1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "memory/allocation.hpp"
25
26 #include "gc/shared/gcTimer.hpp"
27 #include "gc/shared/gcTraceTime.inline.hpp"
28 #include "gc/shared/parallelCleaning.hpp"
29
30 #include "gc/shenandoah/brooksPointer.hpp"
31 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
32 #include "gc/shenandoah/shenandoahCollectionSet.hpp"
33 #include "gc/shenandoah/shenandoahCollectorPolicy.hpp"
34 #include "gc/shenandoah/shenandoahConcurrentMark.hpp"
35 #include "gc/shenandoah/shenandoahConcurrentMark.inline.hpp"
36 #include "gc/shenandoah/shenandoahConcurrentThread.hpp"
37 #include "gc/shenandoah/shenandoahFreeSet.hpp"
38 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
39 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
40 #include "gc/shenandoah/shenandoahHeapRegionSet.hpp"
41 #include "gc/shenandoah/shenandoahHumongous.hpp"
42 #include "gc/shenandoah/shenandoahMarkCompact.hpp"
43 #include "gc/shenandoah/shenandoahMonitoringSupport.hpp"
44 #include "gc/shenandoah/shenandoahPartialGC.hpp"
45 #include "gc/shenandoah/shenandoahRootProcessor.hpp"
46 #include "gc/shenandoah/vm_operations_shenandoah.hpp"
47
48 #include "runtime/vmThread.hpp"
49 #include "services/mallocTracker.hpp"
50
51 SCMUpdateRefsClosure::SCMUpdateRefsClosure() : _heap(ShenandoahHeap::heap()) {}
52
53 #ifdef ASSERT
54 template <class T>
55 void AssertToSpaceClosure::do_oop_nv(T* p) {
56 T o = oopDesc::load_heap_oop(p);
57 if (! oopDesc::is_null(o)) {
58 oop obj = oopDesc::decode_heap_oop_not_null(o);
59 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)),
60 "need to-space object here obj: "PTR_FORMAT" , rb(obj): "PTR_FORMAT", p: "PTR_FORMAT,
61 p2i(obj), p2i(ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), p2i(p));
62 }
63 }
64
65 void AssertToSpaceClosure::do_oop(narrowOop* p) { do_oop_nv(p); }
66 void AssertToSpaceClosure::do_oop(oop* p) { do_oop_nv(p); }
67 #endif
68
69 const char* ShenandoahHeap::name() const {
70 return "Shenandoah";
71 }
72
73 void ShenandoahHeap::print_heap_locations(HeapWord* start, HeapWord* end) {
74 HeapWord* cur = NULL;
75 for (cur = start; cur < end; cur++) {
76 tty->print_cr(PTR_FORMAT" : "PTR_FORMAT, p2i(cur), p2i(*((HeapWord**) cur)));
77 }
78 }
79
80 class PrintHeapRegionsClosure : public
81 ShenandoahHeapRegionClosure {
82 private:
83 outputStream* _st;
84 public:
85 PrintHeapRegionsClosure() : _st(tty) {}
86 PrintHeapRegionsClosure(outputStream* st) : _st(st) {}
87
88 bool doHeapRegion(ShenandoahHeapRegion* r) {
89 r->print_on(_st);
90 return false;
91 }
92 };
93
94 class ShenandoahPretouchTask : public AbstractGangTask {
95 private:
96 ShenandoahHeapRegionSet* _regions;
97 const size_t _bitmap_size;
98 const size_t _page_size;
99 char* _bitmap0_base;
100 char* _bitmap1_base;
101 public:
102 ShenandoahPretouchTask(ShenandoahHeapRegionSet* regions,
103 char* bitmap0_base, char* bitmap1_base, size_t bitmap_size,
104 size_t page_size) :
105 AbstractGangTask("Shenandoah PreTouch",
106 Universe::is_fully_initialized() ? GCId::current_raw() :
107 // During VM initialization there is
108 // no GC cycle that this task can be
109 // associated with.
110 GCId::undefined()),
111 _bitmap0_base(bitmap0_base),
112 _bitmap1_base(bitmap1_base),
113 _regions(regions),
114 _bitmap_size(bitmap_size),
115 _page_size(page_size) {
116 _regions->clear_current_index();
117 };
118
119 virtual void work(uint worker_id) {
120 ShenandoahHeapRegion* r = _regions->claim_next();
121 while (r != NULL) {
122 log_trace(gc, heap)("Pretouch region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT,
123 r->region_number(), p2i(r->bottom()), p2i(r->end()));
124 os::pretouch_memory(r->bottom(), r->end(), _page_size);
125
126 size_t start = r->region_number() * ShenandoahHeapRegion::RegionSizeBytes / CMBitMap::heap_map_factor();
127 size_t end = (r->region_number() + 1) * ShenandoahHeapRegion::RegionSizeBytes / CMBitMap::heap_map_factor();
128 assert (end <= _bitmap_size, "end is sane: " SIZE_FORMAT " < " SIZE_FORMAT, end, _bitmap_size);
129
130 log_trace(gc, heap)("Pretouch bitmap under region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT,
131 r->region_number(), p2i(_bitmap0_base + start), p2i(_bitmap0_base + end));
132 os::pretouch_memory(_bitmap0_base + start, _bitmap0_base + end, _page_size);
133
134 log_trace(gc, heap)("Pretouch bitmap under region " SIZE_FORMAT ": " PTR_FORMAT " -> " PTR_FORMAT,
135 r->region_number(), p2i(_bitmap1_base + start), p2i(_bitmap1_base + end));
136 os::pretouch_memory(_bitmap1_base + start, _bitmap1_base + end, _page_size);
137
138 r = _regions->claim_next();
139 }
140 }
141 };
142
143 jint ShenandoahHeap::initialize() {
144 CollectedHeap::pre_initialize();
145
146 size_t init_byte_size = collector_policy()->initial_heap_byte_size();
147 size_t max_byte_size = collector_policy()->max_heap_byte_size();
148
149 Universe::check_alignment(max_byte_size,
150 ShenandoahHeapRegion::RegionSizeBytes,
151 "shenandoah heap");
152 Universe::check_alignment(init_byte_size,
153 ShenandoahHeapRegion::RegionSizeBytes,
154 "shenandoah heap");
155
156 ReservedSpace heap_rs = Universe::reserve_heap(max_byte_size,
157 Arguments::conservative_max_heap_alignment());
158 initialize_reserved_region((HeapWord*)heap_rs.base(), (HeapWord*) (heap_rs.base() + heap_rs.size()));
159
160 set_barrier_set(new ShenandoahBarrierSet(this));
161 ReservedSpace pgc_rs = heap_rs.first_part(max_byte_size);
162 _storage.initialize(pgc_rs, init_byte_size);
163
164 _num_regions = init_byte_size / ShenandoahHeapRegion::RegionSizeBytes;
165 _max_regions = max_byte_size / ShenandoahHeapRegion::RegionSizeBytes;
166 _initialSize = _num_regions * ShenandoahHeapRegion::RegionSizeBytes;
167 size_t regionSizeWords = ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize;
168 assert(init_byte_size == _initialSize, "tautology");
169 _ordered_regions = new ShenandoahHeapRegionSet(_max_regions);
170 _collection_set = new ShenandoahCollectionSet(_max_regions);
171 _free_regions = new ShenandoahFreeSet(_max_regions);
172
173 // Initialize fast collection set test structure.
174 _in_cset_fast_test_length = _max_regions;
175 _in_cset_fast_test_base =
176 NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length, mtGC);
177 _in_cset_fast_test = _in_cset_fast_test_base -
178 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift);
179
180 _next_top_at_mark_starts_base =
181 NEW_C_HEAP_ARRAY(HeapWord*, _max_regions, mtGC);
182 _next_top_at_mark_starts = _next_top_at_mark_starts_base -
183 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift);
184
185 _complete_top_at_mark_starts_base =
186 NEW_C_HEAP_ARRAY(HeapWord*, _max_regions, mtGC);
187 _complete_top_at_mark_starts = _complete_top_at_mark_starts_base -
188 ((uintx) pgc_rs.base() >> ShenandoahHeapRegion::RegionSizeShift);
189
190 size_t i = 0;
191 for (i = 0; i < _num_regions; i++) {
192 _in_cset_fast_test_base[i] = false; // Not in cset
193 HeapWord* bottom = (HeapWord*) pgc_rs.base() + regionSizeWords * i;
194 _complete_top_at_mark_starts_base[i] = bottom;
195 _next_top_at_mark_starts_base[i] = bottom;
196 }
197
198 {
199 ShenandoahHeapLock lock(this);
200 for (i = 0; i < _num_regions; i++) {
201 ShenandoahHeapRegion* current = new ShenandoahHeapRegion(this, (HeapWord*) pgc_rs.base() +
202 regionSizeWords * i, regionSizeWords, i);
203 _free_regions->add_region(current);
204 _ordered_regions->add_region(current);
205 }
206 }
207 assert(((size_t) _ordered_regions->active_regions()) == _num_regions, "");
208 _first_region = _ordered_regions->get(0);
209 _first_region_bottom = _first_region->bottom();
210 assert((((size_t) _first_region_bottom) &
211 (ShenandoahHeapRegion::RegionSizeBytes - 1)) == 0,
212 "misaligned heap: "PTR_FORMAT, p2i(_first_region_bottom));
213
214 _numAllocs = 0;
215
216 if (log_is_enabled(Trace, gc, region)) {
217 ResourceMark rm;
218 outputStream* out = Log(gc, region)::trace_stream();
219 log_trace(gc, region)("All Regions");
220 _ordered_regions->print(out);
221 log_trace(gc, region)("Free Regions");
222 _free_regions->print(out);
223 }
224
225 // The call below uses stuff (the SATB* things) that are in G1, but probably
226 // belong into a shared location.
227 JavaThread::satb_mark_queue_set().initialize(SATB_Q_CBL_mon,
228 SATB_Q_FL_lock,
229 20 /*G1SATBProcessCompletedThreshold */,
230 Shared_SATB_Q_lock);
231
232 // Reserve space for prev and next bitmap.
233 _bitmap_size = CMBitMap::compute_size(heap_rs.size());
234 _heap_region = MemRegion((HeapWord*) heap_rs.base(), heap_rs.size() / HeapWordSize);
235
236 size_t page_size = UseLargePages ? (size_t)os::large_page_size() : (size_t)os::vm_page_size();
237
238 ReservedSpace bitmap0(_bitmap_size, page_size);
239 os::commit_memory_or_exit(bitmap0.base(), bitmap0.size(), false, "couldn't allocate mark bitmap");
240 MemTracker::record_virtual_memory_type(bitmap0.base(), mtGC);
241 MemRegion bitmap_region0 = MemRegion((HeapWord*) bitmap0.base(), bitmap0.size() / HeapWordSize);
242
243 ReservedSpace bitmap1(_bitmap_size, page_size);
244 os::commit_memory_or_exit(bitmap1.base(), bitmap1.size(), false, "couldn't allocate mark bitmap");
245 MemTracker::record_virtual_memory_type(bitmap1.base(), mtGC);
246 MemRegion bitmap_region1 = MemRegion((HeapWord*) bitmap1.base(), bitmap1.size() / HeapWordSize);
247
248 if (ShenandoahAlwaysPreTouch) {
249 assert (!AlwaysPreTouch, "Should have been overridden");
250
251 // For NUMA, it is important to pre-touch the storage under bitmaps with worker threads,
252 // before initialize() below zeroes it with initializing thread. For any given region,
253 // we touch the region and the corresponding bitmaps from the same thread.
254
255 log_info(gc, heap)("Parallel pretouch " SIZE_FORMAT " regions with " SIZE_FORMAT " byte pages",
256 _ordered_regions->count(), page_size);
257 ShenandoahPretouchTask cl(_ordered_regions, bitmap0.base(), bitmap1.base(), _bitmap_size, page_size);
258 _workers->run_task(&cl);
259 }
260
261 _mark_bit_map0.initialize(_heap_region, bitmap_region0);
262 _complete_mark_bit_map = &_mark_bit_map0;
263
264 _mark_bit_map1.initialize(_heap_region, bitmap_region1);
265 _next_mark_bit_map = &_mark_bit_map1;
266
267 _connection_matrix = new ShenandoahConnectionMatrix(_max_regions);
268 _partial_gc = new ShenandoahPartialGC(this, _max_regions);
269
270 _monitoring_support = new ShenandoahMonitoringSupport(this);
271
272 _concurrent_gc_thread = new ShenandoahConcurrentThread();
273
274 ShenandoahMarkCompact::initialize();
275
276 return JNI_OK;
277 }
278
279 ShenandoahHeap::ShenandoahHeap(ShenandoahCollectorPolicy* policy) :
280 CollectedHeap(),
281 _shenandoah_policy(policy),
282 _concurrent_mark_in_progress(0),
283 _evacuation_in_progress(0),
284 _full_gc_in_progress(false),
285 _free_regions(NULL),
286 _collection_set(NULL),
287 _bytes_allocated_since_cm(0),
288 _bytes_allocated_during_cm(0),
289 _max_allocated_gc(0),
290 _allocated_last_gc(0),
291 _used_start_gc(0),
292 _max_workers(MAX2(ConcGCThreads, ParallelGCThreads)),
293 _ref_processor(NULL),
294 _in_cset_fast_test(NULL),
295 _in_cset_fast_test_base(NULL),
296 _next_top_at_mark_starts(NULL),
297 _next_top_at_mark_starts_base(NULL),
298 _complete_top_at_mark_starts(NULL),
299 _complete_top_at_mark_starts_base(NULL),
300 _mark_bit_map0(),
301 _mark_bit_map1(),
302 _connection_matrix(NULL),
303 _cancelled_concgc(false),
304 _need_update_refs(false),
305 _need_reset_bitmaps(false),
306 _heap_lock(0),
307 #ifdef ASSERT
308 _heap_lock_owner(NULL),
309 #endif
310 _gc_timer(new (ResourceObj::C_HEAP, mtGC) ConcurrentGCTimer())
311
312 {
313 log_info(gc, init)("Parallel GC threads: "UINT32_FORMAT, ParallelGCThreads);
314 log_info(gc, init)("Concurrent GC threads: "UINT32_FORMAT, ConcGCThreads);
315 log_info(gc, init)("Parallel reference processing enabled: %s", BOOL_TO_STR(ParallelRefProcEnabled));
316
317 _scm = new ShenandoahConcurrentMark();
318 _used = 0;
319
320 _max_workers = MAX2(_max_workers, 1U);
321 _workers = new ShenandoahWorkGang("Shenandoah GC Threads", _max_workers,
322 /* are_GC_task_threads */true,
323 /* are_ConcurrentGC_threads */false);
324 if (_workers == NULL) {
325 vm_exit_during_initialization("Failed necessary allocation.");
326 } else {
327 _workers->initialize_workers();
328 }
329 }
330
331 class ResetNextBitmapTask : public AbstractGangTask {
332 private:
333 ShenandoahHeapRegionSet* _regions;
334
335 public:
336 ResetNextBitmapTask(ShenandoahHeapRegionSet* regions) :
337 AbstractGangTask("Parallel Reset Bitmap Task"),
338 _regions(regions) {
339 _regions->clear_current_index();
340 }
341
342 void work(uint worker_id) {
343 ShenandoahHeapRegion* region = _regions->claim_next();
344 ShenandoahHeap* heap = ShenandoahHeap::heap();
345 while (region != NULL) {
346 HeapWord* bottom = region->bottom();
347 HeapWord* top = heap->next_top_at_mark_start(region->bottom());
348 if (top > bottom) {
349 heap->next_mark_bit_map()->clear_range_large(MemRegion(bottom, top));
350 }
351 region = _regions->claim_next();
352 }
353 }
354 };
355
356 void ShenandoahHeap::reset_next_mark_bitmap(WorkGang* workers) {
357 ResetNextBitmapTask task = ResetNextBitmapTask(_ordered_regions);
358 workers->run_task(&task);
359 }
360
361 class ResetCompleteBitmapTask : public AbstractGangTask {
362 private:
363 ShenandoahHeapRegionSet* _regions;
364
365 public:
366 ResetCompleteBitmapTask(ShenandoahHeapRegionSet* regions) :
367 AbstractGangTask("Parallel Reset Bitmap Task"),
368 _regions(regions) {
369 _regions->clear_current_index();
370 }
371
372 void work(uint worker_id) {
373 ShenandoahHeapRegion* region = _regions->claim_next();
374 ShenandoahHeap* heap = ShenandoahHeap::heap();
375 while (region != NULL) {
376 HeapWord* bottom = region->bottom();
377 HeapWord* top = heap->complete_top_at_mark_start(region->bottom());
378 if (top > bottom) {
379 heap->complete_mark_bit_map()->clear_range_large(MemRegion(bottom, top));
380 }
381 region = _regions->claim_next();
382 }
383 }
384 };
385
386 void ShenandoahHeap::reset_complete_mark_bitmap(WorkGang* workers) {
387 ResetCompleteBitmapTask task = ResetCompleteBitmapTask(_ordered_regions);
388 workers->run_task(&task);
389 }
390
391 bool ShenandoahHeap::is_next_bitmap_clear() {
392 HeapWord* start = _ordered_regions->bottom();
393 HeapWord* end = _ordered_regions->end();
394 return _next_mark_bit_map->getNextMarkedWordAddress(start, end) == end;
395 }
396
397 bool ShenandoahHeap::is_complete_bitmap_clear_range(HeapWord* start, HeapWord* end) {
398 return _complete_mark_bit_map->getNextMarkedWordAddress(start, end) == end;
399 }
400
401 void ShenandoahHeap::print_on(outputStream* st) const {
402 st->print("Shenandoah Heap");
403 st->print(" total = " SIZE_FORMAT " K, used " SIZE_FORMAT " K ", capacity()/ K, used() /K);
404 st->print(" [" PTR_FORMAT ", " PTR_FORMAT ") ",
405 p2i(reserved_region().start()),
406 p2i(reserved_region().end()));
407 st->print("Region size = " SIZE_FORMAT "K ", ShenandoahHeapRegion::RegionSizeBytes / K);
408 if (_concurrent_mark_in_progress) {
409 st->print("marking ");
410 }
411 if (_evacuation_in_progress) {
412 st->print("evacuating ");
413 }
414 if (cancelled_concgc()) {
415 st->print("cancelled ");
416 }
417 st->print("\n");
418
419 // Adapted from VirtualSpace::print_on(), which is non-PRODUCT only
420 st->print ("Virtual space:");
421 if (_storage.special()) st->print(" (pinned in memory)");
422 st->cr();
423 st->print_cr(" - committed: " SIZE_FORMAT, _storage.committed_size());
424 st->print_cr(" - reserved: " SIZE_FORMAT, _storage.reserved_size());
425 st->print_cr(" - [low, high]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_storage.low()), p2i(_storage.high()));
426 st->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_storage.low_boundary()), p2i(_storage.high_boundary()));
427
428 if (Verbose) {
429 print_heap_regions(st);
430 }
431 }
432
433 class InitGCLABClosure : public ThreadClosure {
434 public:
435 void do_thread(Thread* thread) {
436 thread->gclab().initialize(true);
437 }
438 };
439
440 void ShenandoahHeap::post_initialize() {
441 if (UseTLAB) {
442 // This is a very tricky point in VM lifetime. We cannot easily call Threads::threads_do
443 // here, because some system threads (VMThread, WatcherThread, etc) are not yet available.
444 // Their initialization should be handled separately. Is we miss some threads here,
445 // then any other TLAB-related activity would fail with asserts.
446
447 InitGCLABClosure init_gclabs;
448 {
449 MutexLocker ml(Threads_lock);
450 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
451 init_gclabs.do_thread(thread);
452 }
453 }
454 gc_threads_do(&init_gclabs);
455
456 // gclab can not be initialized early during VM startup, as it can not determinate its max_size.
457 // Now, we will let WorkGang to initialize gclab when new worker is created.
458 _workers->set_initialize_gclab();
459 }
460
461 _scm->initialize(_max_workers);
462
463 ref_processing_init();
464 }
465
466 class CalculateUsedRegionClosure : public ShenandoahHeapRegionClosure {
467 size_t sum;
468 public:
469
470 CalculateUsedRegionClosure() {
471 sum = 0;
472 }
473
474 bool doHeapRegion(ShenandoahHeapRegion* r) {
475 sum = sum + r->used();
476 return false;
477 }
478
479 size_t getResult() { return sum;}
480 };
481
482 size_t ShenandoahHeap::calculateUsed() {
483 CalculateUsedRegionClosure cl;
484 heap_region_iterate(&cl);
485 return cl.getResult();
486 }
487
488 void ShenandoahHeap::verify_heap_size_consistency() {
489
490 assert(calculateUsed() == used(),
491 "heap used size must be consistent heap-used: "SIZE_FORMAT" regions-used: "SIZE_FORMAT, used(), calculateUsed());
492 }
493
494 size_t ShenandoahHeap::used() const {
495 OrderAccess::acquire();
496 return _used;
497 }
498
499 void ShenandoahHeap::increase_used(size_t bytes) {
500 assert_heaplock_or_safepoint();
501 _used += bytes;
502 }
503
504 void ShenandoahHeap::set_used(size_t bytes) {
505 assert_heaplock_or_safepoint();
506 _used = bytes;
507 }
508
509 void ShenandoahHeap::decrease_used(size_t bytes) {
510 assert_heaplock_or_safepoint();
511 assert(_used >= bytes, "never decrease heap size by more than we've left");
512 _used -= bytes;
513 }
514
515 size_t ShenandoahHeap::capacity() const {
516 return _num_regions * ShenandoahHeapRegion::RegionSizeBytes;
517 }
518
519 bool ShenandoahHeap::is_maximal_no_gc() const {
520 Unimplemented();
521 return true;
522 }
523
524 size_t ShenandoahHeap::max_capacity() const {
525 return _max_regions * ShenandoahHeapRegion::RegionSizeBytes;
526 }
527
528 size_t ShenandoahHeap::min_capacity() const {
529 return _initialSize;
530 }
531
532 VirtualSpace* ShenandoahHeap::storage() const {
533 return (VirtualSpace*) &_storage;
534 }
535
536 bool ShenandoahHeap::is_in(const void* p) const {
537 HeapWord* first_region_bottom = _first_region->bottom();
538 HeapWord* last_region_end = first_region_bottom + (ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize) * _num_regions;
539 return p >= _first_region_bottom && p < last_region_end;
540 }
541
542 bool ShenandoahHeap::is_scavengable(const void* p) {
543 return true;
544 }
545
546 HeapWord* ShenandoahHeap::allocate_from_gclab_slow(Thread* thread, size_t size) {
547 // Retain tlab and allocate object in shared space if
548 // the amount free in the tlab is too large to discard.
549 if (thread->gclab().free() > thread->gclab().refill_waste_limit()) {
550 thread->gclab().record_slow_allocation(size);
551 return NULL;
552 }
553
554 // Discard gclab and allocate a new one.
555 // To minimize fragmentation, the last GCLAB may be smaller than the rest.
556 size_t new_gclab_size = thread->gclab().compute_size(size);
557
558 thread->gclab().clear_before_allocation();
559
560 if (new_gclab_size == 0) {
561 return NULL;
562 }
563
564 // Allocate a new GCLAB...
565 HeapWord* obj = allocate_new_gclab(new_gclab_size);
566 if (obj == NULL) {
567 return NULL;
568 }
569
570 if (ZeroTLAB) {
571 // ..and clear it.
572 Copy::zero_to_words(obj, new_gclab_size);
573 } else {
574 // ...and zap just allocated object.
575 #ifdef ASSERT
576 // Skip mangling the space corresponding to the object header to
577 // ensure that the returned space is not considered parsable by
578 // any concurrent GC thread.
579 size_t hdr_size = oopDesc::header_size();
580 Copy::fill_to_words(obj + hdr_size, new_gclab_size - hdr_size, badHeapWordVal);
581 #endif // ASSERT
582 }
583 thread->gclab().fill(obj, obj + size, new_gclab_size);
584 return obj;
585 }
586
587 HeapWord* ShenandoahHeap::allocate_new_tlab(size_t word_size) {
588 return allocate_new_tlab(word_size, false);
589 }
590
591 HeapWord* ShenandoahHeap::allocate_new_gclab(size_t word_size) {
592 return allocate_new_tlab(word_size, true);
593 }
594
595 HeapWord* ShenandoahHeap::allocate_new_tlab(size_t word_size, bool evacuating) {
596 HeapWord* result = allocate_memory(word_size, evacuating);
597
598 if (result != NULL) {
599 assert(! in_collection_set(result), "Never allocate in dirty region");
600 _bytes_allocated_since_cm += word_size * HeapWordSize;
601
602 log_develop_trace(gc, tlab)("allocating new tlab of size "SIZE_FORMAT" at addr "PTR_FORMAT, word_size, p2i(result));
603
604 }
605 return result;
606 }
607
608 ShenandoahHeap* ShenandoahHeap::heap() {
609 CollectedHeap* heap = Universe::heap();
610 assert(heap != NULL, "Unitialized access to ShenandoahHeap::heap()");
611 assert(heap->kind() == CollectedHeap::ShenandoahHeap, "not a shenandoah heap");
612 return (ShenandoahHeap*) heap;
613 }
614
615 ShenandoahHeap* ShenandoahHeap::heap_no_check() {
616 CollectedHeap* heap = Universe::heap();
617 return (ShenandoahHeap*) heap;
618 }
619
620 HeapWord* ShenandoahHeap::allocate_memory_work(size_t word_size) {
621
622 ShenandoahHeapLock heap_lock(this);
623
624 HeapWord* result = allocate_memory_under_lock(word_size);
625 int grow_by = (word_size * HeapWordSize + ShenandoahHeapRegion::RegionSizeBytes - 1) / ShenandoahHeapRegion::RegionSizeBytes;
626
627 while (result == NULL && _num_regions + grow_by <= _max_regions) {
628 grow_heap_by(grow_by);
629 result = allocate_memory_under_lock(word_size);
630 }
631
632 return result;
633 }
634
635 HeapWord* ShenandoahHeap::allocate_memory(size_t word_size, bool evacuating) {
636 HeapWord* result = NULL;
637 result = allocate_memory_work(word_size);
638
639 if (!evacuating) {
640 // Allocation failed, try full-GC, then retry allocation.
641 //
642 // It might happen that one of the threads requesting allocation would unblock
643 // way later after full-GC happened, only to fail the second allocation, because
644 // other threads have already depleted the free storage. In this case, a better
645 // strategy would be to try full-GC again.
646 //
647 // Lacking the way to detect progress from "collect" call, we are left with blindly
648 // retrying for some bounded number of times.
649 // TODO: Poll if Full GC made enough progress to warrant retry.
650 int tries = 0;
651 while ((result == NULL) && (tries++ < ShenandoahFullGCTries)) {
652 log_debug(gc)("[" PTR_FORMAT " Failed to allocate " SIZE_FORMAT " bytes, doing full GC, try %d",
653 p2i(Thread::current()), word_size * HeapWordSize, tries);
654 collect(GCCause::_allocation_failure);
655 result = allocate_memory_work(word_size);
656 }
657 }
658
659 // Only update monitoring counters when not calling from a write-barrier.
660 // Otherwise we might attempt to grab the Service_lock, which we must
661 // not do when coming from a write-barrier (because the thread might
662 // already hold the Compile_lock).
663 if (! evacuating) {
664 monitoring_support()->update_counters();
665 }
666
667 log_develop_trace(gc, alloc)("allocate memory chunk of size "SIZE_FORMAT" at addr "PTR_FORMAT " by thread %d ",
668 word_size, p2i(result), Thread::current()->osthread()->thread_id());
669
670 return result;
671 }
672
673 bool ShenandoahHeap::call_from_write_barrier(bool evacuating) {
674 return evacuating && Thread::current()->is_Java_thread();
675 }
676
677 HeapWord* ShenandoahHeap::allocate_memory_under_lock(size_t word_size) {
678 assert_heaplock_owned_by_current_thread();
679
680 if (word_size * HeapWordSize > ShenandoahHeapRegion::RegionSizeBytes) {
681 return allocate_large_memory(word_size);
682 }
683
684 // Not enough memory in free region set.
685 // Coming out of full GC, it is possible that there is not
686 // free region available, so current_index may not be valid.
687 if (word_size * HeapWordSize > _free_regions->capacity()) return NULL;
688
689 ShenandoahHeapRegion* my_current_region = _free_regions->current_no_humongous();
690
691 if (my_current_region == NULL) {
692 return NULL; // No more room to make a new region. OOM.
693 }
694 assert(my_current_region != NULL, "should have a region at this point");
695
696 #ifdef ASSERT
697 if (in_collection_set(my_current_region)) {
698 print_heap_regions();
699 }
700 #endif
701 assert(! in_collection_set(my_current_region), "never get targetted regions in free-lists");
702 assert(! my_current_region->is_humongous(), "never attempt to allocate from humongous object regions");
703
704 HeapWord* result = my_current_region->allocate(word_size);
705
706 while (result == NULL) {
707 // 2nd attempt. Try next region.
708 _free_regions->increase_used(my_current_region->free());
709 ShenandoahHeapRegion* next_region = _free_regions->next_no_humongous();
710 assert(next_region != my_current_region, "must not get current again");
711 my_current_region = next_region;
712
713 if (my_current_region == NULL) {
714 return NULL; // No more room to make a new region. OOM.
715 }
716 assert(my_current_region != NULL, "should have a region at this point");
717 assert(! in_collection_set(my_current_region), "never get targetted regions in free-lists");
718 assert(! my_current_region->is_humongous(), "never attempt to allocate from humongous object regions");
719 result = my_current_region->allocate(word_size);
720 }
721
722 my_current_region->increase_live_data_words(word_size);
723 increase_used(word_size * HeapWordSize);
724 _free_regions->increase_used(word_size * HeapWordSize);
725 return result;
726 }
727
728 HeapWord* ShenandoahHeap::allocate_large_memory(size_t words) {
729 assert_heaplock_owned_by_current_thread();
730
731 uint required_regions = ShenandoahHumongous::required_regions(words * HeapWordSize);
732 if (required_regions > _max_regions) return NULL;
733
734 ShenandoahHeapRegion* r = _free_regions->allocate_contiguous(required_regions);
735
736 HeapWord* result = NULL;
737
738 if (r != NULL) {
739 result = r->bottom();
740
741 log_debug(gc, humongous)("allocating humongous object of size: "SIZE_FORMAT" KB at location "PTR_FORMAT" in start region "SIZE_FORMAT,
742 (words * HeapWordSize) / K, p2i(result), r->region_number());
743 } else {
744 log_debug(gc, humongous)("allocating humongous object of size: "SIZE_FORMAT" KB at location "PTR_FORMAT" failed",
745 (words * HeapWordSize) / K, p2i(result));
746 }
747
748
749 return result;
750
751 }
752
753 HeapWord* ShenandoahHeap::mem_allocate(size_t size,
754 bool* gc_overhead_limit_was_exceeded) {
755
756 #ifdef ASSERT
757 if (ShenandoahVerify && _numAllocs > 1000000) {
758 _numAllocs = 0;
759 }
760 _numAllocs++;
761 #endif
762 HeapWord* filler = allocate_memory(BrooksPointer::word_size() + size, false);
763 HeapWord* result = filler + BrooksPointer::word_size();
764 if (filler != NULL) {
765 BrooksPointer::initialize(oop(result));
766 _bytes_allocated_since_cm += size * HeapWordSize;
767
768 assert(! in_collection_set(result), "never allocate in targetted region");
769 return result;
770 } else {
771 /*
772 tty->print_cr("Out of memory. Requested number of words: "SIZE_FORMAT" used heap: "INT64_FORMAT", bytes allocated since last CM: "INT64_FORMAT,
773 size, used(), _bytes_allocated_since_cm);
774 {
775 print_heap_regions();
776 tty->print("Printing "SIZE_FORMAT" free regions:\n", _free_regions->count());
777 _free_regions->print();
778 }
779 */
780 return NULL;
781 }
782 }
783
784 class ParallelEvacuateRegionObjectClosure : public ObjectClosure {
785 private:
786 ShenandoahHeap* _heap;
787 Thread* _thread;
788 public:
789 ParallelEvacuateRegionObjectClosure(ShenandoahHeap* heap) :
790 _heap(heap), _thread(Thread::current()) {
791 }
792
793 void do_object(oop p) {
794
795 log_develop_trace(gc, compaction)("Calling ParallelEvacuateRegionObjectClosure on "PTR_FORMAT" of size %d\n", p2i((HeapWord*) p), p->size());
796
797 assert(_heap->is_marked_complete(p), "expect only marked objects");
798 if (oopDesc::unsafe_equals(p, ShenandoahBarrierSet::resolve_oop_static_not_null(p))) {
799 bool evac;
800 _heap->evacuate_object(p, _thread, evac);
801 }
802 }
803 };
804
805 #ifdef ASSERT
806 class VerifyEvacuatedObjectClosure : public ObjectClosure {
807
808 public:
809
810 void do_object(oop p) {
811 if (ShenandoahHeap::heap()->is_marked_complete(p)) {
812 oop p_prime = oopDesc::bs()->read_barrier(p);
813 assert(! oopDesc::unsafe_equals(p, p_prime), "Should point to evacuated copy");
814 if (p->klass() != p_prime->klass()) {
815 tty->print_cr("copy has different class than original:");
816 p->klass()->print_on(tty);
817 p_prime->klass()->print_on(tty);
818 }
819 assert(p->klass() == p_prime->klass(), "Should have the same class p: "PTR_FORMAT", p_prime: "PTR_FORMAT, p2i(p), p2i(p_prime));
820 // assert(p->mark() == p_prime->mark(), "Should have the same mark");
821 assert(p->size() == p_prime->size(), "Should be the same size");
822 assert(oopDesc::unsafe_equals(p_prime, oopDesc::bs()->read_barrier(p_prime)), "One forward once");
823 }
824 }
825 };
826
827 void ShenandoahHeap::verify_evacuated_region(ShenandoahHeapRegion* from_region) {
828 VerifyEvacuatedObjectClosure verify_evacuation;
829 marked_object_iterate(from_region, &verify_evacuation);
830 }
831 #endif
832
833 void ShenandoahHeap::parallel_evacuate_region(ShenandoahHeapRegion* from_region) {
834
835 assert(from_region->has_live(), "all-garbage regions are reclaimed earlier");
836
837 ParallelEvacuateRegionObjectClosure evacuate_region(this);
838
839 marked_object_iterate(from_region, &evacuate_region);
840
841 #ifdef ASSERT
842 if (ShenandoahVerify && ! cancelled_concgc()) {
843 verify_evacuated_region(from_region);
844 }
845 #endif
846 }
847
848 class ParallelEvacuationTask : public AbstractGangTask {
849 private:
850 ShenandoahHeap* _sh;
851 ShenandoahCollectionSet* _cs;
852
853 public:
854 ParallelEvacuationTask(ShenandoahHeap* sh,
855 ShenandoahCollectionSet* cs) :
856 AbstractGangTask("Parallel Evacuation Task"),
857 _cs(cs),
858 _sh(sh) {}
859
860 void work(uint worker_id) {
861
862 ShenandoahHeapRegion* from_hr = _cs->claim_next();
863
864 while (from_hr != NULL) {
865 log_develop_trace(gc, region)("Thread "INT32_FORMAT" claimed Heap Region "SIZE_FORMAT,
866 worker_id,
867 from_hr->region_number());
868
869 assert(from_hr->has_live(), "all-garbage regions are reclaimed early");
870 _sh->parallel_evacuate_region(from_hr);
871
872 if (_sh->cancelled_concgc()) {
873 log_develop_trace(gc, region)("Cancelled concgc while evacuating region " SIZE_FORMAT "\n", from_hr->region_number());
874 break;
875 }
876 from_hr = _cs->claim_next();
877 }
878 }
879 };
880
881 class RecycleDirtyRegionsClosure: public ShenandoahHeapRegionClosure {
882 private:
883 ShenandoahHeap* _heap;
884 size_t _bytes_reclaimed;
885 public:
886 RecycleDirtyRegionsClosure() : _heap(ShenandoahHeap::heap()) {}
887
888 bool doHeapRegion(ShenandoahHeapRegion* r) {
889
890 assert (! _heap->cancelled_concgc(), "no recycling after cancelled marking");
891
892 if (_heap->in_collection_set(r)) {
893 log_develop_trace(gc, region)("Recycling region " SIZE_FORMAT ":", r->region_number());
894 _heap->decrease_used(r->used());
895 _bytes_reclaimed += r->used();
896 r->recycle();
897 }
898
899 return false;
900 }
901 size_t bytes_reclaimed() { return _bytes_reclaimed;}
902 void clear_bytes_reclaimed() {_bytes_reclaimed = 0;}
903 };
904
905 void ShenandoahHeap::recycle_dirty_regions() {
906 RecycleDirtyRegionsClosure cl;
907 cl.clear_bytes_reclaimed();
908
909 heap_region_iterate(&cl);
910
911 _shenandoah_policy->record_bytes_reclaimed(cl.bytes_reclaimed());
912 if (! cancelled_concgc()) {
913 clear_cset_fast_test();
914 }
915 }
916
917 ShenandoahFreeSet* ShenandoahHeap::free_regions() {
918 return _free_regions;
919 }
920
921 void ShenandoahHeap::print_heap_regions(outputStream* st) const {
922 _ordered_regions->print(st);
923 }
924
925 class PrintAllRefsOopClosure: public ExtendedOopClosure {
926 private:
927 int _index;
928 const char* _prefix;
929
930 public:
931 PrintAllRefsOopClosure(const char* prefix) : _index(0), _prefix(prefix) {}
932
933 private:
934 template <class T>
935 inline void do_oop_work(T* p) {
936 oop o = oopDesc::load_decode_heap_oop(p);
937 if (o != NULL) {
938 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop()) {
939 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT")-> "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT")",
940 _prefix, _index,
941 p2i(p), p2i(o),
942 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(o)),
943 o->klass()->internal_name(), p2i(o->klass()));
944 } else {
945 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT" dirty -> "PTR_FORMAT" (not in heap, possibly corrupted or dirty)",
946 _prefix, _index,
947 p2i(p), p2i(o));
948 }
949 } else {
950 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT") -> "PTR_FORMAT, _prefix, _index, p2i(p), p2i((HeapWord*) o));
951 }
952 _index++;
953 }
954
955 public:
956 void do_oop(oop* p) {
957 do_oop_work(p);
958 }
959
960 void do_oop(narrowOop* p) {
961 do_oop_work(p);
962 }
963
964 };
965
966 class PrintAllRefsObjectClosure : public ObjectClosure {
967 const char* _prefix;
968
969 public:
970 PrintAllRefsObjectClosure(const char* prefix) : _prefix(prefix) {}
971
972 void do_object(oop p) {
973 if (ShenandoahHeap::heap()->is_in(p)) {
974 tty->print_cr("%s object "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT") refers to:",
975 _prefix, p2i(p),
976 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(p)),
977 p->klass()->internal_name(), p2i(p->klass()));
978 PrintAllRefsOopClosure cl(_prefix);
979 p->oop_iterate(&cl);
980 }
981 }
982 };
983
984 void ShenandoahHeap::print_all_refs(const char* prefix) {
985 tty->print_cr("printing all references in the heap");
986 tty->print_cr("root references:");
987
988 ensure_parsability(false);
989
990 PrintAllRefsOopClosure cl(prefix);
991 roots_iterate(&cl);
992
993 tty->print_cr("heap references:");
994 PrintAllRefsObjectClosure cl2(prefix);
995 object_iterate(&cl2);
996 }
997
998 class VerifyAfterMarkingOopClosure: public ExtendedOopClosure {
999 private:
1000 ShenandoahHeap* _heap;
1001
1002 public:
1003 VerifyAfterMarkingOopClosure() :
1004 _heap(ShenandoahHeap::heap()) { }
1005
1006 private:
1007 template <class T>
1008 inline void do_oop_work(T* p) {
1009 oop o = oopDesc::load_decode_heap_oop(p);
1010 if (o != NULL) {
1011 if (! _heap->is_marked_complete(o)) {
1012 _heap->print_heap_regions();
1013 _heap->print_all_refs("post-mark");
1014 tty->print_cr("oop not marked, although referrer is marked: "PTR_FORMAT": in_heap: %s, is_marked: %s",
1015 p2i((HeapWord*) o), BOOL_TO_STR(_heap->is_in(o)), BOOL_TO_STR(_heap->is_marked_complete(o)));
1016 _heap->print_heap_locations((HeapWord*) o, (HeapWord*) o + o->size());
1017
1018 tty->print_cr("oop class: %s", o->klass()->internal_name());
1019 if (_heap->is_in(p)) {
1020 oop referrer = oop(_heap->heap_region_containing(p)->block_start_const(p));
1021 tty->print_cr("Referrer starts at addr "PTR_FORMAT, p2i((HeapWord*) referrer));
1022 referrer->print();
1023 _heap->print_heap_locations((HeapWord*) referrer, (HeapWord*) referrer + referrer->size());
1024 }
1025 tty->print_cr("heap region containing object:");
1026 _heap->heap_region_containing(o)->print();
1027 tty->print_cr("heap region containing referrer:");
1028 _heap->heap_region_containing(p)->print();
1029 tty->print_cr("heap region containing forwardee:");
1030 _heap->heap_region_containing(oopDesc::bs()->read_barrier(o))->print();
1031 }
1032 assert(o->is_oop(), "oop must be an oop");
1033 assert(Metaspace::contains(o->klass()), "klass pointer must go to metaspace");
1034 if (! oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o))) {
1035 tty->print_cr("oops has forwardee: p: "PTR_FORMAT" (%s), o = "PTR_FORMAT" (%s), new-o: "PTR_FORMAT" (%s)",
1036 p2i(p),
1037 BOOL_TO_STR(_heap->in_collection_set(p)),
1038 p2i(o),
1039 BOOL_TO_STR(_heap->in_collection_set(o)),
1040 p2i((HeapWord*) oopDesc::bs()->read_barrier(o)),
1041 BOOL_TO_STR(_heap->in_collection_set(oopDesc::bs()->read_barrier(o))));
1042 tty->print_cr("oop class: %s", o->klass()->internal_name());
1043 }
1044 assert(oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o)), "oops must not be forwarded");
1045 assert(! _heap->in_collection_set(o), "references must not point to dirty heap regions");
1046 assert(_heap->is_marked_complete(o), "live oops must be marked current");
1047 }
1048 }
1049
1050 public:
1051 void do_oop(oop* p) {
1052 do_oop_work(p);
1053 }
1054
1055 void do_oop(narrowOop* p) {
1056 do_oop_work(p);
1057 }
1058
1059 };
1060
1061 void ShenandoahHeap::verify_heap_after_marking() {
1062
1063 verify_heap_size_consistency();
1064
1065 log_trace(gc)("verifying heap after marking");
1066
1067 VerifyAfterMarkingOopClosure cl;
1068 roots_iterate(&cl);
1069 ObjectToOopClosure objs(&cl);
1070 object_iterate(&objs);
1071 }
1072
1073
1074 void ShenandoahHeap::reclaim_humongous_region_at(ShenandoahHeapRegion* r) {
1075 assert(r->is_humongous_start(), "reclaim regions starting with the first one");
1076
1077 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size());
1078 size_t size = humongous_obj->size() + BrooksPointer::word_size();
1079 uint required_regions = ShenandoahHumongous::required_regions(size * HeapWordSize);
1080 uint index = r->region_number();
1081
1082
1083 assert(!r->has_live(), "liveness must be zero");
1084
1085 for(size_t i = 0; i < required_regions; i++) {
1086
1087 ShenandoahHeapRegion* region = _ordered_regions->get(index++);
1088
1089 assert((region->is_humongous_start() || region->is_humongous_continuation()),
1090 "expect correct humongous start or continuation");
1091
1092 if (log_is_enabled(Debug, gc, humongous)) {
1093 log_debug(gc, humongous)("reclaiming "UINT32_FORMAT" humongous regions for object of size: "SIZE_FORMAT" words", required_regions, size);
1094 ResourceMark rm;
1095 outputStream* out = Log(gc, humongous)::debug_stream();
1096 region->print_on(out);
1097 }
1098
1099 region->recycle();
1100 ShenandoahHeap::heap()->decrease_used(ShenandoahHeapRegion::RegionSizeBytes);
1101 }
1102 }
1103
1104 class ShenandoahReclaimHumongousRegionsClosure : public ShenandoahHeapRegionClosure {
1105
1106 bool doHeapRegion(ShenandoahHeapRegion* r) {
1107 ShenandoahHeap* heap = ShenandoahHeap::heap();
1108
1109 if (r->is_humongous_start()) {
1110 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size());
1111 if (! heap->is_marked_complete(humongous_obj)) {
1112
1113 heap->reclaim_humongous_region_at(r);
1114 }
1115 }
1116 return false;
1117 }
1118 };
1119
1120 #ifdef ASSERT
1121 class CheckCollectionSetClosure: public ShenandoahHeapRegionClosure {
1122 bool doHeapRegion(ShenandoahHeapRegion* r) {
1123 assert(! ShenandoahHeap::heap()->in_collection_set(r), "Should have been cleared by now");
1124 return false;
1125 }
1126 };
1127 #endif
1128
1129 void ShenandoahHeap::prepare_for_concurrent_evacuation() {
1130 assert(_ordered_regions->get(0)->region_number() == 0, "FIXME CHF. FIXME CHF!");
1131
1132 log_develop_trace(gc)("Thread %d started prepare_for_concurrent_evacuation", Thread::current()->osthread()->thread_id());
1133
1134 if (!cancelled_concgc()) {
1135
1136 recycle_dirty_regions();
1137
1138 ensure_parsability(true);
1139
1140 if (UseShenandoahMatrix) {
1141 if (PrintShenandoahMatrix) {
1142 outputStream* log = Log(gc)::info_stream();
1143 connection_matrix()->print_on(log);
1144 }
1145 }
1146
1147 if (ShenandoahVerify || (UseShenandoahMatrix && VerifyShenandoahMatrix)) {
1148 verify_heap_reachable_at_safepoint();
1149 }
1150
1151 #ifdef ASSERT
1152 if (ShenandoahVerify) {
1153 verify_heap_after_marking();
1154 }
1155 #endif
1156
1157 // NOTE: This needs to be done during a stop the world pause, because
1158 // putting regions into the collection set concurrently with Java threads
1159 // will create a race. In particular, acmp could fail because when we
1160 // resolve the first operand, the containing region might not yet be in
1161 // the collection set, and thus return the original oop. When the 2nd
1162 // operand gets resolved, the region could be in the collection set
1163 // and the oop gets evacuated. If both operands have originally been
1164 // the same, we get false negatives.
1165
1166 {
1167 ShenandoahHeapLock lock(this);
1168 _collection_set->clear();
1169 _free_regions->clear();
1170
1171 ShenandoahReclaimHumongousRegionsClosure reclaim;
1172 heap_region_iterate(&reclaim);
1173
1174 #ifdef ASSERT
1175 CheckCollectionSetClosure ccsc;
1176 _ordered_regions->heap_region_iterate(&ccsc);
1177 #endif
1178
1179 _shenandoah_policy->choose_collection_set(_collection_set);
1180
1181 _shenandoah_policy->choose_free_set(_free_regions);
1182 }
1183
1184 _bytes_allocated_since_cm = 0;
1185
1186 Universe::update_heap_info_at_gc();
1187 }
1188 }
1189
1190
1191 class RetireTLABClosure : public ThreadClosure {
1192 private:
1193 bool _retire;
1194
1195 public:
1196 RetireTLABClosure(bool retire) : _retire(retire) {
1197 }
1198
1199 void do_thread(Thread* thread) {
1200 thread->gclab().make_parsable(_retire);
1201 }
1202 };
1203
1204 void ShenandoahHeap::ensure_parsability(bool retire_tlabs) {
1205 if (UseTLAB) {
1206 CollectedHeap::ensure_parsability(retire_tlabs);
1207 RetireTLABClosure cl(retire_tlabs);
1208 Threads::threads_do(&cl);
1209 }
1210 }
1211
1212 class ShenandoahEvacuateUpdateRootsClosure: public ExtendedOopClosure {
1213 private:
1214 ShenandoahHeap* _heap;
1215 Thread* _thread;
1216 public:
1217 ShenandoahEvacuateUpdateRootsClosure() :
1218 _heap(ShenandoahHeap::heap()), _thread(Thread::current()) {
1219 }
1220
1221 private:
1222 template <class T>
1223 void do_oop_work(T* p) {
1224 assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
1225
1226 T o = oopDesc::load_heap_oop(p);
1227 if (! oopDesc::is_null(o)) {
1228 oop obj = oopDesc::decode_heap_oop_not_null(o);
1229 if (_heap->in_collection_set(obj)) {
1230 assert(_heap->is_marked_complete(obj), "only evacuate marked objects %d %d",
1231 _heap->is_marked_complete(obj), _heap->is_marked_complete(ShenandoahBarrierSet::resolve_oop_static_not_null(obj)));
1232 oop resolved = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
1233 if (oopDesc::unsafe_equals(resolved, obj)) {
1234 bool evac;
1235 resolved = _heap->evacuate_object(obj, _thread, evac);
1236 }
1237 oopDesc::encode_store_heap_oop(p, resolved);
1238 }
1239 }
1240 #ifdef ASSERT
1241 else {
1242 // tty->print_cr("not updating root at: "PTR_FORMAT" with object: "PTR_FORMAT", is_in_heap: %s, is_in_cset: %s, is_marked: %s",
1243 // p2i(p),
1244 // p2i((HeapWord*) obj),
1245 // BOOL_TO_STR(_heap->is_in(obj)),
1246 // BOOL_TO_STR(_heap->in_cset_fast_test(obj)),
1247 // BOOL_TO_STR(_heap->is_marked_complete(obj)));
1248 }
1249 #endif
1250 }
1251
1252 public:
1253 void do_oop(oop* p) {
1254 do_oop_work(p);
1255 }
1256 void do_oop(narrowOop* p) {
1257 do_oop_work(p);
1258 }
1259 };
1260
1261 class ShenandoahEvacuateUpdateRootsTask : public AbstractGangTask {
1262 ShenandoahRootEvacuator* _rp;
1263 public:
1264
1265 ShenandoahEvacuateUpdateRootsTask(ShenandoahRootEvacuator* rp) :
1266 AbstractGangTask("Shenandoah evacuate and update roots"),
1267 _rp(rp)
1268 {
1269 // Nothing else to do.
1270 }
1271
1272 void work(uint worker_id) {
1273 ShenandoahEvacuateUpdateRootsClosure cl;
1274 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations);
1275
1276 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id);
1277 }
1278 };
1279
1280 class ShenandoahFixRootsTask : public AbstractGangTask {
1281 ShenandoahRootEvacuator* _rp;
1282 public:
1283
1284 ShenandoahFixRootsTask(ShenandoahRootEvacuator* rp) :
1285 AbstractGangTask("Shenandoah update roots"),
1286 _rp(rp)
1287 {
1288 // Nothing else to do.
1289 }
1290
1291 void work(uint worker_id) {
1292 SCMUpdateRefsClosure cl;
1293 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations);
1294
1295 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id);
1296 }
1297 };
1298 void ShenandoahHeap::evacuate_and_update_roots() {
1299
1300 COMPILER2_PRESENT(DerivedPointerTable::clear());
1301
1302 #ifdef ASSERT
1303 if (ShenandoahVerifyReadsToFromSpace) {
1304 set_from_region_protection(false);
1305 }
1306 #endif
1307
1308 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped");
1309 ClassLoaderDataGraph::clear_claimed_marks();
1310
1311 {
1312 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots);
1313 ShenandoahEvacuateUpdateRootsTask roots_task(&rp);
1314 workers()->run_task(&roots_task);
1315 }
1316
1317 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
1318
1319 if (cancelled_concgc()) {
1320 // If initial evacuation has been cancelled, we need to update all references
1321 // after all workers have finished. Otherwise we might run into the following problem:
1322 // GC thread 1 cannot allocate anymore, thus evacuation fails, leaves from-space ptr of object X.
1323 // GC thread 2 evacuates the same object X to to-space
1324 // which leaves a truly dangling from-space reference in the first root oop*. This must not happen.
1325 // clear() and update_pointers() must always be called in pairs,
1326 // cannot nest with above clear()/update_pointers().
1327 COMPILER2_PRESENT(DerivedPointerTable::clear());
1328 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots);
1329 ShenandoahFixRootsTask update_roots_task(&rp);
1330 workers()->run_task(&update_roots_task);
1331 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
1332 }
1333
1334 #ifdef ASSERT
1335 if (ShenandoahVerifyReadsToFromSpace) {
1336 set_from_region_protection(true);
1337 }
1338 #endif
1339
1340 #ifdef ASSERT
1341 {
1342 AssertToSpaceClosure cl;
1343 CodeBlobToOopClosure code_cl(&cl, !CodeBlobToOopClosure::FixRelocations);
1344 ShenandoahRootEvacuator rp(this, 1);
1345 rp.process_evacuate_roots(&cl, &code_cl, 0);
1346 }
1347 #endif
1348 }
1349
1350
1351 void ShenandoahHeap::do_evacuation() {
1352
1353 parallel_evacuate();
1354
1355 if (ShenandoahVerify && ! cancelled_concgc()) {
1356 VM_ShenandoahVerifyHeapAfterEvacuation verify_after_evacuation;
1357 if (Thread::current()->is_VM_thread()) {
1358 verify_after_evacuation.doit();
1359 } else {
1360 VMThread::execute(&verify_after_evacuation);
1361 }
1362 }
1363
1364 }
1365
1366 void ShenandoahHeap::parallel_evacuate() {
1367 log_develop_trace(gc)("starting parallel_evacuate");
1368
1369 _shenandoah_policy->record_phase_start(ShenandoahCollectorPolicy::conc_evac);
1370
1371 if (log_is_enabled(Trace, gc, region)) {
1372 ResourceMark rm;
1373 outputStream *out = Log(gc, region)::trace_stream();
1374 out->print("Printing all available regions");
1375 print_heap_regions(out);
1376 }
1377
1378 if (log_is_enabled(Trace, gc, cset)) {
1379 ResourceMark rm;
1380 outputStream *out = Log(gc, cset)::trace_stream();
1381 out->print("Printing collection set which contains "SIZE_FORMAT" regions:\n", _collection_set->count());
1382 _collection_set->print(out);
1383
1384 out->print("Printing free set which contains "SIZE_FORMAT" regions:\n", _free_regions->count());
1385 _free_regions->print(out);
1386 }
1387
1388 ParallelEvacuationTask evacuationTask = ParallelEvacuationTask(this, _collection_set);
1389
1390
1391 workers()->run_task(&evacuationTask);
1392
1393 if (log_is_enabled(Trace, gc, cset)) {
1394 ResourceMark rm;
1395 outputStream *out = Log(gc, cset)::trace_stream();
1396 out->print("Printing postgc collection set which contains "SIZE_FORMAT" regions:\n",
1397 _collection_set->count());
1398
1399 _collection_set->print(out);
1400
1401 out->print("Printing postgc free regions which contain "SIZE_FORMAT" free regions:\n",
1402 _free_regions->count());
1403 _free_regions->print(out);
1404
1405 }
1406
1407 if (log_is_enabled(Trace, gc, region)) {
1408 ResourceMark rm;
1409 outputStream *out = Log(gc, region)::trace_stream();
1410 out->print_cr("all regions after evacuation:");
1411 print_heap_regions(out);
1412 }
1413
1414 _shenandoah_policy->record_phase_end(ShenandoahCollectorPolicy::conc_evac);
1415 }
1416
1417 class VerifyEvacuationClosure: public ExtendedOopClosure {
1418 private:
1419 ShenandoahHeap* _heap;
1420 ShenandoahHeapRegion* _from_region;
1421
1422 public:
1423 VerifyEvacuationClosure(ShenandoahHeapRegion* from_region) :
1424 _heap(ShenandoahHeap::heap()), _from_region(from_region) { }
1425 private:
1426 template <class T>
1427 inline void do_oop_work(T* p) {
1428 oop heap_oop = oopDesc::load_decode_heap_oop(p);
1429 if (! oopDesc::is_null(heap_oop)) {
1430 guarantee(! _from_region->is_in(heap_oop), "no references to from-region allowed after evacuation: "PTR_FORMAT, p2i((HeapWord*) heap_oop));
1431 }
1432 }
1433
1434 public:
1435 void do_oop(oop* p) {
1436 do_oop_work(p);
1437 }
1438
1439 void do_oop(narrowOop* p) {
1440 do_oop_work(p);
1441 }
1442
1443 };
1444
1445 void ShenandoahHeap::roots_iterate(OopClosure* cl) {
1446
1447 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped");
1448
1449 CodeBlobToOopClosure blobsCl(cl, false);
1450 CLDToOopClosure cldCl(cl);
1451
1452 ClassLoaderDataGraph::clear_claimed_marks();
1453
1454 ShenandoahRootProcessor rp(this, 1);
1455 rp.process_all_roots(cl, NULL, &cldCl, &blobsCl, 0);
1456 }
1457
1458 void ShenandoahHeap::verify_evacuation(ShenandoahHeapRegion* from_region) {
1459
1460 VerifyEvacuationClosure rootsCl(from_region);
1461 roots_iterate(&rootsCl);
1462
1463 }
1464
1465 bool ShenandoahHeap::supports_tlab_allocation() const {
1466 return true;
1467 }
1468
1469
1470 size_t ShenandoahHeap::unsafe_max_tlab_alloc(Thread *thread) const {
1471 size_t idx = _free_regions->current_index();
1472 ShenandoahHeapRegion* current = _free_regions->get(idx);
1473 if (current == NULL) {
1474 return 0;
1475 } else if (current->free() > MinTLABSize) {
1476 // Current region has enough space left, can use it.
1477 return current->free();
1478 } else {
1479 // No more space in current region, we will take next free region
1480 // on the next TLAB allocation.
1481 return ShenandoahHeapRegion::RegionSizeBytes;
1482 }
1483 }
1484
1485 size_t ShenandoahHeap::max_tlab_size() const {
1486 return ShenandoahHeapRegion::RegionSizeBytes;
1487 }
1488
1489 class ResizeGCLABClosure : public ThreadClosure {
1490 public:
1491 void do_thread(Thread* thread) {
1492 thread->gclab().resize();
1493 }
1494 };
1495
1496 void ShenandoahHeap::resize_all_tlabs() {
1497 CollectedHeap::resize_all_tlabs();
1498
1499 ResizeGCLABClosure cl;
1500 Threads::threads_do(&cl);
1501 }
1502
1503 class AccumulateStatisticsGCLABClosure : public ThreadClosure {
1504 public:
1505 void do_thread(Thread* thread) {
1506 thread->gclab().accumulate_statistics();
1507 thread->gclab().initialize_statistics();
1508 }
1509 };
1510
1511 void ShenandoahHeap::accumulate_statistics_all_gclabs() {
1512 AccumulateStatisticsGCLABClosure cl;
1513 Threads::threads_do(&cl);
1514 }
1515
1516 bool ShenandoahHeap::can_elide_tlab_store_barriers() const {
1517 return true;
1518 }
1519
1520 oop ShenandoahHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) {
1521 // Overridden to do nothing.
1522 return new_obj;
1523 }
1524
1525 bool ShenandoahHeap::can_elide_initializing_store_barrier(oop new_obj) {
1526 return true;
1527 }
1528
1529 bool ShenandoahHeap::card_mark_must_follow_store() const {
1530 return false;
1531 }
1532
1533 void ShenandoahHeap::collect(GCCause::Cause cause) {
1534 assert(cause != GCCause::_gc_locker, "no JNI critical callback");
1535 if (GCCause::is_user_requested_gc(cause)) {
1536 if (! DisableExplicitGC) {
1537 _concurrent_gc_thread->do_full_gc(cause);
1538 }
1539 } else if (cause == GCCause::_allocation_failure) {
1540 collector_policy()->set_should_clear_all_soft_refs(true);
1541 _concurrent_gc_thread->do_full_gc(cause);
1542 }
1543 }
1544
1545 void ShenandoahHeap::do_full_collection(bool clear_all_soft_refs) {
1546 //assert(false, "Shouldn't need to do full collections");
1547 }
1548
1549 AdaptiveSizePolicy* ShenandoahHeap::size_policy() {
1550 Unimplemented();
1551 return NULL;
1552
1553 }
1554
1555 CollectorPolicy* ShenandoahHeap::collector_policy() const {
1556 return _shenandoah_policy;
1557 }
1558
1559
1560 HeapWord* ShenandoahHeap::block_start(const void* addr) const {
1561 Space* sp = heap_region_containing(addr);
1562 if (sp != NULL) {
1563 return sp->block_start(addr);
1564 }
1565 return NULL;
1566 }
1567
1568 size_t ShenandoahHeap::block_size(const HeapWord* addr) const {
1569 Space* sp = heap_region_containing(addr);
1570 assert(sp != NULL, "block_size of address outside of heap");
1571 return sp->block_size(addr);
1572 }
1573
1574 bool ShenandoahHeap::block_is_obj(const HeapWord* addr) const {
1575 Space* sp = heap_region_containing(addr);
1576 return sp->block_is_obj(addr);
1577 }
1578
1579 jlong ShenandoahHeap::millis_since_last_gc() {
1580 return 0;
1581 }
1582
1583 void ShenandoahHeap::prepare_for_verify() {
1584 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
1585 ensure_parsability(false);
1586 }
1587 }
1588
1589 void ShenandoahHeap::print_gc_threads_on(outputStream* st) const {
1590 workers()->print_worker_threads_on(st);
1591 }
1592
1593 void ShenandoahHeap::gc_threads_do(ThreadClosure* tcl) const {
1594 workers()->threads_do(tcl);
1595 }
1596
1597 void ShenandoahHeap::print_tracing_info() const {
1598 if (log_is_enabled(Info, gc, stats)) {
1599 ResourceMark rm;
1600 outputStream* out = Log(gc, stats)::info_stream();
1601 _shenandoah_policy->print_tracing_info(out);
1602 }
1603 }
1604
1605 class ShenandoahVerifyRootsClosure: public ExtendedOopClosure {
1606 private:
1607 ShenandoahHeap* _heap;
1608 VerifyOption _vo;
1609 bool _failures;
1610 public:
1611 // _vo == UsePrevMarking -> use "prev" marking information,
1612 // _vo == UseNextMarking -> use "next" marking information,
1613 // _vo == UseMarkWord -> use mark word from object header.
1614 ShenandoahVerifyRootsClosure(VerifyOption vo) :
1615 _heap(ShenandoahHeap::heap()),
1616 _vo(vo),
1617 _failures(false) { }
1618
1619 bool failures() { return _failures; }
1620
1621 private:
1622 template <class T>
1623 inline void do_oop_work(T* p) {
1624 oop obj = oopDesc::load_decode_heap_oop(p);
1625 if (! oopDesc::is_null(obj) && ! obj->is_oop()) {
1626 { // Just for debugging.
1627 tty->print_cr("Root location "PTR_FORMAT
1628 "verified "PTR_FORMAT, p2i(p), p2i((void*) obj));
1629 // obj->print_on(tty);
1630 }
1631 }
1632 guarantee(obj->is_oop_or_null(), "is oop or null");
1633 }
1634
1635 public:
1636 void do_oop(oop* p) {
1637 do_oop_work(p);
1638 }
1639
1640 void do_oop(narrowOop* p) {
1641 do_oop_work(p);
1642 }
1643
1644 };
1645
1646 class ShenandoahVerifyHeapClosure: public ObjectClosure {
1647 private:
1648 ShenandoahVerifyRootsClosure _rootsCl;
1649 public:
1650 ShenandoahVerifyHeapClosure(ShenandoahVerifyRootsClosure rc) :
1651 _rootsCl(rc) {};
1652
1653 void do_object(oop p) {
1654 _rootsCl.do_oop(&p);
1655 }
1656 };
1657
1658 class ShenandoahVerifyKlassClosure: public KlassClosure {
1659 OopClosure *_oop_closure;
1660 public:
1661 ShenandoahVerifyKlassClosure(OopClosure* cl) : _oop_closure(cl) {}
1662 void do_klass(Klass* k) {
1663 k->oops_do(_oop_closure);
1664 }
1665 };
1666
1667 void ShenandoahHeap::verify(VerifyOption vo) {
1668 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
1669
1670 ShenandoahVerifyRootsClosure rootsCl(vo);
1671
1672 assert(Thread::current()->is_VM_thread(),
1673 "Expected to be executed serially by the VM thread at this point");
1674
1675 roots_iterate(&rootsCl);
1676
1677 bool failures = rootsCl.failures();
1678 log_trace(gc)("verify failures: %s", BOOL_TO_STR(failures));
1679
1680 ShenandoahVerifyHeapClosure heapCl(rootsCl);
1681
1682 object_iterate(&heapCl);
1683 // TODO: Implement rest of it.
1684 } else {
1685 tty->print("(SKIPPING roots, heapRegions, remset) ");
1686 }
1687 }
1688 size_t ShenandoahHeap::tlab_capacity(Thread *thr) const {
1689 return _free_regions->capacity();
1690 }
1691
1692 class ShenandoahIterateObjectClosureRegionClosure: public ShenandoahHeapRegionClosure {
1693 ObjectClosure* _cl;
1694 public:
1695 ShenandoahIterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {}
1696 bool doHeapRegion(ShenandoahHeapRegion* r) {
1697 ShenandoahHeap::heap()->marked_object_iterate(r, _cl);
1698 return false;
1699 }
1700 };
1701
1702 void ShenandoahHeap::object_iterate(ObjectClosure* cl) {
1703 ShenandoahIterateObjectClosureRegionClosure blk(cl);
1704 heap_region_iterate(&blk, false, true);
1705 }
1706
1707 class ShenandoahSafeObjectIterateAdjustPtrsClosure : public MetadataAwareOopClosure {
1708 private:
1709 ShenandoahHeap* _heap;
1710
1711 public:
1712 ShenandoahSafeObjectIterateAdjustPtrsClosure() : _heap(ShenandoahHeap::heap()) {}
1713
1714 private:
1715 template <class T>
1716 inline void do_oop_work(T* p) {
1717 T o = oopDesc::load_heap_oop(p);
1718 if (!oopDesc::is_null(o)) {
1719 oop obj = oopDesc::decode_heap_oop_not_null(o);
1720 oopDesc::encode_store_heap_oop(p, BrooksPointer::forwardee(obj));
1721 }
1722 }
1723 public:
1724 void do_oop(oop* p) {
1725 do_oop_work(p);
1726 }
1727 void do_oop(narrowOop* p) {
1728 do_oop_work(p);
1729 }
1730 };
1731
1732 class ShenandoahSafeObjectIterateAndUpdate : public ObjectClosure {
1733 private:
1734 ObjectClosure* _cl;
1735 public:
1736 ShenandoahSafeObjectIterateAndUpdate(ObjectClosure *cl) : _cl(cl) {}
1737
1738 virtual void do_object(oop obj) {
1739 assert (oopDesc::unsafe_equals(obj, BrooksPointer::forwardee(obj)),
1740 "avoid double-counting: only non-forwarded objects here");
1741
1742 // Fix up the ptrs.
1743 ShenandoahSafeObjectIterateAdjustPtrsClosure adjust_ptrs;
1744 obj->oop_iterate(&adjust_ptrs);
1745
1746 // Can reply the object now:
1747 _cl->do_object(obj);
1748 }
1749 };
1750
1751 void ShenandoahHeap::safe_object_iterate(ObjectClosure* cl) {
1752 assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints");
1753
1754 // Safe iteration does objects only with correct references.
1755 // This is why we skip dirty regions that have stale copies of objects,
1756 // and fix up the pointers in the returned objects.
1757
1758 ShenandoahSafeObjectIterateAndUpdate safe_cl(cl);
1759 ShenandoahIterateObjectClosureRegionClosure blk(&safe_cl);
1760 heap_region_iterate(&blk,
1761 /* skip_dirty_regions = */ true,
1762 /* skip_humongous_continuations = */ true);
1763
1764 _need_update_refs = false; // already updated the references
1765 }
1766
1767 // Apply blk->doHeapRegion() on all committed regions in address order,
1768 // terminating the iteration early if doHeapRegion() returns true.
1769 void ShenandoahHeap::heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions, bool skip_humongous_continuation) const {
1770 for (size_t i = 0; i < _num_regions; i++) {
1771 ShenandoahHeapRegion* current = _ordered_regions->get(i);
1772 if (skip_humongous_continuation && current->is_humongous_continuation()) {
1773 continue;
1774 }
1775 if (skip_dirty_regions && in_collection_set(current)) {
1776 continue;
1777 }
1778 if (blk->doHeapRegion(current)) {
1779 return;
1780 }
1781 }
1782 }
1783
1784 class ClearLivenessClosure : public ShenandoahHeapRegionClosure {
1785 ShenandoahHeap* sh;
1786 public:
1787 ClearLivenessClosure(ShenandoahHeap* heap) : sh(heap) { }
1788
1789 bool doHeapRegion(ShenandoahHeapRegion* r) {
1790 r->clear_live_data();
1791 sh->set_next_top_at_mark_start(r->bottom(), r->top());
1792 return false;
1793 }
1794 };
1795
1796 void ShenandoahHeap::start_concurrent_marking() {
1797
1798 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::accumulate_stats);
1799 accumulate_statistics_all_tlabs();
1800 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::accumulate_stats);
1801
1802 set_concurrent_mark_in_progress(true);
1803 // We need to reset all TLABs because we'd lose marks on all objects allocated in them.
1804 if (UseTLAB) {
1805 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::make_parsable);
1806 ensure_parsability(true);
1807 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::make_parsable);
1808 }
1809
1810 _shenandoah_policy->record_bytes_allocated(_bytes_allocated_since_cm);
1811 _used_start_gc = used();
1812
1813 #ifdef ASSERT
1814 if (ShenandoahDumpHeapBeforeConcurrentMark) {
1815 ensure_parsability(false);
1816 print_all_refs("pre-mark");
1817 }
1818 #endif
1819
1820 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::clear_liveness);
1821 ClearLivenessClosure clc(this);
1822 heap_region_iterate(&clc);
1823 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::clear_liveness);
1824
1825 if (UseShenandoahMatrix) {
1826 connection_matrix()->clear_all();
1827 }
1828 // print_all_refs("pre -mark");
1829
1830 // oopDesc::_debug = true;
1831
1832 // Make above changes visible to worker threads
1833 OrderAccess::fence();
1834
1835 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::scan_roots);
1836 concurrentMark()->init_mark_roots();
1837 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::scan_roots);
1838
1839 // print_all_refs("pre-mark2");
1840 }
1841
1842 class VerifyAfterEvacuationClosure : public ExtendedOopClosure {
1843
1844 ShenandoahHeap* _sh;
1845
1846 public:
1847 VerifyAfterEvacuationClosure() : _sh ( ShenandoahHeap::heap() ) {}
1848
1849 template<class T> void do_oop_nv(T* p) {
1850 T heap_oop = oopDesc::load_heap_oop(p);
1851 if (!oopDesc::is_null(heap_oop)) {
1852 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1853 guarantee(_sh->in_collection_set(obj) == (! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))),
1854 "forwarded objects can only exist in dirty (from-space) regions is_dirty: %s, is_forwarded: %s obj-klass: %s, marked: %s",
1855 BOOL_TO_STR(_sh->in_collection_set(obj)),
1856 BOOL_TO_STR(! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))),
1857 obj->klass()->external_name(),
1858 BOOL_TO_STR(_sh->is_marked_complete(obj))
1859 );
1860 obj = oopDesc::bs()->read_barrier(obj);
1861 guarantee(! _sh->in_collection_set(obj), "forwarded oops must not point to dirty regions");
1862 guarantee(obj->is_oop(), "is_oop");
1863 guarantee(Metaspace::contains(obj->klass()), "klass pointer must go to metaspace");
1864 }
1865 }
1866
1867 void do_oop(oop* p) { do_oop_nv(p); }
1868 void do_oop(narrowOop* p) { do_oop_nv(p); }
1869
1870 };
1871
1872 void ShenandoahHeap::verify_heap_after_evacuation() {
1873
1874 verify_heap_size_consistency();
1875
1876 ensure_parsability(false);
1877
1878 VerifyAfterEvacuationClosure cl;
1879 roots_iterate(&cl);
1880
1881 ObjectToOopClosure objs(&cl);
1882 object_iterate(&objs);
1883
1884 }
1885
1886 class VerifyRegionsAfterUpdateRefsClosure : public ShenandoahHeapRegionClosure {
1887 public:
1888 bool doHeapRegion(ShenandoahHeapRegion* r) {
1889 assert(! ShenandoahHeap::heap()->in_collection_set(r), "no region must be in collection set");
1890 return false;
1891 }
1892 };
1893
1894 void ShenandoahHeap::swap_mark_bitmaps() {
1895 // Swap bitmaps.
1896 CMBitMap* tmp1 = _complete_mark_bit_map;
1897 _complete_mark_bit_map = _next_mark_bit_map;
1898 _next_mark_bit_map = tmp1;
1899
1900 // Swap top-at-mark-start pointers
1901 HeapWord** tmp2 = _complete_top_at_mark_starts;
1902 _complete_top_at_mark_starts = _next_top_at_mark_starts;
1903 _next_top_at_mark_starts = tmp2;
1904
1905 HeapWord** tmp3 = _complete_top_at_mark_starts_base;
1906 _complete_top_at_mark_starts_base = _next_top_at_mark_starts_base;
1907 _next_top_at_mark_starts_base = tmp3;
1908 }
1909
1910 class VerifyReachableHeapClosure : public ExtendedOopClosure {
1911 private:
1912 SCMObjToScanQueue* _queue;
1913 ShenandoahHeap* _heap;
1914 CMBitMap* _map;
1915 bool _check_matrix;
1916 oop _obj;
1917 public:
1918 VerifyReachableHeapClosure(SCMObjToScanQueue* queue, CMBitMap* map, bool check_matrix) :
1919 _queue(queue), _heap(ShenandoahHeap::heap()), _map(map), _check_matrix(check_matrix) {};
1920 template <class T>
1921 void do_oop_work(T* p) {
1922 T o = oopDesc::load_heap_oop(p);
1923 if (!oopDesc::is_null(o)) {
1924 oop obj = oopDesc::decode_heap_oop_not_null(o);
1925 guarantee(check_obj_alignment(obj), "sanity");
1926
1927 guarantee(!oopDesc::is_null(obj), "sanity");
1928 guarantee(_heap->is_in(obj), "sanity");
1929
1930 oop forw = BrooksPointer::forwardee(obj);
1931 guarantee(!oopDesc::is_null(forw), "sanity");
1932 guarantee(_heap->is_in(forw), "sanity");
1933
1934 guarantee(oopDesc::unsafe_equals(obj, forw), "should not be forwarded");
1935
1936 if (_check_matrix) {
1937 uint from_idx = _heap->heap_region_index_containing(p);
1938 uint to_idx = _heap->heap_region_index_containing(obj);
1939 if (!_heap->connection_matrix()->is_connected(from_idx, to_idx)) {
1940 tty->print_cr("from-obj: ");
1941 _obj->print_on(tty);
1942 tty->print_cr("to-obj:");
1943 obj->print_on(tty);
1944 tty->print_cr("from-obj allocated after mark: %s", BOOL_TO_STR(_heap->allocated_after_complete_mark_start((HeapWord*) _obj)));
1945 tty->print_cr("to-obj allocated after mark: %s", BOOL_TO_STR(_heap->allocated_after_complete_mark_start((HeapWord*) obj)));
1946 tty->print_cr("from-obj marked: %s", BOOL_TO_STR(_heap->is_marked_complete(_obj)));
1947 tty->print_cr("to-obj marked: %s", BOOL_TO_STR(_heap->is_marked_complete(obj)));
1948 tty->print_cr("from-idx: %u, to-idx: %u", from_idx, to_idx);
1949
1950 oop fwd_from = BrooksPointer::forwardee(_obj);
1951 oop fwd_to = BrooksPointer::forwardee(obj);
1952 tty->print_cr("from-obj forwardee: " PTR_FORMAT, p2i(fwd_from));
1953 tty->print_cr("to-obj forwardee: " PTR_FORMAT, p2i(fwd_to));
1954 tty->print_cr("forward(from-obj) marked: %s", BOOL_TO_STR(_heap->is_marked_complete(fwd_from)));
1955 tty->print_cr("forward(to-obj) marked: %s", BOOL_TO_STR(_heap->is_marked_complete(fwd_to)));
1956 uint fwd_from_idx = _heap->heap_region_index_containing(fwd_from);
1957 uint fwd_to_idx = _heap->heap_region_index_containing(fwd_to);
1958 tty->print_cr("forward(from-idx): %u, forward(to-idx): %u", fwd_from_idx, fwd_to_idx);
1959 tty->print_cr("forward(from) connected with forward(to)? %s", BOOL_TO_STR(_heap->connection_matrix()->is_connected(fwd_from_idx, fwd_to_idx)));
1960 }
1961 guarantee(oopDesc::unsafe_equals(ShenandoahBarrierSet::resolve_oop_static_not_null(obj), obj), "polizeilich verboten");
1962 guarantee(_heap->connection_matrix()->is_connected(from_idx, to_idx), "must be connected");
1963 }
1964
1965 if (_map->parMark((HeapWord*) obj)) {
1966 _queue->push(SCMTask(obj));
1967 }
1968 }
1969 }
1970
1971 void do_oop(oop* p) { do_oop_work(p); }
1972 void do_oop(narrowOop* p) { do_oop_work(p); }
1973 void set_obj(oop o) { _obj = o; }
1974 };
1975
1976 void ShenandoahHeap::verify_heap_reachable_at_safepoint() {
1977 guarantee(SafepointSynchronize::is_at_safepoint(), "only when nothing else happens");
1978
1979 OrderAccess::fence();
1980 ensure_parsability(false);
1981
1982 // Allocate temporary bitmap for storing marking wavefront:
1983 ReservedSpace bm(_bitmap_size, os::vm_page_size());
1984 os::commit_memory_or_exit(bm.base(), bm.size(), false, "couldn't allocate verification bitmap");
1985 MemTracker::record_virtual_memory_type(bm.base(), mtGC);
1986 MemRegion verify_bitmap_region = MemRegion((HeapWord*) bm.base(), bm.size() / HeapWordSize);
1987
1988 CMBitMap _verification_bit_map;
1989 _verification_bit_map.initialize(_heap_region, verify_bitmap_region);
1990 MemRegion mr = MemRegion(_verification_bit_map.startWord(), _verification_bit_map.endWord());
1991 _verification_bit_map.clear_range_large(mr);
1992
1993 // Initialize a single queue
1994 SCMObjToScanQueue* q = new SCMObjToScanQueue();
1995 q->initialize();
1996
1997 // Scan root set
1998 ClassLoaderDataGraph::clear_claimed_marks();
1999 ShenandoahRootProcessor rp(this, 1);
2000
2001 {
2002 VerifyReachableHeapClosure cl(q, &_verification_bit_map, false);
2003 CLDToOopClosure cld_cl(&cl);
2004 CodeBlobToOopClosure code_cl(&cl, ! CodeBlobToOopClosure::FixRelocations);
2005 rp.process_all_roots(&cl, &cl, &cld_cl, &code_cl, 0);
2006 }
2007
2008 // Finish the scan
2009 {
2010 VerifyReachableHeapClosure cl(q, &_verification_bit_map, UseShenandoahMatrix && VerifyShenandoahMatrix);
2011 SCMTask task;
2012 while ((q->pop_buffer(task) ||
2013 q->pop_local(task) ||
2014 q->pop_overflow(task))) {
2015 oop obj = task.obj();
2016 assert(!oopDesc::is_null(obj), "must not be null");
2017 cl.set_obj(obj);
2018 obj->oop_iterate(&cl);
2019 }
2020 }
2021
2022 // Clean up!
2023 os::uncommit_memory(bm.base(), bm.size());
2024 delete(q);
2025 }
2026
2027 void ShenandoahHeap::stop_concurrent_marking() {
2028 assert(concurrent_mark_in_progress(), "How else could we get here?");
2029 if (! cancelled_concgc()) {
2030 // If we needed to update refs, and concurrent marking has been cancelled,
2031 // we need to finish updating references.
2032 set_need_update_refs(false);
2033 swap_mark_bitmaps();
2034 }
2035 set_concurrent_mark_in_progress(false);
2036
2037 if (log_is_enabled(Trace, gc, region)) {
2038 ResourceMark rm;
2039 outputStream* out = Log(gc, region)::trace_stream();
2040 print_heap_regions(out);
2041 }
2042
2043 }
2044
2045 void ShenandoahHeap::set_concurrent_mark_in_progress(bool in_progress) {
2046 _concurrent_mark_in_progress = in_progress ? 1 : 0;
2047 JavaThread::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress);
2048 }
2049
2050 void ShenandoahHeap::set_evacuation_in_progress_concurrently(bool in_progress) {
2051 // Note: it is important to first release the _evacuation_in_progress flag here,
2052 // so that Java threads can get out of oom_during_evacuation() and reach a safepoint,
2053 // in case a VM task is pending.
2054 set_evacuation_in_progress(in_progress);
2055 MutexLocker mu(Threads_lock);
2056 JavaThread::set_evacuation_in_progress_all_threads(in_progress);
2057 }
2058
2059 void ShenandoahHeap::set_evacuation_in_progress_at_safepoint(bool in_progress) {
2060 assert(SafepointSynchronize::is_at_safepoint(), "Only call this at safepoint");
2061 set_evacuation_in_progress(in_progress);
2062 JavaThread::set_evacuation_in_progress_all_threads(in_progress);
2063 }
2064
2065 void ShenandoahHeap::set_evacuation_in_progress(bool in_progress) {
2066 _evacuation_in_progress = in_progress ? 1 : 0;
2067 OrderAccess::fence();
2068 }
2069
2070 void ShenandoahHeap::verify_copy(oop p,oop c){
2071 assert(! oopDesc::unsafe_equals(p, oopDesc::bs()->read_barrier(p)), "forwarded correctly");
2072 assert(oopDesc::unsafe_equals(oopDesc::bs()->read_barrier(p), c), "verify pointer is correct");
2073 if (p->klass() != c->klass()) {
2074 print_heap_regions();
2075 }
2076 assert(p->klass() == c->klass(), "verify class p-size: "INT32_FORMAT" c-size: "INT32_FORMAT, p->size(), c->size());
2077 assert(p->size() == c->size(), "verify size");
2078 // Object may have been locked between copy and verification
2079 // assert(p->mark() == c->mark(), "verify mark");
2080 assert(oopDesc::unsafe_equals(c, oopDesc::bs()->read_barrier(c)), "verify only forwarded once");
2081 }
2082
2083 void ShenandoahHeap::oom_during_evacuation() {
2084 log_develop_trace(gc)("Out of memory during evacuation, cancel evacuation, schedule full GC by thread %d",
2085 Thread::current()->osthread()->thread_id());
2086
2087 // We ran out of memory during evacuation. Cancel evacuation, and schedule a full-GC.
2088 collector_policy()->set_should_clear_all_soft_refs(true);
2089 concurrent_thread()->try_set_full_gc();
2090 cancel_concgc(_oom_evacuation);
2091
2092 if ((! Thread::current()->is_GC_task_thread()) && (! Thread::current()->is_ConcurrentGC_thread())) {
2093 assert(! Threads_lock->owned_by_self()
2094 || SafepointSynchronize::is_at_safepoint(), "must not hold Threads_lock here");
2095 log_warning(gc)("OOM during evacuation. Let Java thread wait until evacuation finishes.");
2096 while (_evacuation_in_progress) { // wait.
2097 Thread::current()->_ParkEvent->park(1);
2098 }
2099 }
2100
2101 }
2102
2103 HeapWord* ShenandoahHeap::tlab_post_allocation_setup(HeapWord* obj) {
2104 // Initialize Brooks pointer for the next object
2105 HeapWord* result = obj + BrooksPointer::word_size();
2106 BrooksPointer::initialize(oop(result));
2107 return result;
2108 }
2109
2110 uint ShenandoahHeap::oop_extra_words() {
2111 return BrooksPointer::word_size();
2112 }
2113
2114 void ShenandoahHeap::grow_heap_by(size_t num_regions) {
2115 size_t base = _num_regions;
2116 ensure_new_regions(num_regions);
2117 for (size_t i = 0; i < num_regions; i++) {
2118 size_t new_region_index = i + base;
2119 HeapWord* start = _first_region_bottom + (ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize) * new_region_index;
2120 ShenandoahHeapRegion* new_region = new ShenandoahHeapRegion(this, start, ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize, new_region_index);
2121
2122 if (log_is_enabled(Trace, gc, region)) {
2123 ResourceMark rm;
2124 outputStream* out = Log(gc, region)::trace_stream();
2125 out->print_cr("allocating new region at index: "SIZE_FORMAT, new_region_index);
2126 new_region->print_on(out);
2127 }
2128
2129 assert(_ordered_regions->active_regions() == new_region->region_number(), "must match");
2130 _ordered_regions->add_region(new_region);
2131 _in_cset_fast_test_base[new_region_index] = false; // Not in cset
2132 _next_top_at_mark_starts_base[new_region_index] = new_region->bottom();
2133 _complete_top_at_mark_starts_base[new_region_index] = new_region->bottom();
2134
2135 _free_regions->add_region(new_region);
2136 }
2137 }
2138
2139 void ShenandoahHeap::ensure_new_regions(size_t new_regions) {
2140
2141 size_t num_regions = _num_regions;
2142 size_t new_num_regions = num_regions + new_regions;
2143 assert(new_num_regions <= _max_regions, "we checked this earlier");
2144
2145 size_t expand_size = new_regions * ShenandoahHeapRegion::RegionSizeBytes;
2146 log_trace(gc, region)("expanding storage by "SIZE_FORMAT_HEX" bytes, for "SIZE_FORMAT" new regions", expand_size, new_regions);
2147 bool success = _storage.expand_by(expand_size, ShenandoahAlwaysPreTouch);
2148 assert(success, "should always be able to expand by requested size");
2149
2150 _num_regions = new_num_regions;
2151
2152 }
2153
2154 ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() :
2155 _heap(ShenandoahHeap::heap_no_check()) {
2156 }
2157
2158 void ShenandoahForwardedIsAliveClosure::init(ShenandoahHeap* heap) {
2159 _heap = heap;
2160 }
2161
2162 bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) {
2163
2164 assert(_heap != NULL, "sanity");
2165 obj = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
2166 #ifdef ASSERT
2167 if (_heap->concurrent_mark_in_progress()) {
2168 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), "only query to-space");
2169 }
2170 #endif
2171 assert(!oopDesc::is_null(obj), "null");
2172 return _heap->is_marked_next(obj);
2173 }
2174
2175 void ShenandoahHeap::ref_processing_init() {
2176 MemRegion mr = reserved_region();
2177
2178 isAlive.init(ShenandoahHeap::heap());
2179 assert(_max_workers > 0, "Sanity");
2180
2181 _ref_processor =
2182 new ReferenceProcessor(mr, // span
2183 ParallelRefProcEnabled,
2184 // mt processing
2185 _max_workers,
2186 // degree of mt processing
2187 true,
2188 // mt discovery
2189 _max_workers,
2190 // degree of mt discovery
2191 false,
2192 // Reference discovery is not atomic
2193 &isAlive);
2194 }
2195
2196 #ifdef ASSERT
2197 void ShenandoahHeap::set_from_region_protection(bool protect) {
2198 for (uint i = 0; i < _num_regions; i++) {
2199 ShenandoahHeapRegion* region = _ordered_regions->get(i);
2200 if (region != NULL && in_collection_set(region)) {
2201 if (protect) {
2202 region->memProtectionOn();
2203 } else {
2204 region->memProtectionOff();
2205 }
2206 }
2207 }
2208 }
2209 #endif
2210
2211 size_t ShenandoahHeap::num_regions() {
2212 return _num_regions;
2213 }
2214
2215 size_t ShenandoahHeap::max_regions() {
2216 return _max_regions;
2217 }
2218
2219 GCTracer* ShenandoahHeap::tracer() {
2220 return shenandoahPolicy()->tracer();
2221 }
2222
2223 size_t ShenandoahHeap::tlab_used(Thread* thread) const {
2224 return _free_regions->used();
2225 }
2226
2227 void ShenandoahHeap::cancel_concgc(GCCause::Cause cause) {
2228 if (try_cancel_concgc()) {
2229 log_info(gc)("Cancelling concurrent GC: %s", GCCause::to_string(cause));
2230 _shenandoah_policy->report_concgc_cancelled();
2231 }
2232 }
2233
2234 void ShenandoahHeap::cancel_concgc(ShenandoahCancelCause cause) {
2235 if (try_cancel_concgc()) {
2236 log_info(gc)("Cancelling concurrent GC: %s", cancel_cause_to_string(cause));
2237 _shenandoah_policy->report_concgc_cancelled();
2238 }
2239 }
2240
2241 const char* ShenandoahHeap::cancel_cause_to_string(ShenandoahCancelCause cause) {
2242 switch (cause) {
2243 case _oom_evacuation:
2244 return "Out of memory for evacuation";
2245 case _vm_stop:
2246 return "Stopping VM";
2247 default:
2248 return "Unknown";
2249 }
2250 }
2251
2252 void ShenandoahHeap::clear_cancelled_concgc() {
2253 set_cancelled_concgc(false);
2254 }
2255
2256 uint ShenandoahHeap::max_workers() {
2257 return _max_workers;
2258 }
2259
2260 void ShenandoahHeap::stop() {
2261 // The shutdown sequence should be able to terminate when GC is running.
2262
2263 // Step 1. Notify control thread that we are in shutdown.
2264 // Note that we cannot do that with stop(), because stop() is blocking and waits for the actual shutdown.
2265 // Doing stop() here would wait for the normal GC cycle to complete, never falling through to cancel below.
2266 _concurrent_gc_thread->prepare_for_graceful_shutdown();
2267
2268 // Step 2. Notify GC workers that we are cancelling GC.
2269 cancel_concgc(_vm_stop);
2270
2271 // Step 3. Wait until GC worker exits normally.
2272 _concurrent_gc_thread->stop();
2273 }
2274
2275 void ShenandoahHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols) {
2276
2277 StringSymbolTableUnlinkTask shenandoah_unlink_task(is_alive, process_strings, process_symbols);
2278 workers()->run_task(&shenandoah_unlink_task);
2279
2280 // if (G1StringDedup::is_enabled()) {
2281 // G1StringDedup::unlink(is_alive);
2282 // }
2283 }
2284
2285 void ShenandoahHeap::set_need_update_refs(bool need_update_refs) {
2286 _need_update_refs = need_update_refs;
2287 }
2288
2289 //fixme this should be in heapregionset
2290 ShenandoahHeapRegion* ShenandoahHeap::next_compaction_region(const ShenandoahHeapRegion* r) {
2291 size_t region_idx = r->region_number() + 1;
2292 ShenandoahHeapRegion* next = _ordered_regions->get(region_idx);
2293 guarantee(next->region_number() == region_idx, "region number must match");
2294 while (next->is_humongous()) {
2295 region_idx = next->region_number() + 1;
2296 next = _ordered_regions->get(region_idx);
2297 guarantee(next->region_number() == region_idx, "region number must match");
2298 }
2299 return next;
2300 }
2301
2302 void ShenandoahHeap::set_region_in_collection_set(size_t region_index, bool b) {
2303 _in_cset_fast_test_base[region_index] = b;
2304 }
2305
2306 ShenandoahMonitoringSupport* ShenandoahHeap::monitoring_support() {
2307 return _monitoring_support;
2308 }
2309
2310 CMBitMap* ShenandoahHeap::complete_mark_bit_map() {
2311 return _complete_mark_bit_map;
2312 }
2313
2314 CMBitMap* ShenandoahHeap::next_mark_bit_map() {
2315 return _next_mark_bit_map;
2316 }
2317
2318 void ShenandoahHeap::add_free_region(ShenandoahHeapRegion* r) {
2319 _free_regions->add_region(r);
2320 }
2321
2322 void ShenandoahHeap::clear_free_regions() {
2323 _free_regions->clear();
2324 }
2325
2326 address ShenandoahHeap::in_cset_fast_test_addr() {
2327 return (address) (ShenandoahHeap::heap()->_in_cset_fast_test);
2328 }
2329
2330 address ShenandoahHeap::cancelled_concgc_addr() {
2331 return (address) &(ShenandoahHeap::heap()->_cancelled_concgc);
2332 }
2333
2334 void ShenandoahHeap::clear_cset_fast_test() {
2335 assert(_in_cset_fast_test_base != NULL, "sanity");
2336 memset(_in_cset_fast_test_base, false,
2337 _in_cset_fast_test_length * sizeof(bool));
2338 }
2339
2340 size_t ShenandoahHeap::conservative_max_heap_alignment() {
2341 return ShenandoahMaxRegionSize;
2342 }
2343
2344 size_t ShenandoahHeap::bytes_allocated_since_cm() {
2345 return _bytes_allocated_since_cm;
2346 }
2347
2348 void ShenandoahHeap::set_bytes_allocated_since_cm(size_t bytes) {
2349 _bytes_allocated_since_cm = bytes;
2350 }
2351
2352 size_t ShenandoahHeap::max_allocated_gc() {
2353 return _max_allocated_gc;
2354 }
2355
2356 void ShenandoahHeap::set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr) {
2357 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2358 _next_top_at_mark_starts[index] = addr;
2359 }
2360
2361 HeapWord* ShenandoahHeap::next_top_at_mark_start(HeapWord* region_base) {
2362 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2363 return _next_top_at_mark_starts[index];
2364 }
2365
2366 void ShenandoahHeap::set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr) {
2367 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2368 _complete_top_at_mark_starts[index] = addr;
2369 }
2370
2371 HeapWord* ShenandoahHeap::complete_top_at_mark_start(HeapWord* region_base) {
2372 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2373 return _complete_top_at_mark_starts[index];
2374 }
2375
2376 void ShenandoahHeap::set_full_gc_in_progress(bool in_progress) {
2377 _full_gc_in_progress = in_progress;
2378 }
2379
2380 bool ShenandoahHeap::is_full_gc_in_progress() const {
2381 return _full_gc_in_progress;
2382 }
2383
2384 class NMethodOopInitializer : public OopClosure {
2385 private:
2386 ShenandoahHeap* _heap;
2387 public:
2388 NMethodOopInitializer() : _heap(ShenandoahHeap::heap()) {
2389 }
2390
2391 private:
2392 template <class T>
2393 inline void do_oop_work(T* p) {
2394 T o = oopDesc::load_heap_oop(p);
2395 if (! oopDesc::is_null(o)) {
2396 oop obj1 = oopDesc::decode_heap_oop_not_null(o);
2397 oop obj2 = oopDesc::bs()->write_barrier(obj1);
2398 if (! oopDesc::unsafe_equals(obj1, obj2)) {
2399 oopDesc::encode_store_heap_oop(p, obj2);
2400 }
2401 }
2402 }
2403
2404 public:
2405 void do_oop(oop* o) {
2406 do_oop_work(o);
2407 }
2408 void do_oop(narrowOop* o) {
2409 do_oop_work(o);
2410 }
2411 };
2412
2413 void ShenandoahHeap::register_nmethod(nmethod* nm) {
2414 NMethodOopInitializer init;
2415 nm->oops_do(&init);
2416 nm->fix_oop_relocations();
2417 }
2418
2419 void ShenandoahHeap::unregister_nmethod(nmethod* nm) {
2420 }
2421
2422 void ShenandoahHeap::pin_object(oop o) {
2423 heap_region_containing(o)->pin();
2424 }
2425
2426 void ShenandoahHeap::unpin_object(oop o) {
2427 heap_region_containing(o)->unpin();
2428 }
2429
2430
2431 GCTimer* ShenandoahHeap::gc_timer() const {
2432 return _gc_timer;
2433 }
2434
2435 class RecordAllRefsOopClosure: public ExtendedOopClosure {
2436 private:
2437 int _x;
2438 int *_matrix;
2439 int _num_regions;
2440 oop _p;
2441
2442 public:
2443 RecordAllRefsOopClosure(int *matrix, int x, size_t num_regions, oop p) :
2444 _matrix(matrix), _x(x), _num_regions(num_regions), _p(p) {}
2445
2446 template <class T>
2447 void do_oop_work(T* p) {
2448 oop o = oopDesc::load_decode_heap_oop(p);
2449 if (o != NULL) {
2450 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop() ) {
2451 int y = ShenandoahHeap::heap()->heap_region_containing(o)->region_number();
2452 _matrix[_x * _num_regions + y]++;
2453 }
2454 }
2455 }
2456 void do_oop(oop* p) {
2457 do_oop_work(p);
2458 }
2459
2460 void do_oop(narrowOop* p) {
2461 do_oop_work(p);
2462 }
2463
2464 };
2465
2466 class RecordAllRefsObjectClosure : public ObjectClosure {
2467 int *_matrix;
2468 size_t _num_regions;
2469
2470 public:
2471 RecordAllRefsObjectClosure(int *matrix, size_t num_regions) :
2472 _matrix(matrix), _num_regions(num_regions) {}
2473
2474 void do_object(oop p) {
2475 if (ShenandoahHeap::heap()->is_in(p) && ShenandoahHeap::heap()->is_marked_next(p) && p->is_oop()) {
2476 int x = ShenandoahHeap::heap()->heap_region_containing(p)->region_number();
2477 RecordAllRefsOopClosure cl(_matrix, x, _num_regions, p);
2478 p->oop_iterate(&cl);
2479 }
2480 }
2481 };
2482 void ShenandoahHeap::calculate_matrix(int* connections) {
2483 log_develop_trace(gc)("calculating matrix");
2484 ensure_parsability(false);
2485 int num = num_regions();
2486
2487 for (int i = 0; i < num; i++) {
2488 for (int j = 0; j < num; j++) {
2489 connections[i * num + j] = 0;
2490 }
2491 }
2492
2493 RecordAllRefsOopClosure cl(connections, 0, num, NULL);
2494 roots_iterate(&cl);
2495
2496 RecordAllRefsObjectClosure cl2(connections, num);
2497 object_iterate(&cl2);
2498
2499 }
2500
2501 void ShenandoahHeap::print_matrix(int* connections) {
2502 int num = num_regions();
2503 int cs_regions = 0;
2504 int referenced = 0;
2505
2506 for (int i = 0; i < num; i++) {
2507 size_t liveData = ShenandoahHeap::heap()->regions()->get(i)->get_live_data_bytes();
2508
2509 int numReferencedRegions = 0;
2510 int numReferencedByRegions = 0;
2511
2512 for (int j = 0; j < num; j++) {
2513 if (connections[i * num + j] > 0)
2514 numReferencedRegions++;
2515
2516 if (connections [j * num + i] > 0)
2517 numReferencedByRegions++;
2518
2519 cs_regions++;
2520 referenced += numReferencedByRegions;
2521 }
2522
2523 if (ShenandoahHeap::heap()->regions()->get(i)->has_live()) {
2524 tty->print("Region %d is referenced by %d regions {",
2525 i, numReferencedByRegions);
2526 int col_count = 0;
2527 for (int j = 0; j < num; j++) {
2528 int foo = connections[j * num + i];
2529 if (foo > 0) {
2530 col_count++;
2531 if ((col_count % 10) == 0)
2532 tty->print("\n");
2533 tty->print("%d(%d), ", j,foo);
2534 }
2535 }
2536 tty->print("} \n");
2537 }
2538 }
2539
2540 double avg = (double)referenced / (double) cs_regions;
2541 tty->print("Average Number of regions scanned / region = %lf\n", avg);
2542 }
2543
2544 class ShenandoahCountGarbageClosure : public ShenandoahHeapRegionClosure {
2545 private:
2546 size_t _garbage;
2547 public:
2548 ShenandoahCountGarbageClosure() : _garbage(0) {
2549 }
2550
2551 bool doHeapRegion(ShenandoahHeapRegion* r) {
2552 if (! r->is_humongous() && ! r->is_pinned() && ! r->in_collection_set()) {
2553 _garbage += r->garbage();
2554 }
2555 return false;
2556 }
2557
2558 size_t garbage() {
2559 return _garbage;
2560 }
2561 };
2562
2563 size_t ShenandoahHeap::garbage() {
2564 ShenandoahCountGarbageClosure cl;
2565 heap_region_iterate(&cl);
2566 return cl.garbage();
2567 }
2568
2569 ShenandoahConnectionMatrix* ShenandoahHeap::connection_matrix() {
2570 return _connection_matrix;
2571 }
2572
2573 ShenandoahPartialGC* ShenandoahHeap::partial_gc() {
2574 return _partial_gc;
2575 }
2576
2577 void ShenandoahHeap::do_partial_collection() {
2578 {
2579 ShenandoahHeapLock lock(this);
2580 partial_gc()->prepare();
2581 }
2582 partial_gc()->do_partial_collection();
2583 }
2584
2585 #ifdef ASSERT
2586 void ShenandoahHeap::assert_heaplock_owned_by_current_thread() {
2587 assert(_heap_lock == locked, "must be locked");
2588 assert(_heap_lock_owner == Thread::current(), "must be owned by current thread");
2589 }
2590
2591 void ShenandoahHeap::assert_heaplock_or_safepoint() {
2592 Thread* thr = Thread::current();
2593 assert((_heap_lock == locked && _heap_lock_owner == thr) ||
2594 (SafepointSynchronize::is_at_safepoint() && thr->is_VM_thread()),
2595 "must own heap lock or by VM thread at safepoint");
2596 }
2597
2598 #endif