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