class_linker.h revision 7de5dfe37f3cf24e1166412b589f6f67dcd1f1c0 
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 <string>
21#include <utility>
22#include <vector>
23
24#include "base/allocator.h"
25#include "base/hash_set.h"
26#include "base/macros.h"
27#include "base/mutex.h"
28#include "class_table.h"
29#include "dex_file.h"
30#include "gc_root.h"
31#include "jni.h"
32#include "oat_file.h"
33#include "object_callbacks.h"
34
35namespace art {
36
37namespace gc {
38namespace space {
39  class ImageSpace;
40}  // namespace space
41}  // namespace gc
42namespace mirror {
43  class ClassLoader;
44  class DexCache;
45  class DexCachePointerArray;
46  class DexCacheTest_Open_Test;
47  class IfTable;
48  template<class T> class ObjectArray;
49  class StackTraceElement;
50}  // namespace mirror
51
52template<class T> class Handle;
53template<class T> class MutableHandle;
54class InternTable;
55template<class T> class ObjectLock;
56class Runtime;
57class ScopedObjectAccessAlreadyRunnable;
58template<size_t kNumReferences> class PACKED(4) StackHandleScope;
59
60enum VisitRootFlags : uint8_t;
61
62class ClassLoaderVisitor {
63 public:
64  virtual ~ClassLoaderVisitor() {}
65  virtual void Visit(mirror::ClassLoader* class_loader)
66      SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_) = 0;
67};
68
69class ClassLinker {
70 public:
71  // Well known mirror::Class roots accessed via GetClassRoot.
72  enum ClassRoot {
73    kJavaLangClass,
74    kJavaLangObject,
75    kClassArrayClass,
76    kObjectArrayClass,
77    kJavaLangString,
78    kJavaLangDexCache,
79    kJavaLangRefReference,
80    kJavaLangReflectConstructor,
81    kJavaLangReflectField,
82    kJavaLangReflectMethod,
83    kJavaLangReflectProxy,
84    kJavaLangStringArrayClass,
85    kJavaLangReflectConstructorArrayClass,
86    kJavaLangReflectFieldArrayClass,
87    kJavaLangReflectMethodArrayClass,
88    kJavaLangClassLoader,
89    kJavaLangThrowable,
90    kJavaLangClassNotFoundException,
91    kJavaLangStackTraceElement,
92    kPrimitiveBoolean,
93    kPrimitiveByte,
94    kPrimitiveChar,
95    kPrimitiveDouble,
96    kPrimitiveFloat,
97    kPrimitiveInt,
98    kPrimitiveLong,
99    kPrimitiveShort,
100    kPrimitiveVoid,
101    kBooleanArrayClass,
102    kByteArrayClass,
103    kCharArrayClass,
104    kDoubleArrayClass,
105    kFloatArrayClass,
106    kIntArrayClass,
107    kLongArrayClass,
108    kShortArrayClass,
109    kJavaLangStackTraceElementArrayClass,
110    kClassRootsMax,
111  };
112
113  explicit ClassLinker(InternTable* intern_table);
114  ~ClassLinker();
115
116  // Initialize class linker by bootstraping from dex files.
117  void InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path)
118      SHARED_REQUIRES(Locks::mutator_lock_)
119      REQUIRES(!dex_lock_);
120
121  // Initialize class linker from one or more images.
122  void InitFromImage() SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!dex_lock_);
123
124  // Finds a class by its descriptor, loading it if necessary.
125  // If class_loader is null, searches boot_class_path_.
126  mirror::Class* FindClass(Thread* self,
127                           const char* descriptor,
128                           Handle<mirror::ClassLoader> class_loader)
129      SHARED_REQUIRES(Locks::mutator_lock_)
130      REQUIRES(!dex_lock_);
131
132  // Finds a class in the path class loader, loading it if necessary without using JNI. Hash
133  // function is supposed to be ComputeModifiedUtf8Hash(descriptor). Returns true if the
134  // class-loader chain could be handled, false otherwise, i.e., a non-supported class-loader
135  // was encountered while walking the parent chain (currently only BootClassLoader and
136  // PathClassLoader are supported).
137  bool FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa,
138                                  Thread* self,
139                                  const char* descriptor,
140                                  size_t hash,
141                                  Handle<mirror::ClassLoader> class_loader,
142                                  mirror::Class** result)
143      SHARED_REQUIRES(Locks::mutator_lock_)
144      REQUIRES(!dex_lock_);
145
146  // Finds a class by its descriptor using the "system" class loader, ie by searching the
147  // boot_class_path_.
148  mirror::Class* FindSystemClass(Thread* self, const char* descriptor)
149      SHARED_REQUIRES(Locks::mutator_lock_)
150      REQUIRES(!dex_lock_);
151
152  // Finds the array class given for the element class.
153  mirror::Class* FindArrayClass(Thread* self, mirror::Class** element_class)
154      SHARED_REQUIRES(Locks::mutator_lock_)
155      REQUIRES(!dex_lock_);
156
157  // Returns true if the class linker is initialized.
158  bool IsInitialized() const {
159    return init_done_;
160  }
161
162  // Define a new a class based on a ClassDef from a DexFile
163  mirror::Class* DefineClass(Thread* self,
164                             const char* descriptor,
165                             size_t hash,
166                             Handle<mirror::ClassLoader> class_loader,
167                             const DexFile& dex_file,
168                             const DexFile::ClassDef& dex_class_def)
169      SHARED_REQUIRES(Locks::mutator_lock_)
170      REQUIRES(!dex_lock_);
171
172  // Finds a class by its descriptor, returning null if it isn't wasn't loaded
173  // by the given 'class_loader'.
174  mirror::Class* LookupClass(Thread* self,
175                             const char* descriptor,
176                             size_t hash,
177                             mirror::ClassLoader* class_loader)
178      REQUIRES(!Locks::classlinker_classes_lock_)
179      SHARED_REQUIRES(Locks::mutator_lock_);
180
181  // Finds all the classes with the given descriptor, regardless of ClassLoader.
182  void LookupClasses(const char* descriptor, std::vector<mirror::Class*>& classes)
183      REQUIRES(!Locks::classlinker_classes_lock_)
184      SHARED_REQUIRES(Locks::mutator_lock_);
185
186  mirror::Class* FindPrimitiveClass(char type) SHARED_REQUIRES(Locks::mutator_lock_);
187
188  // General class unloading is not supported, this is used to prune
189  // unwanted classes during image writing.
190  bool RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader)
191      REQUIRES(!Locks::classlinker_classes_lock_)
192      SHARED_REQUIRES(Locks::mutator_lock_);
193
194  void DumpAllClasses(int flags)
195      REQUIRES(!Locks::classlinker_classes_lock_)
196      SHARED_REQUIRES(Locks::mutator_lock_);
197
198  void DumpForSigQuit(std::ostream& os) REQUIRES(!Locks::classlinker_classes_lock_);
199
200  size_t NumLoadedClasses()
201      REQUIRES(!Locks::classlinker_classes_lock_)
202      SHARED_REQUIRES(Locks::mutator_lock_);
203
204  // Resolve a String with the given index from the DexFile, storing the
205  // result in the DexCache. The referrer is used to identify the
206  // target DexCache and ClassLoader to use for resolution.
207  mirror::String* ResolveString(uint32_t string_idx, ArtMethod* referrer)
208      SHARED_REQUIRES(Locks::mutator_lock_);
209
210  // Resolve a String with the given index from the DexFile, storing the
211  // result in the DexCache.
212  mirror::String* ResolveString(const DexFile& dex_file, uint32_t string_idx,
213                                Handle<mirror::DexCache> dex_cache)
214      SHARED_REQUIRES(Locks::mutator_lock_);
215
216  // Resolve a Type with the given index from the DexFile, storing the
217  // result in the DexCache. The referrer is used to identity the
218  // target DexCache and ClassLoader to use for resolution.
219  mirror::Class* ResolveType(const DexFile& dex_file, uint16_t type_idx, mirror::Class* referrer)
220      SHARED_REQUIRES(Locks::mutator_lock_)
221      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
222
223  // Resolve a Type with the given index from the DexFile, storing the
224  // result in the DexCache. The referrer is used to identify the
225  // target DexCache and ClassLoader to use for resolution.
226  mirror::Class* ResolveType(uint16_t type_idx, ArtMethod* referrer)
227      SHARED_REQUIRES(Locks::mutator_lock_)
228      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
229
230  mirror::Class* ResolveType(uint16_t type_idx, ArtField* referrer)
231      SHARED_REQUIRES(Locks::mutator_lock_)
232      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
233
234  // Resolve a type with the given ID from the DexFile, storing the
235  // result in DexCache. The ClassLoader is used to search for the
236  // type, since it may be referenced from but not contained within
237  // the given DexFile.
238  mirror::Class* ResolveType(const DexFile& dex_file,
239                             uint16_t type_idx,
240                             Handle<mirror::DexCache> dex_cache,
241                             Handle<mirror::ClassLoader> class_loader)
242      SHARED_REQUIRES(Locks::mutator_lock_)
243      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
244
245  // Resolve a method with a given ID from the DexFile, storing the
246  // result in DexCache. The ClassLinker and ClassLoader are used as
247  // in ResolveType. What is unique is the method type argument which
248  // is used to determine if this method is a direct, static, or
249  // virtual method.
250  ArtMethod* ResolveMethod(const DexFile& dex_file,
251                           uint32_t method_idx,
252                           Handle<mirror::DexCache> dex_cache,
253                           Handle<mirror::ClassLoader> class_loader,
254                           ArtMethod* referrer,
255                           InvokeType type)
256      SHARED_REQUIRES(Locks::mutator_lock_)
257      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
258
259  ArtMethod* GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer)
260      SHARED_REQUIRES(Locks::mutator_lock_);
261  ArtMethod* ResolveMethod(Thread* self, uint32_t method_idx, ArtMethod* referrer, InvokeType type)
262      SHARED_REQUIRES(Locks::mutator_lock_)
263      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
264  ArtMethod* ResolveMethodWithoutInvokeType(const DexFile& dex_file,
265                                            uint32_t method_idx,
266                                            Handle<mirror::DexCache> dex_cache,
267                                            Handle<mirror::ClassLoader> class_loader)
268      SHARED_REQUIRES(Locks::mutator_lock_)
269      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
270
271  ArtField* GetResolvedField(uint32_t field_idx, mirror::Class* field_declaring_class)
272      SHARED_REQUIRES(Locks::mutator_lock_);
273  ArtField* GetResolvedField(uint32_t field_idx, mirror::DexCache* dex_cache)
274      SHARED_REQUIRES(Locks::mutator_lock_);
275  ArtField* ResolveField(uint32_t field_idx, ArtMethod* referrer, bool is_static)
276      SHARED_REQUIRES(Locks::mutator_lock_)
277      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
278
279  // Resolve a field with a given ID from the DexFile, storing the
280  // result in DexCache. The ClassLinker and ClassLoader are used as
281  // in ResolveType. What is unique is the is_static argument which is
282  // used to determine if we are resolving a static or non-static
283  // field.
284  ArtField* ResolveField(const DexFile& dex_file, uint32_t field_idx,
285                         Handle<mirror::DexCache> dex_cache,
286                         Handle<mirror::ClassLoader> class_loader, bool is_static)
287      SHARED_REQUIRES(Locks::mutator_lock_)
288      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
289
290  // Resolve a field with a given ID from the DexFile, storing the
291  // result in DexCache. The ClassLinker and ClassLoader are used as
292  // in ResolveType. No is_static argument is provided so that Java
293  // field resolution semantics are followed.
294  ArtField* ResolveFieldJLS(const DexFile& dex_file,
295                            uint32_t field_idx,
296                            Handle<mirror::DexCache> dex_cache,
297                            Handle<mirror::ClassLoader> class_loader)
298      SHARED_REQUIRES(Locks::mutator_lock_)
299      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
300
301  // Get shorty from method index without resolution. Used to do handlerization.
302  const char* MethodShorty(uint32_t method_idx, ArtMethod* referrer, uint32_t* length)
303      SHARED_REQUIRES(Locks::mutator_lock_);
304
305  // Returns true on success, false if there's an exception pending.
306  // can_run_clinit=false allows the compiler to attempt to init a class,
307  // given the restriction that no <clinit> execution is possible.
308  bool EnsureInitialized(Thread* self,
309                         Handle<mirror::Class> c,
310                         bool can_init_fields,
311                         bool can_init_parents)
312      SHARED_REQUIRES(Locks::mutator_lock_)
313      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
314
315  // Initializes classes that have instances in the image but that have
316  // <clinit> methods so they could not be initialized by the compiler.
317  void RunRootClinits()
318      SHARED_REQUIRES(Locks::mutator_lock_)
319      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
320
321  mirror::DexCache* RegisterDexFile(const DexFile& dex_file)
322      REQUIRES(!dex_lock_)
323      SHARED_REQUIRES(Locks::mutator_lock_);
324  void RegisterDexFile(const DexFile& dex_file, Handle<mirror::DexCache> dex_cache)
325      REQUIRES(!dex_lock_)
326      SHARED_REQUIRES(Locks::mutator_lock_);
327
328  const OatFile* RegisterOatFile(const OatFile* oat_file)
329      REQUIRES(!dex_lock_);
330
331  const std::vector<const DexFile*>& GetBootClassPath() {
332    return boot_class_path_;
333  }
334
335  // Returns the first non-image oat file in the class path.
336  const OatFile* GetPrimaryOatFile()
337      REQUIRES(!dex_lock_);
338
339  void VisitClasses(ClassVisitor* visitor)
340      REQUIRES(!Locks::classlinker_classes_lock_)
341      SHARED_REQUIRES(Locks::mutator_lock_);
342
343  // Less efficient variant of VisitClasses that copies the class_table_ into secondary storage
344  // so that it can visit individual classes without holding the doesn't hold the
345  // Locks::classlinker_classes_lock_. As the Locks::classlinker_classes_lock_ isn't held this code
346  // can race with insertion and deletion of classes while the visitor is being called.
347  void VisitClassesWithoutClassesLock(ClassVisitor* visitor)
348      SHARED_REQUIRES(Locks::mutator_lock_)
349      REQUIRES(!dex_lock_);
350
351  void VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags)
352      REQUIRES(!Locks::classlinker_classes_lock_)
353      SHARED_REQUIRES(Locks::mutator_lock_);
354  void VisitRoots(RootVisitor* visitor, VisitRootFlags flags)
355      REQUIRES(!dex_lock_)
356      SHARED_REQUIRES(Locks::mutator_lock_);
357
358  mirror::DexCache* FindDexCache(Thread* self,
359                                 const DexFile& dex_file,
360                                 bool allow_failure = false)
361      REQUIRES(!dex_lock_)
362      SHARED_REQUIRES(Locks::mutator_lock_);
363  void FixupDexCaches(ArtMethod* resolution_method)
364      REQUIRES(!dex_lock_)
365      SHARED_REQUIRES(Locks::mutator_lock_);
366
367  // Finds or creates the oat file holding dex_location. Then loads and returns
368  // all corresponding dex files (there may be more than one dex file loaded
369  // in the case of multidex).
370  // This may return the original, unquickened dex files if the oat file could
371  // not be generated.
372  //
373  // Returns an empty vector if the dex files could not be loaded. In this
374  // case, there will be at least one error message returned describing why no
375  // dex files could not be loaded. The 'error_msgs' argument must not be
376  // null, regardless of whether there is an error or not.
377  //
378  // This method should not be called with the mutator_lock_ held, because it
379  // could end up starving GC if we need to generate or relocate any oat
380  // files.
381  std::vector<std::unique_ptr<const DexFile>> OpenDexFilesFromOat(
382      const char* dex_location,
383      const char* oat_location,
384      std::vector<std::string>* error_msgs)
385      REQUIRES(!dex_lock_, !Locks::mutator_lock_);
386
387  // Allocate an instance of a java.lang.Object.
388  mirror::Object* AllocObject(Thread* self)
389      SHARED_REQUIRES(Locks::mutator_lock_)
390      REQUIRES(!Roles::uninterruptible_);
391
392  // TODO: replace this with multiple methods that allocate the correct managed type.
393  template <class T>
394  mirror::ObjectArray<T>* AllocObjectArray(Thread* self, size_t length)
395      SHARED_REQUIRES(Locks::mutator_lock_)
396      REQUIRES(!Roles::uninterruptible_);
397
398  mirror::ObjectArray<mirror::Class>* AllocClassArray(Thread* self, size_t length)
399      SHARED_REQUIRES(Locks::mutator_lock_)
400      REQUIRES(!Roles::uninterruptible_);
401
402  mirror::ObjectArray<mirror::String>* AllocStringArray(Thread* self, size_t length)
403      SHARED_REQUIRES(Locks::mutator_lock_)
404      REQUIRES(!Roles::uninterruptible_);
405
406  LengthPrefixedArray<ArtField>* AllocArtFieldArray(Thread* self, size_t length);
407
408  LengthPrefixedArray<ArtMethod>* AllocArtMethodArray(Thread* self, size_t length);
409
410  mirror::PointerArray* AllocPointerArray(Thread* self, size_t length)
411      SHARED_REQUIRES(Locks::mutator_lock_)
412      REQUIRES(!Roles::uninterruptible_);
413
414  mirror::IfTable* AllocIfTable(Thread* self, size_t ifcount)
415      SHARED_REQUIRES(Locks::mutator_lock_)
416      REQUIRES(!Roles::uninterruptible_);
417
418  mirror::ObjectArray<mirror::StackTraceElement>* AllocStackTraceElementArray(Thread* self,
419                                                                              size_t length)
420      SHARED_REQUIRES(Locks::mutator_lock_)
421      REQUIRES(!Roles::uninterruptible_);
422
423  void VerifyClass(Thread* self, Handle<mirror::Class> klass)
424      SHARED_REQUIRES(Locks::mutator_lock_)
425      REQUIRES(!dex_lock_);
426  bool VerifyClassUsingOatFile(const DexFile& dex_file,
427                               mirror::Class* klass,
428                               mirror::Class::Status& oat_file_class_status)
429      SHARED_REQUIRES(Locks::mutator_lock_)
430      REQUIRES(!dex_lock_);
431  void ResolveClassExceptionHandlerTypes(const DexFile& dex_file,
432                                         Handle<mirror::Class> klass)
433      SHARED_REQUIRES(Locks::mutator_lock_)
434      REQUIRES(!dex_lock_);
435  void ResolveMethodExceptionHandlerTypes(const DexFile& dex_file, ArtMethod* klass)
436      SHARED_REQUIRES(Locks::mutator_lock_)
437      REQUIRES(!dex_lock_);
438
439  mirror::Class* CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa,
440                                  jstring name,
441                                  jobjectArray interfaces,
442                                  jobject loader,
443                                  jobjectArray methods,
444                                  jobjectArray throws)
445      SHARED_REQUIRES(Locks::mutator_lock_);
446  std::string GetDescriptorForProxy(mirror::Class* proxy_class)
447      SHARED_REQUIRES(Locks::mutator_lock_);
448  ArtMethod* FindMethodForProxy(mirror::Class* proxy_class, ArtMethod* proxy_method)
449      REQUIRES(!dex_lock_)
450      SHARED_REQUIRES(Locks::mutator_lock_);
451
452  // Get the oat code for a method when its class isn't yet initialized
453  const void* GetQuickOatCodeFor(ArtMethod* method)
454      SHARED_REQUIRES(Locks::mutator_lock_);
455
456  // Get the oat code for a method from a method index.
457  const void* GetQuickOatCodeFor(const DexFile& dex_file,
458                                 uint16_t class_def_idx,
459                                 uint32_t method_idx)
460      SHARED_REQUIRES(Locks::mutator_lock_);
461
462  // Get compiled code for a method, return null if no code
463  // exists. This is unlike Get..OatCodeFor which will return a bridge
464  // or interpreter entrypoint.
465  const void* GetOatMethodQuickCodeFor(ArtMethod* method)
466      SHARED_REQUIRES(Locks::mutator_lock_);
467
468  const OatFile::OatMethod FindOatMethodFor(ArtMethod* method, bool* found)
469      SHARED_REQUIRES(Locks::mutator_lock_);
470
471  pid_t GetClassesLockOwner();  // For SignalCatcher.
472  pid_t GetDexLockOwner();  // For SignalCatcher.
473
474  mirror::Class* GetClassRoot(ClassRoot class_root) SHARED_REQUIRES(Locks::mutator_lock_);
475
476  static const char* GetClassRootDescriptor(ClassRoot class_root);
477
478  // Is the given entry point quick code to run the resolution stub?
479  bool IsQuickResolutionStub(const void* entry_point) const;
480
481  // Is the given entry point quick code to bridge into the interpreter?
482  bool IsQuickToInterpreterBridge(const void* entry_point) const;
483
484  // Is the given entry point quick code to run the generic JNI stub?
485  bool IsQuickGenericJniStub(const void* entry_point) const;
486
487  InternTable* GetInternTable() const {
488    return intern_table_;
489  }
490
491  // Set the entrypoints up for method to the given code.
492  void SetEntryPointsToCompiledCode(ArtMethod* method, const void* method_code) const
493      SHARED_REQUIRES(Locks::mutator_lock_);
494
495  // Set the entrypoints up for method to the enter the interpreter.
496  void SetEntryPointsToInterpreter(ArtMethod* method) const
497      SHARED_REQUIRES(Locks::mutator_lock_);
498
499  // Attempts to insert a class into a class table.  Returns null if
500  // the class was inserted, otherwise returns an existing class with
501  // the same descriptor and ClassLoader.
502  mirror::Class* InsertClass(const char* descriptor, mirror::Class* klass, size_t hash)
503      REQUIRES(!Locks::classlinker_classes_lock_)
504      SHARED_REQUIRES(Locks::mutator_lock_);
505
506  mirror::ObjectArray<mirror::Class>* GetClassRoots() SHARED_REQUIRES(Locks::mutator_lock_) {
507    mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
508    DCHECK(class_roots != nullptr);
509    return class_roots;
510  }
511
512  // Move all of the image classes into the class table for faster lookups.
513  void MoveImageClassesToClassTable()
514      REQUIRES(!Locks::classlinker_classes_lock_)
515      SHARED_REQUIRES(Locks::mutator_lock_);
516  // Move the class table to the pre-zygote table to reduce memory usage. This works by ensuring
517  // that no more classes are ever added to the pre zygote table which makes it that the pages
518  // always remain shared dirty instead of private dirty.
519  void MoveClassTableToPreZygote()
520      REQUIRES(!Locks::classlinker_classes_lock_)
521      SHARED_REQUIRES(Locks::mutator_lock_);
522
523  // Returns true if the method can be called with its direct code pointer, false otherwise.
524  bool MayBeCalledWithDirectCodePointer(ArtMethod* m)
525      SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!dex_lock_);
526
527  // Creates a GlobalRef PathClassLoader that can be used to load classes from the given dex files.
528  // Note: the objects are not completely set up. Do not use this outside of tests and the compiler.
529  jobject CreatePathClassLoader(Thread* self, std::vector<const DexFile*>& dex_files)
530      SHARED_REQUIRES(Locks::mutator_lock_)
531      REQUIRES(!dex_lock_);
532
533  size_t GetImagePointerSize() const {
534    DCHECK(ValidPointerSize(image_pointer_size_)) << image_pointer_size_;
535    return image_pointer_size_;
536  }
537
538  // Used by image writer for checking.
539  bool ClassInClassTable(mirror::Class* klass)
540      REQUIRES(Locks::classlinker_classes_lock_)
541      SHARED_REQUIRES(Locks::mutator_lock_);
542
543  ArtMethod* CreateRuntimeMethod();
544
545  // Clear the ArrayClass cache. This is necessary when cleaning up for the image, as the cache
546  // entries are roots, but potentially not image classes.
547  void DropFindArrayClassCache() SHARED_REQUIRES(Locks::mutator_lock_);
548
549 private:
550  // The RemoveClearedLoaders version removes cleared weak global class loaders and frees their
551  // class tables. This version can only be called with reader access to the
552  // classlinker_classes_lock_ since it modifies the class_loaders_ list.
553  void VisitClassLoadersAndRemoveClearedLoaders(ClassLoaderVisitor* visitor)
554      REQUIRES(Locks::classlinker_classes_lock_)
555      SHARED_REQUIRES(Locks::mutator_lock_);
556  void VisitClassLoaders(ClassLoaderVisitor* visitor) const
557      SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
558
559
560  void VisitClassesInternal(ClassVisitor* visitor)
561      SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
562
563  // Returns the number of zygote and image classes.
564  size_t NumZygoteClasses() const
565      REQUIRES(Locks::classlinker_classes_lock_)
566      SHARED_REQUIRES(Locks::mutator_lock_);
567
568  // Returns the number of non zygote nor image classes.
569  size_t NumNonZygoteClasses() const
570      REQUIRES(Locks::classlinker_classes_lock_)
571      SHARED_REQUIRES(Locks::mutator_lock_);
572
573  OatFile& GetImageOatFile(gc::space::ImageSpace* space)
574      REQUIRES(!dex_lock_)
575      SHARED_REQUIRES(Locks::mutator_lock_);
576
577  void FinishInit(Thread* self)
578  SHARED_REQUIRES(Locks::mutator_lock_)
579      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
580
581  // For early bootstrapping by Init
582  mirror::Class* AllocClass(Thread* self, mirror::Class* java_lang_Class, uint32_t class_size)
583      SHARED_REQUIRES(Locks::mutator_lock_)
584      REQUIRES(!Roles::uninterruptible_);
585
586  // Alloc* convenience functions to avoid needing to pass in mirror::Class*
587  // values that are known to the ClassLinker such as
588  // kObjectArrayClass and kJavaLangString etc.
589  mirror::Class* AllocClass(Thread* self, uint32_t class_size)
590      SHARED_REQUIRES(Locks::mutator_lock_)
591      REQUIRES(!Roles::uninterruptible_);
592  mirror::DexCache* AllocDexCache(Thread* self, const DexFile& dex_file)
593      SHARED_REQUIRES(Locks::mutator_lock_)
594      REQUIRES(!Roles::uninterruptible_);
595
596  mirror::Class* CreatePrimitiveClass(Thread* self, Primitive::Type type)
597      SHARED_REQUIRES(Locks::mutator_lock_)
598      REQUIRES(!Roles::uninterruptible_);
599  mirror::Class* InitializePrimitiveClass(mirror::Class* primitive_class, Primitive::Type type)
600      SHARED_REQUIRES(Locks::mutator_lock_)
601      REQUIRES(!Roles::uninterruptible_);
602
603  mirror::Class* CreateArrayClass(Thread* self,
604                                  const char* descriptor,
605                                  size_t hash,
606                                  Handle<mirror::ClassLoader> class_loader)
607      SHARED_REQUIRES(Locks::mutator_lock_)
608      REQUIRES(!dex_lock_, !Roles::uninterruptible_);
609
610  void AppendToBootClassPath(Thread* self, const DexFile& dex_file)
611      SHARED_REQUIRES(Locks::mutator_lock_)
612      REQUIRES(!dex_lock_);
613  void AppendToBootClassPath(const DexFile& dex_file, Handle<mirror::DexCache> dex_cache)
614      SHARED_REQUIRES(Locks::mutator_lock_)
615      REQUIRES(!dex_lock_);
616
617  // Precomputes size needed for Class, in the case of a non-temporary class this size must be
618  // sufficient to hold all static fields.
619  uint32_t SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file,
620                                            const DexFile::ClassDef& dex_class_def);
621
622  // Setup the classloader, class def index, type idx so that we can insert this class in the class
623  // table.
624  void SetupClass(const DexFile& dex_file,
625                  const DexFile::ClassDef& dex_class_def,
626                  Handle<mirror::Class> klass,
627                  mirror::ClassLoader* class_loader)
628      SHARED_REQUIRES(Locks::mutator_lock_);
629
630  void LoadClass(Thread* self,
631                 const DexFile& dex_file,
632                 const DexFile::ClassDef& dex_class_def,
633                 Handle<mirror::Class> klass)
634      SHARED_REQUIRES(Locks::mutator_lock_);
635  void LoadClassMembers(Thread* self,
636                        const DexFile& dex_file,
637                        const uint8_t* class_data,
638                        Handle<mirror::Class> klass,
639                        const OatFile::OatClass* oat_class)
640      SHARED_REQUIRES(Locks::mutator_lock_);
641
642  void LoadField(const ClassDataItemIterator& it, Handle<mirror::Class> klass, ArtField* dst)
643      SHARED_REQUIRES(Locks::mutator_lock_);
644
645  void LoadMethod(Thread* self,
646                  const DexFile& dex_file,
647                  const ClassDataItemIterator& it,
648                  Handle<mirror::Class> klass, ArtMethod* dst)
649      SHARED_REQUIRES(Locks::mutator_lock_);
650
651  void FixupStaticTrampolines(mirror::Class* klass) SHARED_REQUIRES(Locks::mutator_lock_);
652
653  // Finds the associated oat class for a dex_file and descriptor. Returns an invalid OatClass on
654  // error and sets found to false.
655  OatFile::OatClass FindOatClass(const DexFile& dex_file, uint16_t class_def_idx, bool* found)
656      SHARED_REQUIRES(Locks::mutator_lock_);
657
658  void RegisterDexFileLocked(const DexFile& dex_file, Handle<mirror::DexCache> dex_cache)
659      REQUIRES(dex_lock_)
660      SHARED_REQUIRES(Locks::mutator_lock_);
661  mirror::DexCache* FindDexCacheLocked(Thread* self, const DexFile& dex_file, bool allow_failure)
662      REQUIRES(dex_lock_)
663      SHARED_REQUIRES(Locks::mutator_lock_);
664
665  bool InitializeClass(Thread* self,
666                       Handle<mirror::Class> klass,
667                       bool can_run_clinit,
668                       bool can_init_parents)
669      SHARED_REQUIRES(Locks::mutator_lock_)
670      REQUIRES(!dex_lock_);
671  bool WaitForInitializeClass(Handle<mirror::Class> klass,
672                              Thread* self,
673                              ObjectLock<mirror::Class>& lock);
674  bool ValidateSuperClassDescriptors(Handle<mirror::Class> klass)
675      SHARED_REQUIRES(Locks::mutator_lock_);
676
677  bool IsSameDescriptorInDifferentClassContexts(Thread* self,
678                                                const char* descriptor,
679                                                Handle<mirror::ClassLoader> class_loader1,
680                                                Handle<mirror::ClassLoader> class_loader2)
681      SHARED_REQUIRES(Locks::mutator_lock_);
682
683  bool IsSameMethodSignatureInDifferentClassContexts(Thread* self,
684                                                     ArtMethod* method,
685                                                     mirror::Class* klass1,
686                                                     mirror::Class* klass2)
687      SHARED_REQUIRES(Locks::mutator_lock_);
688
689  bool LinkClass(Thread* self,
690                 const char* descriptor,
691                 Handle<mirror::Class> klass,
692                 Handle<mirror::ObjectArray<mirror::Class>> interfaces,
693                 MutableHandle<mirror::Class>* h_new_class_out)
694      SHARED_REQUIRES(Locks::mutator_lock_)
695      REQUIRES(!Locks::classlinker_classes_lock_);
696
697  bool LinkSuperClass(Handle<mirror::Class> klass)
698      SHARED_REQUIRES(Locks::mutator_lock_);
699
700  bool LoadSuperAndInterfaces(Handle<mirror::Class> klass, const DexFile& dex_file)
701      SHARED_REQUIRES(Locks::mutator_lock_)
702      REQUIRES(!dex_lock_);
703
704  bool LinkMethods(Thread* self,
705                   Handle<mirror::Class> klass,
706                   Handle<mirror::ObjectArray<mirror::Class>> interfaces,
707                   ArtMethod** out_imt)
708      SHARED_REQUIRES(Locks::mutator_lock_);
709
710  bool LinkVirtualMethods(Thread* self, Handle<mirror::Class> klass)
711      SHARED_REQUIRES(Locks::mutator_lock_);
712
713  bool LinkInterfaceMethods(Thread* self,
714                            Handle<mirror::Class> klass,
715                            Handle<mirror::ObjectArray<mirror::Class>> interfaces,
716                            ArtMethod** out_imt)
717      SHARED_REQUIRES(Locks::mutator_lock_);
718
719  bool LinkStaticFields(Thread* self, Handle<mirror::Class> klass, size_t* class_size)
720      SHARED_REQUIRES(Locks::mutator_lock_);
721  bool LinkInstanceFields(Thread* self, Handle<mirror::Class> klass)
722      SHARED_REQUIRES(Locks::mutator_lock_);
723  bool LinkFields(Thread* self, Handle<mirror::Class> klass, bool is_static, size_t* class_size)
724      SHARED_REQUIRES(Locks::mutator_lock_);
725  void LinkCode(ArtMethod* method,
726                const OatFile::OatClass* oat_class,
727                uint32_t class_def_method_index)
728      SHARED_REQUIRES(Locks::mutator_lock_);
729  void CreateReferenceInstanceOffsets(Handle<mirror::Class> klass)
730      SHARED_REQUIRES(Locks::mutator_lock_);
731
732  void CheckProxyConstructor(ArtMethod* constructor) const
733      SHARED_REQUIRES(Locks::mutator_lock_);
734  void CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const
735      SHARED_REQUIRES(Locks::mutator_lock_);
736
737  // For use by ImageWriter to find DexCaches for its roots
738  ReaderWriterMutex* DexLock()
739      SHARED_REQUIRES(Locks::mutator_lock_)
740      LOCK_RETURNED(dex_lock_) {
741    return &dex_lock_;
742  }
743  size_t GetDexCacheCount() SHARED_REQUIRES(Locks::mutator_lock_, dex_lock_) {
744    return dex_caches_.size();
745  }
746  const std::list<jweak>& GetDexCaches() SHARED_REQUIRES(Locks::mutator_lock_, dex_lock_) {
747    return dex_caches_;
748  }
749
750  const OatFile* FindOpenedOatFileFromOatLocation(const std::string& oat_location)
751      REQUIRES(!dex_lock_);
752
753  // Returns the boot image oat file.
754  const OatFile* GetBootOatFile() SHARED_REQUIRES(dex_lock_);
755
756  void CreateProxyConstructor(Handle<mirror::Class> klass, ArtMethod* out)
757      SHARED_REQUIRES(Locks::mutator_lock_);
758  void CreateProxyMethod(Handle<mirror::Class> klass, ArtMethod* prototype, ArtMethod* out)
759      SHARED_REQUIRES(Locks::mutator_lock_);
760
761  // Ensures that methods have the kAccPreverified bit set. We use the kAccPreverfied bit on the
762  // class access flags to determine whether this has been done before.
763  void EnsurePreverifiedMethods(Handle<mirror::Class> c)
764      SHARED_REQUIRES(Locks::mutator_lock_);
765
766  mirror::Class* LookupClassFromImage(const char* descriptor)
767      SHARED_REQUIRES(Locks::mutator_lock_);
768
769  // Returns null if not found.
770  ClassTable* ClassTableForClassLoader(mirror::ClassLoader* class_loader)
771      SHARED_REQUIRES(Locks::mutator_lock_, Locks::classlinker_classes_lock_);
772  // Insert a new class table if not found.
773  ClassTable* InsertClassTableForClassLoader(mirror::ClassLoader* class_loader)
774      SHARED_REQUIRES(Locks::mutator_lock_)
775      REQUIRES(Locks::classlinker_classes_lock_);
776
777  // EnsureResolved is called to make sure that a class in the class_table_ has been resolved
778  // before returning it to the caller. Its the responsibility of the thread that placed the class
779  // in the table to make it resolved. The thread doing resolution must notify on the class' lock
780  // when resolution has occurred. This happens in mirror::Class::SetStatus. As resolution may
781  // retire a class, the version of the class in the table is returned and this may differ from
782  // the class passed in.
783  mirror::Class* EnsureResolved(Thread* self, const char* descriptor, mirror::Class* klass)
784      WARN_UNUSED
785      SHARED_REQUIRES(Locks::mutator_lock_)
786      REQUIRES(!dex_lock_);
787
788  void FixupTemporaryDeclaringClass(mirror::Class* temp_class, mirror::Class* new_class)
789      SHARED_REQUIRES(Locks::mutator_lock_);
790
791  void SetClassRoot(ClassRoot class_root, mirror::Class* klass)
792      SHARED_REQUIRES(Locks::mutator_lock_);
793
794  // Return the quick generic JNI stub for testing.
795  const void* GetRuntimeQuickGenericJniStub() const;
796
797  // Throw the class initialization failure recorded when first trying to initialize the given
798  // class.
799  // Note: Currently we only store the descriptor, so we cannot throw the exact throwable, only
800  //       a recreation with a custom string.
801  void ThrowEarlierClassFailure(mirror::Class* c)
802      SHARED_REQUIRES(Locks::mutator_lock_)
803      REQUIRES(!dex_lock_);
804
805  // Check for duplicate class definitions of the given oat file against all open oat files.
806  bool HasCollisions(const OatFile* oat_file, std::string* error_msg) REQUIRES(!dex_lock_);
807
808  bool HasInitWithString(Thread* self, const char* descriptor)
809      SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(!dex_lock_);
810
811  bool CanWeInitializeClass(mirror::Class* klass, bool can_init_statics, bool can_init_parents)
812      SHARED_REQUIRES(Locks::mutator_lock_);
813
814  void UpdateClassVirtualMethods(mirror::Class* klass,
815                                 LengthPrefixedArray<ArtMethod>* new_methods)
816      SHARED_REQUIRES(Locks::mutator_lock_)
817      REQUIRES(!Locks::classlinker_classes_lock_);
818
819  std::vector<const DexFile*> boot_class_path_;
820  std::vector<std::unique_ptr<const DexFile>> opened_dex_files_;
821
822  mutable ReaderWriterMutex dex_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
823  // JNI weak globals to allow dex caches to get unloaded. We lazily delete weak globals when we
824  // register new dex files.
825  std::list<jweak> dex_caches_ GUARDED_BY(dex_lock_);
826  std::vector<const OatFile*> oat_files_ GUARDED_BY(dex_lock_);
827
828  // This contains the class loaders which have class tables. It is populated by
829  // InsertClassTableForClassLoader. Weak roots to enable class unloading.
830  std::list<jweak> class_loaders_
831      GUARDED_BY(Locks::classlinker_classes_lock_);
832
833  // Boot class path table. Since the class loader for this is null.
834  ClassTable boot_class_table_ GUARDED_BY(Locks::classlinker_classes_lock_);
835
836  // New class roots, only used by CMS since the GC needs to mark these in the pause.
837  std::vector<GcRoot<mirror::Class>> new_class_roots_ GUARDED_BY(Locks::classlinker_classes_lock_);
838
839  // Do we need to search dex caches to find image classes?
840  bool dex_cache_image_class_lookup_required_;
841  // Number of times we've searched dex caches for a class. After a certain number of misses we move
842  // the classes into the class_table_ to avoid dex cache based searches.
843  Atomic<uint32_t> failed_dex_cache_class_lookups_;
844
845  // Well known mirror::Class roots.
846  GcRoot<mirror::ObjectArray<mirror::Class>> class_roots_;
847
848  // The interface table used by all arrays.
849  GcRoot<mirror::IfTable> array_iftable_;
850
851  // A cache of the last FindArrayClass results. The cache serves to avoid creating array class
852  // descriptors for the sake of performing FindClass.
853  static constexpr size_t kFindArrayCacheSize = 16;
854  GcRoot<mirror::Class> find_array_class_cache_[kFindArrayCacheSize];
855  size_t find_array_class_cache_next_victim_;
856
857  bool init_done_;
858  bool log_new_class_table_roots_ GUARDED_BY(Locks::classlinker_classes_lock_);
859
860  InternTable* intern_table_;
861
862  // Trampolines within the image the bounce to runtime entrypoints. Done so that there is a single
863  // patch point within the image. TODO: make these proper relocations.
864  const void* quick_resolution_trampoline_;
865  const void* quick_imt_conflict_trampoline_;
866  const void* quick_generic_jni_trampoline_;
867  const void* quick_to_interpreter_bridge_trampoline_;
868
869  // Image pointer size.
870  size_t image_pointer_size_;
871
872  friend class ImageWriter;  // for GetClassRoots
873  friend class ImageDumper;  // for FindOpenedOatFileFromOatLocation
874  friend class JniCompilerTest;  // for GetRuntimeQuickGenericJniStub
875  ART_FRIEND_TEST(mirror::DexCacheTest, Open);  // for AllocDexCache
876
877  DISALLOW_COPY_AND_ASSIGN(ClassLinker);
878};
879
880}  // namespace art
881
882#endif  // ART_RUNTIME_CLASS_LINKER_H_
883