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 "oops/oop.inline.hpp"
47 #include "runtime/safepoint.hpp"
48 #include "runtime/thread.hpp"
49 #include "utilities/align.hpp"
50 #include "utilities/debug.hpp"
51
52 static const ZStatSampler ZSamplerHeapUsedBeforeMark("Memory", "Heap Used Before Mark", ZStatUnitBytes);
53 static const ZStatSampler ZSamplerHeapUsedAfterMark("Memory", "Heap Used After Mark", ZStatUnitBytes);
54 static const ZStatSampler ZSamplerHeapUsedBeforeRelocation("Memory", "Heap Used Before Relocation", ZStatUnitBytes);
55 static const ZStatSampler ZSamplerHeapUsedAfterRelocation("Memory", "Heap Used After Relocation", ZStatUnitBytes);
56 static const ZStatCounter ZCounterUndoPageAllocation("Memory", "Undo Page Allocation", ZStatUnitOpsPerSecond);
57 static const ZStatCounter ZCounterOutOfMemory("Memory", "Out Of Memory", ZStatUnitOpsPerSecond);
58
59 ZHeap* ZHeap::_heap = NULL;
60
61 ZHeap::ZHeap() :
62 _initialize(),
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 ZPageTableEntry* ZHeap::pagetable_addr() const {
194 return _pagetable.addr();
195 }
196
197 void ZHeap::set_boost_worker_threads(bool boost) {
198 _workers.set_boost(boost);
199 }
200
201 void ZHeap::worker_threads_do(ThreadClosure* tc) const {
202 _workers.threads_do(tc);
203 }
204
205 void ZHeap::print_worker_threads_on(outputStream* st) const {
206 _workers.print_threads_on(st);
207 }
208
209 void ZHeap::out_of_memory() {
210 ResourceMark rm;
211
212 ZStatInc(ZCounterOutOfMemory);
213 log_info(gc)("Out Of Memory (%s)", Thread::current()->name());
214 }
215
216 ZPage* ZHeap::alloc_page(uint8_t type, size_t size, ZAllocationFlags flags) {
217 ZPage* const page = _page_allocator.alloc_page(type, size, flags);
218 if (page != NULL) {
219 // Update pagetable
220 _pagetable.insert(page);
221 }
222
223 return page;
224 }
225
226 void ZHeap::undo_alloc_page(ZPage* page) {
227 assert(page->is_allocating(), "Invalid page state");
228
229 ZStatInc(ZCounterUndoPageAllocation);
230 log_trace(gc)("Undo page allocation, thread: " PTR_FORMAT " (%s), page: " PTR_FORMAT ", size: " SIZE_FORMAT,
231 ZThread::id(), ZThread::name(), p2i(page), page->size());
232
233 release_page(page, false /* reclaimed */);
234 }
235
236 bool ZHeap::retain_page(ZPage* page) {
237 return page->inc_refcount();
238 }
239
240 void ZHeap::release_page(ZPage* page, bool reclaimed) {
241 if (page->dec_refcount()) {
242 _page_allocator.free_page(page, reclaimed);
243 }
244 }
245
246 void ZHeap::flip_views() {
247 // For debugging only
248 if (ZUnmapBadViews) {
249 // Flip pages
250 ZPageTableIterator iter(&_pagetable);
251 for (ZPage* page; iter.next(&page);) {
252 if (!page->is_detached()) {
253 _page_allocator.flip_page(page);
254 }
255 }
256
257 // Flip pre-mapped memory
258 _page_allocator.flip_pre_mapped();
259 }
260 }
261
262 void ZHeap::mark_start() {
263 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
264
265 // Update statistics
266 ZStatSample(ZSamplerHeapUsedBeforeMark, used());
267
268 // Retire TLABs
269 _object_allocator.retire_tlabs();
270
271 // Flip address view
272 ZAddressMasks::flip_to_marked();
273 flip_views();
274
275 // Reset allocated/reclaimed/used statistics
276 _page_allocator.reset_statistics();
277
278 // Reset encountered/dropped/enqueued statistics
279 _reference_processor.reset_statistics();
280
281 // Enter mark phase
282 ZGlobalPhase = ZPhaseMark;
283
284 // Reset marking information and mark roots
285 _mark.start();
286
287 // Update statistics
288 ZStatHeap::set_at_mark_start(capacity(), used());
289 }
290
291 void ZHeap::mark() {
292 _mark.mark();
293 }
294
295 void ZHeap::mark_flush_and_free() {
296 _mark.flush_and_free();
297 }
298
299 class ZFixupPartialLoadsTask : public ZTask {
300 private:
301 ZThreadRootsIterator _thread_roots;
302
303 public:
304 ZFixupPartialLoadsTask() :
305 ZTask("ZFixupPartialLoadsTask"),
306 _thread_roots() {}
307
308 virtual void work() {
309 ZMarkRootOopClosure cl;
310 _thread_roots.oops_do(&cl);
311 }
312 };
313
314 void ZHeap::fixup_partial_loads() {
315 ZFixupPartialLoadsTask task;
316 _workers.run_parallel(&task);
317 }
318
319 bool ZHeap::mark_end() {
320 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
321
322 // C2 can generate code where a safepoint poll is inserted
323 // between a load and the associated load barrier. To handle
324 // this case we need to rescan the thread stack here to make
325 // sure such oops are marked.
326 fixup_partial_loads();
327
328 // Try end marking
329 if (!_mark.end()) {
330 // Marking not completed, continue concurrent mark
331 return false;
332 }
333
334 // Enter mark completed phase
335 ZGlobalPhase = ZPhaseMarkCompleted;
336
337 // Resize metaspace
338 MetaspaceGC::compute_new_size();
339
340 // Update statistics
341 ZStatSample(ZSamplerHeapUsedAfterMark, used());
342 ZStatHeap::set_at_mark_end(capacity(), allocated(), used());
343
344 // Block resurrection of weak/phantom references
345 ZResurrection::block();
346
347 // Process weak roots
348 _weak_roots_processor.process_weak_roots();
349
350 // Verification
351 if (VerifyBeforeGC || VerifyDuringGC || VerifyAfterGC) {
352 Universe::verify();
353 }
354
355 return true;
356 }
357
358 void ZHeap::set_soft_reference_policy(bool clear) {
359 _reference_processor.set_soft_reference_policy(clear);
360 }
361
362 void ZHeap::process_non_strong_references() {
363 // Process and enqueue Soft/Weak/Final/PhantomReferences
364 _reference_processor.process_and_enqueue_references();
365
366 // Process concurrent weak roots
367 _weak_roots_processor.process_concurrent_weak_roots();
368
369 // Unblock resurrection of weak/phantom references
370 ZResurrection::unblock();
371 }
372
373 void ZHeap::destroy_detached_pages() {
374 ZList<ZPage> list;
375
376 _page_allocator.flush_detached_pages(&list);
377
378 for (ZPage* page = list.remove_first(); page != NULL; page = list.remove_first()) {
379 // Remove pagetable entry
380 _pagetable.remove(page);
381
382 // Delete the page
383 _page_allocator.destroy_page(page);
384 }
385 }
386
387 void ZHeap::select_relocation_set() {
388 // Register relocatable pages with selector
389 ZRelocationSetSelector selector;
390 ZPageTableIterator iter(&_pagetable);
391 for (ZPage* page; iter.next(&page);) {
392 if (!page->is_relocatable()) {
393 // Not relocatable, don't register
394 continue;
395 }
396
397 if (page->is_marked()) {
398 // Register live page
399 selector.register_live_page(page);
400 } else {
401 // Register garbage page
402 selector.register_garbage_page(page);
403
404 // Reclaim page immediately
405 release_page(page, true /* reclaimed */);
406 }
407 }
408
409 // Select pages to relocate
410 selector.select(&_relocation_set);
411
412 // Update statistics
413 ZStatRelocation::set_at_select_relocation_set(selector.relocating());
414 ZStatHeap::set_at_select_relocation_set(selector.live(),
415 selector.garbage(),
416 reclaimed());
417 }
418
419 void ZHeap::prepare_relocation_set() {
420 ZRelocationSetIterator iter(&_relocation_set);
421 for (ZPage* page; iter.next(&page);) {
422 // Prepare for relocation
423 page->set_forwarding();
424
425 // Update pagetable
426 _pagetable.set_relocating(page);
427 }
428 }
429
430 void ZHeap::reset_relocation_set() {
431 ZRelocationSetIterator iter(&_relocation_set);
432 for (ZPage* page; iter.next(&page);) {
433 // Reset relocation information
434 page->reset_forwarding();
435
436 // Update pagetable
437 _pagetable.clear_relocating(page);
438 }
439 }
440
441 void ZHeap::relocate_start() {
442 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
443
444 // Update statistics
445 ZStatSample(ZSamplerHeapUsedBeforeRelocation, used());
446
447 // Flip address view
448 ZAddressMasks::flip_to_remapped();
449 flip_views();
450
451 // Remap TLABs
452 _object_allocator.remap_tlabs();
453
454 // Enter relocate phase
455 ZGlobalPhase = ZPhaseRelocate;
456
457 // Update statistics
458 ZStatHeap::set_at_relocate_start(capacity(), allocated(), used());
459
460 // Remap/Relocate roots
461 _relocate.start();
462 }
463
464 uintptr_t ZHeap::relocate_object(uintptr_t addr) {
465 assert(ZGlobalPhase == ZPhaseRelocate, "Relocate not allowed");
466 ZPage* const page = _pagetable.get(addr);
467 const bool retained = retain_page(page);
468 const uintptr_t new_addr = page->relocate_object(addr);
469 if (retained) {
470 release_page(page, true /* reclaimed */);
471 }
472
473 return new_addr;
474 }
475
476 uintptr_t ZHeap::forward_object(uintptr_t addr) {
477 assert(ZGlobalPhase == ZPhaseMark ||
478 ZGlobalPhase == ZPhaseMarkCompleted, "Forward not allowed");
479 ZPage* const page = _pagetable.get(addr);
480 return page->forward_object(addr);
481 }
482
483 void ZHeap::relocate() {
484 // Relocate relocation set
485 const bool success = _relocate.relocate(&_relocation_set);
486
487 // Update statistics
488 ZStatSample(ZSamplerHeapUsedAfterRelocation, used());
489 ZStatRelocation::set_at_relocate_end(success);
490 ZStatHeap::set_at_relocate_end(capacity(), allocated(), reclaimed(),
491 used(), used_high(), used_low());
492 }
493
494 void ZHeap::object_iterate(ObjectClosure* cl) {
495 // Should only be called in a safepoint after mark end.
496 assert(SafepointSynchronize::is_at_safepoint(), "Should be at safepoint");
497
498 ZHeapIterator iter;
499 iter.objects_do(cl);
500 }
501
502 void ZHeap::serviceability_initialize() {
503 _serviceability.initialize();
504 }
505
506 GCMemoryManager* ZHeap::serviceability_memory_manager() {
507 return _serviceability.memory_manager();
508 }
509
510 MemoryPool* ZHeap::serviceability_memory_pool() {
511 return _serviceability.memory_pool();
512 }
513
514 ZServiceabilityCounters* ZHeap::serviceability_counters() {
515 return _serviceability.counters();
516 }
517
518 void ZHeap::print_on(outputStream* st) const {
519 st->print_cr(" ZHeap used " SIZE_FORMAT "M, capacity " SIZE_FORMAT "M, max capacity " SIZE_FORMAT "M",
520 used() / M,
521 capacity() / M,
522 max_capacity() / M);
523 MetaspaceAux::print_on(st);
524 }
525
526 void ZHeap::print_extended_on(outputStream* st) const {
527 print_on(st);
528 st->cr();
529
530 ZPageTableIterator iter(&_pagetable);
531 for (ZPage* page; iter.next(&page);) {
532 page->print_on(st);
533 }
534
535 st->cr();
536 }
537
538 class ZVerifyRootsTask : public ZTask {
539 private:
540 ZRootsIterator _strong_roots;
541 ZWeakRootsIterator _weak_roots;
542
543 public:
544 ZVerifyRootsTask() :
545 ZTask("ZVerifyRootsTask"),
546 _strong_roots(),
547 _weak_roots() {}
548
549 virtual void work() {
550 ZVerifyRootOopClosure cl;
551 _strong_roots.oops_do(&cl);
552 _weak_roots.oops_do(&cl);
553 }
554 };
555
556 void ZHeap::verify() {
557 // Heap verification can only be done between mark end and
558 // relocate start. This is the only window where all oop are
559 // good and the whole heap is in a consistent state.
560 guarantee(ZGlobalPhase == ZPhaseMarkCompleted, "Invalid phase");
561
562 {
563 ZVerifyRootsTask task;
564 _workers.run_parallel(&task);
565 }
566
567 {
568 ZVerifyObjectClosure cl;
569 object_iterate(&cl);
570 }
571 }