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1 /**
2  * Copyright (c) 2021-2024 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "runtime/mem/gc/gc_root.h"
17 
18 #include "libpandafile/panda_cache.h"
19 #include "runtime/include/object_header.h"
20 #include "runtime/include/runtime.h"
21 #include "runtime/include/stack_walker-inl.h"
22 #include "runtime/mem/refstorage/reference_storage.h"
23 #include "runtime/mem/gc/card_table-inl.h"
24 #include "runtime/mem/gc/gc.h"
25 #include "runtime/mem/gc/gc_root_type.h"
26 #include "runtime/mem/object_helpers.h"
27 #include "runtime/mem/refstorage/global_object_storage.h"
28 #include "runtime/include/panda_vm.h"
29 
30 namespace ark::mem {
31 
GCRoot(RootType type,ObjectHeader * obj)32 GCRoot::GCRoot(RootType type, ObjectHeader *obj)
33 {
34     type_ = type;
35     fromObject_ = nullptr;
36     object_ = obj;
37 }
38 
GCRoot(RootType type,ObjectHeader * fromObject,ObjectHeader * obj)39 GCRoot::GCRoot(RootType type, ObjectHeader *fromObject, ObjectHeader *obj)
40 {
41     ASSERT((fromObject != nullptr && type == RootType::ROOT_TENURED) || type != RootType::ROOT_TENURED);
42     type_ = type;
43     fromObject_ = fromObject;
44     object_ = obj;
45 }
46 
GetType() const47 RootType GCRoot::GetType() const
48 {
49     return type_;
50 }
51 
GetObjectHeader() const52 ObjectHeader *GCRoot::GetObjectHeader() const
53 {
54     return object_;
55 }
56 
GetFromObjectHeader() const57 ObjectHeader *GCRoot::GetFromObjectHeader() const
58 {
59     ASSERT((fromObject_ != nullptr && type_ == RootType::ROOT_TENURED) || type_ != RootType::ROOT_TENURED);
60     return fromObject_;
61 }
62 
operator <<(std::ostream & os,const GCRoot & root)63 std::ostream &operator<<(std::ostream &os, const GCRoot &root)
64 {
65     switch (root.GetType()) {
66         case RootType::ROOT_CLASS:
67             os << "ROOT CLASS";
68             break;
69         case RootType::ROOT_FRAME:
70             os << "ROOT FRAME";
71             break;
72         case RootType::ROOT_THREAD:
73             os << "ROOT THREAD";
74             break;
75         case RootType::ROOT_TENURED:
76             os << "ROOT TENURED";
77             break;
78         case RootType::ROOT_NATIVE_GLOBAL:
79             os << "ROOT NATIVE_GLOBAL";
80             break;
81         case RootType::ROOT_NATIVE_LOCAL:
82             os << "ROOT NATIVE_LOCAL";
83             break;
84         case RootType::ROOT_AOT_STRING_SLOT:
85             os << "ROOT AOT_STRING_SLOT";
86             break;
87         case RootType::ROOT_UNKNOWN:
88         default:
89             LOG(FATAL, GC) << "ROOT UNKNOWN";
90             break;
91     }
92     os << std::hex << " " << root.GetObjectHeader() << std::endl;
93     return os;
94 }
95 
96 template <class LanguageConfig>
VisitNonHeapRoots(const GCRootVisitor & gcRootVisitor,VisitGCRootFlags flags) const97 void RootManager<LanguageConfig>::VisitNonHeapRoots(const GCRootVisitor &gcRootVisitor, VisitGCRootFlags flags) const
98 {
99     VisitLocalRoots(gcRootVisitor);
100     VisitClassRoots(gcRootVisitor, flags);
101     VisitAotStringRoots(gcRootVisitor, flags);
102     VisitClassLinkerContextRoots(gcRootVisitor);
103     VisitVmRoots(gcRootVisitor);
104     auto *storage = vm_->GetGlobalObjectStorage();
105     if (storage != nullptr) {
106         storage->VisitObjects(gcRootVisitor, mem::RootType::ROOT_NATIVE_GLOBAL);
107     }
108 }
109 
110 template <class LanguageConfig>
VisitCardTableRoots(CardTable * cardTable,ObjectAllocatorBase * allocator,GCRootVisitor rootVisitor,MemRangeChecker rangeChecker,ObjectChecker rangeObjectChecker,ObjectChecker fromObjectChecker,uint32_t processedFlag) const111 void RootManager<LanguageConfig>::VisitCardTableRoots(CardTable *cardTable, ObjectAllocatorBase *allocator,
112                                                       GCRootVisitor rootVisitor, MemRangeChecker rangeChecker,
113                                                       ObjectChecker rangeObjectChecker, ObjectChecker fromObjectChecker,
114                                                       uint32_t processedFlag) const
115 {
116     cardTable->VisitMarked(
117         [&allocator, &rootVisitor, &rangeChecker, &rangeObjectChecker, &fromObjectChecker,
118          &cardTable](MemRange memRange) {
119             if (rangeChecker(memRange)) {
120                 auto objectsInRangeVisitor = [&rootVisitor, &rangeObjectChecker,
121                                               &fromObjectChecker](ObjectHeader *objectHeader) {
122                     auto traverseObjectInRange = [&rootVisitor, &rangeObjectChecker](ObjectHeader *fromObject,
123                                                                                      ObjectHeader *objectToTraverse) {
124                         if (rangeObjectChecker(objectToTraverse)) {
125                             // The weak references from dynobjects should not be regarded as roots.
126                             TaggedValue value(objectToTraverse);
127                             if (!value.IsWeak()) {
128                                 rootVisitor(GCRoot(RootType::ROOT_TENURED, fromObject, objectToTraverse));
129                             }
130                         }
131                     };
132                     if (objectHeader->ClassAddr<BaseClass>() != nullptr && fromObjectChecker(objectHeader)) {
133                         // The class may be null in the situation when a new object is allocated in the card
134                         // we are visiting now, but the class is not set yet.
135                         ObjectHelpers<LanguageConfig::LANG_TYPE>::TraverseAllObjects(objectHeader,
136                                                                                      traverseObjectInRange);
137                     }
138                 };
139                 allocator->IterateOverObjectsInRange(memRange, objectsInRangeVisitor);
140             } else {
141                 auto *card = cardTable->GetCardPtr(memRange.GetStartAddress());
142                 // Use SetCard instead of MarkCard because the card can be IsProcessed
143                 card->SetCard(CardTable::Card::GetMarkedValue());
144             }
145         },
146         processedFlag);
147 }
148 
149 template <class LanguageConfig>
VisitRootsForThread(ManagedThread * thread,const GCRootVisitor & gcRootVisitor) const150 void RootManager<LanguageConfig>::VisitRootsForThread(ManagedThread *thread, const GCRootVisitor &gcRootVisitor) const
151 {
152     LOG(DEBUG, GC) << "Start collecting roots for thread " << thread->GetId();
153 
154     thread->VisitGCRoots([&gcRootVisitor](ObjectHeader *obj) {
155         LOG(DEBUG, GC) << " Found root for thread" << GetDebugInfoAboutObject(obj);
156         gcRootVisitor({RootType::ROOT_THREAD, obj});
157     });
158     LOG(DEBUG, GC) << "Finish collecting roots for thread " << thread->GetId();
159 }
160 
161 template <class LanguageConfig>
VisitLocalRoots(const GCRootVisitor & gcRootVisitor) const162 void RootManager<LanguageConfig>::VisitLocalRoots(const GCRootVisitor &gcRootVisitor) const
163 {
164     auto threadVisitor = [this, &gcRootVisitor](ManagedThread *thread) {
165         VisitRootsForThread(thread, gcRootVisitor);
166         for (auto stack = StackWalker::Create(thread); stack.HasFrame(); stack.NextFrame()) {
167             LOG(DEBUG, GC) << " VisitRoots frame " << std::hex << stack.GetFp();
168             stack.IterateObjects([this, &gcRootVisitor](auto &vreg) {
169                 this->VisitRegisterRoot(vreg, gcRootVisitor);
170                 return true;
171             });
172         }
173         return true;
174     };
175     vm_->GetThreadManager()->EnumerateThreads(threadVisitor);
176 }
177 
178 template <class LanguageConfig>
179 template <class VRegRef>
VisitRegisterRoot(const VRegRef & vRegister,const GCRootVisitor & gcRootVisitor) const180 void RootManager<LanguageConfig>::VisitRegisterRoot(const VRegRef &vRegister, const GCRootVisitor &gcRootVisitor) const
181 {
182     if (UNLIKELY(vRegister.HasObject())) {
183         ObjectHeader *objectHeader = vRegister.GetReference();
184         if (objectHeader != nullptr) {
185             LOG(DEBUG, GC) << " Found root for register" << GetDebugInfoAboutObject(objectHeader);
186             gcRootVisitor({RootType::ROOT_FRAME, objectHeader});
187         }
188     }
189 }
190 
191 template <class LanguageConfig>
VisitVmRoots(const GCRootVisitor & gcRootVisitor) const192 void RootManager<LanguageConfig>::VisitVmRoots(const GCRootVisitor &gcRootVisitor) const
193 {
194     vm_->VisitVmRoots(gcRootVisitor);
195 }
196 
197 template <class LanguageConfig>
VisitAotStringRoots(const GCRootVisitor & gcRootVisitor,VisitGCRootFlags flags) const198 void RootManager<LanguageConfig>::VisitAotStringRoots(const GCRootVisitor &gcRootVisitor, VisitGCRootFlags flags) const
199 {
200     trace::ScopedTrace scopedTrace(__FUNCTION__);
201     LOG(DEBUG, GC) << "Start collecting AOT string slot roots";
202     Runtime::GetCurrent()->GetClassLinker()->GetAotManager()->VisitAotStringRoots(
203         [&gcRootVisitor](ObjectHeader **slot) {
204             gcRootVisitor({RootType::ROOT_AOT_STRING_SLOT, *slot});
205         },
206         (flags & VisitGCRootFlags::ACCESS_ROOT_AOT_STRINGS_ONLY_YOUNG) != 0);
207     LOG(DEBUG, GC) << "Finish collecting AOT string slot roots";
208 }
209 
210 template <class LanguageConfig>
UpdateAotStringRoots()211 void RootManager<LanguageConfig>::UpdateAotStringRoots()
212 {
213     trace::ScopedTrace scopedTrace(__FUNCTION__);
214     LOG(DEBUG, GC) << "=== AOT string slot roots update. BEGIN ===";
215     auto hm = vm_->GetHeapManager();
216     Runtime::GetCurrent()->GetClassLinker()->GetAotManager()->UpdateAotStringRoots(
217         [](ObjectHeader **root) {
218             auto rootValue = *root;
219             if (rootValue->IsForwarded()) {
220                 *root = ::ark::mem::GetForwardAddress(rootValue);
221             }
222         },
223         [&hm](const ObjectHeader *root) { return hm->IsObjectInYoungSpace(root); });
224     LOG(DEBUG, GC) << "=== AOT string slot roots update. END ===";
225 }
226 
227 template <class LanguageConfig>
UpdateVmRefs()228 void RootManager<LanguageConfig>::UpdateVmRefs()
229 {
230     vm_->UpdateVmRefs();
231 }
232 
233 template <class LanguageConfig>
UpdateGlobalObjectStorage()234 void RootManager<LanguageConfig>::UpdateGlobalObjectStorage()
235 {
236     auto globalStorage = vm_->GetGlobalObjectStorage();
237     if (globalStorage != nullptr) {
238         globalStorage->UpdateMovedRefs();
239     }
240 }
241 
242 template <class LanguageConfig>
VisitClassRoots(const GCRootVisitor & gcRootVisitor,VisitGCRootFlags flags) const243 void RootManager<LanguageConfig>::VisitClassRoots(const GCRootVisitor &gcRootVisitor, VisitGCRootFlags flags) const
244 {
245     LOG(DEBUG, GC) << "Start collecting roots for classes";
246     auto classLinker = Runtime::GetCurrent()->GetClassLinker();
247     auto classRootVisitor = [&gcRootVisitor](Class *cls) {
248         gcRootVisitor({RootType::ROOT_CLASS, cls->GetManagedObject()});
249         LOG(DEBUG, GC) << " Found class root " << GetDebugInfoAboutObject(cls->GetManagedObject());
250         return true;
251     };
252     auto *extension = classLinker->GetExtension(LanguageConfig::LANG);
253     extension->EnumerateClasses(classRootVisitor, flags);
254 
255     LOG(DEBUG, GC) << "Finish collecting roots for classes";
256 }
257 
258 template <class LanguageConfig>
UpdateThreadLocals()259 void RootManager<LanguageConfig>::UpdateThreadLocals()
260 {
261     LOG(DEBUG, GC) << "=== ThreadLocals Update moved. BEGIN ===";
262     vm_->GetThreadManager()->EnumerateThreads([](ManagedThread *thread) {
263         thread->UpdateGCRoots();
264         return true;
265     });
266     LOG(DEBUG, GC) << "=== ThreadLocals Update moved. END ===";
267 }
268 
269 template <class LanguageConfig>
VisitClassLinkerContextRoots(const GCRootVisitor & gcRootVisitor) const270 void RootManager<LanguageConfig>::VisitClassLinkerContextRoots(const GCRootVisitor &gcRootVisitor) const
271 {
272     LOG(DEBUG, GC) << "Start collecting roots for class linker contexts";
273     auto classLinker = Runtime::GetCurrent()->GetClassLinker();
274     auto *extension = classLinker->GetExtension(LanguageConfig::LANG);
275     extension->EnumerateContexts([&gcRootVisitor](ClassLinkerContext *ctx) {
276         ctx->VisitGCRoots([&gcRootVisitor](ObjectHeader *obj) {
277             LOG(DEBUG, GC) << " Found root for class linker context " << GetDebugInfoAboutObject(obj);
278             gcRootVisitor({RootType::ROOT_CLASS_LINKER, obj});
279         });
280         return true;
281     });
282     LOG(DEBUG, GC) << "Finish collecting roots for class linker contexts";
283 }
284 
285 template <class LanguageConfig>
UpdateClassLinkerContextRoots()286 void RootManager<LanguageConfig>::UpdateClassLinkerContextRoots()
287 {
288     auto classLinker = Runtime::GetCurrent()->GetClassLinker();
289     auto *extension = classLinker->GetExtension(LanguageConfig::LANG);
290     extension->EnumerateContexts([](ClassLinkerContext *ctx) {
291         ctx->UpdateGCRoots();
292         return true;
293     });
294 }
295 
operator &(VisitGCRootFlags left,VisitGCRootFlags right)296 uint32_t operator&(VisitGCRootFlags left, VisitGCRootFlags right)
297 {
298     return static_cast<uint32_t>(left) & static_cast<uint32_t>(right);
299 }
300 
operator |(VisitGCRootFlags left,VisitGCRootFlags right)301 VisitGCRootFlags operator|(VisitGCRootFlags left, VisitGCRootFlags right)
302 {
303     return static_cast<VisitGCRootFlags>(static_cast<uint32_t>(left) | static_cast<uint32_t>(right));
304 }
305 
306 TEMPLATE_CLASS_LANGUAGE_CONFIG(RootManager);
307 
308 }  // namespace ark::mem
309