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();
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::capacity() const {
111 return _page_allocator.capacity();
112 }
113
114 size_t ZHeap::max_reserve() const {
115 return _page_allocator.max_reserve();
116 }
117
118 size_t ZHeap::used_high() const {
119 return _page_allocator.used_high();
120 }
121
122 size_t ZHeap::used_low() const {
123 return _page_allocator.used_low();
124 }
125
126 size_t ZHeap::used() const {
127 return _page_allocator.used();
128 }
129
130 size_t ZHeap::allocated() const {
131 return _page_allocator.allocated();
132 }
133
134 size_t ZHeap::reclaimed() const {
135 return _page_allocator.reclaimed();
136 }
137
138 size_t ZHeap::tlab_capacity() const {
139 return capacity();
140 }
141
142 size_t ZHeap::tlab_used() const {
143 return _object_allocator.used();
144 }
145
146 size_t ZHeap::max_tlab_size() const {
147 return ZObjectSizeLimitSmall;
148 }
149
150 size_t ZHeap::unsafe_max_tlab_alloc() const {
151 size_t size = _object_allocator.remaining();
152
153 if (size < MinTLABSize) {
154 // The remaining space in the allocator is not enough to
155 // fit the smallest possible TLAB. This means that the next
156 // TLAB allocation will force the allocator to get a new
157 // backing page anyway, which in turn means that we can then
158 // fit the larges possible TLAB.
159 size = max_tlab_size();
160 }
161
162 return MIN2(size, max_tlab_size());
163 }
164
165 bool ZHeap::is_in(uintptr_t addr) const {
166 if (addr < ZAddressReservedStart() || addr >= ZAddressReservedEnd()) {
167 return false;
168 }
169
170 const ZPage* const page = _pagetable.get(addr);
171 if (page != NULL) {
172 return page->is_in(addr);
173 }
174
175 return false;
176 }
177
178 uintptr_t ZHeap::block_start(uintptr_t addr) const {
179 const ZPage* const page = _pagetable.get(addr);
180 return page->block_start(addr);
181 }
182
183 size_t ZHeap::block_size(uintptr_t addr) const {
184 const ZPage* const page = _pagetable.get(addr);
185 return page->block_size(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 // Retire TLABs
273 _object_allocator.retire_tlabs();
274
275 // Flip address view
276 ZAddressMasks::flip_to_marked();
277 flip_views();
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() {
296 _mark.mark();
297 }
298
299 void ZHeap::mark_flush_and_free(Thread* thread) {
300 _mark.flush_and_free(thread);
301 }
302
303 class ZFixupPartialLoadsTask : public ZTask {
304 private:
305 ZThreadRootsIterator _thread_roots;
306
307 public:
308 ZFixupPartialLoadsTask() :
309 ZTask("ZFixupPartialLoadsTask"),
310 _thread_roots() {}
311
312 virtual void work() {
313 ZMarkRootOopClosure cl;
314 _thread_roots.oops_do(&cl);
315 }
316 };
317
318 void ZHeap::fixup_partial_loads() {
319 ZFixupPartialLoadsTask task;
320 _workers.run_parallel(&task);
321 }
322
323 bool ZHeap::mark_end() {
324 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
325
326 // C2 can generate code where a safepoint poll is inserted
327 // between a load and the associated load barrier. To handle
328 // this case we need to rescan the thread stack here to make
329 // sure such oops are marked.
330 fixup_partial_loads();
331
332 // Try end marking
333 if (!_mark.end()) {
334 // Marking not completed, continue concurrent mark
335 return false;
336 }
337
338 // Enter mark completed phase
339 ZGlobalPhase = ZPhaseMarkCompleted;
340
341 // Resize metaspace
342 MetaspaceGC::compute_new_size();
343
344 // Update statistics
345 ZStatSample(ZSamplerHeapUsedAfterMark, used());
346 ZStatHeap::set_at_mark_end(capacity(), allocated(), used());
347
348 // Block resurrection of weak/phantom references
349 ZResurrection::block();
350
351 // Process weak roots
352 _weak_roots_processor.process_weak_roots();
353
354 // Verification
355 if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {
356 Universe::verify();
357 }
358
359 return true;
360 }
361
362 void ZHeap::set_soft_reference_policy(bool clear) {
363 _reference_processor.set_soft_reference_policy(clear);
364 }
365
366 void ZHeap::process_non_strong_references() {
367 // Process Soft/Weak/Final/PhantomReferences
368 _reference_processor.process_references();
369
370 // Process concurrent weak roots
371 _weak_roots_processor.process_concurrent_weak_roots();
372
373 // Unblock resurrection of weak/phantom references
374 ZResurrection::unblock();
375
376 // Enqueue Soft/Weak/Final/PhantomReferences. Note that this
377 // must be done after unblocking resurrection. Otherwise the
378 // Finalizer thread could call Reference.get() on the Finalizers
379 // that were just enqueued, which would incorrectly return null
380 // during the resurrection block window, since such referents
381 // are only Finalizable marked.
382 _reference_processor.enqueue_references();
383 }
384
385 void ZHeap::destroy_detached_pages() {
386 ZList<ZPage> list;
387
388 _page_allocator.flush_detached_pages(&list);
389
390 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {
391 // Remove pagetable entry
392 _pagetable.remove(page);
393
394 // Delete the page
395 _page_allocator.destroy_page(page);
396 }
397 }
398
399 void ZHeap::select_relocation_set() {
400 // Register relocatable pages with selector
401 ZRelocationSetSelector selector;
402 ZPageTableIterator iter(&_pagetable);
403 for (ZPage* page; iter.next(&page);) {
404 if (!page->is_relocatable()) {
405 // Not relocatable, don't register
406 continue;
407 }
408
409 if (page->is_marked()) {
410 // Register live page
411 selector.register_live_page(page);
412 } else {
413 // Register garbage page
414 selector.register_garbage_page(page);
415
416 // Reclaim page immediately
417 release_page(page, true /* reclaimed */);
418 }
419 }
420
421 // Select pages to relocate
422 selector.select(&_relocation_set);
423
424 // Update statistics
425 ZStatRelocation::set_at_select_relocation_set(selector.relocating());
426 ZStatHeap::set_at_select_relocation_set(selector.live(),
427 selector.garbage(),
428 reclaimed());
429 }
430
431 void ZHeap::prepare_relocation_set() {
432 ZRelocationSetIterator iter(&_relocation_set);
433 for (ZPage* page; iter.next(&page);) {
434 // Prepare for relocation
435 page->set_forwarding();
436
437 // Update pagetable
438 _pagetable.set_relocating(page);
439 }
440 }
441
442 void ZHeap::reset_relocation_set() {
443 ZRelocationSetIterator iter(&_relocation_set);
444 for (ZPage* page; iter.next(&page);) {
445 // Reset relocation information
446 page->reset_forwarding();
447
448 // Update pagetable
449 _pagetable.clear_relocating(page);
450 }
451 }
452
453 void ZHeap::relocate_start() {
454 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
455
456 // Update statistics
457 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());
458
459 // Flip address view
460 ZAddressMasks::flip_to_remapped();
461 flip_views();
462
463 // Remap TLABs
464 _object_allocator.remap_tlabs();
465
466 // Enter relocate phase
467 ZGlobalPhase = ZPhaseRelocate;
468
469 // Update statistics
470 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used());
471
472 // Remap/Relocate roots
473 _relocate.start();
474 }
475
476 uintptr_t ZHeap::relocate_object(uintptr_t addr) {
477 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed");
478 ZPage* const page = _pagetable.get(addr);
479 const bool retained = retain_page(page);
480 const uintptr_t new_addr = page->relocate_object(addr);
481 if (retained) {
482 release_page(page, true /* reclaimed */);
483 }
484
485 return new_addr;
486 }
487
488 uintptr_t ZHeap::forward_object(uintptr_t addr) {
489 assert(ZGlobalPhase == ZPhaseMark ||
490 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed");
491 ZPage* const page = _pagetable.get(addr);
492 return page->forward_object(addr);
493 }
494
495 void ZHeap::relocate() {
496 // Relocate relocation set
497 const bool success = _relocate.relocate(&_relocation_set);
498
499 // Update statistics
500 ZStatSample(ZSamplerHeapUsedAfterRelocation, used());
501 ZStatRelocation::set_at_relocate_end(success);
502 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(),
503 used(), used_high(), used_low());
504 }
505
506 void ZHeap::object_iterate(ObjectClosure* cl) {
507 // Should only be called in a safepoint after mark end.
508 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
509
510 ZHeapIterator iter;
511 iter.objects_do(cl);
512 }
513
514 void ZHeap::serviceability_initialize() {
515 _serviceability.initialize();
516 }
517
518 GCMemoryManager* ZHeap::serviceability_memory_manager() {
519 return _serviceability.memory_manager();
520 }
521
522 MemoryPool* ZHeap::serviceability_memory_pool() {
523 return _serviceability.memory_pool();
524 }
525
526 ZServiceabilityCounters* ZHeap::serviceability_counters() {
527 return _serviceability.counters();
528 }
529
530 void ZHeap::print_on(outputStream* st) const {
531 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M",
532 used() / M,
533 capacity() / M,
534 max_capacity() / M);
535 MetaspaceUtils::print_on(st);
536 }
537
538 void ZHeap::print_extended_on(outputStream* st) const {
539 print_on(st);
540 st->cr();
541
542 ZPageTableIterator iter(&_pagetable);
543 for (ZPage* page; iter.next(&page);) {
544 page->print_on(st);
545 }
546
547 st->cr();
548 }
549
550 class ZVerifyRootsTask : public ZTask {
551 private:
552 ZRootsIterator _strong_roots;
553 ZWeakRootsIterator _weak_roots;
554
555 public:
556 ZVerifyRootsTask() :
557 ZTask("ZVerifyRootsTask"),
558 _strong_roots(),
559 _weak_roots() {}
560
561 virtual void work() {
562 ZVerifyRootOopClosure cl;
563 _strong_roots.oops_do(&cl);
564 _weak_roots.oops_do(&cl);
565 }
566 };
567
568 void ZHeap::verify() {
569 // Heap verification can only be done between mark end and
570 // relocate start. This is the only window where all oop are
571 // good and the whole heap is in a consistent state.
572 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase");
573
574 {
575 ZVerifyRootsTask task;
576 _workers.run_parallel(&task);
577 }
578
579 {
580 ZVerifyObjectClosure cl;
581 object_iterate(&cl);
582 }
583 }