1 /*
2 * Copyright (c) 2015, 2019, Red Hat, Inc. All rights reserved.
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 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
25 #define SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP
26
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shenandoah/shenandoahAsserts.hpp"
29 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
30 #include "gc/shenandoah/shenandoahCollectionSet.inline.hpp"
31 #include "gc/shenandoah/shenandoahForwarding.inline.hpp"
32 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
33 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
34 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
35 #include "gc/shenandoah/shenandoahSafepoint.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 assert(ShenandoahHeap::heap()->in_collection_set(p) ||
42 ShenandoahSafepoint::is_at_shenandoah_safepoint(),
43 "No forwarding oops outside cset");
44 return ShenandoahForwarding::get_forwardee(p);
45 }
46
47 inline oop ShenandoahBarrierSet::resolve_forwarded(oop p) {
48 if (((HeapWord*) p) != NULL) {
49 return resolve_forwarded_not_null(p);
50 } else {
51 return p;
52 }
53 }
54
55 inline oop ShenandoahBarrierSet::resolve_forwarded_checked(oop p) {
56 if (p == NULL) return p;
57 ShenandoahHeap* const heap = ShenandoahHeap::heap();
58 if (heap->in_collection_set(p) ||
59 (heap->is_concurrent_traversal_in_progress() && heap->is_degenerated_gc_in_progress())) {
60 return resolve_forwarded_not_null(p);
61 } else {
62 return p;
63 }
64 }
65
66 inline void ShenandoahBarrierSet::enqueue(oop obj) {
67 shenandoah_assert_not_forwarded_if(NULL, obj, _heap->is_concurrent_traversal_in_progress());
68 assert(_satb_mark_queue_set.is_active(), "only get here when SATB active");
69
70 // Filter marked objects before hitting the SATB queues. The same predicate would
71 // be used by SATBMQ::filter to eliminate already marked objects downstream, but
72 // filtering here helps to avoid wasteful SATB queueing work to begin with.
73 if (!_heap->requires_marking<false>(obj)) return;
74
75 ShenandoahThreadLocalData::satb_mark_queue(Thread::current()).enqueue_known_active(obj);
76 }
77
78 template <DecoratorSet decorators, typename T>
79 inline void ShenandoahBarrierSet::satb_barrier(T *field) {
80 if (HasDecorator<decorators, IS_DEST_UNINITIALIZED>::value ||
81 HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
82 return;
83 }
84 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
85 T heap_oop = RawAccess<>::oop_load(field);
86 if (!CompressedOops::is_null(heap_oop)) {
87 enqueue(CompressedOops::decode(heap_oop));
88 }
89 }
90 }
91
92 inline void ShenandoahBarrierSet::satb_enqueue(oop value) {
93 assert(value != NULL, "checked before");
94 if (ShenandoahSATBBarrier && _heap->is_concurrent_mark_in_progress()) {
95 enqueue(value);
96 }
97 }
98
99 inline void ShenandoahBarrierSet::storeval_barrier(oop obj) {
100 if (obj != NULL && ShenandoahStoreValEnqueueBarrier && _heap->is_concurrent_traversal_in_progress()) {
101 enqueue(obj);
102 }
103 }
104
105 inline void ShenandoahBarrierSet::keep_alive_barrier(oop value) {
106 assert(value != NULL, "checked before");
107 if (ShenandoahKeepAliveBarrier && _heap->is_concurrent_mark_in_progress()) {
108 enqueue(value);
109 }
110 }
111
112 inline void ShenandoahBarrierSet::keep_alive_if_weak(DecoratorSet decorators, oop value) {
113 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
114 const bool on_strong_oop_ref = (decorators & ON_STRONG_OOP_REF) != 0;
115 const bool peek = (decorators & AS_NO_KEEPALIVE) != 0;
116 if (!peek && !on_strong_oop_ref) {
117 keep_alive_barrier(value);
118 }
119 }
120
121 template <DecoratorSet decorators>
122 inline void ShenandoahBarrierSet::keep_alive_if_weak(oop value) {
123 assert((decorators & ON_UNKNOWN_OOP_REF) == 0, "Reference strength must be known");
124 if (!HasDecorator<decorators, ON_STRONG_OOP_REF>::value &&
125 !HasDecorator<decorators, AS_NO_KEEPALIVE>::value) {
126 keep_alive_barrier(value);
127 }
128 }
129
130 template <DecoratorSet decorators, typename BarrierSetT>
131 template <typename T>
132 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_not_in_heap(T* addr) {
133 oop value = Raw::oop_load_not_in_heap(addr);
134 if (value != NULL) {
135 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
136 value = bs->load_reference_barrier_native(value, addr);
137 if (value != NULL) {
138 bs->keep_alive_if_weak<decorators>(value);
139 }
140 }
141 return value;
142 }
143
144 template <DecoratorSet decorators, typename BarrierSetT>
145 template <typename T>
146 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap(T* addr) {
147 oop value = Raw::oop_load_in_heap(addr);
148 if (value != NULL) {
149 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
150 value = bs->load_reference_barrier_not_null(value);
151 bs->keep_alive_if_weak<decorators>(value);
152 }
153 return value;
154 }
155
156 template <DecoratorSet decorators, typename BarrierSetT>
157 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_load_in_heap_at(oop base, ptrdiff_t offset) {
158 oop value = Raw::oop_load_in_heap_at(base, offset);
159 if (value != NULL) {
160 ShenandoahBarrierSet *const bs = ShenandoahBarrierSet::barrier_set();
161 value = bs->load_reference_barrier_not_null(value);
162 bs->keep_alive_if_weak(AccessBarrierSupport::resolve_possibly_unknown_oop_ref_strength<decorators>(base, offset),
163 value);
164 }
165 return value;
166 }
167
168 template <DecoratorSet decorators, typename BarrierSetT>
169 template <typename T>
170 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_not_in_heap(T* addr, oop value) {
171 shenandoah_assert_marked_if(NULL, value, !CompressedOops::is_null(value) && ShenandoahHeap::heap()->is_evacuation_in_progress());
172 ShenandoahBarrierSet* const bs = ShenandoahBarrierSet::barrier_set();
173 bs->storeval_barrier(value);
174 bs->satb_barrier<decorators>(addr);
175 Raw::oop_store(addr, value);
176 }
177
178 template <DecoratorSet decorators, typename BarrierSetT>
179 template <typename T>
180 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap(T* addr, oop value) {
181 shenandoah_assert_not_in_cset_loc_except(addr, ShenandoahHeap::heap()->cancelled_gc());
182 shenandoah_assert_not_forwarded_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
183 shenandoah_assert_not_in_cset_except (addr, value, value == NULL || ShenandoahHeap::heap()->cancelled_gc() || !ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
184
185 oop_store_not_in_heap(addr, value);
186 }
187
188 template <DecoratorSet decorators, typename BarrierSetT>
189 inline void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_store_in_heap_at(oop base, ptrdiff_t offset, oop value) {
190 oop_store_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), value);
191 }
192
193 template <DecoratorSet decorators, typename BarrierSetT>
194 template <typename T>
195 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_not_in_heap(T* addr, oop compare_value, oop new_value) {
196 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
197 bs->storeval_barrier(new_value);
198
199 oop res;
200 oop expected = compare_value;
201 do {
202 compare_value = expected;
203 res = Raw::oop_atomic_cmpxchg(addr, compare_value, new_value);
204 expected = res;
205 } while ((compare_value != expected) && (resolve_forwarded_checked(compare_value) == resolve_forwarded_checked(expected)));
206
207 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
208 // because it must be the previous value.
209 if (res != NULL) {
210 res = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(res);
211 bs->satb_enqueue(res);
212 }
213 return res;
214 }
215
216 template <DecoratorSet decorators, typename BarrierSetT>
217 template <typename T>
218 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap(T* addr, oop compare_value, oop new_value) {
219 return oop_atomic_cmpxchg_not_in_heap(addr, compare_value, new_value);
220 }
221
222 template <DecoratorSet decorators, typename BarrierSetT>
223 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_cmpxchg_in_heap_at(oop base, ptrdiff_t offset, oop compare_value, oop new_value) {
224 return oop_atomic_cmpxchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), compare_value, new_value);
225 }
226
227 template <DecoratorSet decorators, typename BarrierSetT>
228 template <typename T>
229 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_not_in_heap(T* addr, oop new_value) {
230 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
231 bs->storeval_barrier(new_value);
232
233 oop previous = Raw::oop_atomic_xchg(addr, new_value);
234
235 // Note: We don't need a keep-alive-barrier here. We already enqueue any loaded reference for SATB anyway,
236 // because it must be the previous value.
237 if (previous != NULL) {
238 previous = ShenandoahBarrierSet::barrier_set()->load_reference_barrier_not_null(previous);
239 bs->satb_enqueue(previous);
240 }
241 return previous;
242 }
243
244 template <DecoratorSet decorators, typename BarrierSetT>
245 template <typename T>
246 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap(T* addr, oop new_value) {
247 return oop_atomic_xchg_not_in_heap(addr, new_value);
248 }
249
250 template <DecoratorSet decorators, typename BarrierSetT>
251 inline oop ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_atomic_xchg_in_heap_at(oop base, ptrdiff_t offset, oop new_value) {
252 return oop_atomic_xchg_in_heap(AccessInternal::oop_field_addr<decorators>(base, offset), new_value);
253 }
254
255 // Clone barrier support
256 template <DecoratorSet decorators, typename BarrierSetT>
257 void ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::clone_in_heap(oop src, oop dst, size_t size) {
258 if (ShenandoahCloneBarrier) {
259 ShenandoahBarrierSet::barrier_set()->clone_barrier_runtime(src);
260 }
261 Raw::clone(src, dst, size);
262 }
263
264 template <DecoratorSet decorators, typename BarrierSetT>
265 template <typename T>
266 bool ShenandoahBarrierSet::AccessBarrier<decorators, BarrierSetT>::oop_arraycopy_in_heap(arrayOop src_obj, size_t src_offset_in_bytes, T* src_raw,
267 arrayOop dst_obj, size_t dst_offset_in_bytes, T* dst_raw,
268 size_t length) {
269 ShenandoahBarrierSet* bs = ShenandoahBarrierSet::barrier_set();
270 bs->arraycopy_pre(arrayOopDesc::obj_offset_to_raw(src_obj, src_offset_in_bytes, src_raw),
271 arrayOopDesc::obj_offset_to_raw(dst_obj, dst_offset_in_bytes, dst_raw),
272 length);
273 return Raw::oop_arraycopy_in_heap(src_obj, src_offset_in_bytes, src_raw, dst_obj, dst_offset_in_bytes, dst_raw, length);
274 }
275
276 template <class T, bool HAS_FWD, bool EVAC, bool ENQUEUE>
277 void ShenandoahBarrierSet::arraycopy_work(T* src, size_t count) {
278 Thread* thread = Thread::current();
279 SATBMarkQueue& queue = ShenandoahThreadLocalData::satb_mark_queue(thread);
280 ShenandoahMarkingContext* ctx = _heap->marking_context();
281 const ShenandoahCollectionSet* const cset = _heap->collection_set();
282 T* end = src + count;
283 for (T* elem_ptr = src; elem_ptr < end; elem_ptr++) {
284 T o = RawAccess<>::oop_load(elem_ptr);
285 if (!CompressedOops::is_null(o)) {
286 oop obj = CompressedOops::decode_not_null(o);
287 if (HAS_FWD && cset->is_in((HeapWord *) obj)) {
288 assert(_heap->has_forwarded_objects(), "only get here with forwarded objects");
289 oop fwd = resolve_forwarded_not_null(obj);
290 if (EVAC && obj == fwd) {
291 fwd = _heap->evacuate_object(obj, thread);
292 }
293 assert(obj != fwd || _heap->cancelled_gc(), "must be forwarded");
294 oop witness = ShenandoahHeap::cas_oop(fwd, elem_ptr, o);
295 obj = fwd;
296 }
297 if (ENQUEUE && !ctx->is_marked(obj)) {
298 queue.enqueue_known_active(obj);
299 }
300 }
301 }
302 }
303
304 template <class T>
305 void ShenandoahBarrierSet::arraycopy_pre_work(T* src, T* dst, size_t count) {
306 if (_heap->is_concurrent_mark_in_progress()) {
307 if (_heap->has_forwarded_objects()) {
308 arraycopy_work<T, true, false, true>(dst, count);
309 } else {
310 arraycopy_work<T, false, false, true>(dst, count);
311 }
312 }
313
314 arraycopy_update_impl(src, count);
315 }
316
317 void ShenandoahBarrierSet::arraycopy_pre(oop* src, oop* dst, size_t count) {
318 arraycopy_pre_work(src, dst, count);
319 }
320
321 void ShenandoahBarrierSet::arraycopy_pre(narrowOop* src, narrowOop* dst, size_t count) {
322 arraycopy_pre_work(src, dst, count);
323 }
324
325 template <class T>
326 void ShenandoahBarrierSet::arraycopy_update_impl(T* src, size_t count) {
327 if (_heap->is_evacuation_in_progress()) {
328 ShenandoahEvacOOMScope oom_evac;
329 arraycopy_work<T, true, true, false>(src, count);
330 } else if (_heap->is_concurrent_traversal_in_progress()){
331 ShenandoahEvacOOMScope oom_evac;
332 arraycopy_work<T, true, true, true>(src, count);
333 } else if (_heap->has_forwarded_objects()) {
334 arraycopy_work<T, true, false, false>(src, count);
335 }
336 }
337
338 void ShenandoahBarrierSet::arraycopy_update(oop* src, size_t count) {
339 arraycopy_update_impl(src, count);
340 }
341
342 void ShenandoahBarrierSet::arraycopy_update(narrowOop* src, size_t count) {
343 arraycopy_update_impl(src, count);
344 }
345
346 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHBARRIERSET_INLINE_HPP