1 /*
2 * Copyright (c) 2015, 2020, 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.
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23 */
24
25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
27
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shenandoah/shenandoahAsserts.hpp"
30 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
31 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
32 #include "gc/shenandoah/shenandoahEvacOOMHandler.inline.hpp"
33 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
34 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
35 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
36 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
37 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
38 #include "memory/iterator.inline.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 != NULL) {
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) {
59 assert(ShenandoahLoadRefBarrier, "should be enabled");
60 shenandoah_assert_in_cset(load_addr, obj);
61
62 oop fwd = resolve_forwarded_not_null_mutator(obj);
63 if (obj == fwd) {
64 assert(_heap->is_evacuation_in_progress(),
65 "evac should be in progress");
66 Thread* const t = Thread::current();
67 ShenandoahEvacOOMScope scope(_heap, t);
68 fwd = _heap->evacuate_object(obj, t);
69 }
70
71 if (load_addr != NULL && fwd != obj) {
72 // Since we are here and we know the load address, update the reference.
73 ShenandoahHeap::cas_oop(fwd, load_addr, obj);
74 }
75
76 return fwd;
77 }
78
79 inline void ShenandoahBarrierSet::enqueue(oop obj) {
80 assert(_satb_mark_queue_set.is_active(), "only get here when SATB active");
81
82 // Filter marked objects before hitting the SATB queues. The same predicate would
83 // be used by SATBMQ::filter to eliminate already marked objects downstream, but
84 // filtering here helps to avoid wasteful SATB queueing work to begin with.
85 if (!_heap->requires_marking<false>(obj)) return;
86
87 ShenandoahThreadLocalData::satb_mark_queue(Thread::current()).enqueue_known_active(obj);
88 }
89
90 template <DecoratorSet decorators, typename T>
91 inline void ShenandoahBarrierSet::satb_barrier(T *field) {
92 if (HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value ||
93 HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
94 return;
95 }
96 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
97 T heap_oop = RawAccess<>::oop_load(field);
98 if (!CompressedOops::is_null(heap_oop)) {
99 enqueue(CompressedOops::decode(heap_oop));
100 }
101 }
102 }
103
104 inline void ShenandoahBarrierSet::satb_enqueue(oop value) {
105 assert(value != NULL, "checked before");
106 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
107 enqueue(value);
108 }
109 }
110
111 inline void ShenandoahBarrierSet::storeval_barrier(oop obj) {
112 if (ShenandoahStoreValEnqueueBarrier && obj != NULL && _heap->is_concurrent_mark_in_progress()) {
113 enqueue(obj);
114 }
115 }
116
117 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
118 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
119 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
120 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
121 if (!peek && !on_strong_oop_ref) {
122 satb_enqueue(value);
123 }
124 }
125
126 template <DecoratorSet decorators>
127 inline void ShenandoahBarrierSet::keep_alive_if_weak(oop value) {
128 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
129 if (!HasDecorator<decorators, ON_STRONG_OOP_REF>::value &&
130 !HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
131 satb_enqueue(value);
132 }
133 }
134
135 template <DecoratorSet decorators, typename BarrierSetT>
136 template <typename T>
137 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(T* addr) {
138 oop value = Raw::oop_load_not_in_heap(addr);
139 if (value != NULL) {
140 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
141 value = bs->load_reference_barrier_native(value, addr);
142 if (value != NULL) {
143 bs->keep_alive_if_weak<decorators>(value);
144 }
145 }
146 return value;
147 }
148
149 template <DecoratorSet decorators, typename BarrierSetT>
150 template <typename T>
151 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
152 oop value = Raw::oop_load_in_heap(addr);
153 if (value != NULL) {
154 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
155 value = bs->load_reference_barrier_not_null(value);
156 bs->keep_alive_if_weak<decorators>(value);
157 }
158 return value;
159 }
160
161 template <DecoratorSet decorators, typename BarrierSetT>
162 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
163 oop value = Raw::oop_load_in_heap_at(base, offset);
164 if (value != NULL) {
165 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
166 value = bs->load_reference_barrier_not_null(value);
167 bs->keep_alive_if_weak(AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset),
168 value);
169 }
170 return value;
171 }
172
173 template <DecoratorSet decorators, typename BarrierSetT>
174 template <typename T>
175 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
176 shenandoah_assert_marked_if(NULL, value, !CompressedOops::is_null(value) && ShenandoahHeap::heap()->is_evacuation_in_progress());
177 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
178 bs->storeval_barrier(value);
179 bs->satb_barrier<decorators>(addr);
180 Raw::oop_store(addr, value);
181 }
182
183 template <DecoratorSet decorators, typename BarrierSetT>
184 template <typename T>
185 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
186 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
187 shenandoah_assert_not_forwarded_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
188 shenandoah_assert_not_in_cset_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
189
190 oop_store_not_in_heap(addr, value);
191 }
192
193 template <DecoratorSet decorators, typename BarrierSetT>
194 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
195 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
196 }
197
198 template <DecoratorSet decorators, typename BarrierSetT>
199 template <typename T>
200 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
201 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
202 bs->storeval_barrier(new_value);
203
204 oop res;
205 oop expected = compare_value;
206 do {
207 compare_value = expected;
208 res = Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
209 expected = res;
210 } while ((compare_value != expected) && (resolve_forwarded(compare_value) == resolve_forwarded(expected)));
211
212 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
213 // because it must be the previous value.
214 if (res != NULL) {
215 res = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(res);
216 bs->satb_enqueue(res);
217 }
218 return res;
219 }
220
221 template <DecoratorSet decorators, typename BarrierSetT>
222 template <typename T>
223 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
224 return oop_atomic_cmpxchg_not_in_heap(addr, compare_value, new_value);
225 }
226
227 template <DecoratorSet decorators, typename BarrierSetT>
228 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
229 return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
230 }
231
232 template <DecoratorSet decorators, typename BarrierSetT>
233 template <typename T>
234 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
235 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
236 bs->storeval_barrier(new_value);
237
238 oop previous = Raw::oop_atomic_xchg(addr, new_value);
239
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 if (previous != NULL) {
243 previous = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(previous);
244 bs->satb_enqueue(previous);
245 }
246 return previous;
247 }
248
249 template <DecoratorSet decorators, typename BarrierSetT>
250 template <typename T>
251 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
252 return oop_atomic_xchg_not_in_heap(addr, new_value);
253 }
254
255 template <DecoratorSet decorators, typename BarrierSetT>
256 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
257 return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
258 }
259
260 // Clone barrier support
261 template <DecoratorSet decorators, typename BarrierSetT>
262 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
263 if (ShenandoahCloneBarrier) {
264 ShenandoahBarrierSet::barrier_set()->clone_barrier_runtime(src);
265 }
266 Raw::clone(src, dst, size);
267 }
268
269 template <DecoratorSet decorators, typename BarrierSetT>
270 template <typename T>
271 bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
272 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
273 size_t length) {
274 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
275 bs->arraycopy_barrier(arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw),
276 arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw),
277 length);
278 return Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
279 }
280
281 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
282 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
283 assert(HAS_FWD == _heap->has_forwarded_objects(), "Forwarded object status is sane");
284
285 Thread* thread = Thread::current();
286 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
287 ShenandoahMarkingContext* ctx = _heap->marking_context();
288 const ShenandoahCollectionSet* const cset = _heap->collection_set();
289 T* end = src + count;
290 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
291 T o = RawAccess<>::oop_load(elem_ptr);
292 if (!CompressedOops::is_null(o)) {
293 oop obj = CompressedOops::decode_not_null(o);
294 if (HAS_FWD && cset->is_in(obj)) {
295 oop fwd = resolve_forwarded_not_null(obj);
296 if (EVAC && obj == fwd) {
297 fwd = _heap->evacuate_object(obj, thread);
298 }
299 assert(obj != fwd || _heap->cancelled_gc(), "must be forwarded");
300 oop witness = ShenandoahHeap::cas_oop(fwd, elem_ptr, o);
301 obj = fwd;
302 }
303 if (ENQUEUE && !ctx->is_marked(obj)) {
304 queue.enqueue_known_active(obj);
305 }
306 }
307 }
308 }
309
310 template <class T>
311 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
312 if (count == 0) {
313 return;
314 }
315 int gc_state = _heap->gc_state();
316 if ((gc_state & ShenandoahHeap::MARKING) != 0) {
317 arraycopy_marking(src, dst, count);
318 } else if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
319 arraycopy_evacuation(src, count);
320 } else if ((gc_state & ShenandoahHeap::UPDATEREFS) != 0) {
321 arraycopy_update(src, count);
322 }
323 }
324
325 template <class T>
326 void ShenandoahBarrierSet::arraycopy_marking(T* src, T* dst, size_t count) {
327 assert(_heap->is_concurrent_mark_in_progress(), "only during marking");
328 T* array = ShenandoahSATBBarrier ? dst : src;
329 if (!_heap->marking_context()->allocated_after_mark_start(reinterpret_cast<HeapWord*>(array))) {
330 arraycopy_work<T, false, false, true>(array, count);
331 }
332 }
333
334 inline bool ShenandoahBarrierSet::need_bulk_update(HeapWord* ary) {
335 return ary < _heap->heap_region_containing(ary)->get_update_watermark();
336 }
337
338 template <class T>
339 void ShenandoahBarrierSet::arraycopy_evacuation(T* src, size_t count) {
340 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
341 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
342 ShenandoahEvacOOMScope oom_evac(_heap);
343 arraycopy_work<T, true, true, false>(src, count);
344 }
345 }
346
347 template <class T>
348 void ShenandoahBarrierSet::arraycopy_update(T* src, size_t count) {
349 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
350 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
351 arraycopy_work<T, true, false, false>(src, count);
352 }
353 }
354
355 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP