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