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1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_RUNTIME_CLASS_LINKER_H_
18 #define ART_RUNTIME_CLASS_LINKER_H_
19 
20 #include <list>
21 #include <set>
22 #include <string>
23 #include <unordered_map>
24 #include <unordered_set>
25 #include <utility>
26 #include <vector>
27 
28 #include "base/enums.h"
29 #include "base/locks.h"
30 #include "base/macros.h"
31 #include "dex/class_accessor.h"
32 #include "dex/dex_cache_resolved_classes.h"
33 #include "dex/dex_file_types.h"
34 #include "gc_root.h"
35 #include "handle.h"
36 #include "jni.h"
37 #include "mirror/class.h"
38 #include "verifier/verifier_enums.h"
39 
40 namespace art {
41 
42 namespace dex {
43 struct ClassDef;
44 struct MethodHandleItem;
45 }  // namespace dex
46 
47 namespace gc {
48 namespace space {
49 class ImageSpace;
50 }  // namespace space
51 }  // namespace gc
52 
53 namespace linker {
54 struct CompilationHelper;
55 class ImageWriter;
56 class OatWriter;
57 }  // namespace linker
58 
59 namespace mirror {
60 class ClassLoader;
61 class DexCache;
62 class DexCachePointerArray;
63 class DexCacheMethodHandlesTest_Open_Test;
64 class DexCacheTest_Open_Test;
65 class IfTable;
66 class MethodHandle;
67 class MethodHandlesLookup;
68 class MethodType;
69 template<class T> class ObjectArray;
70 class StackTraceElement;
71 template <typename T> struct NativeDexCachePair;
72 using MethodDexCachePair = NativeDexCachePair<ArtMethod>;
73 using MethodDexCacheType = std::atomic<MethodDexCachePair>;
74 }  // namespace mirror
75 
76 class ArtField;
77 class ArtMethod;
78 class ClassHierarchyAnalysis;
79 enum class ClassRoot : uint32_t;
80 class ClassTable;
81 class DexFile;
82 template<class T> class Handle;
83 class ImtConflictTable;
84 template<typename T> class LengthPrefixedArray;
85 template<class T> class MutableHandle;
86 class InternTable;
87 class LinearAlloc;
88 class OatFile;
89 template<class T> class ObjectLock;
90 class Runtime;
91 class ScopedObjectAccessAlreadyRunnable;
92 template<size_t kNumReferences> class PACKED(4) StackHandleScope;
93 class Thread;
94 
95 enum VisitRootFlags : uint8_t;
96 
97 class ClassVisitor {
98  public:
~ClassVisitor()99   virtual ~ClassVisitor() {}
100   // Return true to continue visiting.
101   virtual bool operator()(ObjPtr<mirror::Class> klass) = 0;
102 };
103 
104 class ClassLoaderVisitor {
105  public:
~ClassLoaderVisitor()106   virtual ~ClassLoaderVisitor() {}
107   virtual void Visit(ObjPtr<mirror::ClassLoader> class_loader)
108       REQUIRES_SHARED(Locks::classlinker_classes_lock_, Locks::mutator_lock_) = 0;
109 };
110 
111 class AllocatorVisitor {
112  public:
~AllocatorVisitor()113   virtual ~AllocatorVisitor() {}
114   // Return true to continue visiting.
115   virtual bool Visit(LinearAlloc* alloc)
116       REQUIRES_SHARED(Locks::classlinker_classes_lock_, Locks::mutator_lock_) = 0;
117 };
118 
119 class ClassLinker {
120  public:
121   static constexpr bool kAppImageMayContainStrings = true;
122 
123   explicit ClassLinker(InternTable* intern_table,
124                        bool fast_class_not_found_exceptions = true);
125   virtual ~ClassLinker();
126 
127   // Initialize class linker by bootstraping from dex files.
128   bool InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path,
129                         std::string* error_msg)
130       REQUIRES_SHARED(Locks::mutator_lock_)
131       REQUIRES(!Locks::dex_lock_);
132 
133   // Initialize class linker from one or more boot images.
134   bool InitFromBootImage(std::string* error_msg)
135       REQUIRES_SHARED(Locks::mutator_lock_)
136       REQUIRES(!Locks::dex_lock_);
137 
138   // Add boot class path dex files that were not included in the boot image.
139   // ClassLinker takes ownership of these dex files.
140   void AddExtraBootDexFiles(Thread* self,
141                             std::vector<std::unique_ptr<const DexFile>>&& additional_dex_files)
142       REQUIRES_SHARED(Locks::mutator_lock_);
143 
144   // Add an image space to the class linker, may fix up classloader fields and dex cache fields.
145   // The dex files that were newly opened for the space are placed in the out argument
146   // out_dex_files. Returns true if the operation succeeded.
147   // The space must be already added to the heap before calling AddImageSpace since we need to
148   // properly handle read barriers and object marking.
149   bool AddImageSpace(gc::space::ImageSpace* space,
150                      Handle<mirror::ClassLoader> class_loader,
151                      jobjectArray dex_elements,
152                      const char* dex_location,
153                      std::vector<std::unique_ptr<const DexFile>>* out_dex_files,
154                      std::string* error_msg)
155       REQUIRES(!Locks::dex_lock_)
156       REQUIRES_SHARED(Locks::mutator_lock_);
157 
158   bool OpenImageDexFiles(gc::space::ImageSpace* space,
159                          std::vector<std::unique_ptr<const DexFile>>* out_dex_files,
160                          std::string* error_msg)
161       REQUIRES(!Locks::dex_lock_)
162       REQUIRES_SHARED(Locks::mutator_lock_);
163 
164   // Finds a class by its descriptor, loading it if necessary.
165   // If class_loader is null, searches boot_class_path_.
166   ObjPtr<mirror::Class> FindClass(Thread* self,
167                                   const char* descriptor,
168                                   Handle<mirror::ClassLoader> class_loader)
169       REQUIRES_SHARED(Locks::mutator_lock_)
170       REQUIRES(!Locks::dex_lock_);
171 
172   // Finds a class by its descriptor using the "system" class loader, ie by searching the
173   // boot_class_path_.
FindSystemClass(Thread * self,const char * descriptor)174   ObjPtr<mirror::Class> FindSystemClass(Thread* self, const char* descriptor)
175       REQUIRES_SHARED(Locks::mutator_lock_)
176       REQUIRES(!Locks::dex_lock_) {
177     return FindClass(self, descriptor, ScopedNullHandle<mirror::ClassLoader>());
178   }
179 
180   // Finds the array class given for the element class.
181   ObjPtr<mirror::Class> FindArrayClass(Thread* self, ObjPtr<mirror::Class> element_class)
182       REQUIRES_SHARED(Locks::mutator_lock_)
183       REQUIRES(!Locks::dex_lock_);
184 
185   // Returns true if the class linker is initialized.
IsInitialized()186   bool IsInitialized() const {
187     return init_done_;
188   }
189 
190   // Define a new a class based on a ClassDef from a DexFile
191   ObjPtr<mirror::Class> DefineClass(Thread* self,
192                                     const char* descriptor,
193                                     size_t hash,
194                                     Handle<mirror::ClassLoader> class_loader,
195                                     const DexFile& dex_file,
196                                     const dex::ClassDef& dex_class_def)
197       REQUIRES_SHARED(Locks::mutator_lock_)
198       REQUIRES(!Locks::dex_lock_);
199 
200   // Finds a class by its descriptor, returning null if it isn't wasn't loaded
201   // by the given 'class_loader'.
202   ObjPtr<mirror::Class> LookupClass(Thread* self,
203                                     const char* descriptor,
204                                     ObjPtr<mirror::ClassLoader> class_loader)
205       REQUIRES(!Locks::classlinker_classes_lock_)
206       REQUIRES_SHARED(Locks::mutator_lock_);
207 
208   // Finds all the classes with the given descriptor, regardless of ClassLoader.
209   void LookupClasses(const char* descriptor, std::vector<ObjPtr<mirror::Class>>& classes)
210       REQUIRES(!Locks::classlinker_classes_lock_)
211       REQUIRES_SHARED(Locks::mutator_lock_);
212 
213   ObjPtr<mirror::Class> LookupPrimitiveClass(char type) REQUIRES_SHARED(Locks::mutator_lock_);
214   ObjPtr<mirror::Class> FindPrimitiveClass(char type) REQUIRES_SHARED(Locks::mutator_lock_);
215 
216   void DumpForSigQuit(std::ostream& os) REQUIRES(!Locks::classlinker_classes_lock_);
217 
218   size_t NumLoadedClasses()
219       REQUIRES(!Locks::classlinker_classes_lock_)
220       REQUIRES_SHARED(Locks::mutator_lock_);
221 
222   // Resolve a String with the given index from the DexFile associated with the given `referrer`,
223   // storing the result in the DexCache. The `referrer` is used to identify the target DexCache
224   // to use for resolution.
225   ObjPtr<mirror::String> ResolveString(dex::StringIndex string_idx,
226                                        ArtField* referrer)
227       REQUIRES_SHARED(Locks::mutator_lock_);
228   ObjPtr<mirror::String> ResolveString(dex::StringIndex string_idx,
229                                        ArtMethod* referrer)
230       REQUIRES_SHARED(Locks::mutator_lock_);
231 
232   // Resolve a String with the given index from the DexFile associated with the given DexCache,
233   // storing the result in the DexCache.
234   ObjPtr<mirror::String> ResolveString(dex::StringIndex string_idx,
235                                        Handle<mirror::DexCache> dex_cache)
236       REQUIRES_SHARED(Locks::mutator_lock_);
237 
238   // Find a String with the given index from the DexFile associated with the given DexCache,
239   // storing the result in the DexCache if found. Return null if not found.
240   ObjPtr<mirror::String> LookupString(dex::StringIndex string_idx,
241                                       ObjPtr<mirror::DexCache> dex_cache)
242       REQUIRES_SHARED(Locks::mutator_lock_);
243 
244   // Resolve a Type with the given index from the DexFile associated with the given `referrer`,
245   // storing the result in the DexCache. The `referrer` is used to identify the target DexCache
246   // and ClassLoader to use for resolution.
247   ObjPtr<mirror::Class> ResolveType(dex::TypeIndex type_idx, ObjPtr<mirror::Class> referrer)
248       REQUIRES_SHARED(Locks::mutator_lock_)
249       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
250   ObjPtr<mirror::Class> ResolveType(dex::TypeIndex type_idx, ArtField* referrer)
251       REQUIRES_SHARED(Locks::mutator_lock_)
252       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
253   ObjPtr<mirror::Class> ResolveType(dex::TypeIndex type_idx, ArtMethod* referrer)
254       REQUIRES_SHARED(Locks::mutator_lock_)
255       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
256 
257   // Resolve a type with the given index from the DexFile associated with the given DexCache
258   // and ClassLoader, storing the result in DexCache. The ClassLoader is used to search for
259   // the type, since it may be referenced from but not contained within the DexFile.
260   ObjPtr<mirror::Class> ResolveType(dex::TypeIndex type_idx,
261                                     Handle<mirror::DexCache> dex_cache,
262                                     Handle<mirror::ClassLoader> class_loader)
263       REQUIRES_SHARED(Locks::mutator_lock_)
264       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
265 
266   // Look up a resolved type with the given index from the DexFile associated with the given
267   // `referrer`, storing the result in the DexCache. The `referrer` is used to identify the
268   // target DexCache and ClassLoader to use for lookup.
269   ObjPtr<mirror::Class> LookupResolvedType(dex::TypeIndex type_idx,
270                                            ObjPtr<mirror::Class> referrer)
271       REQUIRES_SHARED(Locks::mutator_lock_);
272   ObjPtr<mirror::Class> LookupResolvedType(dex::TypeIndex type_idx, ArtField* referrer)
273       REQUIRES_SHARED(Locks::mutator_lock_);
274   ObjPtr<mirror::Class> LookupResolvedType(dex::TypeIndex type_idx, ArtMethod* referrer)
275       REQUIRES_SHARED(Locks::mutator_lock_);
276 
277   // Look up a resolved type with the given index from the DexFile associated with the given
278   // DexCache and ClassLoader. The ClassLoader is used to search for the type, since it may
279   // be referenced from but not contained within the DexFile.
280   ObjPtr<mirror::Class> LookupResolvedType(dex::TypeIndex type_idx,
281                                            ObjPtr<mirror::DexCache> dex_cache,
282                                            ObjPtr<mirror::ClassLoader> class_loader)
283       REQUIRES_SHARED(Locks::mutator_lock_);
284 
285   // Determine whether a dex cache result should be trusted, or an IncompatibleClassChangeError
286   // check and IllegalAccessError check should be performed even after a hit.
287   enum class ResolveMode {  // private.
288     kNoChecks,
289     kCheckICCEAndIAE
290   };
291 
292   // Look up a previously resolved method with the given index.
293   ArtMethod* LookupResolvedMethod(uint32_t method_idx,
294                                   ObjPtr<mirror::DexCache> dex_cache,
295                                   ObjPtr<mirror::ClassLoader> class_loader)
296       REQUIRES_SHARED(Locks::mutator_lock_);
297 
298   // Find a method with the given index from class `klass`, and update the dex cache.
299   ArtMethod* FindResolvedMethod(ObjPtr<mirror::Class> klass,
300                                 ObjPtr<mirror::DexCache> dex_cache,
301                                 ObjPtr<mirror::ClassLoader> class_loader,
302                                 uint32_t method_idx)
303       REQUIRES_SHARED(Locks::mutator_lock_);
304 
305   // Find a method using the wrong lookup mechanism. If `klass` is an interface,
306   // search for a class method. If it is a class, search for an interface method.
307   // This is useful when throwing IncompatibleClassChangeError.
308   ArtMethod* FindIncompatibleMethod(ObjPtr<mirror::Class> klass,
309                                     ObjPtr<mirror::DexCache> dex_cache,
310                                     ObjPtr<mirror::ClassLoader> class_loader,
311                                     uint32_t method_idx)
312       REQUIRES_SHARED(Locks::mutator_lock_);
313 
314   // Resolve a method with a given ID from the DexFile associated with the given DexCache
315   // and ClassLoader, storing the result in DexCache. The ClassLinker and ClassLoader are
316   // used as in ResolveType. What is unique is the method type argument which is used to
317   // determine if this method is a direct, static, or virtual method.
318   template <ResolveMode kResolveMode>
319   ArtMethod* ResolveMethod(uint32_t method_idx,
320                            Handle<mirror::DexCache> dex_cache,
321                            Handle<mirror::ClassLoader> class_loader,
322                            ArtMethod* referrer,
323                            InvokeType type)
324       REQUIRES_SHARED(Locks::mutator_lock_)
325       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
326 
327   template <InvokeType type, ResolveMode kResolveMode>
328   ArtMethod* GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer)
329       REQUIRES_SHARED(Locks::mutator_lock_);
330 
331   template <ResolveMode kResolveMode>
332   ArtMethod* ResolveMethod(Thread* self, uint32_t method_idx, ArtMethod* referrer, InvokeType type)
333       REQUIRES_SHARED(Locks::mutator_lock_)
334       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
335   ArtMethod* ResolveMethodWithoutInvokeType(uint32_t method_idx,
336                                             Handle<mirror::DexCache> dex_cache,
337                                             Handle<mirror::ClassLoader> class_loader)
338       REQUIRES_SHARED(Locks::mutator_lock_)
339       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
340 
341   ArtField* LookupResolvedField(uint32_t field_idx, ArtMethod* referrer, bool is_static)
342       REQUIRES_SHARED(Locks::mutator_lock_);
343   ArtField* ResolveField(uint32_t field_idx, ArtMethod* referrer, bool is_static)
344       REQUIRES_SHARED(Locks::mutator_lock_)
345       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
346 
347   // Resolve a field with a given ID from the DexFile associated with the given DexCache
348   // and ClassLoader, storing the result in DexCache. The ClassLinker and ClassLoader
349   // are used as in ResolveType. What is unique is the is_static argument which is used
350   // to determine if we are resolving a static or non-static field.
351   ArtField* ResolveField(uint32_t field_idx,
352                          Handle<mirror::DexCache> dex_cache,
353                          Handle<mirror::ClassLoader> class_loader,
354                          bool is_static)
355       REQUIRES_SHARED(Locks::mutator_lock_)
356       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
357 
358   // Resolve a field with a given ID from the DexFile associated with the given DexCache
359   // and ClassLoader, storing the result in DexCache. The ClassLinker and ClassLoader
360   // are used as in ResolveType. No is_static argument is provided so that Java
361   // field resolution semantics are followed.
362   ArtField* ResolveFieldJLS(uint32_t field_idx,
363                             Handle<mirror::DexCache> dex_cache,
364                             Handle<mirror::ClassLoader> class_loader)
365       REQUIRES_SHARED(Locks::mutator_lock_)
366       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
367 
368   // Find a field with a given ID from the DexFile associated with the given DexCache
369   // and ClassLoader, storing the result in DexCache. The declaring class is assumed
370   // to have been already resolved into `klass`. The `is_static` argument is used to
371   // determine if we are resolving a static or non-static field.
372   ArtField* FindResolvedField(ObjPtr<mirror::Class> klass,
373                               ObjPtr<mirror::DexCache> dex_cache,
374                               ObjPtr<mirror::ClassLoader> class_loader,
375                               uint32_t field_idx,
376                               bool is_static)
377       REQUIRES_SHARED(Locks::mutator_lock_);
378 
379   // Find a field with a given ID from the DexFile associated with the given DexCache
380   // and ClassLoader, storing the result in DexCache. The declaring class is assumed
381   // to have been already resolved into `klass`. No is_static argument is provided
382   // so that Java field resolution semantics are followed.
383   ArtField* FindResolvedFieldJLS(ObjPtr<mirror::Class> klass,
384                                  ObjPtr<mirror::DexCache> dex_cache,
385                                  ObjPtr<mirror::ClassLoader> class_loader,
386                                  uint32_t field_idx)
387       REQUIRES_SHARED(Locks::mutator_lock_);
388 
389   // Resolve a method type with a given ID from the DexFile associated with a given DexCache
390   // and ClassLoader, storing the result in the DexCache.
391   ObjPtr<mirror::MethodType> ResolveMethodType(Thread* self,
392                                                dex::ProtoIndex proto_idx,
393                                                Handle<mirror::DexCache> dex_cache,
394                                                Handle<mirror::ClassLoader> class_loader)
395       REQUIRES_SHARED(Locks::mutator_lock_)
396       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
397 
398   ObjPtr<mirror::MethodType> ResolveMethodType(Thread* self,
399                                                dex::ProtoIndex proto_idx,
400                                                ArtMethod* referrer)
401       REQUIRES_SHARED(Locks::mutator_lock_);
402 
403   // Resolve a method handle with a given ID from the DexFile. The
404   // result is not cached in the DexCache as the instance will only be
405   // used once in most circumstances.
406   ObjPtr<mirror::MethodHandle> ResolveMethodHandle(Thread* self,
407                                                    uint32_t method_handle_idx,
408                                                    ArtMethod* referrer)
409       REQUIRES_SHARED(Locks::mutator_lock_);
410 
411   // Returns true on success, false if there's an exception pending.
412   // can_run_clinit=false allows the compiler to attempt to init a class,
413   // given the restriction that no <clinit> execution is possible.
414   bool EnsureInitialized(Thread* self,
415                          Handle<mirror::Class> c,
416                          bool can_init_fields,
417                          bool can_init_parents)
418       REQUIRES_SHARED(Locks::mutator_lock_)
419       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
420 
421   // Initializes classes that have instances in the image but that have
422   // <clinit> methods so they could not be initialized by the compiler.
423   void RunRootClinits(Thread* self)
424       REQUIRES_SHARED(Locks::mutator_lock_)
425       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
426 
427   // Directly register an already existing dex cache. RegisterDexFile should be preferred since that
428   // reduplicates DexCaches when possible. The DexCache given to this function must already be fully
429   // initialized and not already registered.
430   void RegisterExistingDexCache(ObjPtr<mirror::DexCache> cache,
431                                 ObjPtr<mirror::ClassLoader> class_loader)
432       REQUIRES(!Locks::dex_lock_)
433       REQUIRES_SHARED(Locks::mutator_lock_);
434   ObjPtr<mirror::DexCache> RegisterDexFile(const DexFile& dex_file,
435                                            ObjPtr<mirror::ClassLoader> class_loader)
436       REQUIRES(!Locks::dex_lock_)
437       REQUIRES_SHARED(Locks::mutator_lock_);
438 
GetBootClassPath()439   const std::vector<const DexFile*>& GetBootClassPath() {
440     return boot_class_path_;
441   }
442 
443   void VisitClasses(ClassVisitor* visitor)
444       REQUIRES(!Locks::classlinker_classes_lock_)
445       REQUIRES_SHARED(Locks::mutator_lock_);
446 
447   // Less efficient variant of VisitClasses that copies the class_table_ into secondary storage
448   // so that it can visit individual classes without holding the doesn't hold the
449   // Locks::classlinker_classes_lock_. As the Locks::classlinker_classes_lock_ isn't held this code
450   // can race with insertion and deletion of classes while the visitor is being called.
451   void VisitClassesWithoutClassesLock(ClassVisitor* visitor)
452       REQUIRES_SHARED(Locks::mutator_lock_)
453       REQUIRES(!Locks::dex_lock_);
454 
455   void VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags)
456       REQUIRES(!Locks::classlinker_classes_lock_, !Locks::trace_lock_)
457       REQUIRES_SHARED(Locks::mutator_lock_);
458   void VisitRoots(RootVisitor* visitor, VisitRootFlags flags)
459       REQUIRES(!Locks::dex_lock_, !Locks::classlinker_classes_lock_, !Locks::trace_lock_)
460       REQUIRES_SHARED(Locks::mutator_lock_);
461 
462   bool IsDexFileRegistered(Thread* self, const DexFile& dex_file)
463       REQUIRES(!Locks::dex_lock_)
464       REQUIRES_SHARED(Locks::mutator_lock_);
465   ObjPtr<mirror::DexCache> FindDexCache(Thread* self, const DexFile& dex_file)
466       REQUIRES(!Locks::dex_lock_)
467       REQUIRES_SHARED(Locks::mutator_lock_);
468   ClassTable* FindClassTable(Thread* self, ObjPtr<mirror::DexCache> dex_cache)
469       REQUIRES(!Locks::dex_lock_)
470       REQUIRES_SHARED(Locks::mutator_lock_);
471 
472   LengthPrefixedArray<ArtField>* AllocArtFieldArray(Thread* self,
473                                                     LinearAlloc* allocator,
474                                                     size_t length);
475 
476   LengthPrefixedArray<ArtMethod>* AllocArtMethodArray(Thread* self,
477                                                       LinearAlloc* allocator,
478                                                       size_t length);
479 
480   ObjPtr<mirror::PointerArray> AllocPointerArray(Thread* self, size_t length)
481       REQUIRES_SHARED(Locks::mutator_lock_)
482       REQUIRES(!Roles::uninterruptible_);
483 
484   ObjPtr<mirror::IfTable> AllocIfTable(Thread* self, size_t ifcount)
485       REQUIRES_SHARED(Locks::mutator_lock_)
486       REQUIRES(!Roles::uninterruptible_);
487 
488   ObjPtr<mirror::ObjectArray<mirror::StackTraceElement>> AllocStackTraceElementArray(Thread* self,
489                                                                                      size_t length)
490       REQUIRES_SHARED(Locks::mutator_lock_)
491       REQUIRES(!Roles::uninterruptible_);
492 
493   verifier::FailureKind VerifyClass(
494       Thread* self,
495       Handle<mirror::Class> klass,
496       verifier::HardFailLogMode log_level = verifier::HardFailLogMode::kLogNone)
497       REQUIRES_SHARED(Locks::mutator_lock_)
498       REQUIRES(!Locks::dex_lock_);
499   bool VerifyClassUsingOatFile(const DexFile& dex_file,
500                                ObjPtr<mirror::Class> klass,
501                                ClassStatus& oat_file_class_status)
502       REQUIRES_SHARED(Locks::mutator_lock_)
503       REQUIRES(!Locks::dex_lock_);
504   void ResolveClassExceptionHandlerTypes(Handle<mirror::Class> klass)
505       REQUIRES_SHARED(Locks::mutator_lock_)
506       REQUIRES(!Locks::dex_lock_);
507   void ResolveMethodExceptionHandlerTypes(ArtMethod* klass)
508       REQUIRES_SHARED(Locks::mutator_lock_)
509       REQUIRES(!Locks::dex_lock_);
510 
511   ObjPtr<mirror::Class> CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa,
512                                          jstring name,
513                                          jobjectArray interfaces,
514                                          jobject loader,
515                                          jobjectArray methods,
516                                          jobjectArray throws)
517       REQUIRES_SHARED(Locks::mutator_lock_);
518 
519   // Get the oat code for a method when its class isn't yet initialized.
520   const void* GetQuickOatCodeFor(ArtMethod* method)
521       REQUIRES_SHARED(Locks::mutator_lock_);
522 
523   pid_t GetClassesLockOwner();  // For SignalCatcher.
524   pid_t GetDexLockOwner();  // For SignalCatcher.
525 
526   // Is the given entry point quick code to run the resolution stub?
527   bool IsQuickResolutionStub(const void* entry_point) const;
528 
529   // Is the given entry point quick code to bridge into the interpreter?
530   bool IsQuickToInterpreterBridge(const void* entry_point) const;
531 
532   // Is the given entry point quick code to run the generic JNI stub?
533   bool IsQuickGenericJniStub(const void* entry_point) const;
534 
535   // Is the given entry point the JNI dlsym lookup stub?
536   bool IsJniDlsymLookupStub(const void* entry_point) const;
537 
GetQuickToInterpreterBridgeTrampoline()538   const void* GetQuickToInterpreterBridgeTrampoline() const {
539     return quick_to_interpreter_bridge_trampoline_;
540   }
541 
GetInternTable()542   InternTable* GetInternTable() const {
543     return intern_table_;
544   }
545 
546   // Set the entrypoints up for method to the enter the interpreter.
547   void SetEntryPointsToInterpreter(ArtMethod* method) const
548       REQUIRES_SHARED(Locks::mutator_lock_);
549 
550   // Set the entrypoints up for an obsolete method.
551   void SetEntryPointsForObsoleteMethod(ArtMethod* method) const
552       REQUIRES_SHARED(Locks::mutator_lock_);
553 
554   // Attempts to insert a class into a class table.  Returns null if
555   // the class was inserted, otherwise returns an existing class with
556   // the same descriptor and ClassLoader.
557   ObjPtr<mirror::Class> InsertClass(const char* descriptor,
558                                     ObjPtr<mirror::Class> klass,
559                                     size_t hash)
560       REQUIRES(!Locks::classlinker_classes_lock_)
561       REQUIRES_SHARED(Locks::mutator_lock_);
562 
563   // Add an oat file with .bss GC roots to be visited again at the end of GC
564   // for collector types that need it.
565   void WriteBarrierForBootOatFileBssRoots(const OatFile* oat_file)
566       REQUIRES(!Locks::classlinker_classes_lock_)
567       REQUIRES_SHARED(Locks::mutator_lock_);
568 
569   template <ReadBarrierOption kReadBarrierOption = kWithReadBarrier>
570   ObjPtr<mirror::ObjectArray<mirror::Class>> GetClassRoots() REQUIRES_SHARED(Locks::mutator_lock_);
571 
572   // Move the class table to the pre-zygote table to reduce memory usage. This works by ensuring
573   // that no more classes are ever added to the pre zygote table which makes it that the pages
574   // always remain shared dirty instead of private dirty.
575   void MoveClassTableToPreZygote()
576       REQUIRES(!Locks::classlinker_classes_lock_)
577       REQUIRES_SHARED(Locks::mutator_lock_);
578 
579   // Creates a GlobalRef PathClassLoader or DelegateLastClassLoader (specified by loader_class)
580   // that can be used to load classes from the given dex files. The parent of the class loader
581   // will be set to `parent_loader`. If `parent_loader` is null the parent will be
582   // the boot class loader.
583   // If class_loader points to a different class than PathClassLoader or DelegateLastClassLoader
584   // this method will abort.
585   // Note: the objects are not completely set up. Do not use this outside of tests and the compiler.
586   jobject CreateWellKnownClassLoader(Thread* self,
587                                      const std::vector<const DexFile*>& dex_files,
588                                      jclass loader_class,
589                                      jobject parent_loader,
590                                      jobject shared_libraries = nullptr)
591       REQUIRES_SHARED(Locks::mutator_lock_)
592       REQUIRES(!Locks::dex_lock_);
593 
594   // Calls CreateWellKnownClassLoader(self,
595   //                                  dex_files,
596   //                                  WellKnownClasses::dalvik_system_PathClassLoader,
597   //                                  nullptr)
598   jobject CreatePathClassLoader(Thread* self, const std::vector<const DexFile*>& dex_files)
599       REQUIRES_SHARED(Locks::mutator_lock_)
600       REQUIRES(!Locks::dex_lock_);
601 
602   // Non-GlobalRef version of CreateWellKnownClassLoader
603   ObjPtr<mirror::ClassLoader> CreateWellKnownClassLoader(
604       Thread* self,
605       const std::vector<const DexFile*>& dex_files,
606       Handle<mirror::Class> loader_class,
607       Handle<mirror::ClassLoader> parent_loader,
608       Handle<mirror::ObjectArray<mirror::ClassLoader>> shared_libraries)
609           REQUIRES_SHARED(Locks::mutator_lock_)
610           REQUIRES(!Locks::dex_lock_);
611 
GetImagePointerSize()612   PointerSize GetImagePointerSize() const {
613     return image_pointer_size_;
614   }
615 
616   // Used by image writer for checking.
617   bool ClassInClassTable(ObjPtr<mirror::Class> klass)
618       REQUIRES(Locks::classlinker_classes_lock_)
619       REQUIRES_SHARED(Locks::mutator_lock_);
620 
621   // Clear the ArrayClass cache. This is necessary when cleaning up for the image, as the cache
622   // entries are roots, but potentially not image classes.
623   void DropFindArrayClassCache() REQUIRES_SHARED(Locks::mutator_lock_);
624 
625   // Clean up class loaders, this needs to happen after JNI weak globals are cleared.
626   void CleanupClassLoaders()
627       REQUIRES(!Locks::classlinker_classes_lock_)
628       REQUIRES_SHARED(Locks::mutator_lock_);
629 
630   // Unlike GetOrCreateAllocatorForClassLoader, GetAllocatorForClassLoader asserts that the
631   // allocator for this class loader is already created.
632   LinearAlloc* GetAllocatorForClassLoader(ObjPtr<mirror::ClassLoader> class_loader)
633       REQUIRES_SHARED(Locks::mutator_lock_);
634 
635   // Return the linear alloc for a class loader if it is already allocated, otherwise allocate and
636   // set it. TODO: Consider using a lock other than classlinker_classes_lock_.
637   LinearAlloc* GetOrCreateAllocatorForClassLoader(ObjPtr<mirror::ClassLoader> class_loader)
638       REQUIRES(!Locks::classlinker_classes_lock_)
639       REQUIRES_SHARED(Locks::mutator_lock_);
640 
641   // May be called with null class_loader due to legacy code. b/27954959
642   void InsertDexFileInToClassLoader(ObjPtr<mirror::Object> dex_file,
643                                     ObjPtr<mirror::ClassLoader> class_loader)
644       REQUIRES(!Locks::classlinker_classes_lock_)
645       REQUIRES_SHARED(Locks::mutator_lock_);
646 
647   static bool ShouldUseInterpreterEntrypoint(ArtMethod* method, const void* quick_code)
648       REQUIRES_SHARED(Locks::mutator_lock_);
649 
650   std::set<DexCacheResolvedClasses> GetResolvedClasses(bool ignore_boot_classes)
651       REQUIRES(!Locks::dex_lock_);
652 
653   static bool IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa,
654                                 ObjPtr<mirror::ClassLoader> class_loader)
655       REQUIRES_SHARED(Locks::mutator_lock_);
656 
657   ArtMethod* AddMethodToConflictTable(ObjPtr<mirror::Class> klass,
658                                       ArtMethod* conflict_method,
659                                       ArtMethod* interface_method,
660                                       ArtMethod* method,
661                                       bool force_new_conflict_method)
662       REQUIRES_SHARED(Locks::mutator_lock_);
663 
664   // Create a conflict table with a specified capacity.
665   ImtConflictTable* CreateImtConflictTable(size_t count, LinearAlloc* linear_alloc);
666 
667   // Static version for when the class linker is not yet created.
668   static ImtConflictTable* CreateImtConflictTable(size_t count,
669                                                   LinearAlloc* linear_alloc,
670                                                   PointerSize pointer_size);
671 
672 
673   // Create the IMT and conflict tables for a class.
674   void FillIMTAndConflictTables(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_);
675 
676   // Visit all of the class tables. This is used by dex2oat to allow pruning dex caches.
677   template <class Visitor>
678   void VisitClassTables(const Visitor& visitor)
679       REQUIRES(!Locks::classlinker_classes_lock_)
680       REQUIRES_SHARED(Locks::mutator_lock_);
681 
682   // Visit all of the allocators that belong to classloaders except boot classloader.
683   // This is used by 616-cha-unloading test to confirm memory reuse.
684   void VisitAllocators(AllocatorVisitor* visitor) const
685       REQUIRES_SHARED(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
686 
687   // Throw the class initialization failure recorded when first trying to initialize the given
688   // class.
689   void ThrowEarlierClassFailure(ObjPtr<mirror::Class> c,
690                                 bool wrap_in_no_class_def = false,
691                                 bool log = false)
692       REQUIRES_SHARED(Locks::mutator_lock_)
693       REQUIRES(!Locks::dex_lock_);
694 
695   // Get the actual holding class for a copied method. Pretty slow, don't call often.
696   ObjPtr<mirror::Class> GetHoldingClassOfCopiedMethod(ArtMethod* method)
697       REQUIRES_SHARED(Locks::mutator_lock_);
698 
699   // Returns null if not found.
700   // This returns a pointer to the class-table, without requiring any locking - including the
701   // boot class-table. It is the caller's responsibility to access this under lock, if required.
702   ClassTable* ClassTableForClassLoader(ObjPtr<mirror::ClassLoader> class_loader)
703       REQUIRES_SHARED(Locks::mutator_lock_)
704       NO_THREAD_SAFETY_ANALYSIS;
705 
706   void AppendToBootClassPath(Thread* self, const DexFile& dex_file)
707       REQUIRES_SHARED(Locks::mutator_lock_)
708       REQUIRES(!Locks::dex_lock_);
709 
710   // Visit all of the class loaders in the class linker.
711   void VisitClassLoaders(ClassLoaderVisitor* visitor) const
712       REQUIRES_SHARED(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
713 
714   // Checks that a class and its superclass from another class loader have the same virtual methods.
715   bool ValidateSuperClassDescriptors(Handle<mirror::Class> klass)
716       REQUIRES_SHARED(Locks::mutator_lock_);
717 
GetClassHierarchyAnalysis()718   ClassHierarchyAnalysis* GetClassHierarchyAnalysis() {
719     return cha_.get();
720   }
721 
722   struct DexCacheData {
723     // Construct an invalid data object.
DexCacheDataDexCacheData724     DexCacheData()
725         : weak_root(nullptr),
726           dex_file(nullptr),
727           class_table(nullptr) { }
728 
729     // Check if the data is valid.
IsValidDexCacheData730     bool IsValid() const {
731       return dex_file != nullptr;
732     }
733 
734     // Weak root to the DexCache. Note: Do not decode this unnecessarily or else class unloading may
735     // not work properly.
736     jweak weak_root;
737     // The following field caches the DexCache's field here to avoid unnecessary jweak decode that
738     // triggers read barriers (and marks them alive unnecessarily and messes with class unloading.)
739     const DexFile* dex_file;
740     // Identify the associated class loader's class table. This is used to make sure that
741     // the Java call to native DexCache.setResolvedType() inserts the resolved type in that
742     // class table. It is also used to make sure we don't register the same dex cache with
743     // multiple class loaders.
744     ClassTable* class_table;
745   };
746 
747  protected:
748   virtual bool InitializeClass(Thread* self,
749                                Handle<mirror::Class> klass,
750                                bool can_run_clinit,
751                                bool can_init_parents)
752       REQUIRES_SHARED(Locks::mutator_lock_)
753       REQUIRES(!Locks::dex_lock_);
754 
755   virtual verifier::FailureKind PerformClassVerification(Thread* self,
756                                                          Handle<mirror::Class> klass,
757                                                          verifier::HardFailLogMode log_level,
758                                                          std::string* error_msg)
759       REQUIRES_SHARED(Locks::mutator_lock_);
760 
761  private:
762   class LinkInterfaceMethodsHelper;
763 
764   struct ClassLoaderData {
765     jweak weak_root;  // Weak root to enable class unloading.
766     ClassTable* class_table;
767     LinearAlloc* allocator;
768   };
769 
770   // Ensures that the supertype of 'klass' ('supertype') is verified. Returns false and throws
771   // appropriate exceptions if verification failed hard. Returns true for successful verification or
772   // soft-failures.
773   bool AttemptSupertypeVerification(Thread* self,
774                                     Handle<mirror::Class> klass,
775                                     Handle<mirror::Class> supertype)
776       REQUIRES(!Locks::dex_lock_)
777       REQUIRES_SHARED(Locks::mutator_lock_);
778 
779   void DeleteClassLoader(Thread* self, const ClassLoaderData& data, bool cleanup_cha)
780       REQUIRES_SHARED(Locks::mutator_lock_);
781 
782   void VisitClassesInternal(ClassVisitor* visitor)
783       REQUIRES_SHARED(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
784 
785   // Returns the number of zygote and image classes.
786   size_t NumZygoteClasses() const
787       REQUIRES(Locks::classlinker_classes_lock_)
788       REQUIRES_SHARED(Locks::mutator_lock_);
789 
790   // Returns the number of non zygote nor image classes.
791   size_t NumNonZygoteClasses() const
792       REQUIRES(Locks::classlinker_classes_lock_)
793       REQUIRES_SHARED(Locks::mutator_lock_);
794 
795   void FinishInit(Thread* self)
796       REQUIRES_SHARED(Locks::mutator_lock_)
797       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
798 
799   // For early bootstrapping by Init.
800   // If we do not allow moving classes (`art::kMovingClass` is false) or if
801   // parameter `kMovable` is false (or both), the class object is allocated in
802   // the non-moving space.
803   template <bool kMovable = true>
804   ObjPtr<mirror::Class> AllocClass(Thread* self,
805                                    ObjPtr<mirror::Class> java_lang_Class,
806                                    uint32_t class_size)
807       REQUIRES_SHARED(Locks::mutator_lock_)
808       REQUIRES(!Roles::uninterruptible_);
809 
810   // Alloc* convenience functions to avoid needing to pass in ObjPtr<mirror::Class>
811   // values that are known to the ClassLinker such as classes corresponding to
812   // ClassRoot::kObjectArrayClass and ClassRoot::kJavaLangString etc.
813   ObjPtr<mirror::Class> AllocClass(Thread* self, uint32_t class_size)
814       REQUIRES_SHARED(Locks::mutator_lock_)
815       REQUIRES(!Roles::uninterruptible_);
816 
817   // Allocate a primitive array class.
818   ObjPtr<mirror::Class> AllocPrimitiveArrayClass(Thread* self,
819                                                  ObjPtr<mirror::Class> java_lang_Class)
820       REQUIRES_SHARED(Locks::mutator_lock_)
821       REQUIRES(!Roles::uninterruptible_);
822 
823   ObjPtr<mirror::DexCache> AllocDexCache(/*out*/ ObjPtr<mirror::String>* out_location,
824                                          Thread* self,
825                                          const DexFile& dex_file)
826       REQUIRES_SHARED(Locks::mutator_lock_)
827       REQUIRES(!Roles::uninterruptible_);
828 
829   // Used for tests and AppendToBootClassPath.
830   ObjPtr<mirror::DexCache> AllocAndInitializeDexCache(Thread* self,
831                                                       const DexFile& dex_file,
832                                                       LinearAlloc* linear_alloc)
833       REQUIRES_SHARED(Locks::mutator_lock_)
834       REQUIRES(!Locks::dex_lock_)
835       REQUIRES(!Roles::uninterruptible_);
836 
837   ObjPtr<mirror::Class> CreatePrimitiveClass(Thread* self, Primitive::Type type)
838       REQUIRES_SHARED(Locks::mutator_lock_)
839       REQUIRES(!Roles::uninterruptible_);
840 
841   ObjPtr<mirror::Class> CreateArrayClass(Thread* self,
842                                          const char* descriptor,
843                                          size_t hash,
844                                          Handle<mirror::ClassLoader> class_loader)
845       REQUIRES_SHARED(Locks::mutator_lock_)
846       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
847 
848   void AppendToBootClassPath(const DexFile& dex_file, ObjPtr<mirror::DexCache> dex_cache)
849       REQUIRES_SHARED(Locks::mutator_lock_)
850       REQUIRES(!Locks::dex_lock_);
851 
852   // Precomputes size needed for Class, in the case of a non-temporary class this size must be
853   // sufficient to hold all static fields.
854   uint32_t SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file,
855                                             const dex::ClassDef& dex_class_def);
856 
857   // Setup the classloader, class def index, type idx so that we can insert this class in the class
858   // table.
859   void SetupClass(const DexFile& dex_file,
860                   const dex::ClassDef& dex_class_def,
861                   Handle<mirror::Class> klass,
862                   ObjPtr<mirror::ClassLoader> class_loader)
863       REQUIRES_SHARED(Locks::mutator_lock_);
864 
865   void LoadClass(Thread* self,
866                  const DexFile& dex_file,
867                  const dex::ClassDef& dex_class_def,
868                  Handle<mirror::Class> klass)
869       REQUIRES_SHARED(Locks::mutator_lock_);
870 
871   void LoadField(const ClassAccessor::Field& field, Handle<mirror::Class> klass, ArtField* dst)
872       REQUIRES_SHARED(Locks::mutator_lock_);
873 
874   void LoadMethod(const DexFile& dex_file,
875                   const ClassAccessor::Method& method,
876                   Handle<mirror::Class> klass,
877                   ArtMethod* dst)
878       REQUIRES_SHARED(Locks::mutator_lock_);
879 
880   void FixupStaticTrampolines(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_);
881 
882   // Finds a class in a Path- or DexClassLoader, loading it if necessary without using JNI. Hash
883   // function is supposed to be ComputeModifiedUtf8Hash(descriptor). Returns true if the
884   // class-loader chain could be handled, false otherwise, i.e., a non-supported class-loader
885   // was encountered while walking the parent chain (currently only BootClassLoader and
886   // PathClassLoader are supported).
887   bool FindClassInBaseDexClassLoader(ScopedObjectAccessAlreadyRunnable& soa,
888                                      Thread* self,
889                                      const char* descriptor,
890                                      size_t hash,
891                                      Handle<mirror::ClassLoader> class_loader,
892                                      /*out*/ ObjPtr<mirror::Class>* result)
893       REQUIRES_SHARED(Locks::mutator_lock_)
894       REQUIRES(!Locks::dex_lock_);
895 
896   bool FindClassInSharedLibraries(ScopedObjectAccessAlreadyRunnable& soa,
897                                   Thread* self,
898                                   const char* descriptor,
899                                   size_t hash,
900                                   Handle<mirror::ClassLoader> class_loader,
901                                   /*out*/ ObjPtr<mirror::Class>* result)
902       REQUIRES_SHARED(Locks::mutator_lock_)
903       REQUIRES(!Locks::dex_lock_);
904 
905   // Finds the class in the classpath of the given class loader. It only searches the class loader
906   // dex files and does not recurse into its parent.
907   // The method checks that the provided class loader is either a PathClassLoader or a
908   // DexClassLoader.
909   // If the class is found the method returns the resolved class. Otherwise it returns null.
910   ObjPtr<mirror::Class> FindClassInBaseDexClassLoaderClassPath(
911           ScopedObjectAccessAlreadyRunnable& soa,
912           const char* descriptor,
913           size_t hash,
914           Handle<mirror::ClassLoader> class_loader)
915       REQUIRES_SHARED(Locks::mutator_lock_)
916       REQUIRES(!Locks::dex_lock_);
917 
918   // Finds the class in the boot class loader.
919   // If the class is found the method returns the resolved class. Otherwise it returns null.
920   ObjPtr<mirror::Class> FindClassInBootClassLoaderClassPath(Thread* self,
921                                                             const char* descriptor,
922                                                             size_t hash)
923       REQUIRES_SHARED(Locks::mutator_lock_)
924       REQUIRES(!Locks::dex_lock_);
925 
926   // Implementation of LookupResolvedType() called when the type was not found in the dex cache.
927   ObjPtr<mirror::Class> DoLookupResolvedType(dex::TypeIndex type_idx,
928                                              ObjPtr<mirror::Class> referrer)
929       REQUIRES_SHARED(Locks::mutator_lock_);
930   ObjPtr<mirror::Class> DoLookupResolvedType(dex::TypeIndex type_idx,
931                                              ObjPtr<mirror::DexCache> dex_cache,
932                                              ObjPtr<mirror::ClassLoader> class_loader)
933       REQUIRES_SHARED(Locks::mutator_lock_);
934 
935   // Implementation of ResolveString() called when the string was not found in the dex cache.
936   ObjPtr<mirror::String> DoResolveString(dex::StringIndex string_idx,
937                                          ObjPtr<mirror::DexCache> dex_cache)
938       REQUIRES_SHARED(Locks::mutator_lock_);
939   ObjPtr<mirror::String> DoResolveString(dex::StringIndex string_idx,
940                                          Handle<mirror::DexCache> dex_cache)
941       REQUIRES_SHARED(Locks::mutator_lock_);
942 
943   // Implementation of LookupString() called when the string was not found in the dex cache.
944   ObjPtr<mirror::String> DoLookupString(dex::StringIndex string_idx,
945                                         ObjPtr<mirror::DexCache> dex_cache)
946       REQUIRES_SHARED(Locks::mutator_lock_);
947 
948   // Implementation of ResolveType() called when the type was not found in the dex cache.
949   template <typename T>
950   ObjPtr<mirror::Class> DoResolveType(dex::TypeIndex type_idx, T referrer)
951       REQUIRES_SHARED(Locks::mutator_lock_)
952       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
953   ObjPtr<mirror::Class> DoResolveType(dex::TypeIndex type_idx,
954                                       Handle<mirror::DexCache> dex_cache,
955                                       Handle<mirror::ClassLoader> class_loader)
956       REQUIRES_SHARED(Locks::mutator_lock_)
957       REQUIRES(!Locks::dex_lock_, !Roles::uninterruptible_);
958 
959   // Finds a class by its descriptor, returning NULL if it isn't wasn't loaded
960   // by the given 'class_loader'. Uses the provided hash for the descriptor.
961   ObjPtr<mirror::Class> LookupClass(Thread* self,
962                                     const char* descriptor,
963                                     size_t hash,
964                                     ObjPtr<mirror::ClassLoader> class_loader)
965       REQUIRES(!Locks::classlinker_classes_lock_)
966       REQUIRES_SHARED(Locks::mutator_lock_);
967 
968   // Find a field by its field index.
969   ArtField* LookupResolvedField(uint32_t field_idx,
970                                 ObjPtr<mirror::DexCache> dex_cache,
971                                 ObjPtr<mirror::ClassLoader> class_loader,
972                                 bool is_static)
973       REQUIRES_SHARED(Locks::mutator_lock_);
974 
975   void RegisterDexFileLocked(const DexFile& dex_file,
976                              ObjPtr<mirror::DexCache> dex_cache,
977                              ObjPtr<mirror::ClassLoader> class_loader)
978       REQUIRES(Locks::dex_lock_)
979       REQUIRES_SHARED(Locks::mutator_lock_);
980   DexCacheData FindDexCacheDataLocked(const DexFile& dex_file)
981       REQUIRES(Locks::dex_lock_)
982       REQUIRES_SHARED(Locks::mutator_lock_);
983   static ObjPtr<mirror::DexCache> DecodeDexCache(Thread* self, const DexCacheData& data)
984       REQUIRES_SHARED(Locks::mutator_lock_);
985   // Called to ensure that the dex cache has been registered with the same class loader.
986   // If yes, returns the dex cache, otherwise throws InternalError and returns null.
987   ObjPtr<mirror::DexCache> EnsureSameClassLoader(Thread* self,
988                                                  ObjPtr<mirror::DexCache> dex_cache,
989                                                  const DexCacheData& data,
990                                                  ObjPtr<mirror::ClassLoader> class_loader)
991       REQUIRES(!Locks::dex_lock_)
992       REQUIRES_SHARED(Locks::mutator_lock_);
993 
994   bool InitializeDefaultInterfaceRecursive(Thread* self,
995                                            Handle<mirror::Class> klass,
996                                            bool can_run_clinit,
997                                            bool can_init_parents)
998       REQUIRES(!Locks::dex_lock_)
999       REQUIRES_SHARED(Locks::mutator_lock_);
1000   bool WaitForInitializeClass(Handle<mirror::Class> klass,
1001                               Thread* self,
1002                               ObjectLock<mirror::Class>& lock);
1003 
1004   bool IsSameDescriptorInDifferentClassContexts(Thread* self,
1005                                                 const char* descriptor,
1006                                                 Handle<mirror::ClassLoader> class_loader1,
1007                                                 Handle<mirror::ClassLoader> class_loader2)
1008       REQUIRES_SHARED(Locks::mutator_lock_);
1009 
1010   bool IsSameMethodSignatureInDifferentClassContexts(Thread* self,
1011                                                      ArtMethod* method,
1012                                                      ObjPtr<mirror::Class> klass1,
1013                                                      ObjPtr<mirror::Class> klass2)
1014       REQUIRES_SHARED(Locks::mutator_lock_);
1015 
1016   bool LinkClass(Thread* self,
1017                  const char* descriptor,
1018                  Handle<mirror::Class> klass,
1019                  Handle<mirror::ObjectArray<mirror::Class>> interfaces,
1020                  MutableHandle<mirror::Class>* h_new_class_out)
1021       REQUIRES_SHARED(Locks::mutator_lock_)
1022       REQUIRES(!Locks::classlinker_classes_lock_);
1023 
1024   bool LinkSuperClass(Handle<mirror::Class> klass)
1025       REQUIRES_SHARED(Locks::mutator_lock_);
1026 
1027   bool LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file)
1028       REQUIRES_SHARED(Locks::mutator_lock_)
1029       REQUIRES(!Locks::dex_lock_);
1030 
1031   bool LinkMethods(Thread* self,
1032                    Handle<mirror::Class> klass,
1033                    Handle<mirror::ObjectArray<mirror::Class>> interfaces,
1034                    bool* out_new_conflict,
1035                    ArtMethod** out_imt)
1036       REQUIRES_SHARED(Locks::mutator_lock_);
1037 
1038   ObjPtr<mirror::MethodHandle> ResolveMethodHandleForField(
1039       Thread* self,
1040       const dex::MethodHandleItem& method_handle,
1041       ArtMethod* referrer) REQUIRES_SHARED(Locks::mutator_lock_);
1042 
1043   ObjPtr<mirror::MethodHandle> ResolveMethodHandleForMethod(
1044       Thread* self,
1045       const dex::MethodHandleItem& method_handle,
1046       ArtMethod* referrer) REQUIRES_SHARED(Locks::mutator_lock_);
1047 
1048   // A wrapper class representing the result of a method translation used for linking methods and
1049   // updating superclass default methods. For each method in a classes vtable there are 4 states it
1050   // could be in:
1051   // 1) No translation is necessary. In this case there is no MethodTranslation object for it. This
1052   //    is the standard case and is true when the method is not overridable by a default method,
1053   //    the class defines a concrete implementation of the method, the default method implementation
1054   //    remains the same, or an abstract method stayed abstract.
1055   // 2) The method must be translated to a different default method. We note this with
1056   //    CreateTranslatedMethod.
1057   // 3) The method must be replaced with a conflict method. This happens when a superclass
1058   //    implements an interface with a default method and this class implements an unrelated
1059   //    interface that also defines that default method. We note this with CreateConflictingMethod.
1060   // 4) The method must be replaced with an abstract miranda method. This happens when a superclass
1061   //    implements an interface with a default method and this class implements a subinterface of
1062   //    the superclass's interface which declares the default method abstract. We note this with
1063   //    CreateAbstractMethod.
1064   //
1065   // When a method translation is unnecessary (case #1), we don't put it into the
1066   // default_translation maps. So an instance of MethodTranslation must be in one of #2-#4.
1067   class MethodTranslation {
1068    public:
1069     // This slot must become a default conflict method.
CreateConflictingMethod()1070     static MethodTranslation CreateConflictingMethod() {
1071       return MethodTranslation(Type::kConflict, /*translation=*/nullptr);
1072     }
1073 
1074     // This slot must become an abstract method.
CreateAbstractMethod()1075     static MethodTranslation CreateAbstractMethod() {
1076       return MethodTranslation(Type::kAbstract, /*translation=*/nullptr);
1077     }
1078 
1079     // Use the given method as the current value for this vtable slot during translation.
CreateTranslatedMethod(ArtMethod * new_method)1080     static MethodTranslation CreateTranslatedMethod(ArtMethod* new_method) {
1081       return MethodTranslation(Type::kTranslation, new_method);
1082     }
1083 
1084     // Returns true if this is a method that must become a conflict method.
IsInConflict()1085     bool IsInConflict() const {
1086       return type_ == Type::kConflict;
1087     }
1088 
1089     // Returns true if this is a method that must become an abstract method.
IsAbstract()1090     bool IsAbstract() const {
1091       return type_ == Type::kAbstract;
1092     }
1093 
1094     // Returns true if this is a method that must become a different method.
IsTranslation()1095     bool IsTranslation() const {
1096       return type_ == Type::kTranslation;
1097     }
1098 
1099     // Get the translated version of this method.
GetTranslation()1100     ArtMethod* GetTranslation() const {
1101       DCHECK(IsTranslation());
1102       DCHECK(translation_ != nullptr);
1103       return translation_;
1104     }
1105 
1106    private:
1107     enum class Type {
1108       kTranslation,
1109       kConflict,
1110       kAbstract,
1111     };
1112 
MethodTranslation(Type type,ArtMethod * translation)1113     MethodTranslation(Type type, ArtMethod* translation)
1114         : translation_(translation), type_(type) {}
1115 
1116     ArtMethod* const translation_;
1117     const Type type_;
1118   };
1119 
1120   // Links the virtual methods for the given class and records any default methods that will need to
1121   // be updated later.
1122   //
1123   // Arguments:
1124   // * self - The current thread.
1125   // * klass - class, whose vtable will be filled in.
1126   // * default_translations - Vtable index to new method map.
1127   //                          Any vtable entries that need to be updated with new default methods
1128   //                          are stored into the default_translations map. The default_translations
1129   //                          map is keyed on the vtable index that needs to be updated. We use this
1130   //                          map because if we override a default method with another default
1131   //                          method we need to update the vtable to point to the new method.
1132   //                          Unfortunately since we copy the ArtMethod* we cannot just do a simple
1133   //                          scan, we therefore store the vtable index's that might need to be
1134   //                          updated with the method they will turn into.
1135   // TODO This whole default_translations thing is very dirty. There should be a better way.
1136   bool LinkVirtualMethods(
1137         Thread* self,
1138         Handle<mirror::Class> klass,
1139         /*out*/std::unordered_map<size_t, MethodTranslation>* default_translations)
1140       REQUIRES_SHARED(Locks::mutator_lock_);
1141 
1142   // Sets up the interface lookup table (IFTable) in the correct order to allow searching for
1143   // default methods.
1144   bool SetupInterfaceLookupTable(Thread* self,
1145                                  Handle<mirror::Class> klass,
1146                                  Handle<mirror::ObjectArray<mirror::Class>> interfaces)
1147       REQUIRES_SHARED(Locks::mutator_lock_);
1148 
1149 
1150   enum class DefaultMethodSearchResult {
1151     kDefaultFound,
1152     kAbstractFound,
1153     kDefaultConflict
1154   };
1155 
1156   // Find the default method implementation for 'interface_method' in 'klass', if one exists.
1157   //
1158   // Arguments:
1159   // * self - The current thread.
1160   // * target_method - The method we are trying to find a default implementation for.
1161   // * klass - The class we are searching for a definition of target_method.
1162   // * out_default_method - The pointer we will store the found default method to on success.
1163   //
1164   // Return value:
1165   // * kDefaultFound - There were no conflicting method implementations found in the class while
1166   //                   searching for target_method. The default method implementation is stored into
1167   //                   out_default_method.
1168   // * kAbstractFound - There were no conflicting method implementations found in the class while
1169   //                   searching for target_method but no default implementation was found either.
1170   //                   out_default_method is set to null and the method should be considered not
1171   //                   implemented.
1172   // * kDefaultConflict - Conflicting method implementations were found when searching for
1173   //                      target_method. The value of *out_default_method is null.
1174   DefaultMethodSearchResult FindDefaultMethodImplementation(
1175       Thread* self,
1176       ArtMethod* target_method,
1177       Handle<mirror::Class> klass,
1178       /*out*/ArtMethod** out_default_method) const
1179       REQUIRES_SHARED(Locks::mutator_lock_);
1180 
1181   // Sets the imt entries and fixes up the vtable for the given class by linking all the interface
1182   // methods. See LinkVirtualMethods for an explanation of what default_translations is.
1183   bool LinkInterfaceMethods(
1184       Thread* self,
1185       Handle<mirror::Class> klass,
1186       const std::unordered_map<size_t, MethodTranslation>& default_translations,
1187       bool* out_new_conflict,
1188       ArtMethod** out_imt)
1189       REQUIRES_SHARED(Locks::mutator_lock_);
1190 
1191   bool LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size)
1192       REQUIRES_SHARED(Locks::mutator_lock_);
1193   bool LinkInstanceFields(Thread* self, Handle<mirror::Class> klass)
1194       REQUIRES_SHARED(Locks::mutator_lock_);
1195   bool LinkFields(Thread* self, Handle<mirror::Class> klass, bool is_static, size_t* class_size)
1196       REQUIRES_SHARED(Locks::mutator_lock_);
1197   void CreateReferenceInstanceOffsets(Handle<mirror::Class> klass)
1198       REQUIRES_SHARED(Locks::mutator_lock_);
1199 
1200   void CheckProxyConstructor(ArtMethod* constructor) const
1201       REQUIRES_SHARED(Locks::mutator_lock_);
1202   void CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const
1203       REQUIRES_SHARED(Locks::mutator_lock_);
1204 
GetDexCacheCount()1205   size_t GetDexCacheCount() REQUIRES_SHARED(Locks::mutator_lock_, Locks::dex_lock_) {
1206     return dex_caches_.size();
1207   }
GetDexCachesData()1208   const std::list<DexCacheData>& GetDexCachesData()
1209       REQUIRES_SHARED(Locks::mutator_lock_, Locks::dex_lock_) {
1210     return dex_caches_;
1211   }
1212 
1213   void CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out)
1214       REQUIRES_SHARED(Locks::mutator_lock_);
1215   void CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype, ArtMethod* out)
1216       REQUIRES_SHARED(Locks::mutator_lock_);
1217 
1218   // Register a class loader and create its class table and allocator. Should not be called if
1219   // these are already created.
1220   void RegisterClassLoader(ObjPtr<mirror::ClassLoader> class_loader)
1221       REQUIRES_SHARED(Locks::mutator_lock_)
1222       REQUIRES(Locks::classlinker_classes_lock_);
1223 
1224   // Insert a new class table if not found.
1225   ClassTable* InsertClassTableForClassLoader(ObjPtr<mirror::ClassLoader> class_loader)
1226       REQUIRES_SHARED(Locks::mutator_lock_)
1227       REQUIRES(Locks::classlinker_classes_lock_);
1228 
1229   // EnsureResolved is called to make sure that a class in the class_table_ has been resolved
1230   // before returning it to the caller. Its the responsibility of the thread that placed the class
1231   // in the table to make it resolved. The thread doing resolution must notify on the class' lock
1232   // when resolution has occurred. This happens in mirror::Class::SetStatus. As resolution may
1233   // retire a class, the version of the class in the table is returned and this may differ from
1234   // the class passed in.
1235   ObjPtr<mirror::Class> EnsureResolved(Thread* self,
1236                                        const char* descriptor,
1237                                        ObjPtr<mirror::Class> klass)
1238       WARN_UNUSED
1239       REQUIRES_SHARED(Locks::mutator_lock_)
1240       REQUIRES(!Locks::dex_lock_);
1241 
1242   void FixupTemporaryDeclaringClass(ObjPtr<mirror::Class> temp_class,
1243                                     ObjPtr<mirror::Class> new_class)
1244       REQUIRES_SHARED(Locks::mutator_lock_);
1245 
1246   void SetClassRoot(ClassRoot class_root, ObjPtr<mirror::Class> klass)
1247       REQUIRES_SHARED(Locks::mutator_lock_);
1248 
1249   // Allocate primitive array class for primitive with class root
1250   // `primitive_class_root`, and associate it to class root
1251   // `primitive_array_class_root`.
1252   //
1253   // Also check this class returned when searching system classes for
1254   // `descriptor` matches the allocated class.
1255   void AllocAndSetPrimitiveArrayClassRoot(Thread* self,
1256                                           ObjPtr<mirror::Class> java_lang_Class,
1257                                           ClassRoot primitive_array_class_root,
1258                                           ClassRoot primitive_class_root,
1259                                           const char* descriptor)
1260       REQUIRES_SHARED(Locks::mutator_lock_)
1261       REQUIRES(!Roles::uninterruptible_);
1262 
1263   // Return the quick generic JNI stub for testing.
1264   const void* GetRuntimeQuickGenericJniStub() const;
1265 
1266   bool CanWeInitializeClass(ObjPtr<mirror::Class> klass,
1267                             bool can_init_statics,
1268                             bool can_init_parents)
1269       REQUIRES_SHARED(Locks::mutator_lock_);
1270 
1271   void UpdateClassMethods(ObjPtr<mirror::Class> klass,
1272                           LengthPrefixedArray<ArtMethod>* new_methods)
1273       REQUIRES_SHARED(Locks::mutator_lock_)
1274       REQUIRES(!Locks::classlinker_classes_lock_);
1275 
1276   // Check that c1 == FindSystemClass(self, descriptor). Abort with class dumps otherwise.
1277   void CheckSystemClass(Thread* self, Handle<mirror::Class> c1, const char* descriptor)
1278       REQUIRES(!Locks::dex_lock_)
1279       REQUIRES_SHARED(Locks::mutator_lock_);
1280 
1281   // Allocate method arrays for interfaces.
1282   bool AllocateIfTableMethodArrays(Thread* self,
1283                                    Handle<mirror::Class> klass,
1284                                    Handle<mirror::IfTable> iftable)
1285       REQUIRES_SHARED(Locks::mutator_lock_);
1286 
1287   // Sets imt_ref appropriately for LinkInterfaceMethods.
1288   // If there is no method in the imt location of imt_ref it will store the given method there.
1289   // Otherwise it will set the conflict method which will figure out which method to use during
1290   // runtime.
1291   void SetIMTRef(ArtMethod* unimplemented_method,
1292                  ArtMethod* imt_conflict_method,
1293                  ArtMethod* current_method,
1294                  /*out*/bool* new_conflict,
1295                  /*out*/ArtMethod** imt_ref) REQUIRES_SHARED(Locks::mutator_lock_);
1296 
1297   void FillIMTFromIfTable(ObjPtr<mirror::IfTable> if_table,
1298                           ArtMethod* unimplemented_method,
1299                           ArtMethod* imt_conflict_method,
1300                           ObjPtr<mirror::Class> klass,
1301                           bool create_conflict_tables,
1302                           bool ignore_copied_methods,
1303                           /*out*/bool* new_conflict,
1304                           /*out*/ArtMethod** imt) REQUIRES_SHARED(Locks::mutator_lock_);
1305 
1306   void FillImtFromSuperClass(Handle<mirror::Class> klass,
1307                              ArtMethod* unimplemented_method,
1308                              ArtMethod* imt_conflict_method,
1309                              bool* new_conflict,
1310                              ArtMethod** imt) REQUIRES_SHARED(Locks::mutator_lock_);
1311 
1312   // Check invoke type against the referenced class. Throws IncompatibleClassChangeError
1313   // (if `kThrowOnError`) and returns true on mismatch (kInterface on a non-interface class,
1314   // kVirtual on interface, kDefault on interface for dex files not supporting default methods),
1315   // otherwise returns false.
1316   template <bool kThrowOnError, typename ClassGetter>
1317   static bool CheckInvokeClassMismatch(ObjPtr<mirror::DexCache> dex_cache,
1318                                        InvokeType type,
1319                                        ClassGetter class_getter)
1320       REQUIRES_SHARED(Locks::mutator_lock_);
1321   // Helper that feeds the above function with `ClassGetter` doing `LookupResolvedType()`.
1322   template <bool kThrow>
1323   bool CheckInvokeClassMismatch(ObjPtr<mirror::DexCache> dex_cache,
1324                                 InvokeType type,
1325                                 uint32_t method_idx,
1326                                 ObjPtr<mirror::ClassLoader> class_loader)
1327       REQUIRES_SHARED(Locks::mutator_lock_);
1328 
1329   ObjPtr<mirror::IfTable> GetArrayIfTable() REQUIRES_SHARED(Locks::mutator_lock_);
1330 
1331   std::vector<const DexFile*> boot_class_path_;
1332   std::vector<std::unique_ptr<const DexFile>> boot_dex_files_;
1333 
1334   // JNI weak globals and side data to allow dex caches to get unloaded. We lazily delete weak
1335   // globals when we register new dex files.
1336   std::list<DexCacheData> dex_caches_ GUARDED_BY(Locks::dex_lock_);
1337 
1338   // This contains the class loaders which have class tables. It is populated by
1339   // InsertClassTableForClassLoader.
1340   std::list<ClassLoaderData> class_loaders_
1341       GUARDED_BY(Locks::classlinker_classes_lock_);
1342 
1343   // Boot class path table. Since the class loader for this is null.
1344   std::unique_ptr<ClassTable> boot_class_table_ GUARDED_BY(Locks::classlinker_classes_lock_);
1345 
1346   // New class roots, only used by CMS since the GC needs to mark these in the pause.
1347   std::vector<GcRoot<mirror::Class>> new_class_roots_ GUARDED_BY(Locks::classlinker_classes_lock_);
1348 
1349   // Boot image oat files with new .bss GC roots to be visited in the pause by CMS.
1350   std::vector<const OatFile*> new_bss_roots_boot_oat_files_
1351       GUARDED_BY(Locks::classlinker_classes_lock_);
1352 
1353   // Number of times we've searched dex caches for a class. After a certain number of misses we move
1354   // the classes into the class_table_ to avoid dex cache based searches.
1355   Atomic<uint32_t> failed_dex_cache_class_lookups_;
1356 
1357   // Well known mirror::Class roots.
1358   GcRoot<mirror::ObjectArray<mirror::Class>> class_roots_;
1359 
1360   // A cache of the last FindArrayClass results. The cache serves to avoid creating array class
1361   // descriptors for the sake of performing FindClass.
1362   static constexpr size_t kFindArrayCacheSize = 16;
1363   GcRoot<mirror::Class> find_array_class_cache_[kFindArrayCacheSize];
1364   size_t find_array_class_cache_next_victim_;
1365 
1366   bool init_done_;
1367   bool log_new_roots_ GUARDED_BY(Locks::classlinker_classes_lock_);
1368 
1369   InternTable* intern_table_;
1370 
1371   const bool fast_class_not_found_exceptions_;
1372 
1373   // Trampolines within the image the bounce to runtime entrypoints. Done so that there is a single
1374   // patch point within the image. TODO: make these proper relocations.
1375   const void* quick_resolution_trampoline_;
1376   const void* quick_imt_conflict_trampoline_;
1377   const void* quick_generic_jni_trampoline_;
1378   const void* quick_to_interpreter_bridge_trampoline_;
1379 
1380   // Image pointer size.
1381   PointerSize image_pointer_size_;
1382 
1383   std::unique_ptr<ClassHierarchyAnalysis> cha_;
1384 
1385   class FindVirtualMethodHolderVisitor;
1386 
1387   friend class AppImageLoadingHelper;
1388   friend class ImageDumper;  // for DexLock
1389   friend struct linker::CompilationHelper;  // For Compile in ImageTest.
1390   friend class linker::ImageWriter;  // for GetClassRoots
1391   friend class JniCompilerTest;  // for GetRuntimeQuickGenericJniStub
1392   friend class JniInternalTest;  // for GetRuntimeQuickGenericJniStub
1393   friend class VMClassLoader;  // for LookupClass and FindClassInBaseDexClassLoader.
1394   ART_FRIEND_TEST(ClassLinkerTest, RegisterDexFileName);  // for DexLock, and RegisterDexFileLocked
1395   ART_FRIEND_TEST(mirror::DexCacheMethodHandlesTest, Open);  // for AllocDexCache
1396   ART_FRIEND_TEST(mirror::DexCacheTest, Open);  // for AllocDexCache
1397   DISALLOW_COPY_AND_ASSIGN(ClassLinker);
1398 };
1399 
1400 class ClassLoadCallback {
1401  public:
~ClassLoadCallback()1402   virtual ~ClassLoadCallback() {}
1403 
1404   // If set we will replace initial_class_def & initial_dex_file with the final versions. The
1405   // callback author is responsible for ensuring these are allocated in such a way they can be
1406   // cleaned up if another transformation occurs. Note that both must be set or null/unchanged on
1407   // return.
1408   // Note: the class may be temporary, in which case a following ClassPrepare event will be a
1409   //       different object. It is the listener's responsibility to handle this.
1410   // Note: This callback is rarely useful so a default implementation has been given that does
1411   //       nothing.
ClassPreDefine(const char * descriptor ATTRIBUTE_UNUSED,Handle<mirror::Class> klass ATTRIBUTE_UNUSED,Handle<mirror::ClassLoader> class_loader ATTRIBUTE_UNUSED,const DexFile & initial_dex_file ATTRIBUTE_UNUSED,const dex::ClassDef & initial_class_def ATTRIBUTE_UNUSED,DexFile const ** final_dex_file ATTRIBUTE_UNUSED,dex::ClassDef const ** final_class_def ATTRIBUTE_UNUSED)1412   virtual void ClassPreDefine(const char* descriptor ATTRIBUTE_UNUSED,
1413                               Handle<mirror::Class> klass ATTRIBUTE_UNUSED,
1414                               Handle<mirror::ClassLoader> class_loader ATTRIBUTE_UNUSED,
1415                               const DexFile& initial_dex_file ATTRIBUTE_UNUSED,
1416                               const dex::ClassDef& initial_class_def ATTRIBUTE_UNUSED,
1417                               /*out*/DexFile const** final_dex_file ATTRIBUTE_UNUSED,
1418                               /*out*/dex::ClassDef const** final_class_def ATTRIBUTE_UNUSED)
1419       REQUIRES_SHARED(Locks::mutator_lock_) {}
1420 
1421   // A class has been loaded.
1422   // Note: the class may be temporary, in which case a following ClassPrepare event will be a
1423   //       different object. It is the listener's responsibility to handle this.
1424   virtual void ClassLoad(Handle<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) = 0;
1425 
1426   // A class has been prepared, i.e., resolved. As the ClassLoad event might have been for a
1427   // temporary class, provide both the former and the current class.
1428   virtual void ClassPrepare(Handle<mirror::Class> temp_klass,
1429                             Handle<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) = 0;
1430 };
1431 
1432 }  // namespace art
1433 
1434 #endif  // ART_RUNTIME_CLASS_LINKER_H_
1435