1 /*
2 * Copyright (c) 2002, 2010, 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::symbolKlassObj()) name = "<symbolKlass>"; else
60 if (_klass == Universe::boolArrayKlassObj()) name = "<boolArrayKlass>"; else
61 if (_klass == Universe::charArrayKlassObj()) name = "<charArrayKlass>"; else
62 if (_klass == Universe::singleArrayKlassObj()) name = "<singleArrayKlass>"; else
63 if (_klass == Universe::doubleArrayKlassObj()) name = "<doubleArrayKlass>"; else
64 if (_klass == Universe::byteArrayKlassObj()) name = "<byteArrayKlass>"; else
65 if (_klass == Universe::shortArrayKlassObj()) name = "<shortArrayKlass>"; else
66 if (_klass == Universe::intArrayKlassObj()) name = "<intArrayKlass>"; else
67 if (_klass == Universe::longArrayKlassObj()) name = "<longArrayKlass>"; else
68 if (_klass == Universe::methodKlassObj()) name = "<methodKlass>"; else
69 if (_klass == Universe::constMethodKlassObj()) name = "<constMethodKlass>"; else
70 if (_klass == Universe::methodDataKlassObj()) name = "<methodDataKlass>"; else
71 if (_klass == Universe::constantPoolKlassObj()) name = "<constantPoolKlass>"; else
72 if (_klass == Universe::constantPoolCacheKlassObj()) name = "<constantPoolCacheKlass>"; else
73 if (_klass == Universe::compiledICHolderKlassObj()) name = "<compiledICHolderKlass>"; else
74 name = "<no name>";
75 }
76 // simplify the formatting (ILP32 vs LP64) - always cast the numbers to 64-bit
77 st->print_cr(INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13) " %s",
78 (jlong) _instance_count,
79 (julong) _instance_words * HeapWordSize,
80 name);
81 }
82
83 KlassInfoEntry* KlassInfoBucket::lookup(const klassOop k) {
84 KlassInfoEntry* elt = _list;
85 while (elt != NULL) {
86 if (elt->is_equal(k)) {
87 return elt;
88 }
89 elt = elt->next();
90 }
91 elt = new KlassInfoEntry(k, list());
92 // We may be out of space to allocate the new entry.
93 if (elt != NULL) {
94 set_list(elt);
95 }
96 return elt;
97 }
98
99 void KlassInfoBucket::iterate(KlassInfoClosure* cic) {
100 KlassInfoEntry* elt = _list;
101 while (elt != NULL) {
102 cic->do_cinfo(elt);
103 elt = elt->next();
104 }
105 }
106
107 void KlassInfoBucket::empty() {
108 KlassInfoEntry* elt = _list;
109 _list = NULL;
110 while (elt != NULL) {
111 KlassInfoEntry* next = elt->next();
112 delete elt;
113 elt = next;
114 }
115 }
116
117 KlassInfoTable::KlassInfoTable(int size, HeapWord* ref) {
118 _size = 0;
119 _ref = ref;
120 _buckets = NEW_C_HEAP_ARRAY(KlassInfoBucket, size);
121 if (_buckets != NULL) {
122 _size = size;
123 for (int index = 0; index < _size; index++) {
124 _buckets[index].initialize();
125 }
126 }
127 }
128
129 KlassInfoTable::~KlassInfoTable() {
130 if (_buckets != NULL) {
131 for (int index = 0; index < _size; index++) {
132 _buckets[index].empty();
133 }
134 FREE_C_HEAP_ARRAY(KlassInfoBucket, _buckets);
135 _size = 0;
136 }
137 }
138
139 uint KlassInfoTable::hash(klassOop p) {
140 assert(Universe::heap()->is_in_permanent((HeapWord*)p), "all klasses in permgen");
141 return (uint)(((uintptr_t)p - (uintptr_t)_ref) >> 2);
142 }
143
144 KlassInfoEntry* KlassInfoTable::lookup(const klassOop k) {
145 uint idx = hash(k) % _size;
146 assert(_buckets != NULL, "Allocation failure should have been caught");
147 KlassInfoEntry* e = _buckets[idx].lookup(k);
148 // Lookup may fail if this is a new klass for which we
149 // could not allocate space for an new entry.
150 assert(e == NULL || k == e->klass(), "must be equal");
151 return e;
152 }
153
154 // Return false if the entry could not be recorded on account
155 // of running out of space required to create a new entry.
156 bool KlassInfoTable::record_instance(const oop obj) {
157 klassOop k = obj->klass();
158 KlassInfoEntry* elt = lookup(k);
159 // elt may be NULL if it's a new klass for which we
160 // could not allocate space for a new entry in the hashtable.
161 if (elt != NULL) {
162 elt->set_count(elt->count() + 1);
163 elt->set_words(elt->words() + obj->size());
164 return true;
165 } else {
166 return false;
167 }
168 }
169
170 void KlassInfoTable::iterate(KlassInfoClosure* cic) {
171 assert(_size == 0 || _buckets != NULL, "Allocation failure should have been caught");
172 for (int index = 0; index < _size; index++) {
173 _buckets[index].iterate(cic);
174 }
175 }
176
177 int KlassInfoHisto::sort_helper(KlassInfoEntry** e1, KlassInfoEntry** e2) {
178 return (*e1)->compare(*e1,*e2);
179 }
180
181 KlassInfoHisto::KlassInfoHisto(const char* title, int estimatedCount) :
182 _title(title) {
183 _elements = new (ResourceObj::C_HEAP) GrowableArray<KlassInfoEntry*>(estimatedCount,true);
184 }
185
186 KlassInfoHisto::~KlassInfoHisto() {
187 delete _elements;
188 }
189
190 void KlassInfoHisto::add(KlassInfoEntry* cie) {
191 elements()->append(cie);
192 }
193
194 void KlassInfoHisto::sort() {
195 elements()->sort(KlassInfoHisto::sort_helper);
196 }
197
198 void KlassInfoHisto::print_elements(outputStream* st) const {
199 // simplify the formatting (ILP32 vs LP64) - store the sum in 64-bit
200 jlong total = 0;
201 julong totalw = 0;
202 for(int i=0; i < elements()->length(); i++) {
203 st->print("%4d: ", i+1);
204 elements()->at(i)->print_on(st);
205 total += elements()->at(i)->count();
206 totalw += elements()->at(i)->words();
207 }
208 st->print_cr("Total " INT64_FORMAT_W(13) " " UINT64_FORMAT_W(13),
209 total, totalw * HeapWordSize);
210 }
211
212 void KlassInfoHisto::print_on(outputStream* st) const {
213 st->print_cr("%s",title());
214 print_elements(st);
215 }
216
217 class HistoClosure : public KlassInfoClosure {
218 private:
219 KlassInfoHisto* _cih;
220 public:
221 HistoClosure(KlassInfoHisto* cih) : _cih(cih) {}
222
223 void do_cinfo(KlassInfoEntry* cie) {
224 _cih->add(cie);
225 }
226 };
227
228 class RecordInstanceClosure : public ObjectClosure {
229 private:
230 KlassInfoTable* _cit;
231 size_t _missed_count;
232 public:
233 RecordInstanceClosure(KlassInfoTable* cit) :
234 _cit(cit), _missed_count(0) {}
235
236 void do_object(oop obj) {
237 if (!_cit->record_instance(obj)) {
238 _missed_count++;
239 }
240 }
241
242 size_t missed_count() { return _missed_count; }
243 };
244
245 void HeapInspection::heap_inspection(outputStream* st, bool need_prologue) {
246 ResourceMark rm;
247 HeapWord* ref;
248
249 CollectedHeap* heap = Universe::heap();
250 bool is_shared_heap = false;
251 switch (heap->kind()) {
252 case CollectedHeap::G1CollectedHeap:
253 case CollectedHeap::GenCollectedHeap: {
254 is_shared_heap = true;
255 SharedHeap* sh = (SharedHeap*)heap;
256 if (need_prologue) {
257 sh->gc_prologue(false /* !full */); // get any necessary locks, etc.
258 }
259 ref = sh->perm_gen()->used_region().start();
260 break;
261 }
262 #ifndef SERIALGC
263 case CollectedHeap::ParallelScavengeHeap: {
264 ParallelScavengeHeap* psh = (ParallelScavengeHeap*)heap;
265 ref = psh->perm_gen()->object_space()->used_region().start();
266 break;
267 }
268 #endif // SERIALGC
269 default:
270 ShouldNotReachHere(); // Unexpected heap kind for this op
271 }
272 // Collect klass instance info
273 KlassInfoTable cit(KlassInfoTable::cit_size, ref);
274 if (!cit.allocation_failed()) {
275 // Iterate over objects in the heap
276 RecordInstanceClosure ric(&cit);
277 // If this operation encounters a bad object when using CMS,
278 // consider using safe_object_iterate() which avoids perm gen
279 // objects that may contain bad references.
280 Universe::heap()->object_iterate(&ric);
281
282 // Report if certain classes are not counted because of
283 // running out of C-heap for the histogram.
284 size_t missed_count = ric.missed_count();
285 if (missed_count != 0) {
286 st->print_cr("WARNING: Ran out of C-heap; undercounted " SIZE_FORMAT
287 " total instances in data below",
288 missed_count);
289 }
290 // Sort and print klass instance info
291 KlassInfoHisto histo("\n"
292 " num #instances #bytes class name\n"
293 "----------------------------------------------",
294 KlassInfoHisto::histo_initial_size);
295 HistoClosure hc(&histo);
296 cit.iterate(&hc);
297 histo.sort();
298 histo.print_on(st);
299 } else {
300 st->print_cr("WARNING: Ran out of C-heap; histogram not generated");
301 }
302 st->flush();
303
304 if (need_prologue && is_shared_heap) {
305 SharedHeap* sh = (SharedHeap*)heap;
306 sh->gc_epilogue(false /* !full */); // release all acquired locks, etc.
307 }
308 }
309
310 class FindInstanceClosure : public ObjectClosure {
311 private:
312 klassOop _klass;
313 GrowableArray<oop>* _result;
314
315 public:
316 FindInstanceClosure(klassOop k, GrowableArray<oop>* result) : _klass(k), _result(result) {};
317
318 void do_object(oop obj) {
319 if (obj->is_a(_klass)) {
320 _result->append(obj);
321 }
322 }
323 };
324
325 void HeapInspection::find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) {
326 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
327 assert(Heap_lock->is_locked(), "should have the Heap_lock");
328
329 // Ensure that the heap is parsable
330 Universe::heap()->ensure_parsability(false); // no need to retire TALBs
331
332 // Iterate over objects in the heap
333 FindInstanceClosure fic(k, result);
334 // If this operation encounters a bad object when using CMS,
335 // consider using safe_object_iterate() which avoids perm gen
336 // objects that may contain bad references.
337 Universe::heap()->object_iterate(&fic);
338 }