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.
22 *
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/shenandoahForwarding.inline.hpp"
33 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
34 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
35 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
36 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
37 #include "memory/iterator.inline.hpp"
38 #include "oops/oop.inline.hpp"
39
40 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null(oop p) {
41 return ShenandoahForwarding::get_forwardee(p);
42 }
43
44 inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {
45 if (p != NULL) {
46 return resolve_forwarded_not_null(p);
47 } else {
48 return p;
49 }
50 }
51
52 inline oop ShenandoahBarrierSet::resolve_forwarded_not_null_mutator(oop p) {
53 return ShenandoahForwarding::get_forwardee_mutator(p);
54 }
55
56 template <class T>
57 inline oop ShenandoahBarrierSet::load_reference_barrier_mutator(oop obj, T* load_addr) {
58 assert(ShenandoahLoadRefBarrier, "should be enabled");
59 shenandoah_assert_in_cset(load_addr, obj);
60
61 oop fwd = resolve_forwarded_not_null_mutator(obj);
62 if (obj == fwd) {
63 assert(_heap->is_evacuation_in_progress(),
64 "evac should be in progress");
65 ShenandoahEvacOOMScope scope;
66 fwd = _heap->evacuate_object(obj, Thread::current());
67 }
68
69 if (load_addr != NULL && fwd != obj) {
70 // Since we are here and we know the load address, update the reference.
71 ShenandoahHeap::cas_oop(fwd, load_addr, obj);
72 }
73
74 return fwd;
75 }
76
77 inline void ShenandoahBarrierSet::enqueue(oop obj) {
78 assert(_satb_mark_queue_set.is_active(), "only get here when SATB active");
79
80 // Filter marked objects before hitting the SATB queues. The same predicate would
81 // be used by SATBMQ::filter to eliminate already marked objects downstream, but
82 // filtering here helps to avoid wasteful SATB queueing work to begin with.
83 if (!_heap->requires_marking<false>(obj)) return;
84
85 ShenandoahThreadLocalData::satb_mark_queue(Thread::current()).enqueue_known_active(obj);
86 }
87
88 template <DecoratorSet decorators, typename T>
89 inline void ShenandoahBarrierSet::satb_barrier(T *field) {
90 if (HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value ||
91 HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
92 return;
93 }
94 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
95 T heap_oop = RawAccess<>::oop_load(field);
96 if (!CompressedOops::is_null(heap_oop)) {
97 enqueue(CompressedOops::decode(heap_oop));
98 }
99 }
100 }
101
102 inline void ShenandoahBarrierSet::satb_enqueue(oop value) {
103 assert(value != NULL, "checked before");
104 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
105 enqueue(value);
106 }
107 }
108
109 inline void ShenandoahBarrierSet::storeval_barrier(oop obj) {
110 if (ShenandoahStoreValEnqueueBarrier && obj != NULL && _heap->is_concurrent_mark_in_progress()) {
111 enqueue(obj);
112 }
113 }
114
115 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
116 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
117 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
118 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
119 if (!peek && !on_strong_oop_ref) {
120 satb_enqueue(value);
121 }
122 }
123
124 template <DecoratorSet decorators>
125 inline void ShenandoahBarrierSet::keep_alive_if_weak(oop value) {
126 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
127 if (!HasDecorator<decorators, ON_STRONG_OOP_REF>::value &&
128 !HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
129 satb_enqueue(value);
130 }
131 }
132
133 template <DecoratorSet decorators, typename BarrierSetT>
134 template <typename T>
135 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(T* addr) {
136 oop value = Raw::oop_load_not_in_heap(addr);
137 if (value != NULL) {
138 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
139 value = bs->load_reference_barrier_native(value, addr);
140 if (value != NULL) {
141 bs->keep_alive_if_weak<decorators>(value);
142 }
143 }
144 return value;
145 }
146
147 template <DecoratorSet decorators, typename BarrierSetT>
148 template <typename T>
149 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
150 oop value = Raw::oop_load_in_heap(addr);
151 if (value != NULL) {
152 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
153 value = bs->load_reference_barrier_not_null(value);
154 bs->keep_alive_if_weak<decorators>(value);
155 }
156 return value;
157 }
158
159 template <DecoratorSet decorators, typename BarrierSetT>
160 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
161 oop value = Raw::oop_load_in_heap_at(base, offset);
162 if (value != NULL) {
163 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
164 value = bs->load_reference_barrier_not_null(value);
165 bs->keep_alive_if_weak(AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset),
166 value);
167 }
168 return value;
169 }
170
171 template <DecoratorSet decorators, typename BarrierSetT>
172 template <typename T>
173 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
174 shenandoah_assert_marked_if(NULL, value, !CompressedOops::is_null(value) && ShenandoahHeap::heap()->is_evacuation_in_progress());
175 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
176 bs->storeval_barrier(value);
177 bs->satb_barrier<decorators>(addr);
178 Raw::oop_store(addr, value);
179 }
180
181 template <DecoratorSet decorators, typename BarrierSetT>
182 template <typename T>
183 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
184 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
185 shenandoah_assert_not_forwarded_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
186 shenandoah_assert_not_in_cset_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
187
188 oop_store_not_in_heap(addr, value);
189 }
190
191 template <DecoratorSet decorators, typename BarrierSetT>
192 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
193 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
194 }
195
196 template <DecoratorSet decorators, typename BarrierSetT>
197 template <typename T>
198 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
199 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
200 bs->storeval_barrier(new_value);
201
202 oop res;
203 oop expected = compare_value;
204 do {
205 compare_value = expected;
206 res = Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
207 expected = res;
208 } while ((compare_value != expected) && (resolve_forwarded(compare_value) == resolve_forwarded(expected)));
209
210 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
211 // because it must be the previous value.
212 if (res != NULL) {
213 res = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(res);
214 bs->satb_enqueue(res);
215 }
216 return res;
217 }
218
219 template <DecoratorSet decorators, typename BarrierSetT>
220 template <typename T>
221 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
222 return oop_atomic_cmpxchg_not_in_heap(addr, compare_value, new_value);
223 }
224
225 template <DecoratorSet decorators, typename BarrierSetT>
226 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
227 return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
228 }
229
230 template <DecoratorSet decorators, typename BarrierSetT>
231 template <typename T>
232 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
233 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
234 bs->storeval_barrier(new_value);
235
236 oop previous = Raw::oop_atomic_xchg(addr, new_value);
237
238 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
239 // because it must be the previous value.
240 if (previous != NULL) {
241 previous = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(previous);
242 bs->satb_enqueue(previous);
243 }
244 return previous;
245 }
246
247 template <DecoratorSet decorators, typename BarrierSetT>
248 template <typename T>
249 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
250 return oop_atomic_xchg_not_in_heap(addr, new_value);
251 }
252
253 template <DecoratorSet decorators, typename BarrierSetT>
254 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
255 return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
256 }
257
258 // Clone barrier support
259 template <DecoratorSet decorators, typename BarrierSetT>
260 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
261 if (ShenandoahCloneBarrier) {
262 ShenandoahBarrierSet::barrier_set()->clone_barrier_runtime(src);
263 }
264 Raw::clone(src, dst, size);
265 }
266
267 template <DecoratorSet decorators, typename BarrierSetT>
268 template <typename T>
269 bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
270 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
271 size_t length) {
272 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
273 bs->arraycopy_barrier(arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw),
274 arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw),
275 length);
276 return Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
277 }
278
279 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
280 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
281 assert(HAS_FWD == _heap->has_forwarded_objects(), "Forwarded object status is sane");
282
283 Thread* thread = Thread::current();
284 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
285 ShenandoahMarkingContext* ctx = _heap->marking_context();
286 const ShenandoahCollectionSet* const cset = _heap->collection_set();
287 T* end = src + count;
288 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
289 T o = RawAccess<>::oop_load(elem_ptr);
290 if (!CompressedOops::is_null(o)) {
291 oop obj = CompressedOops::decode_not_null(o);
292 if (HAS_FWD && cset->is_in(obj)) {
293 oop fwd = resolve_forwarded_not_null(obj);
294 if (EVAC && obj == fwd) {
295 fwd = _heap->evacuate_object(obj, thread);
296 }
297 assert(obj != fwd || _heap->cancelled_gc(), "must be forwarded");
298 oop witness = ShenandoahHeap::cas_oop(fwd, elem_ptr, o);
299 obj = fwd;
300 }
301 if (ENQUEUE && !ctx->is_marked(obj)) {
302 queue.enqueue_known_active(obj);
303 }
304 }
305 }
306 }
307
308 template <class T>
309 void ShenandoahBarrierSet::arraycopy_barrier(T* src, T* dst, size_t count) {
310 if (count == 0) {
311 return;
312 }
313 int gc_state = _heap->gc_state();
314 if ((gc_state & ShenandoahHeap::MARKING) != 0) {
315 arraycopy_marking(src, dst, count);
316 } else if ((gc_state & ShenandoahHeap::EVACUATION) != 0) {
317 arraycopy_evacuation(src, count);
318 } else if ((gc_state & ShenandoahHeap::UPDATEREFS) != 0) {
319 arraycopy_update(src, count);
320 }
321 }
322
323 template <class T>
324 void ShenandoahBarrierSet::arraycopy_marking(T* src, T* dst, size_t count) {
325 assert(_heap->is_concurrent_mark_in_progress(), "only during marking");
326 T* array = ShenandoahSATBBarrier ? dst : src;
327 if (!_heap->marking_context()->allocated_after_mark_start(reinterpret_cast<HeapWord*>(array))) {
328 arraycopy_work<T, false, false, true>(array, count);
329 }
330 }
331
332 inline bool ShenandoahBarrierSet::need_bulk_update(HeapWord* ary) {
333 return ary < _heap->heap_region_containing(ary)->get_update_watermark();
334 }
335
336 template <class T>
337 void ShenandoahBarrierSet::arraycopy_evacuation(T* src, size_t count) {
338 assert(_heap->is_evacuation_in_progress(), "only during evacuation");
339 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
340 ShenandoahEvacOOMScope oom_evac;
341 arraycopy_work<T, true, true, false>(src, count);
342 }
343 }
344
345 template <class T>
346 void ShenandoahBarrierSet::arraycopy_update(T* src, size_t count) {
347 assert(_heap->is_update_refs_in_progress(), "only during update-refs");
348 if (need_bulk_update(reinterpret_cast<HeapWord*>(src))) {
349 arraycopy_work<T, true, false, false>(src, count);
350 }
351 }
352
353 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP