1 /*
2 * Copyright (c) 2015, 2018, 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 #include "gc/shared/oopStorage.hpp"
26 #include "gc/z/zAddress.hpp"
27 #include "gc/z/zGlobals.hpp"
28 #include "gc/z/zHeap.inline.hpp"
29 #include "gc/z/zHeapIterator.hpp"
30 #include "gc/z/zList.inline.hpp"
31 #include "gc/z/zLock.inline.hpp"
32 #include "gc/z/zMark.inline.hpp"
33 #include "gc/z/zOopClosures.inline.hpp"
34 #include "gc/z/zPage.inline.hpp"
35 #include "gc/z/zPageTable.inline.hpp"
36 #include "gc/z/zRelocationSet.inline.hpp"
37 #include "gc/z/zResurrection.hpp"
38 #include "gc/z/zRootsIterator.hpp"
39 #include "gc/z/zStat.hpp"
40 #include "gc/z/zTask.hpp"
41 #include "gc/z/zThread.hpp"
42 #include "gc/z/zTracer.inline.hpp"
43 #include "gc/z/zVirtualMemory.inline.hpp"
44 #include "gc/z/zWorkers.inline.hpp"
45 #include "logging/log.hpp"
46 #include "memory/resourceArea.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "runtime/safepoint.hpp"
49 #include "runtime/thread.hpp"
50 #include "utilities/align.hpp"
51 #include "utilities/debug.hpp"
52
53 static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes);
54 static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes);
55 static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes);
56 static const ZStatSampler ZSamplerHeapUsedAfterRelocation("Memory", "Heap Used After Relocation", ZStatUnitBytes);
57 static const ZStatCounter ZCounterUndoPageAllocation("Memory", "Undo Page Allocation", ZStatUnitOpsPerSecond);
58 static const ZStatCounter ZCounterOutOfMemory("Memory", "Out Of Memory", ZStatUnitOpsPerSecond);
59
60 ZHeap* ZHeap::_heap = NULL;
61
62 ZHeap::ZHeap() :
63 _workers(),
64 _object_allocator(_workers.nworkers()),
65 _page_allocator(heap_min_size(), heap_max_size(), heap_max_reserve_size()),
66 _pagetable(),
67 _mark(&_workers, &_pagetable),
68 _reference_processor(&_workers),
69 _weak_roots_processor(&_workers),
70 _relocate(&_workers),
71 _relocation_set(),
72 _unload(&_workers),
73 _serviceability(heap_min_size(), heap_max_size()) {
74 // Install global heap instance
75 assert(_heap == NULL, "Already initialized");
76 _heap = this;
77
78 // Update statistics
79 ZStatHeap::set_at_initialize(heap_max_size(), heap_max_reserve_size());
80 }
81
82 size_t ZHeap::heap_min_size() const {
83 const size_t aligned_min_size = align_up(InitialHeapSize, ZPageSizeMin);
84 return MIN2(aligned_min_size, heap_max_size());
85 }
86
87 size_t ZHeap::heap_max_size() const {
88 const size_t aligned_max_size = align_up(MaxHeapSize, ZPageSizeMin);
89 return MIN2(aligned_max_size, ZAddressOffsetMax);
90 }
91
92 size_t ZHeap::heap_max_reserve_size() const {
93 // Reserve one small page per worker plus one shared medium page. This is still just
94 // an estimate and doesn't guarantee that we can't run out of memory during relocation.
95 const size_t max_reserve_size = (_workers.nworkers() * ZPageSizeSmall) + ZPageSizeMedium;
96 return MIN2(max_reserve_size, heap_max_size());
97 }
98
99 bool ZHeap::is_initialized() const {
100 return _page_allocator.is_initialized() && _mark.is_initialized();
101 }
102
103 size_t ZHeap::min_capacity() const {
104 return heap_min_size();
105 }
106
107 size_t ZHeap::max_capacity() const {
108 return _page_allocator.max_capacity();
109 }
110
111 size_t ZHeap::current_max_capacity() const {
112 return _page_allocator.current_max_capacity();
113 }
114
115 size_t ZHeap::capacity() const {
116 return _page_allocator.capacity();
117 }
118
119 size_t ZHeap::max_reserve() const {
120 return _page_allocator.max_reserve();
121 }
122
123 size_t ZHeap::used_high() const {
124 return _page_allocator.used_high();
125 }
126
127 size_t ZHeap::used_low() const {
128 return _page_allocator.used_low();
129 }
130
131 size_t ZHeap::used() const {
132 return _page_allocator.used();
133 }
134
135 size_t ZHeap::allocated() const {
136 return _page_allocator.allocated();
137 }
138
139 size_t ZHeap::reclaimed() const {
140 return _page_allocator.reclaimed();
141 }
142
143 size_t ZHeap::tlab_capacity() const {
144 return capacity();
145 }
146
147 size_t ZHeap::tlab_used() const {
148 return _object_allocator.used();
149 }
150
151 size_t ZHeap::max_tlab_size() const {
152 return ZObjectSizeLimitSmall;
153 }
154
155 size_t ZHeap::unsafe_max_tlab_alloc() const {
156 size_t size = _object_allocator.remaining();
157
158 if (size < MinTLABSize) {
159 // The remaining space in the allocator is not enough to
160 // fit the smallest possible TLAB. This means that the next
161 // TLAB allocation will force the allocator to get a new
162 // backing page anyway, which in turn means that we can then
163 // fit the largest possible TLAB.
164 size = max_tlab_size();
165 }
166
167 return MIN2(size, max_tlab_size());
168 }
169
170 bool ZHeap::is_in(uintptr_t addr) const {
171 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) {
172 return false;
173 }
174
175 const ZPage* const page = _pagetable.get(addr);
176 if (page != NULL) {
177 return page->is_in(addr);
178 }
179
180 return false;
181 }
182
183 uintptr_t ZHeap::block_start(uintptr_t addr) const {
184 const ZPage* const page = _pagetable.get(addr);
185 return page->block_start(addr);
186 }
187
188 size_t ZHeap::block_size(uintptr_t addr) const {
189 const ZPage* const page = _pagetable.get(addr);
190 return page->block_size(addr);
191 }
192
193 bool ZHeap::block_is_obj(uintptr_t addr) const {
194 const ZPage* const page = _pagetable.get(addr);
195 return page->block_is_obj(addr);
196 }
197
198 uint ZHeap::nconcurrent_worker_threads() const {
199 return _workers.nconcurrent();
200 }
201
202 uint ZHeap::nconcurrent_no_boost_worker_threads() const {
203 return _workers.nconcurrent_no_boost();
204 }
205
206 void ZHeap::set_boost_worker_threads(bool boost) {
207 _workers.set_boost(boost);
208 }
209
210 void ZHeap::worker_threads_do(ThreadClosure* tc) const {
211 _workers.threads_do(tc);
212 }
213
214 void ZHeap::print_worker_threads_on(outputStream* st) const {
215 _workers.print_threads_on(st);
216 }
217
218 void ZHeap::out_of_memory() {
219 ResourceMark rm;
220
221 ZStatInc(ZCounterOutOfMemory);
222 log_info(gc)("Out Of Memory (%s)", Thread::current()->name());
223 }
224
225 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
226 ZPage* const page = _page_allocator.alloc_page(type, size, flags);
227 if (page != NULL) {
228 // Update pagetable
229 _pagetable.insert(page);
230 }
231
232 return page;
233 }
234
235 void ZHeap::undo_alloc_page(ZPage* page) {
236 assert(page->is_allocating(), "Invalid page state");
237
238 ZStatInc(ZCounterUndoPageAllocation);
239 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT,
240 ZThread::id(), ZThread::name(), p2i(page), page->size());
241
242 release_page(page, false /* reclaimed */);
243 }
244
245 bool ZHeap::retain_page(ZPage* page) {
246 return page->inc_refcount();
247 }
248
249 void ZHeap::release_page(ZPage* page, bool reclaimed) {
250 if (page->dec_refcount()) {
251 _page_allocator.free_page(page, reclaimed);
252 }
253 }
254
255 void ZHeap::flip_views() {
256 // For debugging only
257 if (ZUnmapBadViews) {
258 // Flip pages
259 ZPageTableIterator iter(&_pagetable);
260 for (ZPage* page; iter.next(&page);) {
261 if (!page->is_detached()) {
262 _page_allocator.flip_page(page);
263 }
264 }
265
266 // Flip pre-mapped memory
267 _page_allocator.flip_pre_mapped();
268 }
269 }
270
271 void ZHeap::mark_start() {
272 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
273
274 // Update statistics
275 ZStatSample(ZSamplerHeapUsedBeforeMark, used());
276
277 // Flip address view
278 ZAddressMasks::flip_to_marked();
279 flip_views();
280
281 // Retire allocating pages
282 _object_allocator.retire_pages();
283
284 // Reset allocated/reclaimed/used statistics
285 _page_allocator.reset_statistics();
286
287 // Reset encountered/dropped/enqueued statistics
288 _reference_processor.reset_statistics();
289
290 // Enter mark phase
291 ZGlobalPhase = ZPhaseMark;
292
293 // Reset marking information and mark roots
294 _mark.start();
295
296 // Update statistics
297 ZStatHeap::set_at_mark_start(capacity(), used());
298 }
299
300 void ZHeap::mark(bool initial) {
301 _mark.mark(initial);
302 }
303
304 void ZHeap::mark_flush_and_free(Thread* thread) {
305 _mark.flush_and_free(thread);
306 }
307
308 class ZFixupPartialLoadsClosure : public ZRootsIteratorClosure {
309 public:
310 virtual void do_oop(oop* p) {
311 ZBarrier::mark_barrier_on_root_oop_field(p);
312 }
313
314 virtual void do_oop(narrowOop* p) {
315 ShouldNotReachHere();
316 }
317 };
318
319 class ZFixupPartialLoadsTask : public ZTask {
320 private:
321 ZThreadRootsIterator _thread_roots;
322
323 public:
324 ZFixupPartialLoadsTask() :
325 ZTask("ZFixupPartialLoadsTask"),
326 _thread_roots() {}
327
328 virtual void work() {
329 ZFixupPartialLoadsClosure cl;
330 _thread_roots.oops_do(&cl);
331 }
332 };
333
334 void ZHeap::fixup_partial_loads() {
335 ZFixupPartialLoadsTask task;
336 _workers.run_parallel(&task);
337 }
338
339 bool ZHeap::mark_end() {
340 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
341
342 // C2 can generate code where a safepoint poll is inserted
343 // between a load and the associated load barrier. To handle
344 // this case we need to rescan the thread stack here to make
345 // sure such oops are marked.
346 fixup_partial_loads();
347
348 // Try end marking
349 if (!_mark.end()) {
350 // Marking not completed, continue concurrent mark
351 return false;
352 }
353
354 // Enter mark completed phase
355 ZGlobalPhase = ZPhaseMarkCompleted;
356
357 // Update statistics
358 ZStatSample(ZSamplerHeapUsedAfterMark, used());
359 ZStatHeap::set_at_mark_end(capacity(), allocated(), used());
360
361 // Block resurrection of weak/phantom references
362 ZResurrection::block();
363
364 // Process weak roots
365 _weak_roots_processor.process_weak_roots();
366
367 // Prepare to unload unused classes and code
368 _unload.prepare();
369
370 return true;
371 }
372
373 void ZHeap::set_soft_reference_policy(bool clear) {
374 _reference_processor.set_soft_reference_policy(clear);
375 }
376
377 void ZHeap::process_non_strong_references() {
378 // Process Soft/Weak/Final/PhantomReferences
379 _reference_processor.process_references();
380
381 // Process concurrent weak roots
382 _weak_roots_processor.process_concurrent_weak_roots();
383
384 // Unload unused classes and code
385 _unload.unload();
386
387 // Unblock resurrection of weak/phantom references
388 ZResurrection::unblock();
389
390 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this
391 // must be done after unblocking resurrection. Otherwise the
392 // Finalizer thread could call Reference.get() on the Finalizers
393 // that were just enqueued, which would incorrectly return null
394 // during the resurrection block window, since such referents
395 // are only Finalizable marked.
396 _reference_processor.enqueue_references();
397 }
398
399 void ZHeap::destroy_detached_pages() {
400 ZList<ZPage> list;
401
402 _page_allocator.flush_detached_pages(&list);
403
404 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {
405 // Remove pagetable entry
406 _pagetable.remove(page);
407
408 // Delete the page
409 _page_allocator.destroy_page(page);
410 }
411 }
412
413 void ZHeap::select_relocation_set() {
414 // Register relocatable pages with selector
415 ZRelocationSetSelector selector;
416 ZPageTableIterator iter(&_pagetable);
417 for (ZPage* page; iter.next(&page);) {
418 if (!page->is_relocatable()) {
419 // Not relocatable, don't register
420 continue;
421 }
422
423 if (page->is_marked()) {
424 // Register live page
425 selector.register_live_page(page);
426 } else {
427 // Register garbage page
428 selector.register_garbage_page(page);
429
430 // Reclaim page immediately
431 release_page(page, true /* reclaimed */);
432 }
433 }
434
435 // Select pages to relocate
436 selector.select(&_relocation_set);
437
438 // Update statistics
439 ZStatRelocation::set_at_select_relocation_set(selector.relocating());
440 ZStatHeap::set_at_select_relocation_set(selector.live(),
441 selector.garbage(),
442 reclaimed());
443 }
444
445 void ZHeap::prepare_relocation_set() {
446 ZRelocationSetIterator iter(&_relocation_set);
447 for (ZPage* page; iter.next(&page);) {
448 // Prepare for relocation
449 page->set_forwarding();
450
451 // Update pagetable
452 _pagetable.set_relocating(page);
453 }
454 }
455
456 void ZHeap::reset_relocation_set() {
457 ZRelocationSetIterator iter(&_relocation_set);
458 for (ZPage* page; iter.next(&page);) {
459 // Reset relocation information
460 page->reset_forwarding();
461
462 // Update pagetable
463 _pagetable.clear_relocating(page);
464 }
465 }
466
467 void ZHeap::relocate_start() {
468 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
469
470 // Finish unloading of classes and code
471 _unload.finish();
472
473 // Flip address view
474 ZAddressMasks::flip_to_remapped();
475 flip_views();
476
477 // Enter relocate phase
478 ZGlobalPhase = ZPhaseRelocate;
479
480 // Update statistics
481 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());
482 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used());
483
484 // Remap/Relocate roots
485 _relocate.start();
486 }
487
488 uintptr_t ZHeap::relocate_object(uintptr_t addr) {
489 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed");
490 ZPage* const page = _pagetable.get(addr);
491 const bool retained = retain_page(page);
492 const uintptr_t new_addr = page->relocate_object(addr);
493 if (retained) {
494 release_page(page, true /* reclaimed */);
495 }
496
497 return new_addr;
498 }
499
500 uintptr_t ZHeap::forward_object(uintptr_t addr) {
501 assert(ZGlobalPhase == ZPhaseMark ||
502 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed");
503 ZPage* const page = _pagetable.get(addr);
504 return page->forward_object(addr);
505 }
506
507 void ZHeap::relocate() {
508 // Relocate relocation set
509 const bool success = _relocate.relocate(&_relocation_set);
510
511 // Update statistics
512 ZStatSample(ZSamplerHeapUsedAfterRelocation, used());
513 ZStatRelocation::set_at_relocate_end(success);
514 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(),
515 used(), used_high(), used_low());
516 }
517
518 void ZHeap::object_iterate(ObjectClosure* cl, bool visit_referents) {
519 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
520
521 ZHeapIterator iter(visit_referents);
522 iter.objects_do(cl);
523 }
524
525 void ZHeap::serviceability_initialize() {
526 _serviceability.initialize();
527 }
528
529 GCMemoryManager* ZHeap::serviceability_memory_manager() {
530 return _serviceability.memory_manager();
531 }
532
533 MemoryPool* ZHeap::serviceability_memory_pool() {
534 return _serviceability.memory_pool();
535 }
536
537 ZServiceabilityCounters* ZHeap::serviceability_counters() {
538 return _serviceability.counters();
539 }
540
541 void ZHeap::print_on(outputStream* st) const {
542 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M",
543 used() / M,
544 capacity() / M,
545 max_capacity() / M);
546 MetaspaceUtils::print_on(st);
547 }
548
549 void ZHeap::print_extended_on(outputStream* st) const {
550 print_on(st);
551 st->cr();
552
553 ZPageTableIterator iter(&_pagetable);
554 for (ZPage* page; iter.next(&page);) {
555 page->print_on(st);
556 }
557
558 st->cr();
559 }
560
561 class ZVerifyRootsTask : public ZTask {
562 private:
563 ZRootsIterator _strong_roots;
564 ZWeakRootsIterator _weak_roots;
565
566 public:
567 ZVerifyRootsTask() :
568 ZTask("ZVerifyRootsTask"),
569 _strong_roots(),
570 _weak_roots() {}
571
572 virtual void work() {
573 ZVerifyOopClosure cl;
574 _strong_roots.oops_do(&cl);
575 _weak_roots.oops_do(&cl);
576 }
577 };
578
579 void ZHeap::verify() {
580 // Heap verification can only be done between mark end and
581 // relocate start. This is the only window where all oop are
582 // good and the whole heap is in a consistent state.
583 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase");
584
585 {
586 ZVerifyRootsTask task;
587 _workers.run_parallel(&task);
588 }
589
590 {
591 ZVerifyObjectClosure cl;
592 object_iterate(&cl, false /* visit_referents */);
593 }
594 }