runtime/entrypoints/quick/quick_dexcache_entrypoints.cc - platform/art - Git at Google

 /*
  * Copyright (C) 2012 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.
  */

 #include "art_method-inl.h"
 #include "base/callee_save_type.h"
 #include "callee_save_frame.h"
 #include "class_linker-inl.h"
 #include "class_table-inl.h"
 #include "dex/dex_file-inl.h"
 #include "dex/dex_file_types.h"
 #include "entrypoints/entrypoint_utils-inl.h"
 #include "gc/heap.h"
 #include "mirror/class-inl.h"
 #include "mirror/class_loader.h"
 #include "mirror/object-inl.h"
 #include "mirror/object_array-inl.h"
 #include "oat_file.h"
 #include "runtime.h"

 namespace art {

 static void StoreObjectInBss(ArtMethod* outer_method,
                              const OatFile* oat_file,
                              size_t bss_offset,
                              ObjPtr<mirror::Object> object) REQUIRES_SHARED(Locks::mutator_lock_) {
   // Used for storing Class or String in .bss GC roots.
   static_assert(sizeof(GcRoot<mirror::Class>) == sizeof(GcRoot<mirror::Object>), "Size check.");
   static_assert(sizeof(GcRoot<mirror::String>) == sizeof(GcRoot<mirror::Object>), "Size check.");
   DCHECK_NE(bss_offset, IndexBssMappingLookup::npos);
   DCHECK_ALIGNED(bss_offset, sizeof(GcRoot<mirror::Object>));
   if (UNLIKELY(!oat_file->IsExecutable())) {
     // There are situations where we execute bytecode tied to an oat file opened
     // as non-executable (i.e. the AOT-compiled code cannot be executed) and we
     // can JIT that bytecode and get here without the .bss being mmapped.
     return;
   }
   GcRoot<mirror::Object>* slot = reinterpret_cast<GcRoot<mirror::Object>*>(
       const_cast<uint8_t*>(oat_file->BssBegin() + bss_offset));
   DCHECK_GE(slot, oat_file->GetBssGcRoots().data());
   DCHECK_LT(slot, oat_file->GetBssGcRoots().data() + oat_file->GetBssGcRoots().size());
   if (slot->IsNull()) {
     // This may race with another thread trying to store the very same value but that's OK.
     *slot = GcRoot<mirror::Object>(object);
     // We need a write barrier for the class loader that holds the GC roots in the .bss.
     ObjPtr<mirror::ClassLoader> class_loader = outer_method->GetClassLoader();
     Runtime* runtime = Runtime::Current();
     if (kIsDebugBuild) {
       ClassTable* class_table = runtime->GetClassLinker()->ClassTableForClassLoader(class_loader);
       CHECK(class_table != nullptr && !class_table->InsertOatFile(oat_file))
           << "Oat file with .bss GC roots was not registered in class table: "
           << oat_file->GetLocation();
     }
     if (class_loader != nullptr) {
       WriteBarrier::ForEveryFieldWrite(class_loader);
     } else {
       runtime->GetClassLinker()->WriteBarrierForBootOatFileBssRoots(oat_file);
     }
   } else {
     // Each slot serves to store exactly one Class or String.
     DCHECK_EQ(object, slot->Read());
   }
 }

 static inline void StoreTypeInBss(ArtMethod* outer_method,
                                   dex::TypeIndex type_idx,
                                   ObjPtr<mirror::Class> resolved_type)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   const DexFile* dex_file = outer_method->GetDexFile();
   DCHECK(dex_file != nullptr);
   const OatDexFile* oat_dex_file = dex_file->GetOatDexFile();
   if (oat_dex_file != nullptr) {
     size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetTypeBssMapping(),
                                                             type_idx.index_,
                                                             dex_file->NumTypeIds(),
                                                             sizeof(GcRoot<mirror::Class>));
     if (bss_offset != IndexBssMappingLookup::npos) {
       StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_type);
     }
   }
 }

 static inline void StoreStringInBss(ArtMethod* outer_method,
                                     dex::StringIndex string_idx,
                                     ObjPtr<mirror::String> resolved_string)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   const DexFile* dex_file = outer_method->GetDexFile();
   DCHECK(dex_file != nullptr);
   const OatDexFile* oat_dex_file = dex_file->GetOatDexFile();
   if (oat_dex_file != nullptr) {
     size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetStringBssMapping(),
                                                             string_idx.index_,
                                                             dex_file->NumStringIds(),
                                                             sizeof(GcRoot<mirror::Class>));
     if (bss_offset != IndexBssMappingLookup::npos) {
       StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_string);
     }
   }
 }

 static ALWAYS_INLINE bool CanReferenceBss(ArtMethod* outer_method, ArtMethod* caller)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   // .bss references are used only for AOT-compiled code and only when the instruction
   // originates from the outer method's dex file and the type or string index is tied to
   // that dex file. As we do not want to check if the call is coming from AOT-compiled
   // code (that could be expensive), simply check if the caller has the same dex file.
   //
   // If we've accepted running AOT-compiled code despite the runtime class loader
   // resolving the caller to a different dex file, this check shall prevent us from
   // filling the .bss slot and we shall keep going through the slow path. This is slow
   // but correct; we do not really care that much about performance in this odd case.
   //
   // JIT can inline throwing instructions across dex files and this check prevents
   // looking up the index in the wrong dex file in that case. If the caller and outer
   // method have the same dex file, we may or may not find a .bss slot to update;
   // if we do, this can still benefit AOT-compiled code executed later.
   return outer_method->GetDexFile() == caller->GetDexFile();
 }

 extern "C" mirror::Class* artInitializeStaticStorageFromCode(mirror::Class* klass, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   // Called to ensure static storage base is initialized for direct static field reads and writes.
   // A class may be accessing another class' fields when it doesn't have access, as access has been
   // given by inheritance.
   ScopedQuickEntrypointChecks sqec(self);
   DCHECK(klass != nullptr);
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
   StackHandleScope<1> hs(self);
   Handle<mirror::Class> h_klass = hs.NewHandle(klass);
   bool success = class_linker->EnsureInitialized(
       self, h_klass, /* can_init_fields */ true, /* can_init_parents */ true);
   if (UNLIKELY(!success)) {
     return nullptr;
   }
   return h_klass.Get();
 }

 extern "C" mirror::Class* artInitializeTypeFromCode(uint32_t type_idx, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   // Called when the .bss slot was empty or for main-path runtime call.
   ScopedQuickEntrypointChecks sqec(self);
   auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(
       self, CalleeSaveType::kSaveEverythingForClinit);
   ArtMethod* caller = caller_and_outer.caller;
   ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx),
                                                         caller,
                                                         self,
                                                         /* can_run_clinit */ false,
                                                         /* verify_access */ false);
   if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) {
     StoreTypeInBss(caller_and_outer.outer_method, dex::TypeIndex(type_idx), result);
   }
   return result.Ptr();
 }

 extern "C" mirror::Class* artInitializeTypeAndVerifyAccessFromCode(uint32_t type_idx, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   // Called when caller isn't guaranteed to have access to a type.
   ScopedQuickEntrypointChecks sqec(self);
   auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
                                                                   CalleeSaveType::kSaveEverything);
   ArtMethod* caller = caller_and_outer.caller;
   ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx),
                                                         caller,
                                                         self,
                                                         /* can_run_clinit */ false,
                                                         /* verify_access */ true);
   // Do not StoreTypeInBss(); access check entrypoint is never used together with .bss.
   return result.Ptr();
 }

 extern "C" mirror::MethodHandle* artResolveMethodHandleFromCode(uint32_t method_handle_idx,
                                                                 Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   ScopedQuickEntrypointChecks sqec(self);
   auto caller_and_outer =
       GetCalleeSaveMethodCallerAndOuterMethod(self, CalleeSaveType::kSaveEverything);
   ArtMethod* caller = caller_and_outer.caller;
   ObjPtr<mirror::MethodHandle> result = ResolveMethodHandleFromCode(caller, method_handle_idx);
   return result.Ptr();
 }

 extern "C" mirror::MethodType* artResolveMethodTypeFromCode(uint32_t proto_idx, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   ScopedQuickEntrypointChecks sqec(self);
   auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
                                                                   CalleeSaveType::kSaveEverything);
   ArtMethod* caller = caller_and_outer.caller;
   ObjPtr<mirror::MethodType> result = ResolveMethodTypeFromCode(caller, dex::ProtoIndex(proto_idx));
   return result.Ptr();
 }

 extern "C" mirror::String* artResolveStringFromCode(int32_t string_idx, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   ScopedQuickEntrypointChecks sqec(self);
   auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
                                                                   CalleeSaveType::kSaveEverything);
   ArtMethod* caller = caller_and_outer.caller;
   ObjPtr<mirror::String> result =
       Runtime::Current()->GetClassLinker()->ResolveString(dex::StringIndex(string_idx), caller);
   if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) {
     StoreStringInBss(caller_and_outer.outer_method, dex::StringIndex(string_idx), result);
   }
   return result.Ptr();
 }

 }  // namespace art
	/*
	* Copyright (C) 2012 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.
	*/

	#include "art_method-inl.h"
	#include "base/callee_save_type.h"
	#include "callee_save_frame.h"
	#include "class_linker-inl.h"
	#include "class_table-inl.h"
	#include "dex/dex_file-inl.h"
	#include "dex/dex_file_types.h"
	#include "entrypoints/entrypoint_utils-inl.h"
	#include "gc/heap.h"
	#include "mirror/class-inl.h"
	#include "mirror/class_loader.h"
	#include "mirror/object-inl.h"
	#include "mirror/object_array-inl.h"
	#include "oat_file.h"
	#include "runtime.h"

	namespace art {

	static void StoreObjectInBss(ArtMethod* outer_method,
	const OatFile* oat_file,
	size_t bss_offset,
	ObjPtr<mirror::Object> object) REQUIRES_SHARED(Locks::mutator_lock_) {
	// Used for storing Class or String in .bss GC roots.
	static_assert(sizeof(GcRoot<mirror::Class>) == sizeof(GcRoot<mirror::Object>), "Size check.");
	static_assert(sizeof(GcRoot<mirror::String>) == sizeof(GcRoot<mirror::Object>), "Size check.");
	DCHECK_NE(bss_offset, IndexBssMappingLookup::npos);
	DCHECK_ALIGNED(bss_offset, sizeof(GcRoot<mirror::Object>));
	if (UNLIKELY(!oat_file->IsExecutable())) {
	// There are situations where we execute bytecode tied to an oat file opened
	// as non-executable (i.e. the AOT-compiled code cannot be executed) and we
	// can JIT that bytecode and get here without the .bss being mmapped.
	return;
	}
	GcRoot<mirror::Object>* slot = reinterpret_cast<GcRoot<mirror::Object>*>(
	const_cast<uint8_t*>(oat_file->BssBegin() + bss_offset));
	DCHECK_GE(slot, oat_file->GetBssGcRoots().data());
	DCHECK_LT(slot, oat_file->GetBssGcRoots().data() + oat_file->GetBssGcRoots().size());
	if (slot->IsNull()) {
	// This may race with another thread trying to store the very same value but that's OK.
	*slot = GcRoot<mirror::Object>(object);
	// We need a write barrier for the class loader that holds the GC roots in the .bss.
	ObjPtr<mirror::ClassLoader> class_loader = outer_method->GetClassLoader();
	Runtime* runtime = Runtime::Current();
	if (kIsDebugBuild) {
	ClassTable* class_table = runtime->GetClassLinker()->ClassTableForClassLoader(class_loader);
	CHECK(class_table != nullptr && !class_table->InsertOatFile(oat_file))
	<< "Oat file with .bss GC roots was not registered in class table: "
	<< oat_file->GetLocation();
	}
	if (class_loader != nullptr) {
	WriteBarrier::ForEveryFieldWrite(class_loader);
	} else {
	runtime->GetClassLinker()->WriteBarrierForBootOatFileBssRoots(oat_file);
	}
	} else {
	// Each slot serves to store exactly one Class or String.
	DCHECK_EQ(object, slot->Read());
	}
	}

	static inline void StoreTypeInBss(ArtMethod* outer_method,
	dex::TypeIndex type_idx,
	ObjPtr<mirror::Class> resolved_type)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	const DexFile* dex_file = outer_method->GetDexFile();
	DCHECK(dex_file != nullptr);
	const OatDexFile* oat_dex_file = dex_file->GetOatDexFile();
	if (oat_dex_file != nullptr) {
	size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetTypeBssMapping(),
	type_idx.index_,
	dex_file->NumTypeIds(),
	sizeof(GcRoot<mirror::Class>));
	if (bss_offset != IndexBssMappingLookup::npos) {
	StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_type);
	}
	}
	}

	static inline void StoreStringInBss(ArtMethod* outer_method,
	dex::StringIndex string_idx,
	ObjPtr<mirror::String> resolved_string)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	const DexFile* dex_file = outer_method->GetDexFile();
	DCHECK(dex_file != nullptr);
	const OatDexFile* oat_dex_file = dex_file->GetOatDexFile();
	if (oat_dex_file != nullptr) {
	size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetStringBssMapping(),
	string_idx.index_,
	dex_file->NumStringIds(),
	sizeof(GcRoot<mirror::Class>));
	if (bss_offset != IndexBssMappingLookup::npos) {
	StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_string);
	}
	}
	}

	static ALWAYS_INLINE bool CanReferenceBss(ArtMethod* outer_method, ArtMethod* caller)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// .bss references are used only for AOT-compiled code and only when the instruction
	// originates from the outer method's dex file and the type or string index is tied to
	// that dex file. As we do not want to check if the call is coming from AOT-compiled
	// code (that could be expensive), simply check if the caller has the same dex file.
	//
	// If we've accepted running AOT-compiled code despite the runtime class loader
	// resolving the caller to a different dex file, this check shall prevent us from
	// filling the .bss slot and we shall keep going through the slow path. This is slow
	// but correct; we do not really care that much about performance in this odd case.
	//
	// JIT can inline throwing instructions across dex files and this check prevents
	// looking up the index in the wrong dex file in that case. If the caller and outer
	// method have the same dex file, we may or may not find a .bss slot to update;
	// if we do, this can still benefit AOT-compiled code executed later.
	return outer_method->GetDexFile() == caller->GetDexFile();
	}

	extern "C" mirror::Class* artInitializeStaticStorageFromCode(mirror::Class* klass, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// Called to ensure static storage base is initialized for direct static field reads and writes.
	// A class may be accessing another class' fields when it doesn't have access, as access has been
	// given by inheritance.
	ScopedQuickEntrypointChecks sqec(self);
	DCHECK(klass != nullptr);
	ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
	StackHandleScope<1> hs(self);
	Handle<mirror::Class> h_klass = hs.NewHandle(klass);
	bool success = class_linker->EnsureInitialized(
	self, h_klass, /* can_init_fields / true, / can_init_parents */ true);
	if (UNLIKELY(!success)) {
	return nullptr;
	}
	return h_klass.Get();
	}

	extern "C" mirror::Class* artInitializeTypeFromCode(uint32_t type_idx, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// Called when the .bss slot was empty or for main-path runtime call.
	ScopedQuickEntrypointChecks sqec(self);
	auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(
	self, CalleeSaveType::kSaveEverythingForClinit);
	ArtMethod* caller = caller_and_outer.caller;
	ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx),
	caller,
	self,
	/* can_run_clinit */ false,
	/* verify_access */ false);
	if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) {
	StoreTypeInBss(caller_and_outer.outer_method, dex::TypeIndex(type_idx), result);
	}
	return result.Ptr();
	}

	extern "C" mirror::Class* artInitializeTypeAndVerifyAccessFromCode(uint32_t type_idx, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	// Called when caller isn't guaranteed to have access to a type.
	ScopedQuickEntrypointChecks sqec(self);
	auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
	CalleeSaveType::kSaveEverything);
	ArtMethod* caller = caller_and_outer.caller;
	ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx),
	caller,
	self,
	/* can_run_clinit */ false,
	/* verify_access */ true);
	// Do not StoreTypeInBss(); access check entrypoint is never used together with .bss.
	return result.Ptr();
	}

	extern "C" mirror::MethodHandle* artResolveMethodHandleFromCode(uint32_t method_handle_idx,
	Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	ScopedQuickEntrypointChecks sqec(self);
	auto caller_and_outer =
	GetCalleeSaveMethodCallerAndOuterMethod(self, CalleeSaveType::kSaveEverything);
	ArtMethod* caller = caller_and_outer.caller;
	ObjPtr<mirror::MethodHandle> result = ResolveMethodHandleFromCode(caller, method_handle_idx);
	return result.Ptr();
	}

	extern "C" mirror::MethodType* artResolveMethodTypeFromCode(uint32_t proto_idx, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	ScopedQuickEntrypointChecks sqec(self);
	auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
	CalleeSaveType::kSaveEverything);
	ArtMethod* caller = caller_and_outer.caller;
	ObjPtr<mirror::MethodType> result = ResolveMethodTypeFromCode(caller, dex::ProtoIndex(proto_idx));
	return result.Ptr();
	}

	extern "C" mirror::String* artResolveStringFromCode(int32_t string_idx, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	ScopedQuickEntrypointChecks sqec(self);
	auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self,
	CalleeSaveType::kSaveEverything);
	ArtMethod* caller = caller_and_outer.caller;
	ObjPtr<mirror::String> result =
	Runtime::Current()->GetClassLinker()->ResolveString(dex::StringIndex(string_idx), caller);
	if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) {
	StoreStringInBss(caller_and_outer.outer_method, dex::StringIndex(string_idx), result);
	}
	return result.Ptr();
	}

	} // namespace art