1 /*
2 * Copyright (c) 2013, 2019, 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 #include "precompiled.hpp"
25
26 #include "logging/log.hpp"
27 #include "memory/metaspace.hpp"
28 #include "runtime/atomic.hpp"
29 #include "runtime/os.hpp"
30 #include "runtime/threadCritical.hpp"
31 #include "services/memTracker.hpp"
32 #include "services/threadStackTracker.hpp"
33 #include "services/virtualMemoryTracker.hpp"
34
35 size_t VirtualMemorySummary::_snapshot[CALC_OBJ_SIZE_IN_TYPE(VirtualMemorySnapshot, size_t)];
36
37 void VirtualMemorySummary::initialize() {
38 assert(sizeof(_snapshot) >= sizeof(VirtualMemorySnapshot), "Sanity Check");
39 // Use placement operator new to initialize static data area.
40 ::new ((void*)_snapshot) VirtualMemorySnapshot();
41 }
42
43 void VirtualMemorySummary::snapshot(VirtualMemorySnapshot* s) {
44 // Only if thread stack is backed by virtual memory
45 if (ThreadStackTracker::track_as_vm()) {
46 // Snapshot current thread stacks
47 VirtualMemoryTracker::snapshot_thread_stacks();
48 }
49 as_snapshot()->copy_to(s);
50 }
51
52 SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>* VirtualMemoryTracker::_reserved_regions;
53
54 int compare_committed_region(const CommittedMemoryRegion& r1, const CommittedMemoryRegion& r2) {
55 return r1.compare(r2);
56 }
57
58 int compare_reserved_region_base(const ReservedMemoryRegion& r1, const ReservedMemoryRegion& r2) {
59 return r1.compare(r2);
60 }
61
62 static bool is_mergeable_with(CommittedMemoryRegion* rgn, address addr, size_t size, const NativeCallStack& stack) {
63 return rgn->adjacent_to(addr, size) && rgn->call_stack()->equals(stack);
64 }
65
66 static bool is_same_as(CommittedMemoryRegion* rgn, address addr, size_t size, const NativeCallStack& stack) {
67 // It would have made sense to use rgn->equals(...), but equals returns true for overlapping regions.
68 return rgn->same_region(addr, size) && rgn->call_stack()->equals(stack);
69 }
70
71 static LinkedListNode<CommittedMemoryRegion>* find_preceding_node_from(LinkedListNode<CommittedMemoryRegion>* from, address addr) {
72 LinkedListNode<CommittedMemoryRegion>* preceding = NULL;
73
74 for (LinkedListNode<CommittedMemoryRegion>* node = from; node != NULL; node = node->next()) {
75 CommittedMemoryRegion* rgn = node->data();
76
77 // We searched past the region start.
78 if (rgn->end() > addr) {
79 break;
80 }
81
82 preceding = node;
83 }
84
85 return preceding;
86 }
87
88 static bool try_merge_with(LinkedListNode<CommittedMemoryRegion>* node, address addr, size_t size, const NativeCallStack& stack) {
89 if (node != NULL) {
90 CommittedMemoryRegion* rgn = node->data();
91
92 if (is_mergeable_with(rgn, addr, size, stack)) {
93 rgn->expand_region(addr, size);
94 return true;
95 }
96 }
97
98 return false;
99 }
100
101 static bool try_merge_with(LinkedListNode<CommittedMemoryRegion>* node, LinkedListNode<CommittedMemoryRegion>* other) {
102 if (other == NULL) {
103 return false;
104 }
105
106 CommittedMemoryRegion* rgn = other->data();
107 return try_merge_with(node, rgn->base(), rgn->size(), *rgn->call_stack());
108 }
109
110 bool ReservedMemoryRegion::add_committed_region(address addr, size_t size, const NativeCallStack& stack) {
111 assert(addr != NULL, "Invalid address");
112 assert(size > 0, "Invalid size");
113 assert(contain_region(addr, size), "Not contain this region");
114
115 // Find the region that fully precedes the [addr, addr + size) region.
116 LinkedListNode<CommittedMemoryRegion>* prev = find_preceding_node_from(_committed_regions.head(), addr);
117 LinkedListNode<CommittedMemoryRegion>* next = (prev != NULL ? prev->next() : _committed_regions.head());
118
119 if (next != NULL) {
120 // Ignore request if region already exists.
121 if (is_same_as(next->data(), addr, size, stack)) {
122 return true;
123 }
124
125 // The new region is after prev, and either overlaps with the
126 // next region (and maybe more regions), or overlaps with no region.
127 if (next->data()->overlap_region(addr, size)) {
128 // Remove _all_ overlapping regions, and parts of regions,
129 // in preparation for the addition of this new region.
130 remove_uncommitted_region(addr, size);
131
132 // The remove could have split a region into two and created a
133 // new prev region. Need to reset the prev and next pointers.
134 prev = find_preceding_node_from((prev != NULL ? prev : _committed_regions.head()), addr);
135 next = (prev != NULL ? prev->next() : _committed_regions.head());
136 }
137 }
138
139 // At this point the previous overlapping regions have been
140 // cleared, and the full region is guaranteed to be inserted.
141 VirtualMemorySummary::record_committed_memory(size, flag());
142
143 // Try to merge with prev and possibly next.
144 if (try_merge_with(prev, addr, size, stack)) {
145 if (try_merge_with(prev, next)) {
146 // prev was expanded to contain the new region
147 // and next, need to remove next from the list
148 _committed_regions.remove_after(prev);
149 }
150
151 return true;
152 }
153
154 // Didn't merge with prev, try with next.
155 if (try_merge_with(next, addr, size, stack)) {
156 return true;
157 }
158
159 // Couldn't merge with any regions - create a new region.
160 return add_committed_region(CommittedMemoryRegion(addr, size, stack));
161 }
162
163 bool ReservedMemoryRegion::remove_uncommitted_region(LinkedListNode<CommittedMemoryRegion>* node,
164 address addr, size_t size) {
165 assert(addr != NULL, "Invalid address");
166 assert(size > 0, "Invalid size");
167
168 CommittedMemoryRegion* rgn = node->data();
169 assert(rgn->contain_region(addr, size), "Has to be contained");
170 assert(!rgn->same_region(addr, size), "Can not be the same region");
171
172 if (rgn->base() == addr ||
173 rgn->end() == addr + size) {
174 rgn->exclude_region(addr, size);
175 return true;
176 } else {
177 // split this region
178 address top =rgn->end();
179 // use this region for lower part
180 size_t exclude_size = rgn->end() - addr;
181 rgn->exclude_region(addr, exclude_size);
182
183 // higher part
184 address high_base = addr + size;
185 size_t high_size = top - high_base;
186
187 CommittedMemoryRegion high_rgn(high_base, high_size, *rgn->call_stack());
188 LinkedListNode<CommittedMemoryRegion>* high_node = _committed_regions.add(high_rgn);
189 assert(high_node == NULL || node->next() == high_node, "Should be right after");
190 return (high_node != NULL);
191 }
192
193 return false;
194 }
195
196 bool ReservedMemoryRegion::remove_uncommitted_region(address addr, size_t sz) {
197 assert(addr != NULL, "Invalid address");
198 assert(sz > 0, "Invalid size");
199
200 CommittedMemoryRegion del_rgn(addr, sz, *call_stack());
201 address end = addr + sz;
202
203 LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();
204 LinkedListNode<CommittedMemoryRegion>* prev = NULL;
205 CommittedMemoryRegion* crgn;
206
207 while (head != NULL) {
208 crgn = head->data();
209
210 if (crgn->same_region(addr, sz)) {
211 VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
212 _committed_regions.remove_after(prev);
213 return true;
214 }
215
216 // del_rgn contains crgn
217 if (del_rgn.contain_region(crgn->base(), crgn->size())) {
218 VirtualMemorySummary::record_uncommitted_memory(crgn->size(), flag());
219 head = head->next();
220 _committed_regions.remove_after(prev);
221 continue; // don't update head or prev
222 }
223
224 // Found addr in the current crgn. There are 2 subcases:
225 if (crgn->contain_address(addr)) {
226
227 // (1) Found addr+size in current crgn as well. (del_rgn is contained in crgn)
228 if (crgn->contain_address(end - 1)) {
229 VirtualMemorySummary::record_uncommitted_memory(sz, flag());
230 return remove_uncommitted_region(head, addr, sz); // done!
231 } else {
232 // (2) Did not find del_rgn's end in crgn.
233 size_t size = crgn->end() - del_rgn.base();
234 crgn->exclude_region(addr, size);
235 VirtualMemorySummary::record_uncommitted_memory(size, flag());
236 }
237
238 } else if (crgn->contain_address(end - 1)) {
239 // Found del_rgn's end, but not its base addr.
240 size_t size = del_rgn.end() - crgn->base();
241 crgn->exclude_region(crgn->base(), size);
242 VirtualMemorySummary::record_uncommitted_memory(size, flag());
243 return true; // should be done if the list is sorted properly!
244 }
245
246 prev = head;
247 head = head->next();
248 }
249
250 return true;
251 }
252
253 void ReservedMemoryRegion::move_committed_regions(address addr, ReservedMemoryRegion& rgn) {
254 assert(addr != NULL, "Invalid address");
255
256 // split committed regions
257 LinkedListNode<CommittedMemoryRegion>* head =
258 _committed_regions.head();
259 LinkedListNode<CommittedMemoryRegion>* prev = NULL;
260
261 while (head != NULL) {
262 if (head->data()->base() >= addr) {
263 break;
264 }
265 prev = head;
266 head = head->next();
267 }
268
269 if (head != NULL) {
270 if (prev != NULL) {
271 prev->set_next(head->next());
272 } else {
273 _committed_regions.set_head(NULL);
274 }
275 }
276
277 rgn._committed_regions.set_head(head);
278 }
279
280 size_t ReservedMemoryRegion::committed_size() const {
281 size_t committed = 0;
282 LinkedListNode<CommittedMemoryRegion>* head =
283 _committed_regions.head();
284 while (head != NULL) {
285 committed += head->data()->size();
286 head = head->next();
287 }
288 return committed;
289 }
290
291 void ReservedMemoryRegion::set_flag(MEMFLAGS f) {
292 assert((flag() == mtNone || flag() == f), "Overwrite memory type");
293 if (flag() != f) {
294 VirtualMemorySummary::move_reserved_memory(flag(), f, size());
295 VirtualMemorySummary::move_committed_memory(flag(), f, committed_size());
296 _flag = f;
297 }
298 }
299
300 address ReservedMemoryRegion::thread_stack_uncommitted_bottom() const {
301 assert(flag() == mtThreadStack, "Only for thread stack");
302 LinkedListNode<CommittedMemoryRegion>* head = _committed_regions.head();
303 address bottom = base();
304 address top = base() + size();
305 while (head != NULL) {
306 address committed_top = head->data()->base() + head->data()->size();
307 if (committed_top < top) {
308 // committed stack guard pages, skip them
309 bottom = head->data()->base() + head->data()->size();
310 head = head->next();
311 } else {
312 assert(top == committed_top, "Sanity");
313 break;
314 }
315 }
316
317 return bottom;
318 }
319
320 bool VirtualMemoryTracker::initialize(NMT_TrackingLevel level) {
321 if (level >= NMT_summary) {
322 VirtualMemorySummary::initialize();
323 }
324 return true;
325 }
326
327 bool VirtualMemoryTracker::late_initialize(NMT_TrackingLevel level) {
328 if (level >= NMT_summary) {
329 _reserved_regions = new (std::nothrow, ResourceObj::C_HEAP, mtNMT)
330 SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>();
331 return (_reserved_regions != NULL);
332 }
333 return true;
334 }
335
336 bool VirtualMemoryTracker::add_reserved_region(address base_addr, size_t size,
337 const NativeCallStack& stack, MEMFLAGS flag) {
338 assert(base_addr != NULL, "Invalid address");
339 assert(size > 0, "Invalid size");
340 assert(_reserved_regions != NULL, "Sanity check");
341 ReservedMemoryRegion rgn(base_addr, size, stack, flag);
342 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
343
344 if (reserved_rgn == NULL) {
345 VirtualMemorySummary::record_reserved_memory(size, flag);
346 return _reserved_regions->add(rgn) != NULL;
347 } else {
348 if (reserved_rgn->same_region(base_addr, size)) {
349 reserved_rgn->set_call_stack(stack);
350 reserved_rgn->set_flag(flag);
351 return true;
352 } else if (reserved_rgn->adjacent_to(base_addr, size)) {
353 VirtualMemorySummary::record_reserved_memory(size, flag);
354 reserved_rgn->expand_region(base_addr, size);
355 reserved_rgn->set_call_stack(stack);
356 return true;
357 } else {
358 // Overlapped reservation.
359 // It can happen when the regions are thread stacks, as JNI
360 // thread does not detach from VM before exits, and leads to
361 // leak JavaThread object
362 if (reserved_rgn->flag() == mtThreadStack) {
363 guarantee(!CheckJNICalls, "Attached JNI thread exited without being detached");
364 // Overwrite with new region
365
366 // Release old region
367 VirtualMemorySummary::record_uncommitted_memory(reserved_rgn->committed_size(), reserved_rgn->flag());
368 VirtualMemorySummary::record_released_memory(reserved_rgn->size(), reserved_rgn->flag());
369
370 // Add new region
371 VirtualMemorySummary::record_reserved_memory(rgn.size(), flag);
372
373 *reserved_rgn = rgn;
374 return true;
375 }
376
377 // CDS mapping region.
378 // CDS reserves the whole region for mapping CDS archive, then maps each section into the region.
379 // NMT reports CDS as a whole.
380 if (reserved_rgn->flag() == mtClassShared) {
381 assert(reserved_rgn->contain_region(base_addr, size), "Reserved CDS region should contain this mapping region");
382 return true;
383 }
384
385 // Mapped CDS string region.
386 // The string region(s) is part of the java heap.
387 if (reserved_rgn->flag() == mtJavaHeap) {
388 assert(reserved_rgn->contain_region(base_addr, size), "Reserved heap region should contain this mapping region");
389 return true;
390 }
391
392 ShouldNotReachHere();
393 return false;
394 }
395 }
396 }
397
398 void VirtualMemoryTracker::set_reserved_region_type(address addr, MEMFLAGS flag) {
399 assert(addr != NULL, "Invalid address");
400 assert(_reserved_regions != NULL, "Sanity check");
401
402 ReservedMemoryRegion rgn(addr, 1);
403 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
404 if (reserved_rgn != NULL) {
405 assert(reserved_rgn->contain_address(addr), "Containment");
406 if (reserved_rgn->flag() != flag) {
407 assert(reserved_rgn->flag() == mtNone, "Overwrite memory type");
408 reserved_rgn->set_flag(flag);
409 }
410 }
411 }
412
413 bool VirtualMemoryTracker::add_committed_region(address addr, size_t size,
414 const NativeCallStack& stack) {
415 assert(addr != NULL, "Invalid address");
416 assert(size > 0, "Invalid size");
417 assert(_reserved_regions != NULL, "Sanity check");
418
419 ReservedMemoryRegion rgn(addr, size);
420 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
421
422 assert(reserved_rgn != NULL, "No reserved region");
423 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
424 bool result = reserved_rgn->add_committed_region(addr, size, stack);
425 return result;
426 }
427
428 bool VirtualMemoryTracker::remove_uncommitted_region(address addr, size_t size) {
429 assert(addr != NULL, "Invalid address");
430 assert(size > 0, "Invalid size");
431 assert(_reserved_regions != NULL, "Sanity check");
432
433 ReservedMemoryRegion rgn(addr, size);
434 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
435 assert(reserved_rgn != NULL, "No reserved region");
436 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
437 bool result = reserved_rgn->remove_uncommitted_region(addr, size);
438 return result;
439 }
440
441 bool VirtualMemoryTracker::remove_released_region(address addr, size_t size) {
442 assert(addr != NULL, "Invalid address");
443 assert(size > 0, "Invalid size");
444 assert(_reserved_regions != NULL, "Sanity check");
445
446 ReservedMemoryRegion rgn(addr, size);
447 ReservedMemoryRegion* reserved_rgn = _reserved_regions->find(rgn);
448
449 assert(reserved_rgn != NULL, "No reserved region");
450
451 // uncommit regions within the released region
452 if (!reserved_rgn->remove_uncommitted_region(addr, size)) {
453 return false;
454 }
455
456 if (reserved_rgn->flag() == mtClassShared &&
457 reserved_rgn->contain_region(addr, size) &&
458 !reserved_rgn->same_region(addr, size)) {
459 // This is an unmapped CDS region, which is part of the reserved shared
460 // memory region.
461 // See special handling in VirtualMemoryTracker::add_reserved_region also.
462 return true;
463 }
464
465 VirtualMemorySummary::record_released_memory(size, reserved_rgn->flag());
466
467 if (reserved_rgn->same_region(addr, size)) {
468 return _reserved_regions->remove(rgn);
469 } else {
470 assert(reserved_rgn->contain_region(addr, size), "Not completely contained");
471 if (reserved_rgn->base() == addr ||
472 reserved_rgn->end() == addr + size) {
473 reserved_rgn->exclude_region(addr, size);
474 return true;
475 } else {
476 address top = reserved_rgn->end();
477 address high_base = addr + size;
478 ReservedMemoryRegion high_rgn(high_base, top - high_base,
479 *reserved_rgn->call_stack(), reserved_rgn->flag());
480
481 // use original region for lower region
482 reserved_rgn->exclude_region(addr, top - addr);
483 LinkedListNode<ReservedMemoryRegion>* new_rgn = _reserved_regions->add(high_rgn);
484 if (new_rgn == NULL) {
485 return false;
486 } else {
487 reserved_rgn->move_committed_regions(addr, *new_rgn->data());
488 return true;
489 }
490 }
491 }
492 }
493
494 // Iterate the range, find committed region within its bound.
495 class RegionIterator : public StackObj {
496 private:
497 const address _start;
498 const size_t _size;
499
500 address _current_start;
501 size_t _current_size;
502 public:
503 RegionIterator(address start, size_t size) :
504 _start(start), _size(size), _current_start(start), _current_size(size) {
505 }
506
507 // return true if committed region is found
508 bool next_committed(address& start, size_t& size);
509 private:
510 address end() const { return _start + _size; }
511 };
512
513 bool RegionIterator::next_committed(address& committed_start, size_t& committed_size) {
514 if (end() <= _current_start) return false;
515
516 const size_t page_sz = os::vm_page_size();
517 assert(_current_start + _current_size == end(), "Must be");
518 if (os::committed_in_range(_current_start, _current_size, committed_start, committed_size)) {
519 assert(committed_start != NULL, "Must be");
520 assert(committed_size > 0 && is_aligned(committed_size, os::vm_page_size()), "Must be");
521
522 size_t remaining_size = (_current_start + _current_size) - (committed_start + committed_size);
523 _current_start = committed_start + committed_size;
524 _current_size = remaining_size;
525 return true;
526 } else {
527 return false;
528 }
529 }
530
531 // Walk all known thread stacks, snapshot their committed ranges.
532 class SnapshotThreadStackWalker : public VirtualMemoryWalker {
533 public:
534 SnapshotThreadStackWalker() {}
535
536 bool do_allocation_site(const ReservedMemoryRegion* rgn) {
537 if (rgn->flag() == mtThreadStack) {
538 address stack_bottom = rgn->thread_stack_uncommitted_bottom();
539 address committed_start;
540 size_t committed_size;
541 size_t stack_size = rgn->base() + rgn->size() - stack_bottom;
542
543 ReservedMemoryRegion* region = const_cast<ReservedMemoryRegion*>(rgn);
544 NativeCallStack ncs; // empty stack
545
546 RegionIterator itr(stack_bottom, stack_size);
547 DEBUG_ONLY(bool found_stack = false;)
548 while (itr.next_committed(committed_start, committed_size)) {
549 assert(committed_start != NULL, "Should not be null");
550 assert(committed_size > 0, "Should not be 0");
551 region->add_committed_region(committed_start, committed_size, ncs);
552 DEBUG_ONLY(found_stack = true;)
553 }
554 #ifdef ASSERT
555 if (!found_stack) {
556 log_debug(thread)("Thread exited without proper cleanup, may leak thread object");
557 }
558 #endif
559 }
560 return true;
561 }
562 };
563
564 void VirtualMemoryTracker::snapshot_thread_stacks() {
565 SnapshotThreadStackWalker walker;
566 walk_virtual_memory(&walker);
567 }
568
569 bool VirtualMemoryTracker::walk_virtual_memory(VirtualMemoryWalker* walker) {
570 assert(_reserved_regions != NULL, "Sanity check");
571 ThreadCritical tc;
572 // Check that the _reserved_regions haven't been deleted.
573 if (_reserved_regions != NULL) {
574 LinkedListNode<ReservedMemoryRegion>* head = _reserved_regions->head();
575 while (head != NULL) {
576 const ReservedMemoryRegion* rgn = head->peek();
577 if (!walker->do_allocation_site(rgn)) {
578 return false;
579 }
580 head = head->next();
581 }
582 }
583 return true;
584 }
585
586 // Transition virtual memory tracking level.
587 bool VirtualMemoryTracker::transition(NMT_TrackingLevel from, NMT_TrackingLevel to) {
588 assert (from != NMT_minimal, "cannot convert from the lowest tracking level to anything");
589 if (to == NMT_minimal) {
590 assert(from == NMT_summary || from == NMT_detail, "Just check");
591 // Clean up virtual memory tracking data structures.
592 ThreadCritical tc;
593 // Check for potential race with other thread calling transition
594 if (_reserved_regions != NULL) {
595 delete _reserved_regions;
596 _reserved_regions = NULL;
597 }
598 }
599
600 return true;
601 }
602
603 // Metaspace Support
604 MetaspaceSnapshot::MetaspaceSnapshot() {
605 for (int index = (int)Metaspace::ClassType; index < (int)Metaspace::MetadataTypeCount; index ++) {
606 Metaspace::MetadataType type = (Metaspace::MetadataType)index;
607 assert_valid_metadata_type(type);
608 _reserved_in_bytes[type] = 0;
609 _committed_in_bytes[type] = 0;
610 _used_in_bytes[type] = 0;
611 _free_in_bytes[type] = 0;
612 }
613 }
614
615 void MetaspaceSnapshot::snapshot(Metaspace::MetadataType type, MetaspaceSnapshot& mss) {
616 assert_valid_metadata_type(type);
617
618 mss._reserved_in_bytes[type] = MetaspaceUtils::reserved_bytes(type);
619 mss._committed_in_bytes[type] = MetaspaceUtils::committed_bytes(type);
620 mss._used_in_bytes[type] = MetaspaceUtils::used_bytes(type);
621
622 size_t free_in_bytes = (MetaspaceUtils::capacity_bytes(type) - MetaspaceUtils::used_bytes(type))
623 + MetaspaceUtils::free_chunks_total_bytes(type)
624 + MetaspaceUtils::free_in_vs_bytes(type);
625 mss._free_in_bytes[type] = free_in_bytes;
626 }
627
628 void MetaspaceSnapshot::snapshot(MetaspaceSnapshot& mss) {
629 snapshot(Metaspace::ClassType, mss);
630 if (Metaspace::using_class_space()) {
631 snapshot(Metaspace::NonClassType, mss);
632 }
633 }