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 _serviceability(heap_min_size(), heap_max_size()) {
73 // Install global heap instance
74 assert(_heap == NULL, "Already initialized");
75 _heap = this;
76
77 // Update statistics
78 ZStatHeap::set_at_initialize(heap_max_size(), heap_max_reserve_size());
79 }
80
81 size_t ZHeap::heap_min_size() const {
82 const size_t aligned_min_size = align_up(InitialHeapSize, ZPageSizeMin);
83 return MIN2(aligned_min_size, heap_max_size());
84 }
85
86 size_t ZHeap::heap_max_size() const {
87 const size_t aligned_max_size = align_up(MaxHeapSize, ZPageSizeMin);
88 return MIN2(aligned_max_size, ZAddressOffsetMax);
89 }
90
91 size_t ZHeap::heap_max_reserve_size() const {
92 // Reserve one small page per worker plus one shared medium page. This is still just
93 // an estimate and doesn't guarantee that we can't run out of memory during relocation.
94 const size_t max_reserve_size = (_workers.nworkers() * ZPageSizeSmall) + ZPageSizeMedium;
95 return MIN2(max_reserve_size, heap_max_size());
96 }
97
98 bool ZHeap::is_initialized() const {
99 return _page_allocator.is_initialized() && _mark.is_initialized();
100 }
101
102 size_t ZHeap::min_capacity() const {
103 return heap_min_size();
104 }
105
106 size_t ZHeap::max_capacity() const {
107 return _page_allocator.max_capacity();
108 }
109
110 size_t ZHeap::current_max_capacity() const {
111 return _page_allocator.current_max_capacity();
112 }
113
114 size_t ZHeap::capacity() const {
115 return _page_allocator.capacity();
116 }
117
118 size_t ZHeap::max_reserve() const {
119 return _page_allocator.max_reserve();
120 }
121
122 size_t ZHeap::used_high() const {
123 return _page_allocator.used_high();
124 }
125
126 size_t ZHeap::used_low() const {
127 return _page_allocator.used_low();
128 }
129
130 size_t ZHeap::used() const {
131 return _page_allocator.used();
132 }
133
134 size_t ZHeap::allocated() const {
135 return _page_allocator.allocated();
136 }
137
138 size_t ZHeap::reclaimed() const {
139 return _page_allocator.reclaimed();
140 }
141
142 size_t ZHeap::tlab_capacity() const {
143 return capacity();
144 }
145
146 size_t ZHeap::tlab_used() const {
147 return _object_allocator.used();
148 }
149
150 size_t ZHeap::max_tlab_size() const {
151 return ZObjectSizeLimitSmall;
152 }
153
154 size_t ZHeap::unsafe_max_tlab_alloc() const {
155 size_t size = _object_allocator.remaining();
156
157 if (size < MinTLABSize) {
158 // The remaining space in the allocator is not enough to
159 // fit the smallest possible TLAB. This means that the next
160 // TLAB allocation will force the allocator to get a new
161 // backing page anyway, which in turn means that we can then
162 // fit the largest possible TLAB.
163 size = max_tlab_size();
164 }
165
166 return MIN2(size, max_tlab_size());
167 }
168
169 bool ZHeap::is_in(uintptr_t addr) const {
170 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) {
171 return false;
172 }
173
174 const ZPage* const page = _pagetable.get(addr);
175 if (page != NULL) {
176 return page->is_in(addr);
177 }
178
179 return false;
180 }
181
182 uintptr_t ZHeap::block_start(uintptr_t addr) const {
183 const ZPage* const page = _pagetable.get(addr);
184 return page->block_start(addr);
185 }
186
187 size_t ZHeap::block_size(uintptr_t addr) const {
188 const ZPage* const page = _pagetable.get(addr);
189 return page->block_size(addr);
190 }
191
192 bool ZHeap::block_is_obj(uintptr_t addr) const {
193 const ZPage* const page = _pagetable.get(addr);
194 return page->block_is_obj(addr);
195 }
196
197 uint ZHeap::nconcurrent_worker_threads() const {
198 return _workers.nconcurrent();
199 }
200
201 uint ZHeap::nconcurrent_no_boost_worker_threads() const {
202 return _workers.nconcurrent_no_boost();
203 }
204
205 void ZHeap::set_boost_worker_threads(bool boost) {
206 _workers.set_boost(boost);
207 }
208
209 void ZHeap::worker_threads_do(ThreadClosure* tc) const {
210 _workers.threads_do(tc);
211 }
212
213 void ZHeap::print_worker_threads_on(outputStream* st) const {
214 _workers.print_threads_on(st);
215 }
216
217 void ZHeap::out_of_memory() {
218 ResourceMark rm;
219
220 ZStatInc(ZCounterOutOfMemory);
221 log_info(gc)("Out Of Memory (%s)", Thread::current()->name());
222 }
223
224 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
225 ZPage* const page = _page_allocator.alloc_page(type, size, flags);
226 if (page != NULL) {
227 // Update pagetable
228 _pagetable.insert(page);
229 }
230
231 return page;
232 }
233
234 void ZHeap::undo_alloc_page(ZPage* page) {
235 assert(page->is_allocating(), "Invalid page state");
236
237 ZStatInc(ZCounterUndoPageAllocation);
238 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT,
239 ZThread::id(), ZThread::name(), p2i(page), page->size());
240
241 release_page(page, false /* reclaimed */);
242 }
243
244 bool ZHeap::retain_page(ZPage* page) {
245 return page->inc_refcount();
246 }
247
248 void ZHeap::release_page(ZPage* page, bool reclaimed) {
249 if (page->dec_refcount()) {
250 _page_allocator.free_page(page, reclaimed);
251 }
252 }
253
254 void ZHeap::flip_views() {
255 // For debugging only
256 if (ZUnmapBadViews) {
257 // Flip pages
258 ZPageTableIterator iter(&_pagetable);
259 for (ZPage* page; iter.next(&page);) {
260 if (!page->is_detached()) {
261 _page_allocator.flip_page(page);
262 }
263 }
264
265 // Flip pre-mapped memory
266 _page_allocator.flip_pre_mapped();
267 }
268 }
269
270 void ZHeap::mark_start() {
271 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
272
273 // Update statistics
274 ZStatSample(ZSamplerHeapUsedBeforeMark, used());
275
276 // Flip address view
277 ZAddressMasks::flip_to_marked();
278 flip_views();
279
280 // Retire allocating pages
281 _object_allocator.retire_pages();
282
283 // Reset allocated/reclaimed/used statistics
284 _page_allocator.reset_statistics();
285
286 // Reset encountered/dropped/enqueued statistics
287 _reference_processor.reset_statistics();
288
289 // Enter mark phase
290 ZGlobalPhase = ZPhaseMark;
291
292 // Reset marking information and mark roots
293 _mark.start();
294
295 // Update statistics
296 ZStatHeap::set_at_mark_start(capacity(), used());
297 }
298
299 void ZHeap::mark(bool initial) {
300 _mark.mark(initial);
301 }
302
303 void ZHeap::mark_flush_and_free(Thread* thread) {
304 _mark.flush_and_free(thread);
305 }
306
307 class ZFixupPartialLoadsClosure : public ZRootsIteratorClosure {
308 public:
309 virtual void do_oop(oop* p) {
310 ZBarrier::mark_barrier_on_root_oop_field(p);
311 }
312
313 virtual void do_oop(narrowOop* p) {
314 ShouldNotReachHere();
315 }
316 };
317
318 class ZFixupPartialLoadsTask : public ZTask {
319 private:
320 ZThreadRootsIterator _thread_roots;
321
322 public:
323 ZFixupPartialLoadsTask() :
324 ZTask("ZFixupPartialLoadsTask"),
325 _thread_roots() {}
326
327 virtual void work() {
328 ZFixupPartialLoadsClosure cl;
329 _thread_roots.oops_do(&cl);
330 }
331 };
332
333 void ZHeap::fixup_partial_loads() {
334 ZFixupPartialLoadsTask task;
335 _workers.run_parallel(&task);
336 }
337
338 bool ZHeap::mark_end() {
339 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
340
341 // C2 can generate code where a safepoint poll is inserted
342 // between a load and the associated load barrier. To handle
343 // this case we need to rescan the thread stack here to make
344 // sure such oops are marked.
345 fixup_partial_loads();
346
347 // Try end marking
348 if (!_mark.end()) {
349 // Marking not completed, continue concurrent mark
350 return false;
351 }
352
353 // Enter mark completed phase
354 ZGlobalPhase = ZPhaseMarkCompleted;
355
356 // Resize metaspace
357 MetaspaceGC::compute_new_size();
358
359 // Update statistics
360 ZStatSample(ZSamplerHeapUsedAfterMark, used());
361 ZStatHeap::set_at_mark_end(capacity(), allocated(), used());
362
363 // Block resurrection of weak/phantom references
364 ZResurrection::block();
365
366 // Process weak roots
367 _weak_roots_processor.process_weak_roots();
368
369 // Verification
370 if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {
371 Universe::verify();
372 }
373
374 return true;
375 }
376
377 void ZHeap::set_soft_reference_policy(bool clear) {
378 _reference_processor.set_soft_reference_policy(clear);
379 }
380
381 void ZHeap::process_non_strong_references() {
382 // Process Soft/Weak/Final/PhantomReferences
383 _reference_processor.process_references();
384
385 // Process concurrent weak roots
386 _weak_roots_processor.process_concurrent_weak_roots();
387
388 // Unblock resurrection of weak/phantom references
389 ZResurrection::unblock();
390
391 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this
392 // must be done after unblocking resurrection. Otherwise the
393 // Finalizer thread could call Reference.get() on the Finalizers
394 // that were just enqueued, which would incorrectly return null
395 // during the resurrection block window, since such referents
396 // are only Finalizable marked.
397 _reference_processor.enqueue_references();
398 }
399
400 void ZHeap::destroy_detached_pages() {
401 ZList<ZPage> list;
402
403 _page_allocator.flush_detached_pages(&list);
404
405 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {
406 // Remove pagetable entry
407 _pagetable.remove(page);
408
409 // Delete the page
410 _page_allocator.destroy_page(page);
411 }
412 }
413
414 void ZHeap::select_relocation_set() {
415 // Register relocatable pages with selector
416 ZRelocationSetSelector selector;
417 ZPageTableIterator iter(&_pagetable);
418 for (ZPage* page; iter.next(&page);) {
419 if (!page->is_relocatable()) {
420 // Not relocatable, don't register
421 continue;
422 }
423
424 if (page->is_marked()) {
425 // Register live page
426 selector.register_live_page(page);
427 } else {
428 // Register garbage page
429 selector.register_garbage_page(page);
430
431 // Reclaim page immediately
432 release_page(page, true /* reclaimed */);
433 }
434 }
435
436 // Select pages to relocate
437 selector.select(&_relocation_set);
438
439 // Update statistics
440 ZStatRelocation::set_at_select_relocation_set(selector.relocating());
441 ZStatHeap::set_at_select_relocation_set(selector.live(),
442 selector.garbage(),
443 reclaimed());
444 }
445
446 void ZHeap::prepare_relocation_set() {
447 ZRelocationSetIterator iter(&_relocation_set);
448 for (ZPage* page; iter.next(&page);) {
449 // Prepare for relocation
450 page->set_forwarding();
451
452 // Update pagetable
453 _pagetable.set_relocating(page);
454 }
455 }
456
457 void ZHeap::reset_relocation_set() {
458 ZRelocationSetIterator iter(&_relocation_set);
459 for (ZPage* page; iter.next(&page);) {
460 // Reset relocation information
461 page->reset_forwarding();
462
463 // Update pagetable
464 _pagetable.clear_relocating(page);
465 }
466 }
467
468 void ZHeap::relocate_start() {
469 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
470
471 // Update statistics
472 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());
473
474 // Flip address view
475 ZAddressMasks::flip_to_remapped();
476 flip_views();
477
478 // Enter relocate phase
479 ZGlobalPhase = ZPhaseRelocate;
480
481 // Update statistics
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 ZVerifyRootOopClosure 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 }