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.
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 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/shenandoahEvacOOMHandler.inline.hpp"
 34 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
 35 #include "gc/shenandoah/shenandoahMark.inline.hpp"
 36 #include "gc/shenandoah/shenandoahMarkingContext.inline.hpp"
 37 #include "gc/shenandoah/shenandoahNMethod.inline.hpp"
 38 #include "gc/shenandoah/shenandoahReferenceProcessor.hpp"
 39 #include "gc/shenandoah/shenandoahTaskqueue.inline.hpp"
 40 #include "memory/iterator.inline.hpp"
 41 #include "oops/compressedOops.inline.hpp"
 42 #include "runtime/atomicAccess.hpp"
 43 #include "runtime/javaThread.hpp"
 44 
 45 //
 46 // ========= Super
 47 //
 48 
 49 ShenandoahSuperClosure::ShenandoahSuperClosure() :
 50   MetadataVisitingOopIterateClosure(), _heap(ShenandoahHeap::heap()) {}
 51 
 52 ShenandoahSuperClosure::ShenandoahSuperClosure(ShenandoahReferenceProcessor* rp) :
 53   MetadataVisitingOopIterateClosure(rp), _heap(ShenandoahHeap::heap()) {}
 54 
 55 void ShenandoahSuperClosure::do_nmethod(nmethod* nm) {
 56   nm->run_nmethod_entry_barrier();
 57 }
 58 
 59 //
 60 // ========= Marking
 61 //
 62 ShenandoahFlushSATBHandshakeClosure::ShenandoahFlushSATBHandshakeClosure(SATBMarkQueueSet& qset) :
 63   HandshakeClosure("Shenandoah Flush SATB"),
 64   _qset(qset) {}
 65 
 66 void ShenandoahFlushSATBHandshakeClosure::do_thread(Thread* thread) {
 67   _qset.flush_queue(ShenandoahThreadLocalData::satb_mark_queue(thread));
 68 }
 69 
 70 ShenandoahMarkRefsSuperClosure::ShenandoahMarkRefsSuperClosure(ShenandoahObjToScanQueue* q,
 71                                                                ShenandoahReferenceProcessor* rp,
 72                                                                ShenandoahObjToScanQueue* old_q) :
 73         ShenandoahSuperClosure(rp),
 74         _queue(q),
 75         _old_queue(old_q),
 76         _mark_context(ShenandoahHeap::heap()->marking_context()),
 77         _weak(false) {}
 78 
 79 template<class T, ShenandoahGenerationType GENERATION>
 80 inline void ShenandoahMarkRefsSuperClosure::work(T* p) {
 81   ShenandoahMark::mark_through_ref<T, GENERATION>(p, _queue, _old_queue, _mark_context, _weak);
 82 }
 83 
 84 ShenandoahForwardedIsAliveClosure::ShenandoahForwardedIsAliveClosure() :
 85   _mark_context(ShenandoahHeap::heap()->marking_context()) {}
 86 
 87 bool ShenandoahForwardedIsAliveClosure::do_object_b(oop obj) {
 88   if (CompressedOops::is_null(obj)) {
 89     return false;
 90   }
 91   obj = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
 92   shenandoah_assert_not_forwarded_if(nullptr, obj, ShenandoahHeap::heap()->is_concurrent_mark_in_progress());
 93   return _mark_context->is_marked_or_old(obj);
 94 }
 95 
 96 ShenandoahIsAliveClosure::ShenandoahIsAliveClosure() :
 97   _mark_context(ShenandoahHeap::heap()->marking_context()) {}
 98 
 99 bool ShenandoahIsAliveClosure::do_object_b(oop obj) {
100   if (CompressedOops::is_null(obj)) {
101     return false;
102   }
103   shenandoah_assert_not_forwarded(nullptr, obj);
104   return _mark_context->is_marked_or_old(obj);
105 }
106 
107 BoolObjectClosure* ShenandoahIsAliveSelector::is_alive_closure() {
108   return ShenandoahHeap::heap()->has_forwarded_objects() ?
109          reinterpret_cast<BoolObjectClosure*>(&_fwd_alive_cl) :
110          reinterpret_cast<BoolObjectClosure*>(&_alive_cl);
111 }
112 
113 ShenandoahKeepAliveClosure::ShenandoahKeepAliveClosure() :
114   _bs(ShenandoahBarrierSet::barrier_set()) {}
115 
116 template <typename T>
117 void ShenandoahKeepAliveClosure::do_oop_work(T* p) {
118   assert(ShenandoahHeap::heap()->is_concurrent_mark_in_progress(), "Only for concurrent marking phase");
119   assert(ShenandoahHeap::heap()->is_concurrent_old_mark_in_progress() || !ShenandoahHeap::heap()->has_forwarded_objects(), "Not expected");
120 
121   T o = RawAccess<>::oop_load(p);
122   if (!CompressedOops::is_null(o)) {
123     oop obj = CompressedOops::decode_not_null(o);
124     _bs->enqueue(obj);
125   }
126 }
127 
128 
129 //
130 // ========= Evacuating + Roots
131 //
132 
133 template <bool CONCURRENT, bool STABLE_THREAD>
134 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop(oop* p) {
135   if (CONCURRENT) {
136     ShenandoahEvacOOMScope scope;
137     do_oop_work(p);
138   } else {
139     do_oop_work(p);
140   }
141 }
142 
143 template <bool CONCURRENT, bool STABLE_THREAD>
144 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop(narrowOop* p) {
145   if (CONCURRENT) {
146     ShenandoahEvacOOMScope scope;
147     do_oop_work(p);
148   } else {
149     do_oop_work(p);
150   }
151 }
152 
153 template <bool CONCURRENT, bool STABLE_THREAD>
154 template <class T>
155 void ShenandoahEvacuateUpdateRootClosureBase<CONCURRENT, STABLE_THREAD>::do_oop_work(T* p) {
156   assert(_heap->is_concurrent_weak_root_in_progress() ||
157          _heap->is_concurrent_strong_root_in_progress(),
158          "Only do this in root processing phase");
159 
160   T o = RawAccess<>::oop_load(p);
161   if (!CompressedOops::is_null(o)) {
162     oop obj = CompressedOops::decode_not_null(o);
163     if (_heap->in_collection_set(obj)) {
164       assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
165       shenandoah_assert_marked(p, obj);
166       oop resolved = ShenandoahBarrierSet::resolve_forwarded_not_null(obj);
167       if (resolved == obj) {
168         Thread* thr = STABLE_THREAD ? _thread : Thread::current();
169         assert(thr == Thread::current(), "Wrong thread");
170 
171         resolved = _heap->evacuate_object(obj, thr);
172       }
173       if (CONCURRENT) {
174         ShenandoahHeap::atomic_update_oop(resolved, p, o);
175       } else {
176         RawAccess<IS_NOT_NULL | MO_UNORDERED>::oop_store(p, resolved);
177       }
178     }
179   }
180 }
181 
182 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
183 ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::ShenandoahCleanUpdateWeakOopsClosure(IsAlive* is_alive, KeepAlive* keep_alive) :
184   _is_alive(is_alive), _keep_alive(keep_alive) {
185   if (!CONCURRENT) {
186     assert(SafepointSynchronize::is_at_safepoint(), "Must be at a safepoint");
187   }
188 }
189 
190 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
191 void ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::do_oop(oop* p) {
192   oop obj = RawAccess<>::oop_load(p);
193   if (!CompressedOops::is_null(obj)) {
194     if (_is_alive->do_object_b(obj)) {
195       _keep_alive->do_oop(p);
196     } else {
197       if (CONCURRENT) {
198         ShenandoahHeap::atomic_clear_oop(p, obj);
199       } else {
200         RawAccess<IS_NOT_NULL>::oop_store(p, oop());
201       }
202     }
203   }
204 }
205 
206 template <bool CONCURRENT, typename IsAlive, typename KeepAlive>
207 void ShenandoahCleanUpdateWeakOopsClosure<CONCURRENT, IsAlive, KeepAlive>::do_oop(narrowOop* p) {
208   ShouldNotReachHere();
209 }
210 
211 ShenandoahNMethodAndDisarmClosure::ShenandoahNMethodAndDisarmClosure(OopClosure* cl) :
212   NMethodToOopClosure(cl, true /* fix_relocations */) {}
213 
214 void ShenandoahNMethodAndDisarmClosure::do_nmethod(nmethod* nm) {
215   assert(nm != nullptr, "Sanity");
216   assert(!ShenandoahNMethod::gc_data(nm)->is_unregistered(), "Should not be here");
217   NMethodToOopClosure::do_nmethod(nm);
218   ShenandoahNMethod::disarm_nmethod(nm);
219 }
220 
221 
222 //
223 // ========= Update References
224 //
225 
226 template <ShenandoahGenerationType GENERATION>
227 ShenandoahMarkUpdateRefsClosure<GENERATION>::ShenandoahMarkUpdateRefsClosure(ShenandoahObjToScanQueue* q,
228                                                                              ShenandoahReferenceProcessor* rp,
229                                                                              ShenandoahObjToScanQueue* old_q) :
230   ShenandoahMarkRefsSuperClosure(q, rp, old_q) {
231   assert(_heap->is_stw_gc_in_progress(), "Can only be used for STW GC");
232 }
233 
234 template<ShenandoahGenerationType GENERATION>
235 template<class T>
236 inline void ShenandoahMarkUpdateRefsClosure<GENERATION>::work(T* p) {
237   // Update the location
238   _heap->non_conc_update_with_forwarded(p);
239 
240   // ...then do the usual thing
241   ShenandoahMarkRefsSuperClosure::work<T, GENERATION>(p);
242 }
243 
244 template<class T>
245 inline void ShenandoahNonConcUpdateRefsClosure::work(T* p) {
246   _heap->non_conc_update_with_forwarded(p);
247 }
248 
249 template<class T>
250 inline void ShenandoahConcUpdateRefsClosure::work(T* p) {
251   _heap->conc_update_with_forwarded(p);
252 }
253 
254 inline void ShenandoahFlushSATB::do_thread(Thread* thread) {
255   // Transfer any partial buffer to the qset for completed buffer processing.
256   _satb_qset.flush_queue(ShenandoahThreadLocalData::satb_mark_queue(thread));
257 }
258 
259 //
260 // ========= Utilities
261 //
262 
263 #ifdef ASSERT
264 template <class T>
265 void ShenandoahAssertNotForwardedClosure::do_oop_work(T* p) {
266   T o = RawAccess<>::oop_load(p);
267   if (!CompressedOops::is_null(o)) {
268     oop obj = CompressedOops::decode_not_null(o);
269     shenandoah_assert_not_forwarded(p, obj);
270   }
271 }
272 
273 void ShenandoahAssertNotForwardedClosure::do_oop(narrowOop* p) { do_oop_work(p); }
274 void ShenandoahAssertNotForwardedClosure::do_oop(oop* p)       { do_oop_work(p); }
275 #endif
276 
277 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHCLOSURES_INLINE_HPP