1 /*
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  3  * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
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  7  * under the terms of the GNU General Public License version 2 only, as
  8  * published by the Free Software Foundation.
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 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).
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 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
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 25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHCLOSURES_INLINE_HPP
 26 #define SHARE_GC_SHENANDOAH_SHENANDOAHCLOSURES_INLINE_HPP
 27 
 28 #include "gc/shenandoah/shenandoahClosures.hpp"
 29 
 30 #include "gc/shared/barrierSetNMethod.hpp"
 31 #include "gc/shenandoah/shenandoahAsserts.hpp"
 32 #include "gc/shenandoah/shenandoahBarrierSet.hpp"
 33 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
 34 #include "gc/shenandoah/shenandoahMark.inline.hpp"
 35 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
 36 #include "gc/shenandoah/shenandoahNMethod.inline.hpp"
 37 #include "gc/shenandoah/shenandoahReferenceProcessor.hpp"
 38 #include "gc/shenandoah/shenandoahTaskqueue.inline.hpp"
 39 #include "memory/iterator.inline.hpp"
 40 #include "oops/compressedOops.inline.hpp"
 41 #include "runtime/atomicAccess.hpp"
 42 #include "runtime/javaThread.hpp"
 43 
 44 //
 45 // ========= Super
 46 //
 47 
 48 ShenandoahSuperClosure::ShenandoahSuperClosure() :
 49   MetadataVisitingOopIterateClosure(), _heap(ShenandoahHeap::heap()) {}
 50 
 51 ShenandoahSuperClosure::ShenandoahSuperClosure(ShenandoahReferenceProcessor* rp) :
 52   MetadataVisitingOopIterateClosure(rp), _heap(ShenandoahHeap::heap()) {}
 53 
 54 void ShenandoahSuperClosure::do_nmethod(nmethod* nm) {
 55   nm->run_nmethod_entry_barrier();
 56 }
 57 
 58 //
 59 // ========= Marking
 60 //
 61 ShenandoahFlushSATBHandshakeClosure::ShenandoahFlushSATBHandshakeClosure(SATBMarkQueueSet& qset) :
 62   HandshakeClosure("Shenandoah Flush SATB"),
 63   _qset(qset) {}
 64 
 65 void ShenandoahFlushSATBHandshakeClosure::do_thread(Thread* thread) {
 66   _qset.flush_queue(ShenandoahThreadLocalData::satb_mark_queue(thread));
 67 }
 68 
 69 ShenandoahMarkRefsSuperClosure::ShenandoahMarkRefsSuperClosure(ShenandoahObjToScanQueue* q,
 70                                                                ShenandoahReferenceProcessor* rp,
 71                                                                ShenandoahObjToScanQueue* old_q) :
 72         ShenandoahSuperClosure(rp),
 73         _queue(q),
 74         _old_queue(old_q),
 75         _mark_context(ShenandoahHeap::heap()->marking_context()),
 76         _weak(false) {}
 77 
 78 template<class T, ShenandoahGenerationType GENERATION>
 79 inline void ShenandoahMarkRefsSuperClosure::work(T* p) {
 80   ShenandoahMark::mark_through_ref<T, GENERATION>(p, _queue, _old_queue, _mark_context, _weak);
 81 }
 82 
 83 ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() :
 84   _mark_context(ShenandoahHeap::heap()->marking_context()) {}
 85 
 86 bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) {
 87   if (CompressedOops::is_null(obj)) {
 88     return false;
 89   }
 90   obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
 91   shenandoah_assert_not_forwarded_if(nullptr, obj, ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
 92   return _mark_context->is_marked_or_old(obj);
 93 }
 94 
 95 ShenandoahIsAliveClosure::ShenandoahIsAliveClosure() :
 96   _mark_context(ShenandoahHeap::heap()->marking_context()) {}
 97 
 98 bool ShenandoahIsAliveClosure::do_object_b(oop obj) {
 99   if (CompressedOops::is_null(obj)) {
100     return false;
101   }
102   shenandoah_assert_not_forwarded(nullptr, obj);
103   return _mark_context->is_marked_or_old(obj);
104 }
105 
106 BoolObjectClosure* ShenandoahIsAliveSelector::is_alive_closure() {
107   return ShenandoahHeap::heap()->has_forwarded_objects() ?
108          reinterpret_cast<BoolObjectClosure*>(&_fwd_alive_cl) :
109          reinterpret_cast<BoolObjectClosure*>(&_alive_cl);
110 }
111 
112 ShenandoahKeepAliveClosure::ShenandoahKeepAliveClosure() :
113   _bs(ShenandoahBarrierSet::barrier_set()) {}
114 
115 template <typename T>
116 void ShenandoahKeepAliveClosure::do_oop_work(T* p) {
117   assert(ShenandoahHeap::heap()->is_concurrent_mark_in_progress(), "Only for concurrent marking phase");
118   assert(ShenandoahHeap::heap()->is_concurrent_old_mark_in_progress() || !ShenandoahHeap::heap()->has_forwarded_objects(), "Not expected");
119 
120   T o = RawAccess<>::oop_load(p);
121   if (!CompressedOops::is_null(o)) {
122     oop obj = CompressedOops::decode_not_null(o);
123     _bs->enqueue(obj);
124   }
125 }
126 
127 
128 //
129 // ========= Evacuating + Roots
130 //
131 
132 template <bool CONCURRENT, bool STABLE_THREAD>
133 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop(oop* p) {
134   do_oop_work(p);
135 }
136 
137 template <bool CONCURRENT, bool STABLE_THREAD>
138 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop(narrowOop* p) {
139   do_oop_work(p);
140 }
141 
142 template <bool CONCURRENT, bool STABLE_THREAD>
143 template <class T>
144 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop_work(T* p) {
145   assert(_heap->is_concurrent_weak_root_in_progress() ||
146          _heap->is_concurrent_strong_root_in_progress(),
147          "Only do this in root processing phase");
148 
149   T o = RawAccess<>::oop_load(p);
150   if (!CompressedOops::is_null(o)) {
151     oop obj = CompressedOops::decode_not_null(o);
152     if (_heap->in_collection_set(obj)) {
153       assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
154       shenandoah_assert_marked(p, obj);
155       oop resolved = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
156       if (resolved == obj) {
157         Thread* thr = STABLE_THREAD ? _thread : Thread::current();
158         assert(thr == Thread::current(), "Wrong thread");
159 
160         resolved = _heap->evacuate_object(obj, thr);
161       }
162       if (CONCURRENT) {
163         ShenandoahHeap::atomic_update_oop(resolved, p, o);
164       } else {
165         RawAccess<IS_NOT_NULL | MO_UNORDERED>::oop_store(p, resolved);
166       }
167     }
168   }
169 }
170 
171 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
172 ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::ShenandoahCleanUpdateWeakOopsClosure(IsAlive* is_alive, KeepAlive* keep_alive) :
173   _is_alive(is_alive), _keep_alive(keep_alive) {
174   if (!CONCURRENT) {
175     assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
176   }
177 }
178 
179 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
180 void ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::do_oop(oop* p) {
181   oop obj = RawAccess<>::oop_load(p);
182   if (!CompressedOops::is_null(obj)) {
183     if (_is_alive->do_object_b(obj)) {
184       _keep_alive->do_oop(p);
185     } else {
186       if (CONCURRENT) {
187         ShenandoahHeap::atomic_clear_oop(p, obj);
188       } else {
189         RawAccess<IS_NOT_NULL>::oop_store(p, oop());
190       }
191     }
192   }
193 }
194 
195 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
196 void ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::do_oop(narrowOop* p) {
197   ShouldNotReachHere();
198 }
199 
200 ShenandoahNMethodAndDisarmClosure::ShenandoahNMethodAndDisarmClosure(OopClosure* cl) :
201   NMethodToOopClosure(cl, true /* fix_relocations */) {}
202 
203 void ShenandoahNMethodAndDisarmClosure::do_nmethod(nmethod* nm) {
204   assert(nm != nullptr, "Sanity");
205   assert(!ShenandoahNMethod::gc_data(nm)->is_unregistered(), "Should not be here");
206   NMethodToOopClosure::do_nmethod(nm);
207   ShenandoahNMethod::disarm_nmethod(nm);
208 }
209 
210 
211 //
212 // ========= Update References
213 //
214 
215 template <ShenandoahGenerationType GENERATION>
216 ShenandoahMarkUpdateRefsClosure<GENERATION>::ShenandoahMarkUpdateRefsClosure(ShenandoahObjToScanQueue* q,
217                                                                              ShenandoahReferenceProcessor* rp,
218                                                                              ShenandoahObjToScanQueue* old_q) :
219   ShenandoahMarkRefsSuperClosure(q, rp, old_q) {
220   assert(_heap->is_stw_gc_in_progress(), "Can only be used for STW GC");
221 }
222 
223 template<ShenandoahGenerationType GENERATION>
224 template<class T>
225 inline void ShenandoahMarkUpdateRefsClosure<GENERATION>::work(T* p) {
226   // Update the location
227   _heap->non_conc_update_with_forwarded(p);
228 
229   // ...then do the usual thing
230   ShenandoahMarkRefsSuperClosure::work<T, GENERATION>(p);
231 }
232 
233 template<class T>
234 inline void ShenandoahNonConcUpdateRefsClosure::work(T* p) {
235   _heap->non_conc_update_with_forwarded(p);
236 }
237 
238 template<class T>
239 inline void ShenandoahConcUpdateRefsClosure::work(T* p) {
240   _heap->conc_update_with_forwarded(p);
241 }
242 
243 inline void ShenandoahFlushSATB::do_thread(Thread* thread) {
244   // Transfer any partial buffer to the qset for completed buffer processing.
245   _satb_qset.flush_queue(ShenandoahThreadLocalData::satb_mark_queue(thread));
246 }
247 
248 //
249 // ========= Utilities
250 //
251 
252 #ifdef ASSERT
253 template <class T>
254 void ShenandoahAssertNotForwardedClosure::do_oop_work(T* p) {
255   T o = RawAccess<>::oop_load(p);
256   if (!CompressedOops::is_null(o)) {
257     oop obj = CompressedOops::decode_not_null(o);
258     shenandoah_assert_not_forwarded(p, obj);
259   }
260 }
261 
262 void ShenandoahAssertNotForwardedClosure::do_oop(narrowOop* p) { do_oop_work(p); }
263 void ShenandoahAssertNotForwardedClosure::do_oop(oop* p)       { do_oop_work(p); }
264 #endif
265 
266 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCLOSURES_INLINE_HPP