) {
115      _buckets[index].initialize();
116    }
117  }
118}
119
120KlassInfoTable::~KlassInfoTable() {
121  if (_buckets != NULL) {
122    for (int index = 0; index < _size; index++) {
123      _buckets[index].empty();
124    }
125    FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets);
126    _size = 0;
127  }
128}
129
130uint KlassInfoTable::hash(klassOop p) {
131  assert(Universe::heap()->is_in_permanent((HeapWord*)p), "all klasses in permgen");
132  return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);
133}
134
135KlassInfoEntry* KlassInfoTable::lookup(const klassOop k) {
136  uint         idx = hash(k) % _size;
137  assert(_buckets != NULL, "Allocation failure should have been caught");
138  KlassInfoEntry*  e   = _buckets[idx].lookup(k);
139  // Lookup may fail if this is a new klass for which we
140  // could not allocate space for an new entry.
141  assert(e == NULL || k == e->klass(), "must be equal");
142  return e;
143}
144
145// Return false if the entry could not be recorded on account
146// of running out of space required to create a new entry.
147bool KlassInfoTable::record_instance(const oop obj) {
148  klassOop      k = obj->klass();
149  KlassInfoEntry* elt = lookup(k);
150  // elt may be NULL if it's a new klass for which we
151  // could not allocate space for a new entry in the hashtable.
152  if (elt != NULL) {
153    elt->set_count(elt->count() + 1);
154    elt->set_words(elt->words() + obj->size());
155    return true;
156  } else {
157    return false;
158  }
159}
160
161void KlassInfoTable::iterate(KlassInfoClosure* cic) {
162  assert(_size == 0 || _buckets != NULL, "Allocation failure should have been caught");
163  for (int index = 0; index < _size; index++) {
164    _buckets[index].iterate(cic);
165  }
166}
167
168int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {
169  return (*e1)->compare(*e1,*e2);
170}
171
172KlassInfoHisto::KlassInfoHisto(const char* title, int estimatedCount) :
173  _title(title) {
174  _elements = new (ResourceObj::C_HEAP) GrowableArray<KlassInfoEntry*>(estimatedCount,true);
175}
176
177KlassInfoHisto::~KlassInfoHisto() {
178  delete _elements;
179}
180
181void KlassInfoHisto::add(KlassInfoEntry* cie) {
182  elements()->append(cie);
183}
184
185void KlassInfoHisto::sort() {
186  elements()->sort(KlassInfoHisto::sort_helper);
187}
188
189void KlassInfoHisto::print_elements(outputStream* st) const {
190  // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit
191  jlong total = 0;
192  julong totalw = 0;
193  for(int i=0; i < elements()->length(); i++) {
194    st->print("%4d: ", i+1);
195    elements()->at(i)->print_on(st);
196    total += elements()->at(i)->count();
197    totalw += elements()->at(i)->words();
198  }
199  st->print_cr("Total " INT64_FORMAT_W(13) "  " UINT64_FORMAT_W(13),
200               total, totalw * HeapWordSize);
201}
202
203void KlassInfoHisto::print_on(outputStream* st) const {
204  st->print_cr("%s",title());
205  print_elements(st);
206}
207
208class HistoClosure : public KlassInfoClosure {
209 private:
210  KlassInfoHisto* _cih;
211 public:
212  HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}
213
214  void do_cinfo(KlassInfoEntry* cie) {
215    _cih->add(cie);
216  }
217};
218
219class RecordInstanceClosure : public ObjectClosure {
220 private:
221  KlassInfoTable* _cit;
222  size_t _missed_count;
223 public:
224  RecordInstanceClosure(KlassInfoTable* cit) :
225    _cit(cit), _missed_count(0) {}
226
227  void do_object(oop obj) {
228    if (!_cit->record_instance(obj)) {
229      _missed_count++;
230    }
231  }
232
233  size_t missed_count() { return _missed_count; }
234};
235
236void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) {
237  ResourceMark rm;
238  HeapWord* ref;
239
240  CollectedHeap* heap = Universe::heap();
241  bool is_shared_heap = false;
242  switch (heap->kind()) {
243    case CollectedHeap::G1CollectedHeap:
244    case CollectedHeap::GenCollectedHeap: {
245      is_shared_heap = true;
246      SharedHeap* sh = (SharedHeap*)heap;
247      if (need_prologue) {
248        sh->gc_prologue(false /* !full */); // get any necessary locks, etc.
249      }
250      ref = sh->perm_gen()->used_region().start();
251      break;
252    }
253#ifndef SERIALGC
254    case CollectedHeap::ParallelScavengeHeap: {
255      ParallelScavengeHeap* psh = (ParallelScavengeHeap*)heap;
256      ref = psh->perm_gen()->object_space()->used_region().start();
257      break;
258    }
259#endif // SERIALGC
260    default:
261      ShouldNotReachHere(); // Unexpected heap kind for this op
262  }
263  // Collect klass instance info
264  KlassInfoTable cit(KlassInfoTable::cit_size, ref);
265  if (!cit.allocation_failed()) {
266    // Iterate over objects in the heap
267    RecordInstanceClosure ric(&cit);
268    // If this operation encounters a bad object when using CMS,
269    // consider using safe_object_iterate() which avoids perm gen
270    // objects that may contain bad references.
271    Universe::heap()->object_iterate(&ric);
272
273    // Report if certain classes are not counted because of
274    // running out of C-heap for the histogram.
275    size_t missed_count = ric.missed_count();
276    if (missed_count != 0) {
277      st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT
278                   " total instances in data below",
279                   missed_count);
280    }
281    // Sort and print klass instance info
282    KlassInfoHisto histo("\n"
283                     " num     #instances         #bytes  class name\n"
284                     "----------------------------------------------",
285                     KlassInfoHisto::histo_initial_size);
286    HistoClosure hc(&histo);
287    cit.iterate(&hc);
288    histo.sort();
289    histo.print_on(st);
290  } else {
291    st->print_cr("WARNING: Ran out of C-heap; histogram not generated");
292  }
293  st->flush();
294
295  if (need_prologue && is_shared_heap) {
296    SharedHeap* sh = (SharedHeap*)heap;
297    sh->gc_epilogue(false /* !full */); // release all acquired locks, etc.
298  }
299}
300
301class FindInstanceClosure : public ObjectClosure {
302 private:
303  klassOop _klass;
304  GrowableArray<oop>* _result;
305
306 public:
307  FindInstanceClosure(klassOop k, GrowableArray<oop>* result) : _klass(k), _result(result) {};
308
309  void do_object(oop obj) {
310    if (obj->is_a(_klass)) {
311      _result->append(obj);
312    }
313  }
314};
315
316void HeapInspection::find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) {
317  assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
318  assert(Heap_lock->is_locked(), "should have the Heap_lock");
319
320  // Ensure that the heap is parsable
321  Universe::heap()->ensure_parsability(false);  // no need to retire TALBs
322
323  // Iterate over objects in the heap
324  FindInstanceClosure fic(k, result);
325  // If this operation encounters a bad object when using CMS,
326  // consider using safe_object_iterate() which avoids perm gen
327  // objects that may contain bad references.
328  Universe::heap()->object_iterate(&fic);
329}
330