1 /*
2 * Copyright (c) 2015, 2022, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
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24 */
25
26 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
27 #define SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
28
29 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
30
31 #include "gc/shared/accessBarrierSupport.inline.hpp"
32 #include "gc/shared/cardTable.hpp"
33 #include "gc/shenandoah/mode/shenandoahMode.hpp"
34 #include "gc/shenandoah/shenandoahAsserts.hpp"
35 #include "gc/shenandoah/shenandoahCardTable.hpp"
36 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
37 #include "gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp"
38 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
39 #include "gc/shenandoah/shenandoahGeneration.hpp"
40 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
41 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
42 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
43 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
44 #include "memory/iterator.inline.hpp"
45 #include "oops/oop.inline.hpp"
46
47 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null(oop p) {
48 return ShenandoahForwarding::get_forwardee(p);
49 }
50
51 inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {
52 if (p != nullptr) {
53 return resolve_forwarded_not_null(p);
54 } else {
55 return p;
56 }
57 }
58
59 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null_mutator(oop p) {
60 return ShenandoahForwarding::get_forwardee_mutator(p);
61 }
62
63 template <class T>
64 inline oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, T* load_addr) {
65 assert(ShenandoahLoadRefBarrier, "should be enabled");
66 shenandoah_assert_in_cset(load_addr, obj);
67
68 oop fwd = resolve_forwarded_not_null_mutator(obj);
69 if (obj == fwd) {
70 assert(_heap->is_evacuation_in_progress(), "evac should be in progress");
71 Thread* const t = Thread::current();
72 ShenandoahEvacOOMScope scope(t);
73 fwd = _heap->evacuate_object(obj, t);
74 }
75
76 if (load_addr != nullptr && fwd != obj) {
77 // Since we are here and we know the load address, update the reference.
78 ShenandoahHeap::atomic_update_oop(fwd, load_addr, obj);
79 }
80
81 return fwd;
82 }
83
84 inline oop ShenandoahBarrierSet::load_reference_barrier(oop obj) {
85 if (!ShenandoahLoadRefBarrier) {
86 return obj;
87 }
88 if (_heap->has_forwarded_objects() && _heap->in_collection_set(obj)) {
89 // Subsumes null-check
90 assert(obj != nullptr, "cset check must have subsumed null-check");
91 oop fwd = resolve_forwarded_not_null(obj);
92 if (obj == fwd && _heap->is_evacuation_in_progress()) {
93 Thread* t = Thread::current();
94 ShenandoahEvacOOMScope oom_evac_scope(t);
95 return _heap->evacuate_object(obj, t);
96 }
97 return fwd;
98 }
99 return obj;
100 }
101
102 template <class T>
103 inline oop ShenandoahBarrierSet::load_reference_barrier(DecoratorSet decorators, oop obj, T* load_addr) {
104 if (obj == nullptr) {
105 return nullptr;
106 }
107
108 // Prevent resurrection of unreachable phantom (i.e. weak-native) references.
109 if ((decorators & ON_PHANTOM_OOP_REF) != 0 &&
110 _heap->is_concurrent_weak_root_in_progress() &&
111 _heap->is_in_active_generation(obj) &&
112 !_heap->marking_context()->is_marked(obj)) {
113 return nullptr;
114 }
115
116 // Prevent resurrection of unreachable weak references.
117 if ((decorators & ON_WEAK_OOP_REF) != 0 &&
118 _heap->is_concurrent_weak_root_in_progress() &&
119 _heap->is_in_active_generation(obj) &&
120 !_heap->marking_context()->is_marked_strong(obj)) {
121 return nullptr;
122 }
123
124 // Allow runtime to see unreachable objects that are visited during concurrent class-unloading.
125 if ((decorators & AS_NO_KEEPALIVE) != 0 &&
126 _heap->is_concurrent_weak_root_in_progress() &&
127 !_heap->marking_context()->is_marked(obj)) {
128 return obj;
129 }
130
131 oop fwd = load_reference_barrier(obj);
132 if (load_addr != nullptr && fwd != obj) {
133 // Since we are here and we know the load address, update the reference.
134 ShenandoahHeap::atomic_update_oop(fwd, load_addr, obj);
135 }
136
137 return fwd;
138 }
139
140 inline void ShenandoahBarrierSet::enqueue(oop obj) {
141 assert(obj != nullptr, "checked by caller");
142 assert(_satb_mark_queue_set.is_active(), "only get here when SATB active");
143
144 // Filter marked objects before hitting the SATB queues. The same predicate would
145 // be used by SATBMQ::filter to eliminate already marked objects downstream, but
146 // filtering here helps to avoid wasteful SATB queueing work to begin with.
147 if (!_heap->requires_marking(obj)) return;
148
149 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(Thread::current());
150 _satb_mark_queue_set.enqueue_known_active(queue, obj);
151 }
152
153 template <DecoratorSet decorators, typename T>
154 inline void ShenandoahBarrierSet::satb_barrier(T *field) {
155 // Uninitialized and no-keepalive stores do not need barrier.
156 if (HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value ||
157 HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
158 return;
159 }
160
161 // Stores to weak/phantom require no barrier. The original references would
162 // have been enqueued in the SATB buffer by the load barrier if they were needed.
163 if (HasDecorator<decorators, ON_WEAK_OOP_REF>::value ||
164 HasDecorator<decorators, ON_PHANTOM_OOP_REF>::value) {
165 return;
166 }
167
168 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
169 T heap_oop = RawAccess<>::oop_load(field);
170 if (!CompressedOops::is_null(heap_oop)) {
171 enqueue(CompressedOops::decode(heap_oop));
172 }
173 }
174 }
175
176 inline void ShenandoahBarrierSet::satb_enqueue(oop value) {
177 if (value != nullptr && ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
178 enqueue(value);
179 }
180 }
181
182 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
183 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
184 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
185 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
186 if (!peek && !on_strong_oop_ref) {
187 satb_enqueue(value);
188 }
189 }
190
191 template <DecoratorSet decorators, typename T>
192 inline void ShenandoahBarrierSet::write_ref_field_post(T* field) {
193 assert(ShenandoahCardBarrier, "Should have been checked by caller");
194 if (_heap->is_in_young(field)) {
195 // Young field stores do not require card mark.
196 return;
197 }
198 T heap_oop = RawAccess<>::oop_load(field);
199 if (CompressedOops::is_null(heap_oop)) {
200 // Null reference store do not require card mark.
201 return;
202 }
203 oop obj = CompressedOops::decode_not_null(heap_oop);
204 if (!_heap->is_in_young(obj)) {
205 // Not an old->young reference store.
206 return;
207 }
208 volatile CardTable::CardValue* byte = card_table()->byte_for(field);
209 *byte = CardTable::dirty_card_val();
210 }
211
212 template <typename T>
213 inline oop ShenandoahBarrierSet::oop_load(DecoratorSet decorators, T* addr) {
214 oop value = RawAccess<>::oop_load(addr);
215 value = load_reference_barrier(decorators, value, addr);
216 keep_alive_if_weak(decorators, value);
217 return value;
218 }
219
220 template <typename T>
221 inline oop ShenandoahBarrierSet::oop_cmpxchg(DecoratorSet decorators, T* addr, oop compare_value, oop new_value) {
222 oop res;
223 oop expected = compare_value;
224 do {
225 compare_value = expected;
226 res = RawAccess<>::oop_atomic_cmpxchg(addr, compare_value, new_value);
227 expected = res;
228 } while ((compare_value != expected) && (resolve_forwarded(compare_value) == resolve_forwarded(expected)));
229
230 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
231 // because it must be the previous value.
232 res = load_reference_barrier(decorators, res, static_cast<T*>(nullptr));
233 satb_enqueue(res);
234 return res;
235 }
236
237 template <typename T>
238 inline oop ShenandoahBarrierSet::oop_xchg(DecoratorSet decorators, T* addr, oop new_value) {
239 oop previous = RawAccess<>::oop_atomic_xchg(addr, new_value);
240 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
241 // because it must be the previous value.
242 previous = load_reference_barrier<T>(decorators, previous, static_cast<T*>(nullptr));
243 satb_enqueue(previous);
244 return previous;
245 }
246
247 template <DecoratorSet decorators, typename BarrierSetT>
248 template <typename T>
249 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(T* addr) {
250 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "must be absent");
251 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
252 return bs->oop_load(decorators, addr);
253 }
254
255 template <DecoratorSet decorators, typename BarrierSetT>
256 template <typename T>
257 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
258 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "must be absent");
259 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
260 return bs->oop_load(decorators, addr);
261 }
262
263 template <DecoratorSet decorators, typename BarrierSetT>
264 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
265 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
266 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
267 return bs->oop_load(resolved_decorators, AccessInternal::oop_field_addr<decorators>(base, offset));
268 }
269
270 template <DecoratorSet decorators, typename BarrierSetT>
271 template <typename T>
272 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_common(T* addr, oop value) {
273 shenandoah_assert_marked_if(nullptr, value,
274 !CompressedOops::is_null(value) && ShenandoahHeap::heap()->is_evacuation_in_progress()
275 && !(ShenandoahHeap::heap()->active_generation()->is_young()
276 && ShenandoahHeap::heap()->heap_region_containing(value)->is_old()));
277 shenandoah_assert_not_in_cset_if(addr, value, value != nullptr && !ShenandoahHeap::heap()->cancelled_gc());
278 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
279 bs->satb_barrier<decorators>(addr);
280 Raw::oop_store(addr, value);
281 }
282
283 template <DecoratorSet decorators, typename BarrierSetT>
284 template <typename T>
285 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
286 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
287 oop_store_common(addr, value);
288 }
289
290 template <DecoratorSet decorators, typename BarrierSetT>
291 template <typename T>
292 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
293 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
294 shenandoah_assert_not_forwarded_except (addr, value, value == nullptr || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
295
296 oop_store_common(addr, value);
297 if (ShenandoahCardBarrier) {
298 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
299 bs->write_ref_field_post<decorators>(addr);
300 }
301 }
302
303 template <DecoratorSet decorators, typename BarrierSetT>
304 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
305 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
306 }
307
308 template <DecoratorSet decorators, typename BarrierSetT>
309 template <typename T>
310 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
311 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
312 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
313 return bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
314 }
315
316 template <DecoratorSet decorators, typename BarrierSetT>
317 template <typename T>
318 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
319 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
320 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
321 oop result = bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
322 if (ShenandoahCardBarrier) {
323 bs->write_ref_field_post<decorators>(addr);
324 }
325 return result;
326 }
327
328 template <DecoratorSet decorators, typename BarrierSetT>
329 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
330 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
331 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
332 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
333 auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
334 oop result = bs->oop_cmpxchg(resolved_decorators, addr, compare_value, new_value);
335 if (ShenandoahCardBarrier) {
336 bs->write_ref_field_post<decorators>(addr);
337 }
338 return result;
339 }
340
341 template <DecoratorSet decorators, typename BarrierSetT>
342 template <typename T>
343 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
344 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
345 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
346 return bs->oop_xchg(decorators, addr, new_value);
347 }
348
349 template <DecoratorSet decorators, typename BarrierSetT>
350 template <typename T>
351 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
352 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
353 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
354 oop result = bs->oop_xchg(decorators, addr, new_value);
355 if (ShenandoahCardBarrier) {
356 bs->write_ref_field_post<decorators>(addr);
357 }
358 return result;
359 }
360
361 template <DecoratorSet decorators, typename BarrierSetT>
362 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
363 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
364 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
365 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
366 auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
367 oop result = bs->oop_xchg(resolved_decorators, addr, new_value);
368 if (ShenandoahCardBarrier) {
369 bs->write_ref_field_post<decorators>(addr);
370 }
371 return result;
372 }
373
374 // Clone barrier support
375 template <bool EVAC>
376 class ShenandoahUpdateEvacForCloneOopClosure : public BasicOopIterateClosure {
377 private:
378 ShenandoahHeap* const _heap;
379 const ShenandoahCollectionSet* const _cset;
380 Thread* const _thread;
381
382 template <class T>
383 inline void do_oop_work(T* p) {
384 T o = RawAccess<>::oop_load(p);
385 if (!CompressedOops::is_null(o)) {
386 oop obj = CompressedOops::decode_not_null(o);
387 if (_cset->is_in(obj)) {
388 oop fwd = ShenandoahForwarding::get_forwardee(obj);
389 if (EVAC && obj == fwd) {
390 fwd = _heap->evacuate_object(obj, _thread);
391 }
392 shenandoah_assert_forwarded_except(p, obj, _heap->cancelled_gc());
393 ShenandoahHeap::atomic_update_oop(fwd, p, o);
394 obj = fwd;
395 }
396 }
397 }
398
399 public:
400 ShenandoahUpdateEvacForCloneOopClosure() :
401 _heap(ShenandoahHeap::heap()),
402 _cset(_heap->collection_set()),
403 _thread(Thread::current()) {}
404
405 virtual void do_oop(oop* p) { do_oop_work(p); }
406 virtual void do_oop(narrowOop* p) { do_oop_work(p); }
407 };
408
409 void ShenandoahBarrierSet::clone_evacuation(oop obj) {
410 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
411 if (need_bulk_update(cast_from_oop<HeapWord*>(obj))) {
412 ShenandoahEvacOOMScope oom_evac_scope;
413 ShenandoahUpdateEvacForCloneOopClosure<true> cl;
414 obj->oop_iterate(&cl);
415 }
416 }
417
418 void ShenandoahBarrierSet::clone_update(oop obj) {
419 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
420 if (need_bulk_update(cast_from_oop<HeapWord*>(obj))) {
421 ShenandoahUpdateEvacForCloneOopClosure<false> cl;
422 obj->oop_iterate(&cl);
423 }
424 }
425
426 template <DecoratorSet decorators, typename BarrierSetT>
427 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t count) {
428 // Hot code path, called from compiler/runtime. Make sure fast path is fast.
429
430 // Fix up src before doing the copy, if needed.
431 const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
432 if (gc_state > 0 && ShenandoahCloneBarrier) {
433 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
434 if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
435 bs->clone_evacuation(src);
436 } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
437 bs->clone_update(src);
438 }
439 }
440
441 Raw::clone(src, dst, count);
442
443 // Safety: clone destination must be in young, otherwise we need card barriers.
444 shenandoah_assert_in_young_if(nullptr, dst, ShenandoahCardBarrier);
445 }
446
447 template <DecoratorSet decorators, typename BarrierSetT>
448 template <typename T>
449 OopCopyResult ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
450 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
451 size_t length) {
452 T* src = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
453 T* dst = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);
454
455 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
456 bs->arraycopy_barrier(src, dst, length);
457 OopCopyResult result = Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
458 if (ShenandoahCardBarrier) {
459 bs->write_ref_array((HeapWord*) dst, length);
460 }
461 return result;
462 }
463
464 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
465 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
466 // Young cycles are allowed to run when old marking is in progress. When old marking is in progress,
467 // this barrier will be called with ENQUEUE=true and HAS_FWD=false, even though the young generation
468 // may have forwarded objects.
469 assert(HAS_FWD == _heap->has_forwarded_objects() || _heap->is_concurrent_old_mark_in_progress(), "Forwarded object status is sane");
470 // This function cannot be called to handle marking and evacuation at the same time (they operate on
471 // different sides of the copy).
472 static_assert((HAS_FWD || EVAC) != ENQUEUE, "Cannot evacuate and mark both sides of copy.");
473
474 Thread* thread = Thread::current();
475 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
476 ShenandoahMarkingContext* ctx = _heap->marking_context();
477 const ShenandoahCollectionSet* const cset = _heap->collection_set();
478 T* end = src + count;
479 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
480 T o = RawAccess<>::oop_load(elem_ptr);
481 if (!CompressedOops::is_null(o)) {
482 oop obj = CompressedOops::decode_not_null(o);
483 if (HAS_FWD && cset->is_in(obj)) {
484 oop fwd = resolve_forwarded_not_null(obj);
485 if (EVAC && obj == fwd) {
486 fwd = _heap->evacuate_object(obj, thread);
487 }
488 shenandoah_assert_forwarded_except(elem_ptr, obj, _heap->cancelled_gc());
489 ShenandoahHeap::atomic_update_oop(fwd, elem_ptr, o);
490 }
491 if (ENQUEUE && !ctx->is_marked_strong(obj)) {
492 _satb_mark_queue_set.enqueue_known_active(queue, obj);
493 }
494 }
495 }
496 }
497
498 template <class T>
499 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
500 if (count == 0) {
501 // No elements to copy, no need for barrier
502 return;
503 }
504
505 const char gc_state = ShenandoahThreadLocalData::gc_state(Thread::current());
506 if ((gc_state & ShenandoahHeap::MARKING) != 0) {
507 // If marking old or young, we must evaluate the SATB barrier. This will be the only
508 // action if we are not marking old. If we are marking old, we must still evaluate the
509 // load reference barrier for a young collection.
510 if (_heap->mode()->is_generational()) {
511 arraycopy_marking<true>(dst, count);
512 } else {
513 arraycopy_marking<false>(dst, count);
514 }
515 }
516
517 if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
518 assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during evacuation");
519 arraycopy_evacuation(src, count);
520 } else if ((gc_state & ShenandoahHeap::UPDATE_REFS) != 0) {
521 assert((gc_state & ShenandoahHeap::YOUNG_MARKING) == 0, "Cannot be marking young during update-refs");
522 arraycopy_update(src, count);
523 }
524 }
525
526 template <bool IS_GENERATIONAL, class T>
527 void ShenandoahBarrierSet::arraycopy_marking(T* dst, size_t count) {
528 assert(_heap->is_concurrent_mark_in_progress(), "only during marking");
529 if (ShenandoahSATBBarrier) {
530 if (!_heap->marking_context()->allocated_after_mark_start(reinterpret_cast<HeapWord*>(dst)) ||
531 (IS_GENERATIONAL && _heap->heap_region_containing(dst)->is_old() && _heap->is_concurrent_young_mark_in_progress())) {
532 arraycopy_work<T, false, false, true>(dst, count);
533 }
534 }
535 }
536
537 inline bool ShenandoahBarrierSet::need_bulk_update(HeapWord* ary) {
538 return ary < _heap->heap_region_containing(ary)->get_update_watermark();
539 }
540
541 template <class T>
542 void ShenandoahBarrierSet::arraycopy_evacuation(T* src, size_t count) {
543 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
544 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
545 ShenandoahEvacOOMScope oom_evac;
546 arraycopy_work<T, true, true, false>(src, count);
547 }
548 }
549
550 template <class T>
551 void ShenandoahBarrierSet::arraycopy_update(T* src, size_t count) {
552 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
553 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
554 arraycopy_work<T, true, false, false>(src, count);
555 }
556 }
557
558 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP