runtime/class_linker-inl.h - platform/art - Gitiles

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #ifndef ART_RUNTIME_CLASS_LINKER_INL_H_
 #define ART_RUNTIME_CLASS_LINKER_INL_H_

 #include "art_field.h"
 #include "class_linker.h"
 #include "gc_root-inl.h"
 #include "gc/heap-inl.h"
 #include "obj_ptr-inl.h"
 #include "mirror/class_loader.h"
 #include "mirror/dex_cache-inl.h"
 #include "mirror/iftable.h"
 #include "mirror/object_array.h"
 #include "handle_scope-inl.h"
 #include "scoped_thread_state_change-inl.h"

 #include <atomic>

 namespace art {

 inline mirror::Class* ClassLinker::FindSystemClass(Thread* self, const char* descriptor) {
   return FindClass(self, descriptor, ScopedNullHandle<mirror::ClassLoader>());
 }

 inline mirror::Class* ClassLinker::FindArrayClass(Thread* self,
                                                   ObjPtr<mirror::Class>* element_class) {
   for (size_t i = 0; i < kFindArrayCacheSize; ++i) {
     // Read the cached array class once to avoid races with other threads setting it.
     ObjPtr<mirror::Class> array_class = find_array_class_cache_[i].Read();
     if (array_class != nullptr && array_class->GetComponentType() == *element_class) {
       return array_class.Ptr();
     }
   }
   std::string descriptor = "[";
   std::string temp;
   descriptor += (*element_class)->GetDescriptor(&temp);
   StackHandleScope<2> hs(Thread::Current());
   Handle<mirror::ClassLoader> class_loader(hs.NewHandle((*element_class)->GetClassLoader()));
   HandleWrapperObjPtr<mirror::Class> h_element_class(hs.NewHandleWrapper(element_class));
   ObjPtr<mirror::Class> array_class = FindClass(self, descriptor.c_str(), class_loader);
   if (array_class != nullptr) {
     // Benign races in storing array class and incrementing index.
     size_t victim_index = find_array_class_cache_next_victim_;
     find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class);
     find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize;
   } else {
     // We should have a NoClassDefFoundError.
     self->AssertPendingException();
   }
   return array_class.Ptr();
 }

 inline mirror::String* ClassLinker::ResolveString(dex::StringIndex string_idx,
                                                   ArtMethod* referrer) {
   Thread::PoisonObjectPointersIfDebug();
   ObjPtr<mirror::String> string = referrer->GetDexCache()->GetResolvedString(string_idx);
   if (UNLIKELY(string == nullptr)) {
     StackHandleScope<1> hs(Thread::Current());
     Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
     const DexFile& dex_file = *dex_cache->GetDexFile();
     string = ResolveString(dex_file, string_idx, dex_cache);
   }
   return string.Ptr();
 }

 inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(
     dex::TypeIndex type_idx,
     ObjPtr<mirror::DexCache> dex_cache,
     ObjPtr<mirror::ClassLoader> class_loader) {
   ObjPtr<mirror::Class> type = dex_cache->GetResolvedType(type_idx);
   if (type == nullptr) {
     type = Runtime::Current()->GetClassLinker()->LookupResolvedType(
         *dex_cache->GetDexFile(), type_idx, dex_cache, class_loader);
   }
   return type;
 }

 inline mirror::Class* ClassLinker::ResolveType(dex::TypeIndex type_idx, ArtMethod* referrer) {
   Thread::PoisonObjectPointersIfDebug();
   if (kIsDebugBuild) {
     Thread::Current()->AssertNoPendingException();
   }
   ObjPtr<mirror::Class> resolved_type = referrer->GetDexCache()->GetResolvedType(type_idx);
   if (UNLIKELY(resolved_type == nullptr)) {
     StackHandleScope<2> hs(Thread::Current());
     ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
     Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
     Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
     const DexFile& dex_file = *dex_cache->GetDexFile();
     resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader);
   }
   return resolved_type.Ptr();
 }

 inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) {
   ArtMethod* resolved_method = referrer->GetDexCacheResolvedMethod(method_idx, image_pointer_size_);
   if (resolved_method == nullptr || resolved_method->IsRuntimeMethod()) {
     return nullptr;
   }
   return resolved_method;
 }

 inline mirror::Class* ClassLinker::ResolveReferencedClassOfMethod(
     uint32_t method_idx,
     Handle<mirror::DexCache> dex_cache,
     Handle<mirror::ClassLoader> class_loader) {
   // NB: We cannot simply use `GetResolvedMethod(method_idx, ...)->GetDeclaringClass()`. This is
   // because if we did so than an invoke-super could be incorrectly dispatched in cases where
   // GetMethodId(method_idx).class_idx_ refers to a non-interface, non-direct-superclass
   // (super*-class?) of the referrer and the direct superclass of the referrer contains a concrete
   // implementation of the method. If this class's implementation of the method is copied from an
   // interface (either miranda, default or conflict) we would incorrectly assume that is what we
   // want to invoke on, instead of the 'concrete' implementation that the direct superclass
   // contains.
   const DexFile* dex_file = dex_cache->GetDexFile();
   const DexFile::MethodId& method = dex_file->GetMethodId(method_idx);
   ObjPtr<mirror::Class> resolved_type = dex_cache->GetResolvedType(method.class_idx_);
   if (UNLIKELY(resolved_type == nullptr)) {
     resolved_type = ResolveType(*dex_file, method.class_idx_, dex_cache, class_loader);
   }
   return resolved_type.Ptr();
 }

 template <ClassLinker::ResolveMode kResolveMode>
 inline ArtMethod* ClassLinker::ResolveMethod(Thread* self,
                                              uint32_t method_idx,
                                              ArtMethod* referrer,
                                              InvokeType type) {
   ArtMethod* resolved_method = GetResolvedMethod(method_idx, referrer);
   Thread::PoisonObjectPointersIfDebug();
   if (UNLIKELY(resolved_method == nullptr)) {
     ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
     StackHandleScope<2> hs(self);
     Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(referrer->GetDexCache()));
     Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
     const DexFile* dex_file = h_dex_cache->GetDexFile();
     resolved_method = ResolveMethod<kResolveMode>(*dex_file,
                                                   method_idx,
                                                   h_dex_cache,
                                                   h_class_loader,
                                                   referrer,
                                                   type);
   }
   // Note: We cannot check here to see whether we added the method to the cache. It
   //       might be an erroneous class, which results in it being hidden from us.
   return resolved_method;
 }

 inline ArtField* ClassLinker::GetResolvedField(uint32_t field_idx,
                                                ObjPtr<mirror::DexCache> dex_cache) {
   return dex_cache->GetResolvedField(field_idx, image_pointer_size_);
 }

 inline ArtField* ClassLinker::ResolveField(uint32_t field_idx,
                                            ArtMethod* referrer,
                                            bool is_static) {
   Thread::PoisonObjectPointersIfDebug();
   ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
   ArtField* resolved_field = GetResolvedField(field_idx, referrer->GetDexCache());
   if (UNLIKELY(resolved_field == nullptr)) {
     StackHandleScope<2> hs(Thread::Current());
     Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
     Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
     const DexFile& dex_file = *dex_cache->GetDexFile();
     resolved_field = ResolveField(dex_file, field_idx, dex_cache, class_loader, is_static);
     // Note: We cannot check here to see whether we added the field to the cache. The type
     //       might be an erroneous class, which results in it being hidden from us.
   }
   return resolved_field;
 }

 inline mirror::Object* ClassLinker::AllocObject(Thread* self) {
   return GetClassRoot(kJavaLangObject)->Alloc<true, false>(
       self,
       Runtime::Current()->GetHeap()->GetCurrentAllocator()).Ptr();
 }

 template <class T>
 inline mirror::ObjectArray<T>* ClassLinker::AllocObjectArray(Thread* self, size_t length) {
   return mirror::ObjectArray<T>::Alloc(self, GetClassRoot(kObjectArrayClass), length);
 }

 inline mirror::ObjectArray<mirror::Class>* ClassLinker::AllocClassArray(Thread* self,
                                                                         size_t length) {
   return mirror::ObjectArray<mirror::Class>::Alloc(self, GetClassRoot(kClassArrayClass), length);
 }

 inline mirror::ObjectArray<mirror::String>* ClassLinker::AllocStringArray(Thread* self,
                                                                           size_t length) {
   return mirror::ObjectArray<mirror::String>::Alloc(self,
                                                     GetClassRoot(kJavaLangStringArrayClass),
                                                     length);
 }

 inline mirror::IfTable* ClassLinker::AllocIfTable(Thread* self, size_t ifcount) {
   return down_cast<mirror::IfTable*>(
       mirror::IfTable::Alloc(self,
                              GetClassRoot(kObjectArrayClass),
                              ifcount * mirror::IfTable::kMax));
 }

 inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root) {
   DCHECK(!class_roots_.IsNull());
   mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
   ObjPtr<mirror::Class> klass = class_roots->Get(class_root);
   DCHECK(klass != nullptr);
   return klass.Ptr();
 }

 template<ReadBarrierOption kReadBarrierOption>
 ArtMethod* ClassLinker::FindMethodForProxy(ObjPtr<mirror::Class> proxy_class,
                                            ArtMethod* proxy_method) {
   DCHECK(proxy_class->IsProxyClass());
   DCHECK(proxy_method->IsProxyMethod());
   {
     Thread* const self = Thread::Current();
     ReaderMutexLock mu(self, *Locks::dex_lock_);
     // Locate the dex cache of the original interface/Object
     for (const DexCacheData& data : dex_caches_) {
       if (!self->IsJWeakCleared(data.weak_root) &&
           proxy_method->HasSameDexCacheResolvedMethods(data.resolved_methods,
                                                        image_pointer_size_)) {
         ObjPtr<mirror::DexCache> dex_cache =
             ObjPtr<mirror::DexCache>::DownCast(self->DecodeJObject(data.weak_root));
         if (dex_cache != nullptr) {
           ArtMethod* resolved_method = dex_cache->GetResolvedMethod(
               proxy_method->GetDexMethodIndex(), image_pointer_size_);
           CHECK(resolved_method != nullptr);
           return resolved_method;
         }
       }
     }
   }
   LOG(FATAL) << "Didn't find dex cache for " << proxy_class->PrettyClass() << " "
       << proxy_method->PrettyMethod();
   UNREACHABLE();
 }

 }  // namespace art

 #endif  // ART_RUNTIME_CLASS_LINKER_INL_H_
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#ifndef ART_RUNTIME_CLASS_LINKER_INL_H_
	#define ART_RUNTIME_CLASS_LINKER_INL_H_

	#include "art_field.h"
	#include "class_linker.h"
	#include "gc_root-inl.h"
	#include "gc/heap-inl.h"
	#include "obj_ptr-inl.h"
	#include "mirror/class_loader.h"
	#include "mirror/dex_cache-inl.h"
	#include "mirror/iftable.h"
	#include "mirror/object_array.h"
	#include "handle_scope-inl.h"
	#include "scoped_thread_state_change-inl.h"

	#include <atomic>

	namespace art {

	inline mirror::Class* ClassLinker::FindSystemClass(Thread* self, const char* descriptor) {
	return FindClass(self, descriptor, ScopedNullHandle<mirror::ClassLoader>());
	}

	inline mirror::Class* ClassLinker::FindArrayClass(Thread* self,
	ObjPtr<mirror::Class>* element_class) {
	for (size_t i = 0; i < kFindArrayCacheSize; ++i) {
	// Read the cached array class once to avoid races with other threads setting it.
	ObjPtr<mirror::Class> array_class = find_array_class_cache_[i].Read();
	if (array_class != nullptr && array_class->GetComponentType() == *element_class) {
	return array_class.Ptr();
	}
	}
	std::string descriptor = "[";
	std::string temp;
	descriptor += (*element_class)->GetDescriptor(&temp);
	StackHandleScope<2> hs(Thread::Current());
	Handle<mirror::ClassLoader> class_loader(hs.NewHandle((*element_class)->GetClassLoader()));
	HandleWrapperObjPtr<mirror::Class> h_element_class(hs.NewHandleWrapper(element_class));
	ObjPtr<mirror::Class> array_class = FindClass(self, descriptor.c_str(), class_loader);
	if (array_class != nullptr) {
	// Benign races in storing array class and incrementing index.
	size_t victim_index = find_array_class_cache_next_victim_;
	find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class);
	find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize;
	} else {
	// We should have a NoClassDefFoundError.
	self->AssertPendingException();
	}
	return array_class.Ptr();
	}

	inline mirror::String* ClassLinker::ResolveString(dex::StringIndex string_idx,
	ArtMethod* referrer) {
	Thread::PoisonObjectPointersIfDebug();
	ObjPtr<mirror::String> string = referrer->GetDexCache()->GetResolvedString(string_idx);
	if (UNLIKELY(string == nullptr)) {
	StackHandleScope<1> hs(Thread::Current());
	Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
	const DexFile& dex_file = *dex_cache->GetDexFile();
	string = ResolveString(dex_file, string_idx, dex_cache);
	}
	return string.Ptr();
	}

	inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(
	dex::TypeIndex type_idx,
	ObjPtr<mirror::DexCache> dex_cache,
	ObjPtr<mirror::ClassLoader> class_loader) {
	ObjPtr<mirror::Class> type = dex_cache->GetResolvedType(type_idx);
	if (type == nullptr) {
	type = Runtime::Current()->GetClassLinker()->LookupResolvedType(
	*dex_cache->GetDexFile(), type_idx, dex_cache, class_loader);
	}
	return type;
	}

	inline mirror::Class* ClassLinker::ResolveType(dex::TypeIndex type_idx, ArtMethod* referrer) {
	Thread::PoisonObjectPointersIfDebug();
	if (kIsDebugBuild) {
	Thread::Current()->AssertNoPendingException();
	}
	ObjPtr<mirror::Class> resolved_type = referrer->GetDexCache()->GetResolvedType(type_idx);
	if (UNLIKELY(resolved_type == nullptr)) {
	StackHandleScope<2> hs(Thread::Current());
	ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
	Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
	Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
	const DexFile& dex_file = *dex_cache->GetDexFile();
	resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader);
	}
	return resolved_type.Ptr();
	}

	inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) {
	ArtMethod* resolved_method = referrer->GetDexCacheResolvedMethod(method_idx, image_pointer_size_);
	if (resolved_method == nullptr \|\| resolved_method->IsRuntimeMethod()) {
	return nullptr;
	}
	return resolved_method;
	}

	inline mirror::Class* ClassLinker::ResolveReferencedClassOfMethod(
	uint32_t method_idx,
	Handle<mirror::DexCache> dex_cache,
	Handle<mirror::ClassLoader> class_loader) {
	// NB: We cannot simply use `GetResolvedMethod(method_idx, ...)->GetDeclaringClass()`. This is
	// because if we did so than an invoke-super could be incorrectly dispatched in cases where
	// GetMethodId(method_idx).class_idx_ refers to a non-interface, non-direct-superclass
	// (super*-class?) of the referrer and the direct superclass of the referrer contains a concrete
	// implementation of the method. If this class's implementation of the method is copied from an
	// interface (either miranda, default or conflict) we would incorrectly assume that is what we
	// want to invoke on, instead of the 'concrete' implementation that the direct superclass
	// contains.
	const DexFile* dex_file = dex_cache->GetDexFile();
	const DexFile::MethodId& method = dex_file->GetMethodId(method_idx);
	ObjPtr<mirror::Class> resolved_type = dex_cache->GetResolvedType(method.class_idx_);
	if (UNLIKELY(resolved_type == nullptr)) {
	resolved_type = ResolveType(*dex_file, method.class_idx_, dex_cache, class_loader);
	}
	return resolved_type.Ptr();
	}

	template <ClassLinker::ResolveMode kResolveMode>
	inline ArtMethod* ClassLinker::ResolveMethod(Thread* self,
	uint32_t method_idx,
	ArtMethod* referrer,
	InvokeType type) {
	ArtMethod* resolved_method = GetResolvedMethod(method_idx, referrer);
	Thread::PoisonObjectPointersIfDebug();
	if (UNLIKELY(resolved_method == nullptr)) {
	ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
	StackHandleScope<2> hs(self);
	Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(referrer->GetDexCache()));
	Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
	const DexFile* dex_file = h_dex_cache->GetDexFile();
	resolved_method = ResolveMethod<kResolveMode>(*dex_file,
	method_idx,
	h_dex_cache,
	h_class_loader,
	referrer,
	type);
	}
	// Note: We cannot check here to see whether we added the method to the cache. It
	// might be an erroneous class, which results in it being hidden from us.
	return resolved_method;
	}

	inline ArtField* ClassLinker::GetResolvedField(uint32_t field_idx,
	ObjPtr<mirror::DexCache> dex_cache) {
	return dex_cache->GetResolvedField(field_idx, image_pointer_size_);
	}

	inline ArtField* ClassLinker::ResolveField(uint32_t field_idx,
	ArtMethod* referrer,
	bool is_static) {
	Thread::PoisonObjectPointersIfDebug();
	ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
	ArtField* resolved_field = GetResolvedField(field_idx, referrer->GetDexCache());
	if (UNLIKELY(resolved_field == nullptr)) {
	StackHandleScope<2> hs(Thread::Current());
	Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
	Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
	const DexFile& dex_file = *dex_cache->GetDexFile();
	resolved_field = ResolveField(dex_file, field_idx, dex_cache, class_loader, is_static);
	// Note: We cannot check here to see whether we added the field to the cache. The type
	// might be an erroneous class, which results in it being hidden from us.
	}
	return resolved_field;
	}

	inline mirror::Object* ClassLinker::AllocObject(Thread* self) {
	return GetClassRoot(kJavaLangObject)->Alloc<true, false>(
	self,
	Runtime::Current()->GetHeap()->GetCurrentAllocator()).Ptr();
	}

	template <class T>
	inline mirror::ObjectArray<T>* ClassLinker::AllocObjectArray(Thread* self, size_t length) {
	return mirror::ObjectArray<T>::Alloc(self, GetClassRoot(kObjectArrayClass), length);
	}

	inline mirror::ObjectArray<mirror::Class>* ClassLinker::AllocClassArray(Thread* self,
	size_t length) {
	return mirror::ObjectArray<mirror::Class>::Alloc(self, GetClassRoot(kClassArrayClass), length);
	}

	inline mirror::ObjectArray<mirror::String>* ClassLinker::AllocStringArray(Thread* self,
	size_t length) {
	return mirror::ObjectArray<mirror::String>::Alloc(self,
	GetClassRoot(kJavaLangStringArrayClass),
	length);
	}

	inline mirror::IfTable* ClassLinker::AllocIfTable(Thread* self, size_t ifcount) {
	return down_cast<mirror::IfTable*>(
	mirror::IfTable::Alloc(self,
	GetClassRoot(kObjectArrayClass),
	ifcount * mirror::IfTable::kMax));
	}

	inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root) {
	DCHECK(!class_roots_.IsNull());
	mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
	ObjPtr<mirror::Class> klass = class_roots->Get(class_root);
	DCHECK(klass != nullptr);
	return klass.Ptr();
	}

	template<ReadBarrierOption kReadBarrierOption>
	ArtMethod* ClassLinker::FindMethodForProxy(ObjPtr<mirror::Class> proxy_class,
	ArtMethod* proxy_method) {
	DCHECK(proxy_class->IsProxyClass());
	DCHECK(proxy_method->IsProxyMethod());
	{
	Thread* const self = Thread::Current();
	ReaderMutexLock mu(self, *Locks::dex_lock_);
	// Locate the dex cache of the original interface/Object
	for (const DexCacheData& data : dex_caches_) {
	if (!self->IsJWeakCleared(data.weak_root) &&
	proxy_method->HasSameDexCacheResolvedMethods(data.resolved_methods,
	image_pointer_size_)) {
	ObjPtr<mirror::DexCache> dex_cache =
	ObjPtr<mirror::DexCache>::DownCast(self->DecodeJObject(data.weak_root));
	if (dex_cache != nullptr) {
	ArtMethod* resolved_method = dex_cache->GetResolvedMethod(
	proxy_method->GetDexMethodIndex(), image_pointer_size_);
	CHECK(resolved_method != nullptr);
	return resolved_method;
	}
	}
	}
	}
	LOG(FATAL) << "Didn't find dex cache for " << proxy_class->PrettyClass() << " "
	<< proxy_method->PrettyMethod();
	UNREACHABLE();
	}

	} // namespace art

	#endif // ART_RUNTIME_CLASS_LINKER_INL_H_