1 /*
2 * Copyright (c) 2015, 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 #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, ZGranuleSize);
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, ZGranuleSize);
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 bool ZHeap::block_is_obj(uintptr_t addr) const {
189 const ZPage* const page = _pagetable.get(addr);
190 return page->block_is_obj(addr);
191 }
192
193 uint ZHeap::nconcurrent_worker_threads() const {
194 return _workers.nconcurrent();
195 }
196
197 uint ZHeap::nconcurrent_no_boost_worker_threads() const {
198 return _workers.nconcurrent_no_boost();
199 }
200
201 void ZHeap::set_boost_worker_threads(bool boost) {
202 _workers.set_boost(boost);
203 }
204
205 void ZHeap::worker_threads_do(ThreadClosure* tc) const {
206 _workers.threads_do(tc);
207 }
208
209 void ZHeap::print_worker_threads_on(outputStream* st) const {
210 _workers.print_threads_on(st);
211 }
212
213 void ZHeap::out_of_memory() {
214 ResourceMark rm;
215
216 ZStatInc(ZCounterOutOfMemory);
217 log_info(gc)("Out Of Memory (%s)", Thread::current()->name());
218 }
219
220 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
221 ZPage* const page = _page_allocator.alloc_page(type, size, flags);
222 if (page != NULL) {
223 // Update pagetable
224 _pagetable.insert(page);
225 }
226
227 return page;
228 }
229
230 void ZHeap::undo_alloc_page(ZPage* page) {
231 assert(page->is_allocating(), "Invalid page state");
232
233 ZStatInc(ZCounterUndoPageAllocation);
234 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT,
235 ZThread::id(), ZThread::name(), p2i(page), page->size());
236
237 release_page(page, false /* reclaimed */);
238 }
239
240 bool ZHeap::retain_page(ZPage* page) {
241 return page->inc_refcount();
242 }
243
244 void ZHeap::release_page(ZPage* page, bool reclaimed) {
245 if (page->dec_refcount()) {
246 _page_allocator.free_page(page, reclaimed);
247 }
248 }
249
250 void ZHeap::flip_views() {
251 // For debugging only
252 if (ZUnmapBadViews) {
253 // Flip pages
254 ZPageTableIterator iter(&_pagetable);
255 for (ZPage* page; iter.next(&page);) {
256 if (!page->is_detached()) {
257 _page_allocator.flip_page(page);
258 }
259 }
260
261 // Flip pre-mapped memory
262 _page_allocator.flip_pre_mapped();
263 }
264 }
265
266 void ZHeap::mark_start() {
267 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
268
269 // Update statistics
270 ZStatSample(ZSamplerHeapUsedBeforeMark, used());
271
272 // Flip address view
273 ZAddressMasks::flip_to_marked();
274 flip_views();
275
276 // Retire allocating pages
277 _object_allocator.retire_pages();
278
279 // Reset allocated/reclaimed/used statistics
280 _page_allocator.reset_statistics();
281
282 // Reset encountered/dropped/enqueued statistics
283 _reference_processor.reset_statistics();
284
285 // Enter mark phase
286 ZGlobalPhase = ZPhaseMark;
287
288 // Reset marking information and mark roots
289 _mark.start();
290
291 // Update statistics
292 ZStatHeap::set_at_mark_start(capacity(), used());
293 }
294
295 void ZHeap::mark(bool initial) {
296 _mark.mark(initial);
297 }
298
299 void ZHeap::mark_flush_and_free(Thread* thread) {
300 _mark.flush_and_free(thread);
301 }
302
303 class ZFixupPartialLoadsClosure : public ZRootsIteratorClosure {
304 public:
305 virtual void do_oop(oop* p) {
306 ZBarrier::mark_barrier_on_root_oop_field(p);
307 }
308
309 virtual void do_oop(narrowOop* p) {
310 ShouldNotReachHere();
311 }
312 };
313
314 class ZFixupPartialLoadsTask : public ZTask {
315 private:
316 ZThreadRootsIterator _thread_roots;
317
318 public:
319 ZFixupPartialLoadsTask() :
320 ZTask("ZFixupPartialLoadsTask"),
321 _thread_roots() {}
322
323 virtual void work() {
324 ZFixupPartialLoadsClosure cl;
325 _thread_roots.oops_do(&cl);
326 }
327 };
328
329 void ZHeap::fixup_partial_loads() {
330 ZFixupPartialLoadsTask task;
331 _workers.run_parallel(&task);
332 }
333
334 bool ZHeap::mark_end() {
335 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
336
337 // C2 can generate code where a safepoint poll is inserted
338 // between a load and the associated load barrier. To handle
339 // this case we need to rescan the thread stack here to make
340 // sure such oops are marked.
341 fixup_partial_loads();
342
343 // Try end marking
344 if (!_mark.end()) {
345 // Marking not completed, continue concurrent mark
346 return false;
347 }
348
349 // Enter mark completed phase
350 ZGlobalPhase = ZPhaseMarkCompleted;
351
352 // Update statistics
353 ZStatSample(ZSamplerHeapUsedAfterMark, used());
354 ZStatHeap::set_at_mark_end(capacity(), allocated(), used());
355
356 // Block resurrection of weak/phantom references
357 ZResurrection::block();
358
359 // Process weak roots
360 _weak_roots_processor.process_weak_roots();
361
362 // Prepare to unload unused classes and code
363 _unload.prepare();
364
365 return true;
366 }
367
368 void ZHeap::set_soft_reference_policy(bool clear) {
369 _reference_processor.set_soft_reference_policy(clear);
370 }
371
372 void ZHeap::process_non_strong_references() {
373 // Process Soft/Weak/Final/PhantomReferences
374 _reference_processor.process_references();
375
376 // Process concurrent weak roots
377 _weak_roots_processor.process_concurrent_weak_roots();
378
379 // Unload unused classes and code
380 _unload.unload();
381
382 // Unblock resurrection of weak/phantom references
383 ZResurrection::unblock();
384
385 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this
386 // must be done after unblocking resurrection. Otherwise the
387 // Finalizer thread could call Reference.get() on the Finalizers
388 // that were just enqueued, which would incorrectly return null
389 // during the resurrection block window, since such referents
390 // are only Finalizable marked.
391 _reference_processor.enqueue_references();
392 }
393
394 void ZHeap::destroy_detached_pages() {
395 ZList<ZPage> list;
396
397 _page_allocator.flush_detached_pages(&list);
398
399 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {
400 // Remove pagetable entry
401 _pagetable.remove(page);
402
403 // Delete the page
404 _page_allocator.destroy_page(page);
405 }
406 }
407
408 void ZHeap::select_relocation_set() {
409 // Register relocatable pages with selector
410 ZRelocationSetSelector selector;
411 ZPageTableIterator iter(&_pagetable);
412 for (ZPage* page; iter.next(&page);) {
413 if (!page->is_relocatable()) {
414 // Not relocatable, don't register
415 continue;
416 }
417
418 if (page->is_marked()) {
419 // Register live page
420 selector.register_live_page(page);
421 } else {
422 // Register garbage page
423 selector.register_garbage_page(page);
424
425 // Reclaim page immediately
426 release_page(page, true /* reclaimed */);
427 }
428 }
429
430 // Select pages to relocate
431 selector.select(&_relocation_set);
432
433 // Update statistics
434 ZStatRelocation::set_at_select_relocation_set(selector.relocating());
435 ZStatHeap::set_at_select_relocation_set(selector.live(),
436 selector.garbage(),
437 reclaimed());
438 }
439
440 void ZHeap::prepare_relocation_set() {
441 ZRelocationSetIterator iter(&_relocation_set);
442 for (ZPage* page; iter.next(&page);) {
443 // Prepare for relocation
444 page->set_forwarding();
445
446 // Update pagetable
447 _pagetable.set_relocating(page);
448 }
449 }
450
451 void ZHeap::reset_relocation_set() {
452 ZRelocationSetIterator iter(&_relocation_set);
453 for (ZPage* page; iter.next(&page);) {
454 // Reset relocation information
455 page->reset_forwarding();
456
457 // Update pagetable
458 _pagetable.clear_relocating(page);
459 }
460 }
461
462 void ZHeap::relocate_start() {
463 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
464
465 // Finish unloading of classes and code
466 _unload.finish();
467
468 // Flip address view
469 ZAddressMasks::flip_to_remapped();
470 flip_views();
471
472 // Enter relocate phase
473 ZGlobalPhase = ZPhaseRelocate;
474
475 // Update statistics
476 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());
477 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used());
478
479 // Remap/Relocate roots
480 _relocate.start();
481 }
482
483 uintptr_t ZHeap::relocate_object(uintptr_t addr) {
484 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed");
485 ZPage* const page = _pagetable.get(addr);
486 const bool retained = retain_page(page);
487 const uintptr_t new_addr = page->relocate_object(addr);
488 if (retained) {
489 release_page(page, true /* reclaimed */);
490 }
491
492 return new_addr;
493 }
494
495 uintptr_t ZHeap::forward_object(uintptr_t addr) {
496 assert(ZGlobalPhase == ZPhaseMark ||
497 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed");
498 ZPage* const page = _pagetable.get(addr);
499 return page->forward_object(addr);
500 }
501
502 void ZHeap::relocate() {
503 // Relocate relocation set
504 const bool success = _relocate.relocate(&_relocation_set);
505
506 // Update statistics
507 ZStatSample(ZSamplerHeapUsedAfterRelocation, used());
508 ZStatRelocation::set_at_relocate_end(success);
509 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(),
510 used(), used_high(), used_low());
511 }
512
513 void ZHeap::object_iterate(ObjectClosure* cl, bool visit_referents) {
514 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
515
516 ZHeapIterator iter(visit_referents);
517 iter.objects_do(cl);
518 }
519
520 void ZHeap::serviceability_initialize() {
521 _serviceability.initialize();
522 }
523
524 GCMemoryManager* ZHeap::serviceability_memory_manager() {
525 return _serviceability.memory_manager();
526 }
527
528 MemoryPool* ZHeap::serviceability_memory_pool() {
529 return _serviceability.memory_pool();
530 }
531
532 ZServiceabilityCounters* ZHeap::serviceability_counters() {
533 return _serviceability.counters();
534 }
535
536 void ZHeap::print_on(outputStream* st) const {
537 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M",
538 used() / M,
539 capacity() / M,
540 max_capacity() / M);
541 MetaspaceUtils::print_on(st);
542 }
543
544 void ZHeap::print_extended_on(outputStream* st) const {
545 print_on(st);
546 st->cr();
547
548 ZPageTableIterator iter(&_pagetable);
549 for (ZPage* page; iter.next(&page);) {
550 page->print_on(st);
551 }
552
553 st->cr();
554 }
555
556 class ZVerifyRootsTask : public ZTask {
557 private:
558 ZRootsIterator _strong_roots;
559 ZWeakRootsIterator _weak_roots;
560
561 public:
562 ZVerifyRootsTask() :
563 ZTask("ZVerifyRootsTask"),
564 _strong_roots(),
565 _weak_roots() {}
566
567 virtual void work() {
568 ZVerifyOopClosure cl;
569 _strong_roots.oops_do(&cl);
570 _weak_roots.oops_do(&cl);
571 }
572 };
573
574 void ZHeap::verify() {
575 // Heap verification can only be done between mark end and
576 // relocate start. This is the only window where all oop are
577 // good and the whole heap is in a consistent state.
578 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase");
579
580 {
581 ZVerifyRootsTask task;
582 _workers.run_parallel(&task);
583 }
584
585 {
586 ZVerifyObjectClosure cl;
587 object_iterate(&cl, false /* visit_referents */);
588 }
589 }