1 /*
2 * Copyright (c) 2002, 2011, 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 "gc_interface/collectedHeap.hpp"
27 #include "memory/genCollectedHeap.hpp"
28 #include "memory/heapInspection.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/klassOop.hpp"
31 #include "runtime/os.hpp"
32 #include "utilities/globalDefinitions.hpp"
33 #ifndef SERIALGC
34 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
35 #endif
36
37 // HeapInspection
38
39 int KlassInfoEntry::compare(KlassInfoEntry* e1, KlassInfoEntry* e2) {
40 if(e1->_instance_words > e2->_instance_words) {
41 return -1;
42 } else if(e1->_instance_words < e2->_instance_words) {
43 return 1;
44 }
45 return 0;
46 }
47
48 void KlassInfoEntry::print_on(outputStream* st) const {
49 ResourceMark rm;
50 const char* name;;
51 if (_klass->klass_part()->name() != NULL) {
52 name = _klass->klass_part()->external_name();
53 } else {
54 if (_klass == Universe::klassKlassObj()) name = "<klassKlass>"; else
55 if (_klass == Universe::arrayKlassKlassObj()) name = "<arrayKlassKlass>"; else
56 if (_klass == Universe::objArrayKlassKlassObj()) name = "<objArrayKlassKlass>"; else
57 if (_klass == Universe::instanceKlassKlassObj()) name = "<instanceKlassKlass>"; else
58 if (_klass == Universe::typeArrayKlassKlassObj()) name = "<typeArrayKlassKlass>"; else
59 if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else
60 if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else
61 if (_klass == Universe::singleArrayKlassObj()) name = "<singleArrayKlass>"; else
62 if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else
63 if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else
64 if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else
65 if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else
66 if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else
67 if (_klass == Universe::methodKlassObj()) name = "<methodKlass>"; else
68 if (_klass == Universe::constMethodKlassObj()) name = "<constMethodKlass>"; else
69 if (_klass == Universe::methodDataKlassObj()) name = "<methodDataKlass>"; else
70 if (_klass == Universe::constantPoolKlassObj()) name = "<constantPoolKlass>"; else
71 if (_klass == Universe::constantPoolCacheKlassObj()) name = "<constantPoolCacheKlass>"; else
72 if (_klass == Universe::compiledICHolderKlassObj()) name = "<compiledICHolderKlass>"; else
73 name = "<no name>";
74 }
75 // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit
76 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s",
77 (jlong) _instance_count,
78 (julong) _instance_words * HeapWordSize,
79 name);
80 }
81
82 KlassInfoEntry* KlassInfoBucket::lookup(const klassOop k) {
83 KlassInfoEntry* elt = _list;
84 while (elt != NULL) {
85 if (elt->is_equal(k)) {
86 return elt;
87 }
88 elt = elt->next();
89 }
90 elt = new (std::nothrow) KlassInfoEntry(k, list());
91 // We may be out of space to allocate the new entry.
92 if (elt != NULL) {
93 set_list(elt);
94 }
95 return elt;
96 }
97
98 void KlassInfoBucket::iterate(KlassInfoClosure* cic) {
99 KlassInfoEntry* elt = _list;
100 while (elt != NULL) {
101 cic->do_cinfo(elt);
102 elt = elt->next();
103 }
104 }
105
106 void KlassInfoBucket::empty() {
107 KlassInfoEntry* elt = _list;
108 _list = NULL;
109 while (elt != NULL) {
110 KlassInfoEntry* next = elt->next();
111 delete elt;
112 elt = next;
113 }
114 }
115
116 KlassInfoTable::KlassInfoTable(HeapWord* ref) :
117 _size(0), _ref(ref), _size_of_instances_in_words(0) {
118 _buckets = (KlassInfoBucket *) os::malloc(sizeof(KlassInfoBucket) * _num_buckets, mtInternal);
119 if (_buckets != NULL) {
120 _size = _num_buckets;
121 for (int index = 0; index < _size; index++) {
122 _buckets[index].initialize();
123 }
124 }
125 }
126
127 KlassInfoTable::~KlassInfoTable() {
128 if (_buckets != NULL) {
129 for (int index = 0; index < _size; index++) {
130 _buckets[index].empty();
131 }
132 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets, mtInternal);
133 _size = 0;
134 }
135 }
136
137 uint KlassInfoTable::hash(klassOop p) {
138 assert(Universe::heap()->is_in_permanent((HeapWord*)p), "all klasses in permgen");
139 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);
140 }
141
142 KlassInfoEntry* KlassInfoTable::lookup(const klassOop k) {
143 uint idx = hash(k) % _size;
144 assert(_buckets != NULL, "Allocation failure should have been caught");
145 KlassInfoEntry* e = _buckets[idx].lookup(k);
146 // Lookup may fail if this is a new klass for which we
147 // could not allocate space for an new entry.
148 assert(e == NULL || k == e->klass(), "must be equal");
149 return e;
150 }
151
152 // Return false if the entry could not be recorded on account
153 // of running out of space required to create a new entry.
154 bool KlassInfoTable::record_instance(const oop obj) {
155 klassOop k = obj->klass();
156 KlassInfoEntry* elt = lookup(k);
157 // elt may be NULL if it's a new klass for which we
158 // could not allocate space for a new entry in the hashtable.
159 if (elt != NULL) {
160 elt->set_count(elt->count() + 1);
161 elt->set_words(elt->words() + obj->size());
162 _size_of_instances_in_words += obj->size();
163 return true;
164 } else {
165 return false;
166 }
167 }
168
169 void KlassInfoTable::iterate(KlassInfoClosure* cic) {
170 assert(_size == 0 || _buckets != NULL, "Allocation failure should have been caught");
171 for (int index = 0; index < _size; index++) {
172 _buckets[index].iterate(cic);
173 }
174 }
175
176 size_t KlassInfoTable::size_of_instances_in_words() const {
177 return _size_of_instances_in_words;
178 }
179
180 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {
181 return (*e1)->compare(*e1,*e2);
182 }
183
184 KlassInfoHisto::KlassInfoHisto(const char* title) :
185 _title(title) {
186 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<KlassInfoEntry*>(_histo_initial_size, true);
187 }
188
189 KlassInfoHisto::~KlassInfoHisto() {
190 delete _elements;
191 }
192
193 void KlassInfoHisto::add(KlassInfoEntry* cie) {
194 elements()->append(cie);
195 }
196
197 void KlassInfoHisto::sort() {
198 elements()->sort(KlassInfoHisto::sort_helper);
199 }
200
201 void KlassInfoHisto::print_elements(outputStream* st) const {
202 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit
203 jlong total = 0;
204 julong totalw = 0;
205 for(int i=0; i < elements()->length(); i++) {
206 st->print("%4d: ", i+1);
207 elements()->at(i)->print_on(st);
208 total += elements()->at(i)->count();
209 totalw += elements()->at(i)->words();
210 }
211 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13),
212 total, totalw * HeapWordSize);
213 }
214
215 void KlassInfoHisto::print_on(outputStream* st) const {
216 st->print_cr("%s",title());
217 print_elements(st);
218 }
219
220 class HistoClosure : public KlassInfoClosure {
221 private:
222 KlassInfoHisto* _cih;
223 public:
224 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}
225
226 void do_cinfo(KlassInfoEntry* cie) {
227 _cih->add(cie);
228 }
229 };
230
231 class RecordInstanceClosure : public ObjectClosure {
232 private:
233 KlassInfoTable* _cit;
234 size_t _missed_count;
235 BoolObjectClosure* _filter;
236 public:
237 RecordInstanceClosure(KlassInfoTable* cit, BoolObjectClosure* filter) :
238 _cit(cit), _missed_count(0), _filter(filter) {}
239
240 void do_object(oop obj) {
241 if (should_visit(obj)) {
242 if (!_cit->record_instance(obj)) {
243 _missed_count++;
244 }
245 }
246 }
247
248 size_t missed_count() { return _missed_count; }
249 private:
250 bool should_visit(oop obj) {
251 return _filter == NULL || _filter->do_object_b(obj);
252 }
253 };
254
255 HeapWord* HeapInspection::start_of_perm_gen() {
256 if (is_shared_heap()) {
257 SharedHeap* sh = SharedHeap::heap();
258 return sh->perm_gen()->used_region().start();
259 }
260 #ifndef SERIALGC
261 ParallelScavengeHeap* psh = (ParallelScavengeHeap*)Universe::heap();
262 return psh->perm_gen()->object_space()->used_region().start();
263 #else
264 ShouldNotReachHere();
265 return NULL;
266 #endif // SERIALGC
267 }
268
269 bool HeapInspection::is_shared_heap() {
270 CollectedHeap* heap = Universe::heap();
271 return heap->kind() == CollectedHeap::G1CollectedHeap ||
272 heap->kind() == CollectedHeap::GenCollectedHeap;
273 }
274
275 void HeapInspection::prologue() {
276 if (is_shared_heap()) {
277 SharedHeap* sh = SharedHeap::heap();
278 sh->gc_prologue(false /* !full */); // get any necessary locks, etc.
279 }
280 }
281
282 void HeapInspection::epilogue() {
283 if (is_shared_heap()) {
284 SharedHeap* sh = SharedHeap::heap();
285 sh->gc_epilogue(false /* !full */); // release all acquired locks, etc.
286 }
287 }
288
289 size_t HeapInspection::populate_table(KlassInfoTable* cit,
290 bool need_prologue,
291 BoolObjectClosure *filter) {
292 ResourceMark rm;
293
294 if (need_prologue) {
295 prologue();
296 }
297
298 RecordInstanceClosure ric(cit, filter);
299 Universe::heap()->object_iterate(&ric);
300
301 // need to run epilogue if we run prologue
302 if (need_prologue) {
303 epilogue();
304 }
305
306 return ric.missed_count();
307 }
308
309 void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) {
310 ResourceMark rm;
311
312 KlassInfoTable cit(start_of_perm_gen());
313 if (!cit.allocation_failed()) {
314 size_t missed_count = populate_table(&cit, need_prologue);
315 if (missed_count != 0) {
316 st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT
317 " total instances in data below",
318 missed_count);
319 }
320
321 KlassInfoHisto histo("\n"
322 " num #instances #bytes class name\n"
323 "----------------------------------------------");
324 HistoClosure hc(&histo);
325
326 cit.iterate(&hc);
327
328 histo.sort();
329 histo.print_on(st);
330 } else {
331 st->print_cr("WARNING: Ran out of C-heap; histogram not generated");
332 }
333 st->flush();
334 }
335
336 class FindInstanceClosure : public ObjectClosure {
337 private:
338 klassOop _klass;
339 GrowableArray<oop>* _result;
340
341 public:
342 FindInstanceClosure(klassOop k, GrowableArray<oop>* result) : _klass(k), _result(result) {};
343
344 void do_object(oop obj) {
345 if (obj->is_a(_klass)) {
346 _result->append(obj);
347 }
348 }
349 };
350
351 void HeapInspection::find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) {
352 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
353 assert(Heap_lock->is_locked(), "should have the Heap_lock");
354
355 // Ensure that the heap is parsable
356 Universe::heap()->ensure_parsability(false); // no need to retire TALBs
357
358 // Iterate over objects in the heap
359 FindInstanceClosure fic(k, result);
360 // If this operation encounters a bad object when using CMS,
361 // consider using safe_object_iterate() which avoids perm gen
362 // objects that may contain bad references.
363 Universe::heap()->object_iterate(&fic);
364 }