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 size_t bitmap_size = CMBitMap::compute_size(heap_rs.size());
234 MemRegion 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 _heap->evacuate_object(p, _thread);
800 }
801 }
802 };
803
804 #ifdef ASSERT
805 class VerifyEvacuatedObjectClosure : public ObjectClosure {
806
807 public:
808
809 void do_object(oop p) {
810 if (ShenandoahHeap::heap()->is_marked_complete(p)) {
811 oop p_prime = oopDesc::bs()->read_barrier(p);
812 assert(! oopDesc::unsafe_equals(p, p_prime), "Should point to evacuated copy");
813 if (p->klass() != p_prime->klass()) {
814 tty->print_cr("copy has different class than original:");
815 p->klass()->print_on(tty);
816 p_prime->klass()->print_on(tty);
817 }
818 assert(p->klass() == p_prime->klass(), "Should have the same class p: "PTR_FORMAT", p_prime: "PTR_FORMAT, p2i(p), p2i(p_prime));
819 // assert(p->mark() == p_prime->mark(), "Should have the same mark");
820 assert(p->size() == p_prime->size(), "Should be the same size");
821 assert(oopDesc::unsafe_equals(p_prime, oopDesc::bs()->read_barrier(p_prime)), "One forward once");
822 }
823 }
824 };
825
826 void ShenandoahHeap::verify_evacuated_region(ShenandoahHeapRegion* from_region) {
827 VerifyEvacuatedObjectClosure verify_evacuation;
828 marked_object_iterate(from_region, &verify_evacuation);
829 }
830 #endif
831
832 void ShenandoahHeap::parallel_evacuate_region(ShenandoahHeapRegion* from_region) {
833
834 assert(from_region->has_live(), "all-garbage regions are reclaimed earlier");
835
836 ParallelEvacuateRegionObjectClosure evacuate_region(this);
837
838 marked_object_iterate(from_region, &evacuate_region);
839
840 #ifdef ASSERT
841 if (ShenandoahVerify && ! cancelled_concgc()) {
842 verify_evacuated_region(from_region);
843 }
844 #endif
845 }
846
847 class ParallelEvacuationTask : public AbstractGangTask {
848 private:
849 ShenandoahHeap* _sh;
850 ShenandoahCollectionSet* _cs;
851
852 public:
853 ParallelEvacuationTask(ShenandoahHeap* sh,
854 ShenandoahCollectionSet* cs) :
855 AbstractGangTask("Parallel Evacuation Task"),
856 _cs(cs),
857 _sh(sh) {}
858
859 void work(uint worker_id) {
860
861 ShenandoahHeapRegion* from_hr = _cs->claim_next();
862
863 while (from_hr != NULL) {
864 log_develop_trace(gc, region)("Thread "INT32_FORMAT" claimed Heap Region "SIZE_FORMAT,
865 worker_id,
866 from_hr->region_number());
867
868 assert(from_hr->has_live(), "all-garbage regions are reclaimed early");
869 _sh->parallel_evacuate_region(from_hr);
870
871 if (_sh->cancelled_concgc()) {
872 log_develop_trace(gc, region)("Cancelled concgc while evacuating region " SIZE_FORMAT "\n", from_hr->region_number());
873 break;
874 }
875 from_hr = _cs->claim_next();
876 }
877 }
878 };
879
880 class RecycleDirtyRegionsClosure: public ShenandoahHeapRegionClosure {
881 private:
882 ShenandoahHeap* _heap;
883 size_t _bytes_reclaimed;
884 public:
885 RecycleDirtyRegionsClosure() : _heap(ShenandoahHeap::heap()) {}
886
887 bool doHeapRegion(ShenandoahHeapRegion* r) {
888
889 assert (! _heap->cancelled_concgc(), "no recycling after cancelled marking");
890
891 if (_heap->in_collection_set(r)) {
892 log_develop_trace(gc, region)("Recycling region " SIZE_FORMAT ":", r->region_number());
893 _heap->decrease_used(r->used());
894 _bytes_reclaimed += r->used();
895 r->recycle();
896 }
897
898 return false;
899 }
900 size_t bytes_reclaimed() { return _bytes_reclaimed;}
901 void clear_bytes_reclaimed() {_bytes_reclaimed = 0;}
902 };
903
904 void ShenandoahHeap::recycle_dirty_regions() {
905 RecycleDirtyRegionsClosure cl;
906 cl.clear_bytes_reclaimed();
907
908 heap_region_iterate(&cl);
909
910 _shenandoah_policy->record_bytes_reclaimed(cl.bytes_reclaimed());
911 if (! cancelled_concgc()) {
912 clear_cset_fast_test();
913 }
914 }
915
916 ShenandoahFreeSet* ShenandoahHeap::free_regions() {
917 return _free_regions;
918 }
919
920 void ShenandoahHeap::print_heap_regions(outputStream* st) const {
921 _ordered_regions->print(st);
922 }
923
924 class PrintAllRefsOopClosure: public ExtendedOopClosure {
925 private:
926 int _index;
927 const char* _prefix;
928
929 public:
930 PrintAllRefsOopClosure(const char* prefix) : _index(0), _prefix(prefix) {}
931
932 private:
933 template <class T>
934 inline void do_oop_work(T* p) {
935 oop o = oopDesc::load_decode_heap_oop(p);
936 if (o != NULL) {
937 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop()) {
938 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT")-> "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT")",
939 _prefix, _index,
940 p2i(p), p2i(o),
941 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(o)),
942 o->klass()->internal_name(), p2i(o->klass()));
943 } else {
944 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT" dirty -> "PTR_FORMAT" (not in heap, possibly corrupted or dirty)",
945 _prefix, _index,
946 p2i(p), p2i(o));
947 }
948 } else {
949 tty->print_cr("%s "INT32_FORMAT" ("PTR_FORMAT") -> "PTR_FORMAT, _prefix, _index, p2i(p), p2i((HeapWord*) o));
950 }
951 _index++;
952 }
953
954 public:
955 void do_oop(oop* p) {
956 do_oop_work(p);
957 }
958
959 void do_oop(narrowOop* p) {
960 do_oop_work(p);
961 }
962
963 };
964
965 class PrintAllRefsObjectClosure : public ObjectClosure {
966 const char* _prefix;
967
968 public:
969 PrintAllRefsObjectClosure(const char* prefix) : _prefix(prefix) {}
970
971 void do_object(oop p) {
972 if (ShenandoahHeap::heap()->is_in(p)) {
973 tty->print_cr("%s object "PTR_FORMAT" (marked: %s) (%s "PTR_FORMAT") refers to:",
974 _prefix, p2i(p),
975 BOOL_TO_STR(ShenandoahHeap::heap()->is_marked_complete(p)),
976 p->klass()->internal_name(), p2i(p->klass()));
977 PrintAllRefsOopClosure cl(_prefix);
978 p->oop_iterate(&cl);
979 }
980 }
981 };
982
983 void ShenandoahHeap::print_all_refs(const char* prefix) {
984 tty->print_cr("printing all references in the heap");
985 tty->print_cr("root references:");
986
987 ensure_parsability(false);
988
989 PrintAllRefsOopClosure cl(prefix);
990 roots_iterate(&cl);
991
992 tty->print_cr("heap references:");
993 PrintAllRefsObjectClosure cl2(prefix);
994 object_iterate(&cl2);
995 }
996
997 class VerifyAfterMarkingOopClosure: public ExtendedOopClosure {
998 private:
999 ShenandoahHeap* _heap;
1000
1001 public:
1002 VerifyAfterMarkingOopClosure() :
1003 _heap(ShenandoahHeap::heap()) { }
1004
1005 private:
1006 template <class T>
1007 inline void do_oop_work(T* p) {
1008 oop o = oopDesc::load_decode_heap_oop(p);
1009 if (o != NULL) {
1010 if (! _heap->is_marked_complete(o)) {
1011 _heap->print_heap_regions();
1012 _heap->print_all_refs("post-mark");
1013 tty->print_cr("oop not marked, although referrer is marked: "PTR_FORMAT": in_heap: %s, is_marked: %s",
1014 p2i((HeapWord*) o), BOOL_TO_STR(_heap->is_in(o)), BOOL_TO_STR(_heap->is_marked_complete(o)));
1015 _heap->print_heap_locations((HeapWord*) o, (HeapWord*) o + o->size());
1016
1017 tty->print_cr("oop class: %s", o->klass()->internal_name());
1018 if (_heap->is_in(p)) {
1019 oop referrer = oop(_heap->heap_region_containing(p)->block_start_const(p));
1020 tty->print_cr("Referrer starts at addr "PTR_FORMAT, p2i((HeapWord*) referrer));
1021 referrer->print();
1022 _heap->print_heap_locations((HeapWord*) referrer, (HeapWord*) referrer + referrer->size());
1023 }
1024 tty->print_cr("heap region containing object:");
1025 _heap->heap_region_containing(o)->print();
1026 tty->print_cr("heap region containing referrer:");
1027 _heap->heap_region_containing(p)->print();
1028 tty->print_cr("heap region containing forwardee:");
1029 _heap->heap_region_containing(oopDesc::bs()->read_barrier(o))->print();
1030 }
1031 assert(o->is_oop(), "oop must be an oop");
1032 assert(Metaspace::contains(o->klass()), "klass pointer must go to metaspace");
1033 if (! oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o))) {
1034 tty->print_cr("oops has forwardee: p: "PTR_FORMAT" (%s), o = "PTR_FORMAT" (%s), new-o: "PTR_FORMAT" (%s)",
1035 p2i(p),
1036 BOOL_TO_STR(_heap->in_collection_set(p)),
1037 p2i(o),
1038 BOOL_TO_STR(_heap->in_collection_set(o)),
1039 p2i((HeapWord*) oopDesc::bs()->read_barrier(o)),
1040 BOOL_TO_STR(_heap->in_collection_set(oopDesc::bs()->read_barrier(o))));
1041 tty->print_cr("oop class: %s", o->klass()->internal_name());
1042 }
1043 assert(oopDesc::unsafe_equals(o, oopDesc::bs()->read_barrier(o)), "oops must not be forwarded");
1044 assert(! _heap->in_collection_set(o), "references must not point to dirty heap regions");
1045 assert(_heap->is_marked_complete(o), "live oops must be marked current");
1046 }
1047 }
1048
1049 public:
1050 void do_oop(oop* p) {
1051 do_oop_work(p);
1052 }
1053
1054 void do_oop(narrowOop* p) {
1055 do_oop_work(p);
1056 }
1057
1058 };
1059
1060 void ShenandoahHeap::verify_heap_after_marking() {
1061
1062 verify_heap_size_consistency();
1063
1064 log_trace(gc)("verifying heap after marking");
1065
1066 VerifyAfterMarkingOopClosure cl;
1067 roots_iterate(&cl);
1068 ObjectToOopClosure objs(&cl);
1069 object_iterate(&objs);
1070 }
1071
1072
1073 void ShenandoahHeap::reclaim_humongous_region_at(ShenandoahHeapRegion* r) {
1074 assert(r->is_humongous_start(), "reclaim regions starting with the first one");
1075
1076 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size());
1077 size_t size = humongous_obj->size() + BrooksPointer::word_size();
1078 uint required_regions = ShenandoahHumongous::required_regions(size * HeapWordSize);
1079 uint index = r->region_number();
1080
1081
1082 assert(!r->has_live(), "liveness must be zero");
1083
1084 for(size_t i = 0; i < required_regions; i++) {
1085
1086 ShenandoahHeapRegion* region = _ordered_regions->get(index++);
1087
1088 assert((region->is_humongous_start() || region->is_humongous_continuation()),
1089 "expect correct humongous start or continuation");
1090
1091 if (log_is_enabled(Debug, gc, humongous)) {
1092 log_debug(gc, humongous)("reclaiming "UINT32_FORMAT" humongous regions for object of size: "SIZE_FORMAT" words", required_regions, size);
1093 ResourceMark rm;
1094 outputStream* out = Log(gc, humongous)::debug_stream();
1095 region->print_on(out);
1096 }
1097
1098 region->recycle();
1099 ShenandoahHeap::heap()->decrease_used(ShenandoahHeapRegion::RegionSizeBytes);
1100 }
1101 }
1102
1103 class ShenandoahReclaimHumongousRegionsClosure : public ShenandoahHeapRegionClosure {
1104
1105 bool doHeapRegion(ShenandoahHeapRegion* r) {
1106 ShenandoahHeap* heap = ShenandoahHeap::heap();
1107
1108 if (r->is_humongous_start()) {
1109 oop humongous_obj = oop(r->bottom() + BrooksPointer::word_size());
1110 if (! heap->is_marked_complete(humongous_obj)) {
1111
1112 heap->reclaim_humongous_region_at(r);
1113 }
1114 }
1115 return false;
1116 }
1117 };
1118
1119 #ifdef ASSERT
1120 class CheckCollectionSetClosure: public ShenandoahHeapRegionClosure {
1121 bool doHeapRegion(ShenandoahHeapRegion* r) {
1122 assert(! ShenandoahHeap::heap()->in_collection_set(r), "Should have been cleared by now");
1123 return false;
1124 }
1125 };
1126 #endif
1127
1128 void ShenandoahHeap::prepare_for_concurrent_evacuation() {
1129 assert(_ordered_regions->get(0)->region_number() == 0, "FIXME CHF. FIXME CHF!");
1130
1131 log_develop_trace(gc)("Thread %d started prepare_for_concurrent_evacuation", Thread::current()->osthread()->thread_id());
1132
1133 if (!cancelled_concgc()) {
1134
1135 recycle_dirty_regions();
1136
1137 ensure_parsability(true);
1138
1139 if (UseShenandoahMatrix) {
1140 if (PrintShenandoahMatrix) {
1141 outputStream* log = Log(gc)::info_stream();
1142 connection_matrix()->print_on(log);
1143 }
1144 if (VerifyShenandoahMatrix) {
1145 verify_matrix();
1146 }
1147 }
1148
1149 #ifdef ASSERT
1150 if (ShenandoahVerify) {
1151 verify_heap_after_marking();
1152 }
1153 #endif
1154
1155 // NOTE: This needs to be done during a stop the world pause, because
1156 // putting regions into the collection set concurrently with Java threads
1157 // will create a race. In particular, acmp could fail because when we
1158 // resolve the first operand, the containing region might not yet be in
1159 // the collection set, and thus return the original oop. When the 2nd
1160 // operand gets resolved, the region could be in the collection set
1161 // and the oop gets evacuated. If both operands have originally been
1162 // the same, we get false negatives.
1163
1164 {
1165 ShenandoahHeapLock lock(this);
1166 _collection_set->clear();
1167 _free_regions->clear();
1168
1169 ShenandoahReclaimHumongousRegionsClosure reclaim;
1170 heap_region_iterate(&reclaim);
1171
1172 #ifdef ASSERT
1173 CheckCollectionSetClosure ccsc;
1174 _ordered_regions->heap_region_iterate(&ccsc);
1175 #endif
1176
1177 _shenandoah_policy->choose_collection_set(_collection_set);
1178
1179 _shenandoah_policy->choose_free_set(_free_regions);
1180 }
1181
1182 _bytes_allocated_since_cm = 0;
1183
1184 Universe::update_heap_info_at_gc();
1185 }
1186 }
1187
1188
1189 class RetireTLABClosure : public ThreadClosure {
1190 private:
1191 bool _retire;
1192
1193 public:
1194 RetireTLABClosure(bool retire) : _retire(retire) {
1195 }
1196
1197 void do_thread(Thread* thread) {
1198 thread->gclab().make_parsable(_retire);
1199 }
1200 };
1201
1202 void ShenandoahHeap::ensure_parsability(bool retire_tlabs) {
1203 if (UseTLAB) {
1204 CollectedHeap::ensure_parsability(retire_tlabs);
1205 RetireTLABClosure cl(retire_tlabs);
1206 Threads::threads_do(&cl);
1207 }
1208 }
1209
1210 class ShenandoahEvacuateUpdateRootsClosure: public ExtendedOopClosure {
1211 private:
1212 ShenandoahHeap* _heap;
1213 Thread* _thread;
1214 public:
1215 ShenandoahEvacuateUpdateRootsClosure() :
1216 _heap(ShenandoahHeap::heap()), _thread(Thread::current()) {
1217 }
1218
1219 private:
1220 template <class T>
1221 void do_oop_work(T* p) {
1222 assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
1223
1224 T o = oopDesc::load_heap_oop(p);
1225 if (! oopDesc::is_null(o)) {
1226 oop obj = oopDesc::decode_heap_oop_not_null(o);
1227 if (_heap->in_collection_set(obj)) {
1228 assert(_heap->is_marked_complete(obj), "only evacuate marked objects %d %d",
1229 _heap->is_marked_complete(obj), _heap->is_marked_complete(ShenandoahBarrierSet::resolve_oop_static_not_null(obj)));
1230 oop resolved = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
1231 if (oopDesc::unsafe_equals(resolved, obj)) {
1232 resolved = _heap->evacuate_object(obj, _thread);
1233 }
1234 oopDesc::encode_store_heap_oop(p, resolved);
1235 }
1236 }
1237 #ifdef ASSERT
1238 else {
1239 // tty->print_cr("not updating root at: "PTR_FORMAT" with object: "PTR_FORMAT", is_in_heap: %s, is_in_cset: %s, is_marked: %s",
1240 // p2i(p),
1241 // p2i((HeapWord*) obj),
1242 // BOOL_TO_STR(_heap->is_in(obj)),
1243 // BOOL_TO_STR(_heap->in_cset_fast_test(obj)),
1244 // BOOL_TO_STR(_heap->is_marked_complete(obj)));
1245 }
1246 #endif
1247 }
1248
1249 public:
1250 void do_oop(oop* p) {
1251 do_oop_work(p);
1252 }
1253 void do_oop(narrowOop* p) {
1254 do_oop_work(p);
1255 }
1256 };
1257
1258 class ShenandoahEvacuateUpdateRootsTask : public AbstractGangTask {
1259 ShenandoahRootEvacuator* _rp;
1260 public:
1261
1262 ShenandoahEvacuateUpdateRootsTask(ShenandoahRootEvacuator* rp) :
1263 AbstractGangTask("Shenandoah evacuate and update roots"),
1264 _rp(rp)
1265 {
1266 // Nothing else to do.
1267 }
1268
1269 void work(uint worker_id) {
1270 ShenandoahEvacuateUpdateRootsClosure cl;
1271 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations);
1272
1273 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id);
1274 }
1275 };
1276
1277 class ShenandoahFixRootsTask : public AbstractGangTask {
1278 ShenandoahRootEvacuator* _rp;
1279 public:
1280
1281 ShenandoahFixRootsTask(ShenandoahRootEvacuator* rp) :
1282 AbstractGangTask("Shenandoah update roots"),
1283 _rp(rp)
1284 {
1285 // Nothing else to do.
1286 }
1287
1288 void work(uint worker_id) {
1289 SCMUpdateRefsClosure cl;
1290 MarkingCodeBlobClosure blobsCl(&cl, CodeBlobToOopClosure::FixRelocations);
1291
1292 _rp->process_evacuate_roots(&cl, &blobsCl, worker_id);
1293 }
1294 };
1295 void ShenandoahHeap::evacuate_and_update_roots() {
1296
1297 COMPILER2_PRESENT(DerivedPointerTable::clear());
1298
1299 #ifdef ASSERT
1300 if (ShenandoahVerifyReadsToFromSpace) {
1301 set_from_region_protection(false);
1302 }
1303 #endif
1304
1305 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped");
1306 ClassLoaderDataGraph::clear_claimed_marks();
1307
1308 {
1309 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots);
1310 ShenandoahEvacuateUpdateRootsTask roots_task(&rp);
1311 workers()->run_task(&roots_task);
1312 }
1313
1314 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
1315
1316 if (cancelled_concgc()) {
1317 // If initial evacuation has been cancelled, we need to update all references
1318 // after all workers have finished. Otherwise we might run into the following problem:
1319 // GC thread 1 cannot allocate anymore, thus evacuation fails, leaves from-space ptr of object X.
1320 // GC thread 2 evacuates the same object X to to-space
1321 // which leaves a truly dangling from-space reference in the first root oop*. This must not happen.
1322 // clear() and update_pointers() must always be called in pairs,
1323 // cannot nest with above clear()/update_pointers().
1324 COMPILER2_PRESENT(DerivedPointerTable::clear());
1325 ShenandoahRootEvacuator rp(this, workers()->active_workers(), ShenandoahCollectorPolicy::evac_thread_roots);
1326 ShenandoahFixRootsTask update_roots_task(&rp);
1327 workers()->run_task(&update_roots_task);
1328 COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
1329 }
1330
1331 #ifdef ASSERT
1332 if (ShenandoahVerifyReadsToFromSpace) {
1333 set_from_region_protection(true);
1334 }
1335 #endif
1336
1337 #ifdef ASSERT
1338 {
1339 AssertToSpaceClosure cl;
1340 CodeBlobToOopClosure code_cl(&cl, !CodeBlobToOopClosure::FixRelocations);
1341 ShenandoahRootEvacuator rp(this, 1);
1342 rp.process_evacuate_roots(&cl, &code_cl, 0);
1343 }
1344 #endif
1345 }
1346
1347
1348 void ShenandoahHeap::do_evacuation() {
1349
1350 parallel_evacuate();
1351
1352 if (ShenandoahVerify && ! cancelled_concgc()) {
1353 VM_ShenandoahVerifyHeapAfterEvacuation verify_after_evacuation;
1354 if (Thread::current()->is_VM_thread()) {
1355 verify_after_evacuation.doit();
1356 } else {
1357 VMThread::execute(&verify_after_evacuation);
1358 }
1359 }
1360
1361 }
1362
1363 void ShenandoahHeap::parallel_evacuate() {
1364 log_develop_trace(gc)("starting parallel_evacuate");
1365
1366 _shenandoah_policy->record_phase_start(ShenandoahCollectorPolicy::conc_evac);
1367
1368 if (log_is_enabled(Trace, gc, region)) {
1369 ResourceMark rm;
1370 outputStream *out = Log(gc, region)::trace_stream();
1371 out->print("Printing all available regions");
1372 print_heap_regions(out);
1373 }
1374
1375 if (log_is_enabled(Trace, gc, cset)) {
1376 ResourceMark rm;
1377 outputStream *out = Log(gc, cset)::trace_stream();
1378 out->print("Printing collection set which contains "SIZE_FORMAT" regions:\n", _collection_set->count());
1379 _collection_set->print(out);
1380
1381 out->print("Printing free set which contains "SIZE_FORMAT" regions:\n", _free_regions->count());
1382 _free_regions->print(out);
1383 }
1384
1385 ParallelEvacuationTask evacuationTask = ParallelEvacuationTask(this, _collection_set);
1386
1387
1388 workers()->run_task(&evacuationTask);
1389
1390 if (log_is_enabled(Trace, gc, cset)) {
1391 ResourceMark rm;
1392 outputStream *out = Log(gc, cset)::trace_stream();
1393 out->print("Printing postgc collection set which contains "SIZE_FORMAT" regions:\n",
1394 _collection_set->count());
1395
1396 _collection_set->print(out);
1397
1398 out->print("Printing postgc free regions which contain "SIZE_FORMAT" free regions:\n",
1399 _free_regions->count());
1400 _free_regions->print(out);
1401
1402 }
1403
1404 if (log_is_enabled(Trace, gc, region)) {
1405 ResourceMark rm;
1406 outputStream *out = Log(gc, region)::trace_stream();
1407 out->print_cr("all regions after evacuation:");
1408 print_heap_regions(out);
1409 }
1410
1411 _shenandoah_policy->record_phase_end(ShenandoahCollectorPolicy::conc_evac);
1412 }
1413
1414 class VerifyEvacuationClosure: public ExtendedOopClosure {
1415 private:
1416 ShenandoahHeap* _heap;
1417 ShenandoahHeapRegion* _from_region;
1418
1419 public:
1420 VerifyEvacuationClosure(ShenandoahHeapRegion* from_region) :
1421 _heap(ShenandoahHeap::heap()), _from_region(from_region) { }
1422 private:
1423 template <class T>
1424 inline void do_oop_work(T* p) {
1425 oop heap_oop = oopDesc::load_decode_heap_oop(p);
1426 if (! oopDesc::is_null(heap_oop)) {
1427 guarantee(! _from_region->is_in(heap_oop), "no references to from-region allowed after evacuation: "PTR_FORMAT, p2i((HeapWord*) heap_oop));
1428 }
1429 }
1430
1431 public:
1432 void do_oop(oop* p) {
1433 do_oop_work(p);
1434 }
1435
1436 void do_oop(narrowOop* p) {
1437 do_oop_work(p);
1438 }
1439
1440 };
1441
1442 void ShenandoahHeap::roots_iterate(OopClosure* cl) {
1443
1444 assert(SafepointSynchronize::is_at_safepoint(), "Only iterate roots while world is stopped");
1445
1446 CodeBlobToOopClosure blobsCl(cl, false);
1447 CLDToOopClosure cldCl(cl);
1448
1449 ClassLoaderDataGraph::clear_claimed_marks();
1450
1451 ShenandoahRootProcessor rp(this, 1);
1452 rp.process_all_roots(cl, NULL, &cldCl, &blobsCl, 0);
1453 }
1454
1455 void ShenandoahHeap::verify_evacuation(ShenandoahHeapRegion* from_region) {
1456
1457 VerifyEvacuationClosure rootsCl(from_region);
1458 roots_iterate(&rootsCl);
1459
1460 }
1461
1462 bool ShenandoahHeap::supports_tlab_allocation() const {
1463 return true;
1464 }
1465
1466
1467 size_t ShenandoahHeap::unsafe_max_tlab_alloc(Thread *thread) const {
1468 size_t idx = _free_regions->current_index();
1469 ShenandoahHeapRegion* current = _free_regions->get(idx);
1470 if (current == NULL) {
1471 return 0;
1472 } else if (current->free() > MinTLABSize) {
1473 // Current region has enough space left, can use it.
1474 return current->free();
1475 } else {
1476 // No more space in current region, we will take next free region
1477 // on the next TLAB allocation.
1478 return ShenandoahHeapRegion::RegionSizeBytes;
1479 }
1480 }
1481
1482 size_t ShenandoahHeap::max_tlab_size() const {
1483 return ShenandoahHeapRegion::RegionSizeBytes;
1484 }
1485
1486 class ResizeGCLABClosure : public ThreadClosure {
1487 public:
1488 void do_thread(Thread* thread) {
1489 thread->gclab().resize();
1490 }
1491 };
1492
1493 void ShenandoahHeap::resize_all_tlabs() {
1494 CollectedHeap::resize_all_tlabs();
1495
1496 ResizeGCLABClosure cl;
1497 Threads::threads_do(&cl);
1498 }
1499
1500 class AccumulateStatisticsGCLABClosure : public ThreadClosure {
1501 public:
1502 void do_thread(Thread* thread) {
1503 thread->gclab().accumulate_statistics();
1504 thread->gclab().initialize_statistics();
1505 }
1506 };
1507
1508 void ShenandoahHeap::accumulate_statistics_all_gclabs() {
1509 AccumulateStatisticsGCLABClosure cl;
1510 Threads::threads_do(&cl);
1511 }
1512
1513 bool ShenandoahHeap::can_elide_tlab_store_barriers() const {
1514 return true;
1515 }
1516
1517 oop ShenandoahHeap::new_store_pre_barrier(JavaThread* thread, oop new_obj) {
1518 // Overridden to do nothing.
1519 return new_obj;
1520 }
1521
1522 bool ShenandoahHeap::can_elide_initializing_store_barrier(oop new_obj) {
1523 return true;
1524 }
1525
1526 bool ShenandoahHeap::card_mark_must_follow_store() const {
1527 return false;
1528 }
1529
1530 void ShenandoahHeap::collect(GCCause::Cause cause) {
1531 assert(cause != GCCause::_gc_locker, "no JNI critical callback");
1532 if (GCCause::is_user_requested_gc(cause)) {
1533 if (! DisableExplicitGC) {
1534 _concurrent_gc_thread->do_full_gc(cause);
1535 }
1536 } else if (cause == GCCause::_allocation_failure) {
1537 collector_policy()->set_should_clear_all_soft_refs(true);
1538 _concurrent_gc_thread->do_full_gc(cause);
1539 }
1540 }
1541
1542 void ShenandoahHeap::do_full_collection(bool clear_all_soft_refs) {
1543 //assert(false, "Shouldn't need to do full collections");
1544 }
1545
1546 AdaptiveSizePolicy* ShenandoahHeap::size_policy() {
1547 Unimplemented();
1548 return NULL;
1549
1550 }
1551
1552 CollectorPolicy* ShenandoahHeap::collector_policy() const {
1553 return _shenandoah_policy;
1554 }
1555
1556
1557 HeapWord* ShenandoahHeap::block_start(const void* addr) const {
1558 Space* sp = heap_region_containing(addr);
1559 if (sp != NULL) {
1560 return sp->block_start(addr);
1561 }
1562 return NULL;
1563 }
1564
1565 size_t ShenandoahHeap::block_size(const HeapWord* addr) const {
1566 Space* sp = heap_region_containing(addr);
1567 assert(sp != NULL, "block_size of address outside of heap");
1568 return sp->block_size(addr);
1569 }
1570
1571 bool ShenandoahHeap::block_is_obj(const HeapWord* addr) const {
1572 Space* sp = heap_region_containing(addr);
1573 return sp->block_is_obj(addr);
1574 }
1575
1576 jlong ShenandoahHeap::millis_since_last_gc() {
1577 return 0;
1578 }
1579
1580 void ShenandoahHeap::prepare_for_verify() {
1581 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
1582 ensure_parsability(false);
1583 }
1584 }
1585
1586 void ShenandoahHeap::print_gc_threads_on(outputStream* st) const {
1587 workers()->print_worker_threads_on(st);
1588 }
1589
1590 void ShenandoahHeap::gc_threads_do(ThreadClosure* tcl) const {
1591 workers()->threads_do(tcl);
1592 }
1593
1594 void ShenandoahHeap::print_tracing_info() const {
1595 if (log_is_enabled(Info, gc, stats)) {
1596 ResourceMark rm;
1597 outputStream* out = Log(gc, stats)::info_stream();
1598 _shenandoah_policy->print_tracing_info(out);
1599 }
1600 }
1601
1602 class ShenandoahVerifyRootsClosure: public ExtendedOopClosure {
1603 private:
1604 ShenandoahHeap* _heap;
1605 VerifyOption _vo;
1606 bool _failures;
1607 public:
1608 // _vo == UsePrevMarking -> use "prev" marking information,
1609 // _vo == UseNextMarking -> use "next" marking information,
1610 // _vo == UseMarkWord -> use mark word from object header.
1611 ShenandoahVerifyRootsClosure(VerifyOption vo) :
1612 _heap(ShenandoahHeap::heap()),
1613 _vo(vo),
1614 _failures(false) { }
1615
1616 bool failures() { return _failures; }
1617
1618 private:
1619 template <class T>
1620 inline void do_oop_work(T* p) {
1621 oop obj = oopDesc::load_decode_heap_oop(p);
1622 if (! oopDesc::is_null(obj) && ! obj->is_oop()) {
1623 { // Just for debugging.
1624 tty->print_cr("Root location "PTR_FORMAT
1625 "verified "PTR_FORMAT, p2i(p), p2i((void*) obj));
1626 // obj->print_on(tty);
1627 }
1628 }
1629 guarantee(obj->is_oop_or_null(), "is oop or null");
1630 }
1631
1632 public:
1633 void do_oop(oop* p) {
1634 do_oop_work(p);
1635 }
1636
1637 void do_oop(narrowOop* p) {
1638 do_oop_work(p);
1639 }
1640
1641 };
1642
1643 class ShenandoahVerifyHeapClosure: public ObjectClosure {
1644 private:
1645 ShenandoahVerifyRootsClosure _rootsCl;
1646 public:
1647 ShenandoahVerifyHeapClosure(ShenandoahVerifyRootsClosure rc) :
1648 _rootsCl(rc) {};
1649
1650 void do_object(oop p) {
1651 _rootsCl.do_oop(&p);
1652 }
1653 };
1654
1655 class ShenandoahVerifyKlassClosure: public KlassClosure {
1656 OopClosure *_oop_closure;
1657 public:
1658 ShenandoahVerifyKlassClosure(OopClosure* cl) : _oop_closure(cl) {}
1659 void do_klass(Klass* k) {
1660 k->oops_do(_oop_closure);
1661 }
1662 };
1663
1664 void ShenandoahHeap::verify(VerifyOption vo) {
1665 if (SafepointSynchronize::is_at_safepoint() || ! UseTLAB) {
1666
1667 ShenandoahVerifyRootsClosure rootsCl(vo);
1668
1669 assert(Thread::current()->is_VM_thread(),
1670 "Expected to be executed serially by the VM thread at this point");
1671
1672 roots_iterate(&rootsCl);
1673
1674 bool failures = rootsCl.failures();
1675 log_trace(gc)("verify failures: %s", BOOL_TO_STR(failures));
1676
1677 ShenandoahVerifyHeapClosure heapCl(rootsCl);
1678
1679 object_iterate(&heapCl);
1680 // TODO: Implement rest of it.
1681 } else {
1682 tty->print("(SKIPPING roots, heapRegions, remset) ");
1683 }
1684 }
1685 size_t ShenandoahHeap::tlab_capacity(Thread *thr) const {
1686 return _free_regions->capacity();
1687 }
1688
1689 class ShenandoahIterateObjectClosureRegionClosure: public ShenandoahHeapRegionClosure {
1690 ObjectClosure* _cl;
1691 public:
1692 ShenandoahIterateObjectClosureRegionClosure(ObjectClosure* cl) : _cl(cl) {}
1693 bool doHeapRegion(ShenandoahHeapRegion* r) {
1694 ShenandoahHeap::heap()->marked_object_iterate(r, _cl);
1695 return false;
1696 }
1697 };
1698
1699 void ShenandoahHeap::object_iterate(ObjectClosure* cl) {
1700 ShenandoahIterateObjectClosureRegionClosure blk(cl);
1701 heap_region_iterate(&blk, false, true);
1702 }
1703
1704 class ShenandoahSafeObjectIterateAdjustPtrsClosure : public MetadataAwareOopClosure {
1705 private:
1706 ShenandoahHeap* _heap;
1707
1708 public:
1709 ShenandoahSafeObjectIterateAdjustPtrsClosure() : _heap(ShenandoahHeap::heap()) {}
1710
1711 private:
1712 template <class T>
1713 inline void do_oop_work(T* p) {
1714 T o = oopDesc::load_heap_oop(p);
1715 if (!oopDesc::is_null(o)) {
1716 oop obj = oopDesc::decode_heap_oop_not_null(o);
1717 oopDesc::encode_store_heap_oop(p, BrooksPointer::forwardee(obj));
1718 }
1719 }
1720 public:
1721 void do_oop(oop* p) {
1722 do_oop_work(p);
1723 }
1724 void do_oop(narrowOop* p) {
1725 do_oop_work(p);
1726 }
1727 };
1728
1729 class ShenandoahSafeObjectIterateAndUpdate : public ObjectClosure {
1730 private:
1731 ObjectClosure* _cl;
1732 public:
1733 ShenandoahSafeObjectIterateAndUpdate(ObjectClosure *cl) : _cl(cl) {}
1734
1735 virtual void do_object(oop obj) {
1736 assert (oopDesc::unsafe_equals(obj, BrooksPointer::forwardee(obj)),
1737 "avoid double-counting: only non-forwarded objects here");
1738
1739 // Fix up the ptrs.
1740 ShenandoahSafeObjectIterateAdjustPtrsClosure adjust_ptrs;
1741 obj->oop_iterate(&adjust_ptrs);
1742
1743 // Can reply the object now:
1744 _cl->do_object(obj);
1745 }
1746 };
1747
1748 void ShenandoahHeap::safe_object_iterate(ObjectClosure* cl) {
1749 assert(SafepointSynchronize::is_at_safepoint(), "safe iteration is only available during safepoints");
1750
1751 // Safe iteration does objects only with correct references.
1752 // This is why we skip dirty regions that have stale copies of objects,
1753 // and fix up the pointers in the returned objects.
1754
1755 ShenandoahSafeObjectIterateAndUpdate safe_cl(cl);
1756 ShenandoahIterateObjectClosureRegionClosure blk(&safe_cl);
1757 heap_region_iterate(&blk,
1758 /* skip_dirty_regions = */ true,
1759 /* skip_humongous_continuations = */ true);
1760
1761 _need_update_refs = false; // already updated the references
1762 }
1763
1764 // Apply blk->doHeapRegion() on all committed regions in address order,
1765 // terminating the iteration early if doHeapRegion() returns true.
1766 void ShenandoahHeap::heap_region_iterate(ShenandoahHeapRegionClosure* blk, bool skip_dirty_regions, bool skip_humongous_continuation) const {
1767 for (size_t i = 0; i < _num_regions; i++) {
1768 ShenandoahHeapRegion* current = _ordered_regions->get(i);
1769 if (skip_humongous_continuation && current->is_humongous_continuation()) {
1770 continue;
1771 }
1772 if (skip_dirty_regions && in_collection_set(current)) {
1773 continue;
1774 }
1775 if (blk->doHeapRegion(current)) {
1776 return;
1777 }
1778 }
1779 }
1780
1781 class ClearLivenessClosure : public ShenandoahHeapRegionClosure {
1782 ShenandoahHeap* sh;
1783 public:
1784 ClearLivenessClosure(ShenandoahHeap* heap) : sh(heap) { }
1785
1786 bool doHeapRegion(ShenandoahHeapRegion* r) {
1787 r->clear_live_data();
1788 sh->set_next_top_at_mark_start(r->bottom(), r->top());
1789 return false;
1790 }
1791 };
1792
1793 void ShenandoahHeap::start_concurrent_marking() {
1794
1795 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::accumulate_stats);
1796 accumulate_statistics_all_tlabs();
1797 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::accumulate_stats);
1798
1799 set_concurrent_mark_in_progress(true);
1800 // We need to reset all TLABs because we'd lose marks on all objects allocated in them.
1801 if (UseTLAB) {
1802 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::make_parsable);
1803 ensure_parsability(true);
1804 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::make_parsable);
1805 }
1806
1807 _shenandoah_policy->record_bytes_allocated(_bytes_allocated_since_cm);
1808 _used_start_gc = used();
1809
1810 #ifdef ASSERT
1811 if (ShenandoahDumpHeapBeforeConcurrentMark) {
1812 ensure_parsability(false);
1813 print_all_refs("pre-mark");
1814 }
1815 #endif
1816
1817 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::clear_liveness);
1818 ClearLivenessClosure clc(this);
1819 heap_region_iterate(&clc);
1820 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::clear_liveness);
1821
1822 if (UseShenandoahMatrix) {
1823 connection_matrix()->clear_all();
1824 }
1825 // print_all_refs("pre -mark");
1826
1827 // oopDesc::_debug = true;
1828
1829 // Make above changes visible to worker threads
1830 OrderAccess::fence();
1831
1832 shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::scan_roots);
1833 concurrentMark()->init_mark_roots();
1834 shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::scan_roots);
1835
1836 // print_all_refs("pre-mark2");
1837 }
1838
1839 class VerifyAfterEvacuationClosure : public ExtendedOopClosure {
1840
1841 ShenandoahHeap* _sh;
1842
1843 public:
1844 VerifyAfterEvacuationClosure() : _sh ( ShenandoahHeap::heap() ) {}
1845
1846 template<class T> void do_oop_nv(T* p) {
1847 T heap_oop = oopDesc::load_heap_oop(p);
1848 if (!oopDesc::is_null(heap_oop)) {
1849 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
1850 guarantee(_sh->in_collection_set(obj) == (! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))),
1851 "forwarded objects can only exist in dirty (from-space) regions is_dirty: %s, is_forwarded: %s obj-klass: %s, marked: %s",
1852 BOOL_TO_STR(_sh->in_collection_set(obj)),
1853 BOOL_TO_STR(! oopDesc::unsafe_equals(obj, oopDesc::bs()->read_barrier(obj))),
1854 obj->klass()->external_name(),
1855 BOOL_TO_STR(_sh->is_marked_complete(obj))
1856 );
1857 obj = oopDesc::bs()->read_barrier(obj);
1858 guarantee(! _sh->in_collection_set(obj), "forwarded oops must not point to dirty regions");
1859 guarantee(obj->is_oop(), "is_oop");
1860 guarantee(Metaspace::contains(obj->klass()), "klass pointer must go to metaspace");
1861 }
1862 }
1863
1864 void do_oop(oop* p) { do_oop_nv(p); }
1865 void do_oop(narrowOop* p) { do_oop_nv(p); }
1866
1867 };
1868
1869 void ShenandoahHeap::verify_heap_after_evacuation() {
1870
1871 verify_heap_size_consistency();
1872
1873 ensure_parsability(false);
1874
1875 VerifyAfterEvacuationClosure cl;
1876 roots_iterate(&cl);
1877
1878 ObjectToOopClosure objs(&cl);
1879 object_iterate(&objs);
1880
1881 }
1882
1883 class VerifyRegionsAfterUpdateRefsClosure : public ShenandoahHeapRegionClosure {
1884 public:
1885 bool doHeapRegion(ShenandoahHeapRegion* r) {
1886 assert(! ShenandoahHeap::heap()->in_collection_set(r), "no region must be in collection set");
1887 return false;
1888 }
1889 };
1890
1891 void ShenandoahHeap::swap_mark_bitmaps() {
1892 // Swap bitmaps.
1893 CMBitMap* tmp1 = _complete_mark_bit_map;
1894 _complete_mark_bit_map = _next_mark_bit_map;
1895 _next_mark_bit_map = tmp1;
1896
1897 // Swap top-at-mark-start pointers
1898 HeapWord** tmp2 = _complete_top_at_mark_starts;
1899 _complete_top_at_mark_starts = _next_top_at_mark_starts;
1900 _next_top_at_mark_starts = tmp2;
1901
1902 HeapWord** tmp3 = _complete_top_at_mark_starts_base;
1903 _complete_top_at_mark_starts_base = _next_top_at_mark_starts_base;
1904 _next_top_at_mark_starts_base = tmp3;
1905 }
1906
1907 class ShenandoahVerifyMatrixOopClosure : public ExtendedOopClosure {
1908 private:
1909 oop _obj;
1910
1911 template <class T>
1912 inline void do_oop_nv(T* p) {
1913 T o = oopDesc::load_heap_oop(p);
1914 if (! oopDesc::is_null(o)) {
1915 oop obj = oopDesc::decode_heap_oop_not_null(o);
1916 ShenandoahHeap* heap = ShenandoahHeap::heap();
1917 guarantee(heap->is_marked_complete(obj), "must be marked");
1918
1919 uint from_idx = heap->heap_region_index_containing(p);
1920 uint to_idx = heap->heap_region_index_containing(obj);
1921 if (!heap->connection_matrix()->is_connected(from_idx, to_idx)) {
1922 tty->print_cr("from-obj: ");
1923 _obj->print_on(tty);
1924 tty->print_cr("to-obj:");
1925 obj->print_on(tty);
1926 tty->print_cr("from-obj allocated after mark: %s", BOOL_TO_STR(heap->allocated_after_complete_mark_start((HeapWord*) _obj)));
1927 tty->print_cr("to-obj allocated after mark: %s", BOOL_TO_STR(heap->allocated_after_complete_mark_start((HeapWord*) obj)));
1928 tty->print_cr("from-obj marked: %s", BOOL_TO_STR(heap->is_marked_complete(_obj)));
1929 tty->print_cr("to-obj marked: %s", BOOL_TO_STR(heap->is_marked_complete(obj)));
1930 tty->print_cr("from-idx: %u, to-idx: %u", from_idx, to_idx);
1931
1932 oop fwd_from = BrooksPointer::forwardee(_obj);
1933 oop fwd_to = BrooksPointer::forwardee(obj);
1934 tty->print_cr("from-obj forwardee: " PTR_FORMAT, p2i(fwd_from));
1935 tty->print_cr("to-obj forwardee: " PTR_FORMAT, p2i(fwd_to));
1936 tty->print_cr("forward(from-obj) marked: %s", BOOL_TO_STR(heap->is_marked_complete(fwd_from)));
1937 tty->print_cr("forward(to-obj) marked: %s", BOOL_TO_STR(heap->is_marked_complete(fwd_to)));
1938 uint fwd_from_idx = heap->heap_region_index_containing(fwd_from);
1939 uint fwd_to_idx = heap->heap_region_index_containing(fwd_to);
1940 tty->print_cr("forward(from-idx): %u, forward(to-idx): %u", fwd_from_idx, fwd_to_idx);
1941 tty->print_cr("forward(from) connected with forward(to)? %s", BOOL_TO_STR(heap->connection_matrix()->is_connected(fwd_from_idx, fwd_to_idx)));
1942 tty->print_cr("sizeof(bool): %lu", sizeof(bool));
1943 }
1944 guarantee(oopDesc::unsafe_equals(ShenandoahBarrierSet::resolve_oop_static_not_null(obj), obj), "polizeilich verboten");
1945 guarantee(heap->connection_matrix()->is_connected(from_idx, to_idx), "must be connected");
1946 }
1947 }
1948
1949 public:
1950 ShenandoahVerifyMatrixOopClosure(oop obj) : _obj(obj) {}
1951
1952 void do_oop(oop* o) {
1953 do_oop_nv(o);
1954 }
1955
1956 void do_oop(narrowOop* o) {
1957 do_oop_nv(o);
1958 }
1959 };
1960
1961 class ShenandoahVerifyMatrixObjectClosure : public ObjectClosure {
1962 public:
1963 void do_object(oop obj) {
1964 guarantee(ShenandoahHeap::heap()->is_marked_complete(obj), "must be marked");
1965 ShenandoahVerifyMatrixOopClosure cl(obj);
1966 obj->oop_iterate(&cl);
1967 }
1968
1969 };
1970
1971 class ShenandoahVerifyMatrixRegionClosure : public ShenandoahHeapRegionClosure {
1972 bool doHeapRegion(ShenandoahHeapRegion* r) {
1973 ShenandoahVerifyMatrixObjectClosure cl;
1974 ShenandoahHeap::heap()->marked_object_iterate(r, &cl);
1975 return false;
1976 }
1977 };
1978
1979 void ShenandoahHeap::verify_matrix() {
1980 OrderAccess::fence();
1981 ensure_parsability(false);
1982 ShenandoahVerifyMatrixRegionClosure cl;
1983 heap_region_iterate(&cl, true, true);
1984 }
1985
1986 void ShenandoahHeap::stop_concurrent_marking() {
1987 assert(concurrent_mark_in_progress(), "How else could we get here?");
1988 if (! cancelled_concgc()) {
1989 // If we needed to update refs, and concurrent marking has been cancelled,
1990 // we need to finish updating references.
1991 set_need_update_refs(false);
1992 swap_mark_bitmaps();
1993 }
1994 set_concurrent_mark_in_progress(false);
1995
1996 if (log_is_enabled(Trace, gc, region)) {
1997 ResourceMark rm;
1998 outputStream* out = Log(gc, region)::trace_stream();
1999 print_heap_regions(out);
2000 }
2001
2002 }
2003
2004 void ShenandoahHeap::set_concurrent_mark_in_progress(bool in_progress) {
2005 _concurrent_mark_in_progress = in_progress ? 1 : 0;
2006 JavaThread::satb_mark_queue_set().set_active_all_threads(in_progress, !in_progress);
2007 }
2008
2009 void ShenandoahHeap::set_evacuation_in_progress_concurrently(bool in_progress) {
2010 // Note: it is important to first release the _evacuation_in_progress flag here,
2011 // so that Java threads can get out of oom_during_evacuation() and reach a safepoint,
2012 // in case a VM task is pending.
2013 set_evacuation_in_progress(in_progress);
2014 MutexLocker mu(Threads_lock);
2015 JavaThread::set_evacuation_in_progress_all_threads(in_progress);
2016 }
2017
2018 void ShenandoahHeap::set_evacuation_in_progress_at_safepoint(bool in_progress) {
2019 assert(SafepointSynchronize::is_at_safepoint(), "Only call this at safepoint");
2020 set_evacuation_in_progress(in_progress);
2021 JavaThread::set_evacuation_in_progress_all_threads(in_progress);
2022 }
2023
2024 void ShenandoahHeap::set_evacuation_in_progress(bool in_progress) {
2025 _evacuation_in_progress = in_progress ? 1 : 0;
2026 OrderAccess::fence();
2027 }
2028
2029 void ShenandoahHeap::verify_copy(oop p,oop c){
2030 assert(! oopDesc::unsafe_equals(p, oopDesc::bs()->read_barrier(p)), "forwarded correctly");
2031 assert(oopDesc::unsafe_equals(oopDesc::bs()->read_barrier(p), c), "verify pointer is correct");
2032 if (p->klass() != c->klass()) {
2033 print_heap_regions();
2034 }
2035 assert(p->klass() == c->klass(), "verify class p-size: "INT32_FORMAT" c-size: "INT32_FORMAT, p->size(), c->size());
2036 assert(p->size() == c->size(), "verify size");
2037 // Object may have been locked between copy and verification
2038 // assert(p->mark() == c->mark(), "verify mark");
2039 assert(oopDesc::unsafe_equals(c, oopDesc::bs()->read_barrier(c)), "verify only forwarded once");
2040 }
2041
2042 void ShenandoahHeap::oom_during_evacuation() {
2043 log_develop_trace(gc)("Out of memory during evacuation, cancel evacuation, schedule full GC by thread %d",
2044 Thread::current()->osthread()->thread_id());
2045
2046 // We ran out of memory during evacuation. Cancel evacuation, and schedule a full-GC.
2047 collector_policy()->set_should_clear_all_soft_refs(true);
2048 concurrent_thread()->try_set_full_gc();
2049 cancel_concgc(_oom_evacuation);
2050
2051 if ((! Thread::current()->is_GC_task_thread()) && (! Thread::current()->is_ConcurrentGC_thread())) {
2052 assert(! Threads_lock->owned_by_self()
2053 || SafepointSynchronize::is_at_safepoint(), "must not hold Threads_lock here");
2054 log_warning(gc)("OOM during evacuation. Let Java thread wait until evacuation finishes.");
2055 while (_evacuation_in_progress) { // wait.
2056 Thread::current()->_ParkEvent->park(1);
2057 }
2058 }
2059
2060 }
2061
2062 HeapWord* ShenandoahHeap::tlab_post_allocation_setup(HeapWord* obj) {
2063 // Initialize Brooks pointer for the next object
2064 HeapWord* result = obj + BrooksPointer::word_size();
2065 BrooksPointer::initialize(oop(result));
2066 return result;
2067 }
2068
2069 uint ShenandoahHeap::oop_extra_words() {
2070 return BrooksPointer::word_size();
2071 }
2072
2073 void ShenandoahHeap::grow_heap_by(size_t num_regions) {
2074 size_t base = _num_regions;
2075 ensure_new_regions(num_regions);
2076 for (size_t i = 0; i < num_regions; i++) {
2077 size_t new_region_index = i + base;
2078 HeapWord* start = _first_region_bottom + (ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize) * new_region_index;
2079 ShenandoahHeapRegion* new_region = new ShenandoahHeapRegion(this, start, ShenandoahHeapRegion::RegionSizeBytes / HeapWordSize, new_region_index);
2080
2081 if (log_is_enabled(Trace, gc, region)) {
2082 ResourceMark rm;
2083 outputStream* out = Log(gc, region)::trace_stream();
2084 out->print_cr("allocating new region at index: "SIZE_FORMAT, new_region_index);
2085 new_region->print_on(out);
2086 }
2087
2088 assert(_ordered_regions->active_regions() == new_region->region_number(), "must match");
2089 _ordered_regions->add_region(new_region);
2090 _in_cset_fast_test_base[new_region_index] = false; // Not in cset
2091 _next_top_at_mark_starts_base[new_region_index] = new_region->bottom();
2092 _complete_top_at_mark_starts_base[new_region_index] = new_region->bottom();
2093
2094 _free_regions->add_region(new_region);
2095 }
2096 }
2097
2098 void ShenandoahHeap::ensure_new_regions(size_t new_regions) {
2099
2100 size_t num_regions = _num_regions;
2101 size_t new_num_regions = num_regions + new_regions;
2102 assert(new_num_regions <= _max_regions, "we checked this earlier");
2103
2104 size_t expand_size = new_regions * ShenandoahHeapRegion::RegionSizeBytes;
2105 log_trace(gc, region)("expanding storage by "SIZE_FORMAT_HEX" bytes, for "SIZE_FORMAT" new regions", expand_size, new_regions);
2106 bool success = _storage.expand_by(expand_size, ShenandoahAlwaysPreTouch);
2107 assert(success, "should always be able to expand by requested size");
2108
2109 _num_regions = new_num_regions;
2110
2111 }
2112
2113 ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() :
2114 _heap(ShenandoahHeap::heap_no_check()) {
2115 }
2116
2117 void ShenandoahForwardedIsAliveClosure::init(ShenandoahHeap* heap) {
2118 _heap = heap;
2119 }
2120
2121 bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) {
2122
2123 assert(_heap != NULL, "sanity");
2124 obj = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
2125 #ifdef ASSERT
2126 if (_heap->concurrent_mark_in_progress()) {
2127 assert(oopDesc::unsafe_equals(obj, ShenandoahBarrierSet::resolve_oop_static_not_null(obj)), "only query to-space");
2128 }
2129 #endif
2130 assert(!oopDesc::is_null(obj), "null");
2131 return _heap->is_marked_next(obj);
2132 }
2133
2134 void ShenandoahHeap::ref_processing_init() {
2135 MemRegion mr = reserved_region();
2136
2137 isAlive.init(ShenandoahHeap::heap());
2138 assert(_max_workers > 0, "Sanity");
2139
2140 _ref_processor =
2141 new ReferenceProcessor(mr, // span
2142 ParallelRefProcEnabled,
2143 // mt processing
2144 _max_workers,
2145 // degree of mt processing
2146 true,
2147 // mt discovery
2148 _max_workers,
2149 // degree of mt discovery
2150 false,
2151 // Reference discovery is not atomic
2152 &isAlive);
2153 }
2154
2155 #ifdef ASSERT
2156 void ShenandoahHeap::set_from_region_protection(bool protect) {
2157 for (uint i = 0; i < _num_regions; i++) {
2158 ShenandoahHeapRegion* region = _ordered_regions->get(i);
2159 if (region != NULL && in_collection_set(region)) {
2160 if (protect) {
2161 region->memProtectionOn();
2162 } else {
2163 region->memProtectionOff();
2164 }
2165 }
2166 }
2167 }
2168 #endif
2169
2170 size_t ShenandoahHeap::num_regions() {
2171 return _num_regions;
2172 }
2173
2174 size_t ShenandoahHeap::max_regions() {
2175 return _max_regions;
2176 }
2177
2178 GCTracer* ShenandoahHeap::tracer() {
2179 return shenandoahPolicy()->tracer();
2180 }
2181
2182 size_t ShenandoahHeap::tlab_used(Thread* thread) const {
2183 return _free_regions->used();
2184 }
2185
2186 void ShenandoahHeap::cancel_concgc(GCCause::Cause cause) {
2187 if (try_cancel_concgc()) {
2188 log_info(gc)("Cancelling concurrent GC: %s", GCCause::to_string(cause));
2189 _shenandoah_policy->report_concgc_cancelled();
2190 }
2191 }
2192
2193 void ShenandoahHeap::cancel_concgc(ShenandoahCancelCause cause) {
2194 if (try_cancel_concgc()) {
2195 log_info(gc)("Cancelling concurrent GC: %s", cancel_cause_to_string(cause));
2196 _shenandoah_policy->report_concgc_cancelled();
2197 }
2198 }
2199
2200 const char* ShenandoahHeap::cancel_cause_to_string(ShenandoahCancelCause cause) {
2201 switch (cause) {
2202 case _oom_evacuation:
2203 return "Out of memory for evacuation";
2204 case _vm_stop:
2205 return "Stopping VM";
2206 default:
2207 return "Unknown";
2208 }
2209 }
2210
2211 void ShenandoahHeap::clear_cancelled_concgc() {
2212 set_cancelled_concgc(false);
2213 }
2214
2215 uint ShenandoahHeap::max_workers() {
2216 return _max_workers;
2217 }
2218
2219 void ShenandoahHeap::stop() {
2220 // The shutdown sequence should be able to terminate when GC is running.
2221
2222 // Step 1. Notify control thread that we are in shutdown.
2223 // Note that we cannot do that with stop(), because stop() is blocking and waits for the actual shutdown.
2224 // Doing stop() here would wait for the normal GC cycle to complete, never falling through to cancel below.
2225 _concurrent_gc_thread->prepare_for_graceful_shutdown();
2226
2227 // Step 2. Notify GC workers that we are cancelling GC.
2228 cancel_concgc(_vm_stop);
2229
2230 // Step 3. Wait until GC worker exits normally.
2231 _concurrent_gc_thread->stop();
2232 }
2233
2234 void ShenandoahHeap::unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool process_strings, bool process_symbols) {
2235
2236 StringSymbolTableUnlinkTask shenandoah_unlink_task(is_alive, process_strings, process_symbols);
2237 workers()->run_task(&shenandoah_unlink_task);
2238
2239 // if (G1StringDedup::is_enabled()) {
2240 // G1StringDedup::unlink(is_alive);
2241 // }
2242 }
2243
2244 void ShenandoahHeap::set_need_update_refs(bool need_update_refs) {
2245 _need_update_refs = need_update_refs;
2246 }
2247
2248 //fixme this should be in heapregionset
2249 ShenandoahHeapRegion* ShenandoahHeap::next_compaction_region(const ShenandoahHeapRegion* r) {
2250 size_t region_idx = r->region_number() + 1;
2251 ShenandoahHeapRegion* next = _ordered_regions->get(region_idx);
2252 guarantee(next->region_number() == region_idx, "region number must match");
2253 while (next->is_humongous()) {
2254 region_idx = next->region_number() + 1;
2255 next = _ordered_regions->get(region_idx);
2256 guarantee(next->region_number() == region_idx, "region number must match");
2257 }
2258 return next;
2259 }
2260
2261 void ShenandoahHeap::set_region_in_collection_set(size_t region_index, bool b) {
2262 _in_cset_fast_test_base[region_index] = b;
2263 }
2264
2265 ShenandoahMonitoringSupport* ShenandoahHeap::monitoring_support() {
2266 return _monitoring_support;
2267 }
2268
2269 CMBitMap* ShenandoahHeap::complete_mark_bit_map() {
2270 return _complete_mark_bit_map;
2271 }
2272
2273 CMBitMap* ShenandoahHeap::next_mark_bit_map() {
2274 return _next_mark_bit_map;
2275 }
2276
2277 void ShenandoahHeap::add_free_region(ShenandoahHeapRegion* r) {
2278 _free_regions->add_region(r);
2279 }
2280
2281 void ShenandoahHeap::clear_free_regions() {
2282 _free_regions->clear();
2283 }
2284
2285 address ShenandoahHeap::in_cset_fast_test_addr() {
2286 return (address) (ShenandoahHeap::heap()->_in_cset_fast_test);
2287 }
2288
2289 address ShenandoahHeap::cancelled_concgc_addr() {
2290 return (address) &(ShenandoahHeap::heap()->_cancelled_concgc);
2291 }
2292
2293 void ShenandoahHeap::clear_cset_fast_test() {
2294 assert(_in_cset_fast_test_base != NULL, "sanity");
2295 memset(_in_cset_fast_test_base, false,
2296 _in_cset_fast_test_length * sizeof(bool));
2297 }
2298
2299 size_t ShenandoahHeap::conservative_max_heap_alignment() {
2300 return ShenandoahMaxRegionSize;
2301 }
2302
2303 size_t ShenandoahHeap::bytes_allocated_since_cm() {
2304 return _bytes_allocated_since_cm;
2305 }
2306
2307 void ShenandoahHeap::set_bytes_allocated_since_cm(size_t bytes) {
2308 _bytes_allocated_since_cm = bytes;
2309 }
2310
2311 size_t ShenandoahHeap::max_allocated_gc() {
2312 return _max_allocated_gc;
2313 }
2314
2315 void ShenandoahHeap::set_next_top_at_mark_start(HeapWord* region_base, HeapWord* addr) {
2316 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2317 _next_top_at_mark_starts[index] = addr;
2318 }
2319
2320 HeapWord* ShenandoahHeap::next_top_at_mark_start(HeapWord* region_base) {
2321 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2322 return _next_top_at_mark_starts[index];
2323 }
2324
2325 void ShenandoahHeap::set_complete_top_at_mark_start(HeapWord* region_base, HeapWord* addr) {
2326 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2327 _complete_top_at_mark_starts[index] = addr;
2328 }
2329
2330 HeapWord* ShenandoahHeap::complete_top_at_mark_start(HeapWord* region_base) {
2331 uintx index = ((uintx) region_base) >> ShenandoahHeapRegion::RegionSizeShift;
2332 return _complete_top_at_mark_starts[index];
2333 }
2334
2335 void ShenandoahHeap::set_full_gc_in_progress(bool in_progress) {
2336 _full_gc_in_progress = in_progress;
2337 }
2338
2339 bool ShenandoahHeap::is_full_gc_in_progress() const {
2340 return _full_gc_in_progress;
2341 }
2342
2343 class NMethodOopInitializer : public OopClosure {
2344 private:
2345 ShenandoahHeap* _heap;
2346 public:
2347 NMethodOopInitializer() : _heap(ShenandoahHeap::heap()) {
2348 }
2349
2350 private:
2351 template <class T>
2352 inline void do_oop_work(T* p) {
2353 T o = oopDesc::load_heap_oop(p);
2354 if (! oopDesc::is_null(o)) {
2355 oop obj1 = oopDesc::decode_heap_oop_not_null(o);
2356 oop obj2 = oopDesc::bs()->write_barrier(obj1);
2357 if (! oopDesc::unsafe_equals(obj1, obj2)) {
2358 oopDesc::encode_store_heap_oop(p, obj2);
2359 }
2360 }
2361 }
2362
2363 public:
2364 void do_oop(oop* o) {
2365 do_oop_work(o);
2366 }
2367 void do_oop(narrowOop* o) {
2368 do_oop_work(o);
2369 }
2370 };
2371
2372 void ShenandoahHeap::register_nmethod(nmethod* nm) {
2373 NMethodOopInitializer init;
2374 nm->oops_do(&init);
2375 nm->fix_oop_relocations();
2376 }
2377
2378 void ShenandoahHeap::unregister_nmethod(nmethod* nm) {
2379 }
2380
2381 void ShenandoahHeap::pin_object(oop o) {
2382 heap_region_containing(o)->pin();
2383 }
2384
2385 void ShenandoahHeap::unpin_object(oop o) {
2386 heap_region_containing(o)->unpin();
2387 }
2388
2389
2390 GCTimer* ShenandoahHeap::gc_timer() const {
2391 return _gc_timer;
2392 }
2393
2394 class RecordAllRefsOopClosure: public ExtendedOopClosure {
2395 private:
2396 int _x;
2397 int *_matrix;
2398 int _num_regions;
2399 oop _p;
2400
2401 public:
2402 RecordAllRefsOopClosure(int *matrix, int x, size_t num_regions, oop p) :
2403 _matrix(matrix), _x(x), _num_regions(num_regions), _p(p) {}
2404
2405 template <class T>
2406 void do_oop_work(T* p) {
2407 oop o = oopDesc::load_decode_heap_oop(p);
2408 if (o != NULL) {
2409 if (ShenandoahHeap::heap()->is_in(o) && o->is_oop() ) {
2410 int y = ShenandoahHeap::heap()->heap_region_containing(o)->region_number();
2411 _matrix[_x * _num_regions + y]++;
2412 }
2413 }
2414 }
2415 void do_oop(oop* p) {
2416 do_oop_work(p);
2417 }
2418
2419 void do_oop(narrowOop* p) {
2420 do_oop_work(p);
2421 }
2422
2423 };
2424
2425 class RecordAllRefsObjectClosure : public ObjectClosure {
2426 int *_matrix;
2427 size_t _num_regions;
2428
2429 public:
2430 RecordAllRefsObjectClosure(int *matrix, size_t num_regions) :
2431 _matrix(matrix), _num_regions(num_regions) {}
2432
2433 void do_object(oop p) {
2434 if (ShenandoahHeap::heap()->is_in(p) && ShenandoahHeap::heap()->is_marked_next(p) && p->is_oop()) {
2435 int x = ShenandoahHeap::heap()->heap_region_containing(p)->region_number();
2436 RecordAllRefsOopClosure cl(_matrix, x, _num_regions, p);
2437 p->oop_iterate(&cl);
2438 }
2439 }
2440 };
2441 void ShenandoahHeap::calculate_matrix(int* connections) {
2442 log_develop_trace(gc)("calculating matrix");
2443 ensure_parsability(false);
2444 int num = num_regions();
2445
2446 for (int i = 0; i < num; i++) {
2447 for (int j = 0; j < num; j++) {
2448 connections[i * num + j] = 0;
2449 }
2450 }
2451
2452 RecordAllRefsOopClosure cl(connections, 0, num, NULL);
2453 roots_iterate(&cl);
2454
2455 RecordAllRefsObjectClosure cl2(connections, num);
2456 object_iterate(&cl2);
2457
2458 }
2459
2460 void ShenandoahHeap::print_matrix(int* connections) {
2461 int num = num_regions();
2462 int cs_regions = 0;
2463 int referenced = 0;
2464
2465 for (int i = 0; i < num; i++) {
2466 size_t liveData = ShenandoahHeap::heap()->regions()->get(i)->get_live_data_bytes();
2467
2468 int numReferencedRegions = 0;
2469 int numReferencedByRegions = 0;
2470
2471 for (int j = 0; j < num; j++) {
2472 if (connections[i * num + j] > 0)
2473 numReferencedRegions++;
2474
2475 if (connections [j * num + i] > 0)
2476 numReferencedByRegions++;
2477
2478 cs_regions++;
2479 referenced += numReferencedByRegions;
2480 }
2481
2482 if (ShenandoahHeap::heap()->regions()->get(i)->has_live()) {
2483 tty->print("Region %d is referenced by %d regions {",
2484 i, numReferencedByRegions);
2485 int col_count = 0;
2486 for (int j = 0; j < num; j++) {
2487 int foo = connections[j * num + i];
2488 if (foo > 0) {
2489 col_count++;
2490 if ((col_count % 10) == 0)
2491 tty->print("\n");
2492 tty->print("%d(%d), ", j,foo);
2493 }
2494 }
2495 tty->print("} \n");
2496 }
2497 }
2498
2499 double avg = (double)referenced / (double) cs_regions;
2500 tty->print("Average Number of regions scanned / region = %lf\n", avg);
2501 }
2502
2503 class ShenandoahCountGarbageClosure : public ShenandoahHeapRegionClosure {
2504 private:
2505 size_t _garbage;
2506 public:
2507 ShenandoahCountGarbageClosure() : _garbage(0) {
2508 }
2509
2510 bool doHeapRegion(ShenandoahHeapRegion* r) {
2511 if (! r->is_humongous() && ! r->is_pinned() && ! r->in_collection_set()) {
2512 _garbage += r->garbage();
2513 }
2514 return false;
2515 }
2516
2517 size_t garbage() {
2518 return _garbage;
2519 }
2520 };
2521
2522 size_t ShenandoahHeap::garbage() {
2523 ShenandoahCountGarbageClosure cl;
2524 heap_region_iterate(&cl);
2525 return cl.garbage();
2526 }
2527
2528 ShenandoahConnectionMatrix* ShenandoahHeap::connection_matrix() {
2529 return _connection_matrix;
2530 }
2531
2532 ShenandoahPartialGC* ShenandoahHeap::partial_gc() {
2533 return _partial_gc;
2534 }
2535
2536 void ShenandoahHeap::do_partial_collection() {
2537 {
2538 ShenandoahHeapLock lock(this);
2539 partial_gc()->prepare();
2540 }
2541 partial_gc()->do_partial_collection();
2542 }
2543
2544 #ifdef ASSERT
2545 void ShenandoahHeap::assert_heaplock_owned_by_current_thread() {
2546 assert(_heap_lock == locked, "must be locked");
2547 assert(_heap_lock_owner == Thread::current(), "must be owned by current thread");
2548 }
2549
2550 void ShenandoahHeap::assert_heaplock_or_safepoint() {
2551 Thread* thr = Thread::current();
2552 assert((_heap_lock == locked && _heap_lock_owner == thr) ||
2553 (SafepointSynchronize::is_at_safepoint() && thr->is_VM_thread()),
2554 "must own heap lock or by VM thread at safepoint");
2555 }
2556
2557 #endif