1 /*
2 * Copyright (c) 2015, 2022, Red Hat, Inc. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
27
28 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
29
30 #include "gc/shared/accessBarrierSupport.inline.hpp"
31 #include "gc/shenandoah/shenandoahAsserts.hpp"
32 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
33 #include "gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp"
34 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
35 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
36 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
37 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
38 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
39 #include "oops/oop.inline.hpp"
40
41 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null(oop p) {
42 return ShenandoahForwarding::get_forwardee(p);
43 }
44
45 inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {
46 if (p != nullptr) {
47 return resolve_forwarded_not_null(p);
48 } else {
49 return p;
50 }
51 }
52
53 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null_mutator(oop p) {
54 return ShenandoahForwarding::get_forwardee_mutator(p);
55 }
56
57 template <class T>
58 inline oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, T* load_addr) {
86 oop fwd = resolve_forwarded_not_null(obj);
87 if (obj == fwd && _heap->is_evacuation_in_progress()) {
88 Thread* t = Thread::current();
89 ShenandoahEvacOOMScope oom_evac_scope(t);
90 return _heap->evacuate_object(obj, t);
91 }
92 return fwd;
93 }
94 return obj;
95 }
96
97 template <class T>
98 inline oop ShenandoahBarrierSet::load_reference_barrier(DecoratorSet decorators, oop obj, T* load_addr) {
99 if (obj == nullptr) {
100 return nullptr;
101 }
102
103 // Prevent resurrection of unreachable phantom (i.e. weak-native) references.
104 if ((decorators & ON_PHANTOM_OOP_REF) != 0 &&
105 _heap->is_concurrent_weak_root_in_progress() &&
106 !_heap->marking_context()->is_marked(obj)) {
107 return nullptr;
108 }
109
110 // Prevent resurrection of unreachable weak references.
111 if ((decorators & ON_WEAK_OOP_REF) != 0 &&
112 _heap->is_concurrent_weak_root_in_progress() &&
113 !_heap->marking_context()->is_marked_strong(obj)) {
114 return nullptr;
115 }
116
117 // Prevent resurrection of unreachable objects that are visited during
118 // concurrent class-unloading.
119 if ((decorators & AS_NO_KEEPALIVE) != 0 &&
120 _heap->is_evacuation_in_progress() &&
121 !_heap->marking_context()->is_marked(obj)) {
122 return obj;
123 }
124
125 oop fwd = load_reference_barrier(obj);
126 if (load_addr != nullptr && fwd != obj) {
127 // Since we are here and we know the load address, update the reference.
128 ShenandoahHeap::atomic_update_oop(fwd, load_addr, obj);
129 }
130
131 return fwd;
132 }
162 if (value != nullptr && ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
163 enqueue(value);
164 }
165 }
166
167 inline void ShenandoahBarrierSet::iu_barrier(oop obj) {
168 if (ShenandoahIUBarrier && obj != nullptr && _heap->is_concurrent_mark_in_progress()) {
169 enqueue(obj);
170 }
171 }
172
173 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
174 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
175 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
176 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
177 if (!peek && !on_strong_oop_ref) {
178 satb_enqueue(value);
179 }
180 }
181
182 template <typename T>
183 inline oop ShenandoahBarrierSet::oop_load(DecoratorSet decorators, T* addr) {
184 oop value = RawAccess<>::oop_load(addr);
185 value = load_reference_barrier(decorators, value, addr);
186 keep_alive_if_weak(decorators, value);
187 return value;
188 }
189
190 template <typename T>
191 inline oop ShenandoahBarrierSet::oop_cmpxchg(DecoratorSet decorators, T* addr, oop compare_value, oop new_value) {
192 iu_barrier(new_value);
193 oop res;
194 oop expected = compare_value;
195 do {
196 compare_value = expected;
197 res = RawAccess<>::oop_atomic_cmpxchg(addr, compare_value, new_value);
198 expected = res;
199 } while ((compare_value != expected) && (resolve_forwarded(compare_value) == resolve_forwarded(expected)));
200
201 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
225 }
226
227 template <DecoratorSet decorators, typename BarrierSetT>
228 template <typename T>
229 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
230 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "must be absent");
231 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
232 return bs->oop_load(decorators, addr);
233 }
234
235 template <DecoratorSet decorators, typename BarrierSetT>
236 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
237 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
238 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
239 return bs->oop_load(resolved_decorators, AccessInternal::oop_field_addr<decorators>(base, offset));
240 }
241
242 template <DecoratorSet decorators, typename BarrierSetT>
243 template <typename T>
244 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_common(T* addr, oop value) {
245 shenandoah_assert_marked_if(nullptr, value, !CompressedOops::is_null(value) && ShenandoahHeap::heap()->is_evacuation_in_progress());
246 shenandoah_assert_not_in_cset_if(addr, value, value != nullptr && !ShenandoahHeap::heap()->cancelled_gc());
247 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
248 bs->iu_barrier(value);
249 bs->satb_barrier<decorators>(addr);
250 Raw::oop_store(addr, value);
251 }
252
253 template <DecoratorSet decorators, typename BarrierSetT>
254 template <typename T>
255 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
256 oop_store_common(addr, value);
257 }
258
259 template <DecoratorSet decorators, typename BarrierSetT>
260 template <typename T>
261 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
262 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
263 shenandoah_assert_not_forwarded_except (addr, value, value == nullptr || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
264
265 oop_store_common(addr, value);
266 }
267
268 template <DecoratorSet decorators, typename BarrierSetT>
269 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
270 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
271 }
272
273 template <DecoratorSet decorators, typename BarrierSetT>
274 template <typename T>
275 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
276 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
277 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
278 return bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
279 }
280
281 template <DecoratorSet decorators, typename BarrierSetT>
282 template <typename T>
283 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
284 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
285 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
286 return bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
287 }
288
289 template <DecoratorSet decorators, typename BarrierSetT>
290 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
291 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
292 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
293 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
294 return bs->oop_cmpxchg(resolved_decorators, AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
295 }
296
297 template <DecoratorSet decorators, typename BarrierSetT>
298 template <typename T>
299 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
300 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
301 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
302 return bs->oop_xchg(decorators, addr, new_value);
303 }
304
305 template <DecoratorSet decorators, typename BarrierSetT>
306 template <typename T>
307 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
308 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
309 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
310 return bs->oop_xchg(decorators, addr, new_value);
311 }
312
313 template <DecoratorSet decorators, typename BarrierSetT>
314 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
315 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
316 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
317 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
318 return bs->oop_xchg(resolved_decorators, AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
319 }
320
321 // Clone barrier support
322 template <DecoratorSet decorators, typename BarrierSetT>
323 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
324 if (ShenandoahCloneBarrier) {
325 ShenandoahBarrierSet::barrier_set()->clone_barrier_runtime(src);
326 }
327 Raw::clone(src, dst, size);
328 }
329
330 template <DecoratorSet decorators, typename BarrierSetT>
331 template <typename T>
332 bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
333 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
334 size_t length) {
335 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
336 bs->arraycopy_barrier(arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw),
337 arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw),
338 length);
339 return Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
340 }
341
342 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
343 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
344 assert(HAS_FWD == _heap->has_forwarded_objects(), "Forwarded object status is sane");
345
346 Thread* thread = Thread::current();
347 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
348 ShenandoahMarkingContext* ctx = _heap->marking_context();
349 const ShenandoahCollectionSet* const cset = _heap->collection_set();
350 T* end = src + count;
351 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
352 T o = RawAccess<>::oop_load(elem_ptr);
353 if (!CompressedOops::is_null(o)) {
354 oop obj = CompressedOops::decode_not_null(o);
355 if (HAS_FWD && cset->is_in(obj)) {
356 oop fwd = resolve_forwarded_not_null(obj);
357 if (EVAC && obj == fwd) {
358 fwd = _heap->evacuate_object(obj, thread);
359 }
360 shenandoah_assert_forwarded_except(elem_ptr, obj, _heap->cancelled_gc());
361 ShenandoahHeap::atomic_update_oop(fwd, elem_ptr, o);
362 obj = fwd;
363 }
364 if (ENQUEUE && !ctx->is_marked_strong(obj)) {
365 _satb_mark_queue_set.enqueue_known_active(queue, obj);
366 }
367 }
368 }
369 }
370
371 template <class T>
372 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
373 if (count == 0) {
374 return;
375 }
376 int gc_state = _heap->gc_state();
377 if ((gc_state & ShenandoahHeap::MARKING) != 0) {
378 arraycopy_marking(src, dst, count);
379 } else if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
380 arraycopy_evacuation(src, count);
381 } else if ((gc_state & ShenandoahHeap::UPDATEREFS) != 0) {
382 arraycopy_update(src, count);
383 }
384 }
385
386 template <class T>
387 void ShenandoahBarrierSet::arraycopy_marking(T* src, T* dst, size_t count) {
388 assert(_heap->is_concurrent_mark_in_progress(), "only during marking");
389 T* array = ShenandoahSATBBarrier ? dst : src;
390 if (!_heap->marking_context()->allocated_after_mark_start(reinterpret_cast<HeapWord*>(array))) {
391 arraycopy_work<T, false, false, true>(array, count);
392 }
393 }
394
395 inline bool ShenandoahBarrierSet::need_bulk_update(HeapWord* ary) {
396 return ary < _heap->heap_region_containing(ary)->get_update_watermark();
397 }
398
399 template <class T>
400 void ShenandoahBarrierSet::arraycopy_evacuation(T* src, size_t count) {
401 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
402 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
403 ShenandoahEvacOOMScope oom_evac;
404 arraycopy_work<T, true, true, false>(src, count);
405 }
406 }
407
408 template <class T>
409 void ShenandoahBarrierSet::arraycopy_update(T* src, size_t count) {
410 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
411 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
|
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.
23 *
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/shenandoahAsserts.hpp"
34 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
35 #include "gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp"
36 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
37 #include "gc/shenandoah/shenandoahGeneration.hpp"
38 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
39 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
40 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
41 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
42 #include "gc/shenandoah/mode/shenandoahMode.hpp"
43 #include "memory/iterator.inline.hpp"
44 #include "oops/oop.inline.hpp"
45
46 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null(oop p) {
47 return ShenandoahForwarding::get_forwardee(p);
48 }
49
50 inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {
51 if (p != nullptr) {
52 return resolve_forwarded_not_null(p);
53 } else {
54 return p;
55 }
56 }
57
58 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null_mutator(oop p) {
59 return ShenandoahForwarding::get_forwardee_mutator(p);
60 }
61
62 template <class T>
63 inline oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, T* load_addr) {
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 // Prevent resurrection of unreachable objects that are visited during
125 // concurrent class-unloading.
126 if ((decorators & AS_NO_KEEPALIVE) != 0 &&
127 _heap->is_evacuation_in_progress() &&
128 !_heap->marking_context()->is_marked(obj)) {
129 return obj;
130 }
131
132 oop fwd = load_reference_barrier(obj);
133 if (load_addr != nullptr && fwd != obj) {
134 // Since we are here and we know the load address, update the reference.
135 ShenandoahHeap::atomic_update_oop(fwd, load_addr, obj);
136 }
137
138 return fwd;
139 }
169 if (value != nullptr && ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
170 enqueue(value);
171 }
172 }
173
174 inline void ShenandoahBarrierSet::iu_barrier(oop obj) {
175 if (ShenandoahIUBarrier && obj != nullptr && _heap->is_concurrent_mark_in_progress()) {
176 enqueue(obj);
177 }
178 }
179
180 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
181 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
182 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
183 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
184 if (!peek && !on_strong_oop_ref) {
185 satb_enqueue(value);
186 }
187 }
188
189 template <DecoratorSet decorators, typename T>
190 inline void ShenandoahBarrierSet::write_ref_field_post(T* field) {
191 assert(ShenandoahCardBarrier, "Did you mean to enable ShenandoahCardBarrier?");
192 volatile CardTable::CardValue* byte = card_table()->byte_for(field);
193 *byte = CardTable::dirty_card_val();
194 }
195
196 template <typename T>
197 inline oop ShenandoahBarrierSet::oop_load(DecoratorSet decorators, T* addr) {
198 oop value = RawAccess<>::oop_load(addr);
199 value = load_reference_barrier(decorators, value, addr);
200 keep_alive_if_weak(decorators, value);
201 return value;
202 }
203
204 template <typename T>
205 inline oop ShenandoahBarrierSet::oop_cmpxchg(DecoratorSet decorators, T* addr, oop compare_value, oop new_value) {
206 iu_barrier(new_value);
207 oop res;
208 oop expected = compare_value;
209 do {
210 compare_value = expected;
211 res = RawAccess<>::oop_atomic_cmpxchg(addr, compare_value, new_value);
212 expected = res;
213 } while ((compare_value != expected) && (resolve_forwarded(compare_value) == resolve_forwarded(expected)));
214
215 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
239 }
240
241 template <DecoratorSet decorators, typename BarrierSetT>
242 template <typename T>
243 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
244 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "must be absent");
245 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
246 return bs->oop_load(decorators, addr);
247 }
248
249 template <DecoratorSet decorators, typename BarrierSetT>
250 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
251 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
252 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
253 return bs->oop_load(resolved_decorators, AccessInternal::oop_field_addr<decorators>(base, offset));
254 }
255
256 template <DecoratorSet decorators, typename BarrierSetT>
257 template <typename T>
258 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_common(T* addr, oop value) {
259 shenandoah_assert_marked_if(nullptr, value,
260 !CompressedOops::is_null(value) &&
261 ShenandoahHeap::heap()->is_evacuation_in_progress() &&
262 !(ShenandoahHeap::heap()->active_generation()->is_young() &&
263 ShenandoahHeap::heap()->heap_region_containing(value)->is_old()));
264 shenandoah_assert_not_in_cset_if(addr, value, value != nullptr && !ShenandoahHeap::heap()->cancelled_gc());
265 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
266 bs->iu_barrier(value);
267 bs->satb_barrier<decorators>(addr);
268 Raw::oop_store(addr, value);
269 }
270
271 template <DecoratorSet decorators, typename BarrierSetT>
272 template <typename T>
273 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
274 oop_store_common(addr, value);
275 }
276
277 template <DecoratorSet decorators, typename BarrierSetT>
278 template <typename T>
279 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
280 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
281 shenandoah_assert_not_forwarded_except (addr, value, value == nullptr || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
282
283 oop_store_common(addr, value);
284 if (ShenandoahCardBarrier) {
285 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
286 bs->write_ref_field_post<decorators>(addr);
287 }
288 }
289
290 template <DecoratorSet decorators, typename BarrierSetT>
291 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
292 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
293 }
294
295 template <DecoratorSet decorators, typename BarrierSetT>
296 template <typename T>
297 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
298 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
299 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
300 return bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
301 }
302
303 template <DecoratorSet decorators, typename BarrierSetT>
304 template <typename T>
305 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
306 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
307 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
308 oop result = bs->oop_cmpxchg(decorators, addr, compare_value, new_value);
309 if (ShenandoahCardBarrier) {
310 bs->write_ref_field_post<decorators>(addr);
311 }
312 return result;
313 }
314
315 template <DecoratorSet decorators, typename BarrierSetT>
316 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
317 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
318 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
319 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
320 auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
321 oop result = bs->oop_cmpxchg(resolved_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 template <typename T>
330 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
331 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
332 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
333 return bs->oop_xchg(decorators, addr, new_value);
334 }
335
336 template <DecoratorSet decorators, typename BarrierSetT>
337 template <typename T>
338 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
339 assert((decorators & (AS_NO_KEEPALIVE | ON_UNKNOWN_OOP_REF)) == 0, "must be absent");
340 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
341 oop result = bs->oop_xchg(decorators, addr, new_value);
342 if (ShenandoahCardBarrier) {
343 bs->write_ref_field_post<decorators>(addr);
344 }
345 return result;
346 }
347
348 template <DecoratorSet decorators, typename BarrierSetT>
349 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
350 assert((decorators & AS_NO_KEEPALIVE) == 0, "must be absent");
351 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
352 DecoratorSet resolved_decorators = AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset);
353 auto addr = AccessInternal::oop_field_addr<decorators>(base, offset);
354 oop result = bs->oop_xchg(resolved_decorators, addr, new_value);
355 if (ShenandoahCardBarrier) {
356 bs->write_ref_field_post<decorators>(addr);
357 }
358 return result;
359 }
360
361 // Clone barrier support
362 template <DecoratorSet decorators, typename BarrierSetT>
363 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
364 if (ShenandoahCloneBarrier) {
365 ShenandoahBarrierSet::barrier_set()->clone_barrier_runtime(src);
366 }
367 Raw::clone(src, dst, size);
368 }
369
370 template <DecoratorSet decorators, typename BarrierSetT>
371 template <typename T>
372 bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
373 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
374 size_t length) {
375 T* src = arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw);
376 T* dst = arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw);
377
378 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
379 bs->arraycopy_barrier(src, dst, length);
380 bool result = Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
381 if (ShenandoahCardBarrier) {
382 bs->write_ref_array((HeapWord*) dst, length);
383 }
384 return result;
385 }
386
387 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
388 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
389 // We allow forwarding in young generation and marking in old generation
390 // to happen simultaneously.
391 assert(_heap->mode()->is_generational() || HAS_FWD == _heap->has_forwarded_objects(), "Forwarded object status is sane");
392
393 Thread* thread = Thread::current();
394 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
395 ShenandoahMarkingContext* ctx = _heap->marking_context();
396 const ShenandoahCollectionSet* const cset = _heap->collection_set();
397 T* end = src + count;
398 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
399 T o = RawAccess<>::oop_load(elem_ptr);
400 if (!CompressedOops::is_null(o)) {
401 oop obj = CompressedOops::decode_not_null(o);
402 if (HAS_FWD && cset->is_in(obj)) {
403 oop fwd = resolve_forwarded_not_null(obj);
404 if (EVAC && obj == fwd) {
405 fwd = _heap->evacuate_object(obj, thread);
406 }
407 shenandoah_assert_forwarded_except(elem_ptr, obj, _heap->cancelled_gc());
408 ShenandoahHeap::atomic_update_oop(fwd, elem_ptr, o);
409 obj = fwd;
410 }
411 if (ENQUEUE && !ctx->is_marked_strong_or_old(obj)) {
412 _satb_mark_queue_set.enqueue_known_active(queue, obj);
413 }
414 }
415 }
416 }
417
418 template <class T>
419 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
420 if (count == 0) {
421 return;
422 }
423 int gc_state = _heap->gc_state();
424 if ((gc_state & ShenandoahHeap::YOUNG_MARKING) != 0) {
425 arraycopy_marking(src, dst, count, false);
426 return;
427 }
428
429 if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
430 arraycopy_evacuation(src, count);
431 } else if ((gc_state & ShenandoahHeap::UPDATEREFS) != 0) {
432 arraycopy_update(src, count);
433 }
434
435 if (_heap->mode()->is_generational()) {
436 assert(ShenandoahSATBBarrier, "Generational mode assumes SATB mode");
437 // TODO: Could we optimize here by checking that dst is in an old region?
438 if ((gc_state & ShenandoahHeap::OLD_MARKING) != 0) {
439 // Note that we can't do the arraycopy marking using the 'src' array when
440 // SATB mode is enabled (so we can't do this as part of the iteration for
441 // evacuation or update references).
442 arraycopy_marking(src, dst, count, true);
443 }
444 }
445 }
446
447 template <class T>
448 void ShenandoahBarrierSet::arraycopy_marking(T* src, T* dst, size_t count, bool is_old_marking) {
449 assert(_heap->is_concurrent_mark_in_progress(), "only during marking");
450 /*
451 * Note that an old-gen object is considered live if it is live at the start of OLD marking or if it is promoted
452 * following the start of OLD marking.
453 *
454 * 1. Every object promoted following the start of OLD marking will be above TAMS within its old-gen region
455 * 2. Every object live at the start of OLD marking will be referenced from a "root" or it will be referenced from
456 * another live OLD-gen object. With regards to old-gen, roots include stack locations and all of live young-gen.
457 * All root references to old-gen are identified during a bootstrap young collection. All references from other
458 * old-gen objects will be marked during the traversal of all old objects, or will be marked by the SATB barrier.
459 *
460 * During old-gen marking (which is interleaved with young-gen collections), call arraycopy_work() if:
461 *
462 * 1. The overwritten array resides in old-gen and it is below TAMS within its old-gen region
463 * 2. Do not call arraycopy_work for any array residing in young-gen because young-gen collection is idle at this time
464 *
465 * During young-gen marking, call arraycopy_work() if:
466 *
467 * 1. The overwritten array resides in young-gen and is below TAMS within its young-gen region
468 * 2. Additionally, if array resides in old-gen, regardless of its relationship to TAMS because this old-gen array
469 * may hold references to young-gen
470 */
471 if (ShenandoahSATBBarrier) {
472 T* array = dst;
473 HeapWord* array_addr = reinterpret_cast<HeapWord*>(array);
474 ShenandoahHeapRegion* r = _heap->heap_region_containing(array_addr);
475 if (is_old_marking) {
476 // Generational, old marking
477 assert(_heap->mode()->is_generational(), "Invariant");
478 if (r->is_old() && (array_addr < _heap->marking_context()->top_at_mark_start(r))) {
479 arraycopy_work<T, false, false, true>(array, count);
480 }
481 } else if (_heap->mode()->is_generational()) {
482 // Generational, young marking
483 if (r->is_old() || (array_addr < _heap->marking_context()->top_at_mark_start(r))) {
484 arraycopy_work<T, false, false, true>(array, count);
485 }
486 } else if (array_addr < _heap->marking_context()->top_at_mark_start(r)) {
487 // Non-generational, marking
488 arraycopy_work<T, false, false, true>(array, count);
489 }
490 } else {
491 // Incremental Update mode, marking
492 T* array = src;
493 HeapWord* array_addr = reinterpret_cast<HeapWord*>(array);
494 ShenandoahHeapRegion* r = _heap->heap_region_containing(array_addr);
495 if (array_addr < _heap->marking_context()->top_at_mark_start(r)) {
496 arraycopy_work<T, false, false, true>(array, count);
497 }
498 }
499 }
500
501 inline bool ShenandoahBarrierSet::need_bulk_update(HeapWord* ary) {
502 return ary < _heap->heap_region_containing(ary)->get_update_watermark();
503 }
504
505 template <class T>
506 void ShenandoahBarrierSet::arraycopy_evacuation(T* src, size_t count) {
507 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
508 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
509 ShenandoahEvacOOMScope oom_evac;
510 arraycopy_work<T, true, true, false>(src, count);
511 }
512 }
513
514 template <class T>
515 void ShenandoahBarrierSet::arraycopy_update(T* src, size_t count) {
516 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
517 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
|