runtime/class_table-inl.h - platform/art - Git at Google

 /*
  * Copyright (C) 2015 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_TABLE_INL_H_
 #define ART_RUNTIME_CLASS_TABLE_INL_H_

 #include "class_table.h"

 #include "base/mutex-inl.h"
 #include "dex/utf.h"
 #include "gc_root-inl.h"
 #include "mirror/class.h"
 #include "oat/oat_file.h"
 #include "obj_ptr-inl.h"

 namespace art HIDDEN {

 inline ClassTable::TableSlot::TableSlot(ObjPtr<mirror::Class> klass)
     : TableSlot(klass, klass->DescriptorHash()) {}

 inline uint32_t ClassTable::ClassDescriptorHash::operator()(const TableSlot& slot) const {
   // No read barriers needed, we're reading a chain of constant references
   // for comparison with null and retrieval of constant primitive data.
   // See `ReadBarrierOption` and `Class::DescriptorHash()`.
   return slot.Read<kWithoutReadBarrier>()->DescriptorHash();
 }

 inline uint32_t ClassTable::ClassDescriptorHash::operator()(const DescriptorHashPair& pair) const {
   DCHECK_EQ(ComputeModifiedUtf8Hash(pair.first), pair.second);
   return pair.second;
 }

 inline bool ClassTable::ClassDescriptorEquals::operator()(const TableSlot& a,
                                                           const TableSlot& b) const {
   // No read barrier needed, we're reading a chain of constant references
   // for comparison with null and retrieval of constant primitive data.
   // See ReadBarrierOption and `Class::DescriptorEquals()`.
   if (a.Hash() != b.Hash()) {
     DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.Read<kWithoutReadBarrier>()));
     return false;
   }
   return a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.Read<kWithoutReadBarrier>());
 }

 inline bool ClassTable::ClassDescriptorEquals::operator()(const TableSlot& a,
                                                           const DescriptorHashPair& b) const {
   // No read barrier needed, we're reading a chain of constant references for comparison
   // with null and retrieval of constant primitive data. See ReadBarrierOption.
   if (!a.MaskedHashEquals(b.second)) {
     DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first));
     return false;
   }
   return a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first);
 }

 template <class Visitor>
 void ClassTable::VisitRoots(Visitor& visitor, bool skip_classes) {
   ReaderMutexLock mu(Thread::Current(), lock_);
   if (!skip_classes) {
     for (ClassSet& class_set : classes_) {
       for (TableSlot& table_slot : class_set) {
         table_slot.VisitRoot(visitor);
       }
     }
   }
   for (GcRoot<mirror::Object>& root : strong_roots_) {
     visitor.VisitRoot(root.AddressWithoutBarrier());
   }
   for (const OatFile* oat_file : oat_files_) {
     for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
       visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
     }
   }
 }

 template <class Visitor>
 void ClassTable::VisitRoots(const Visitor& visitor, bool skip_classes) {
   ReaderMutexLock mu(Thread::Current(), lock_);
   if (!skip_classes) {
     for (ClassSet& class_set : classes_) {
       for (TableSlot& table_slot : class_set) {
         table_slot.VisitRoot(visitor);
       }
     }
   }
   for (GcRoot<mirror::Object>& root : strong_roots_) {
     visitor.VisitRoot(root.AddressWithoutBarrier());
   }
   for (const OatFile* oat_file : oat_files_) {
     for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
       visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
     }
   }
 }

 template <class Condition, class Visitor>
 void ClassTable::VisitClassesIfConditionMet(Condition& cond, Visitor& visitor) {
   ReaderMutexLock mu(Thread::Current(), lock_);
   for (ClassSet& class_set : classes_) {
     if (cond(class_set)) {
       for (TableSlot& table_slot : class_set) {
         table_slot.VisitRoot(visitor);
       }
     }
   }
 }

 template <typename Visitor>
 class ClassTable::TableSlot::ClassAndRootVisitor {
  public:
   explicit ClassAndRootVisitor(Visitor& visitor) : visitor_(visitor) {}

   void VisitRoot(mirror::CompressedReference<mirror::Object>* klass) const
       REQUIRES_SHARED(Locks::mutator_lock_) {
     DCHECK(!klass->IsNull());
     // Visit roots in the klass object
     visitor_(klass->AsMirrorPtr());
     // Visit the GC-root holding klass' reference
     visitor_.VisitRoot(klass);
   }

  private:
   Visitor& visitor_;
 };

 template <typename Visitor>
 void ClassTable::VisitClassesAndRoots(Visitor& visitor) {
   TableSlot::ClassAndRootVisitor class_visitor(visitor);
   ReaderMutexLock mu(Thread::Current(), lock_);
   for (ClassSet& class_set : classes_) {
     for (TableSlot& table_slot : class_set) {
       table_slot.VisitRoot(class_visitor);
     }
   }
   for (GcRoot<mirror::Object>& root : strong_roots_) {
     visitor.VisitRoot(root.AddressWithoutBarrier());
   }
   for (const OatFile* oat_file : oat_files_) {
     for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
       visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
     }
   }
 }

 template <ReadBarrierOption kReadBarrierOption, typename Visitor>
 bool ClassTable::Visit(Visitor& visitor) {
   ReaderMutexLock mu(Thread::Current(), lock_);
   for (ClassSet& class_set : classes_) {
     for (TableSlot& table_slot : class_set) {
       if (!visitor(table_slot.Read<kReadBarrierOption>())) {
         return false;
       }
     }
   }
   return true;
 }

 template <ReadBarrierOption kReadBarrierOption, typename Visitor>
 bool ClassTable::Visit(const Visitor& visitor) {
   ReaderMutexLock mu(Thread::Current(), lock_);
   for (ClassSet& class_set : classes_) {
     for (TableSlot& table_slot : class_set) {
       if (!visitor(table_slot.Read<kReadBarrierOption>())) {
         return false;
       }
     }
   }
   return true;
 }

 inline bool ClassTable::TableSlot::IsNull() const {
   return Read<kWithoutReadBarrier>() == nullptr;
 }

 template<ReadBarrierOption kReadBarrierOption>
 inline ObjPtr<mirror::Class> ClassTable::TableSlot::Read() const {
   const uint32_t before = data_.load(std::memory_order_relaxed);
   const ObjPtr<mirror::Class> before_ptr(ExtractPtr(before));
   const ObjPtr<mirror::Class> after_ptr(
       GcRoot<mirror::Class>(before_ptr).Read<kReadBarrierOption>());
   if (kReadBarrierOption != kWithoutReadBarrier && before_ptr != after_ptr) {
     // If another thread raced and updated the reference, do not store the read barrier updated
     // one.
     data_.CompareAndSetStrongRelease(before, Encode(after_ptr, MaskHash(before)));
   }
   return after_ptr;
 }

 template<typename Visitor>
 inline void ClassTable::TableSlot::VisitRoot(const Visitor& visitor) const {
   const uint32_t before = data_.load(std::memory_order_relaxed);
   ObjPtr<mirror::Class> before_ptr(ExtractPtr(before));
   GcRoot<mirror::Class> root(before_ptr);
   visitor.VisitRoot(root.AddressWithoutBarrier());
   ObjPtr<mirror::Class> after_ptr(root.Read<kWithoutReadBarrier>());
   if (before_ptr != after_ptr) {
     // If another thread raced and updated the reference, do not store the read barrier updated
     // one.
     data_.CompareAndSetStrongRelease(before, Encode(after_ptr, MaskHash(before)));
   }
 }

 inline ObjPtr<mirror::Class> ClassTable::TableSlot::ExtractPtr(uint32_t data) {
   return reinterpret_cast<mirror::Class*>(data & ~kHashMask);
 }

 inline uint32_t ClassTable::TableSlot::Encode(ObjPtr<mirror::Class> klass, uint32_t hash_bits) {
   DCHECK_LE(hash_bits, kHashMask);
   return reinterpret_cast<uintptr_t>(klass.Ptr()) | hash_bits;
 }

 inline ClassTable::TableSlot::TableSlot(ObjPtr<mirror::Class> klass, uint32_t descriptor_hash)
     : data_(Encode(klass, MaskHash(descriptor_hash))) {
   DCHECK_EQ(descriptor_hash, klass->DescriptorHash());
 }

 inline ClassTable::TableSlot::TableSlot(uint32_t ptr, uint32_t descriptor_hash)
     : data_(ptr | MaskHash(descriptor_hash)) {
   DCHECK_ALIGNED(ptr, kObjectAlignment);
 }

 template <typename Filter>
 inline void ClassTable::RemoveStrongRoots(const Filter& filter) {
   WriterMutexLock mu(Thread::Current(), lock_);
   strong_roots_.erase(std::remove_if(strong_roots_.begin(), strong_roots_.end(), filter),
                       strong_roots_.end());
 }

 inline ObjPtr<mirror::Class> ClassTable::LookupByDescriptor(ObjPtr<mirror::Class> klass) {
   uint32_t hash = klass->DescriptorHash();
   std::string temp;
   const char* descriptor = klass->GetDescriptor(&temp);
   return Lookup(descriptor, hash);
 }

 inline size_t ClassTable::Size() const {
   ReaderMutexLock mu(Thread::Current(), lock_);
   return classes_.size();
 }

 }  // namespace art

 #endif  // ART_RUNTIME_CLASS_TABLE_INL_H_
	/*
	* Copyright (C) 2015 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_TABLE_INL_H_
	#define ART_RUNTIME_CLASS_TABLE_INL_H_

	#include "class_table.h"

	#include "base/mutex-inl.h"
	#include "dex/utf.h"
	#include "gc_root-inl.h"
	#include "mirror/class.h"
	#include "oat/oat_file.h"
	#include "obj_ptr-inl.h"

	namespace art HIDDEN {

	inline ClassTable::TableSlot::TableSlot(ObjPtr<mirror::Class> klass)
	: TableSlot(klass, klass->DescriptorHash()) {}

	inline uint32_t ClassTable::ClassDescriptorHash::operator()(const TableSlot& slot) const {
	// No read barriers needed, we're reading a chain of constant references
	// for comparison with null and retrieval of constant primitive data.
	// See `ReadBarrierOption` and `Class::DescriptorHash()`.
	return slot.Read<kWithoutReadBarrier>()->DescriptorHash();
	}

	inline uint32_t ClassTable::ClassDescriptorHash::operator()(const DescriptorHashPair& pair) const {
	DCHECK_EQ(ComputeModifiedUtf8Hash(pair.first), pair.second);
	return pair.second;
	}

	inline bool ClassTable::ClassDescriptorEquals::operator()(const TableSlot& a,
	const TableSlot& b) const {
	// No read barrier needed, we're reading a chain of constant references
	// for comparison with null and retrieval of constant primitive data.
	// See ReadBarrierOption and `Class::DescriptorEquals()`.
	if (a.Hash() != b.Hash()) {
	DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.Read<kWithoutReadBarrier>()));
	return false;
	}
	return a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.Read<kWithoutReadBarrier>());
	}

	inline bool ClassTable::ClassDescriptorEquals::operator()(const TableSlot& a,
	const DescriptorHashPair& b) const {
	// No read barrier needed, we're reading a chain of constant references for comparison
	// with null and retrieval of constant primitive data. See ReadBarrierOption.
	if (!a.MaskedHashEquals(b.second)) {
	DCHECK(!a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first));
	return false;
	}
	return a.Read<kWithoutReadBarrier>()->DescriptorEquals(b.first);
	}

	template <class Visitor>
	void ClassTable::VisitRoots(Visitor& visitor, bool skip_classes) {
	ReaderMutexLock mu(Thread::Current(), lock_);
	if (!skip_classes) {
	for (ClassSet& class_set : classes_) {
	for (TableSlot& table_slot : class_set) {
	table_slot.VisitRoot(visitor);
	}
	}
	}
	for (GcRoot<mirror::Object>& root : strong_roots_) {
	visitor.VisitRoot(root.AddressWithoutBarrier());
	}
	for (const OatFile* oat_file : oat_files_) {
	for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
	visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
	}
	}
	}

	template <class Visitor>
	void ClassTable::VisitRoots(const Visitor& visitor, bool skip_classes) {
	ReaderMutexLock mu(Thread::Current(), lock_);
	if (!skip_classes) {
	for (ClassSet& class_set : classes_) {
	for (TableSlot& table_slot : class_set) {
	table_slot.VisitRoot(visitor);
	}
	}
	}
	for (GcRoot<mirror::Object>& root : strong_roots_) {
	visitor.VisitRoot(root.AddressWithoutBarrier());
	}
	for (const OatFile* oat_file : oat_files_) {
	for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
	visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
	}
	}
	}

	template <class Condition, class Visitor>
	void ClassTable::VisitClassesIfConditionMet(Condition& cond, Visitor& visitor) {
	ReaderMutexLock mu(Thread::Current(), lock_);
	for (ClassSet& class_set : classes_) {
	if (cond(class_set)) {
	for (TableSlot& table_slot : class_set) {
	table_slot.VisitRoot(visitor);
	}
	}
	}
	}

	template <typename Visitor>
	class ClassTable::TableSlot::ClassAndRootVisitor {
	public:
	explicit ClassAndRootVisitor(Visitor& visitor) : visitor_(visitor) {}

	void VisitRoot(mirror::CompressedReference<mirror::Object>* klass) const
	REQUIRES_SHARED(Locks::mutator_lock_) {
	DCHECK(!klass->IsNull());
	// Visit roots in the klass object
	visitor_(klass->AsMirrorPtr());
	// Visit the GC-root holding klass' reference
	visitor_.VisitRoot(klass);
	}

	private:
	Visitor& visitor_;
	};

	template <typename Visitor>
	void ClassTable::VisitClassesAndRoots(Visitor& visitor) {
	TableSlot::ClassAndRootVisitor class_visitor(visitor);
	ReaderMutexLock mu(Thread::Current(), lock_);
	for (ClassSet& class_set : classes_) {
	for (TableSlot& table_slot : class_set) {
	table_slot.VisitRoot(class_visitor);
	}
	}
	for (GcRoot<mirror::Object>& root : strong_roots_) {
	visitor.VisitRoot(root.AddressWithoutBarrier());
	}
	for (const OatFile* oat_file : oat_files_) {
	for (GcRoot<mirror::Object>& root : oat_file->GetBssGcRoots()) {
	visitor.VisitRootIfNonNull(root.AddressWithoutBarrier());
	}
	}
	}

	template <ReadBarrierOption kReadBarrierOption, typename Visitor>
	bool ClassTable::Visit(Visitor& visitor) {
	ReaderMutexLock mu(Thread::Current(), lock_);
	for (ClassSet& class_set : classes_) {
	for (TableSlot& table_slot : class_set) {
	if (!visitor(table_slot.Read<kReadBarrierOption>())) {
	return false;
	}
	}
	}
	return true;
	}

	template <ReadBarrierOption kReadBarrierOption, typename Visitor>
	bool ClassTable::Visit(const Visitor& visitor) {
	ReaderMutexLock mu(Thread::Current(), lock_);
	for (ClassSet& class_set : classes_) {
	for (TableSlot& table_slot : class_set) {
	if (!visitor(table_slot.Read<kReadBarrierOption>())) {
	return false;
	}
	}
	}
	return true;
	}

	inline bool ClassTable::TableSlot::IsNull() const {
	return Read<kWithoutReadBarrier>() == nullptr;
	}

	template<ReadBarrierOption kReadBarrierOption>
	inline ObjPtr<mirror::Class> ClassTable::TableSlot::Read() const {
	const uint32_t before = data_.load(std::memory_order_relaxed);
	const ObjPtr<mirror::Class> before_ptr(ExtractPtr(before));
	const ObjPtr<mirror::Class> after_ptr(
	GcRoot<mirror::Class>(before_ptr).Read<kReadBarrierOption>());
	if (kReadBarrierOption != kWithoutReadBarrier && before_ptr != after_ptr) {
	// If another thread raced and updated the reference, do not store the read barrier updated
	// one.
	data_.CompareAndSetStrongRelease(before, Encode(after_ptr, MaskHash(before)));
	}
	return after_ptr;
	}

	template<typename Visitor>
	inline void ClassTable::TableSlot::VisitRoot(const Visitor& visitor) const {
	const uint32_t before = data_.load(std::memory_order_relaxed);
	ObjPtr<mirror::Class> before_ptr(ExtractPtr(before));
	GcRoot<mirror::Class> root(before_ptr);
	visitor.VisitRoot(root.AddressWithoutBarrier());
	ObjPtr<mirror::Class> after_ptr(root.Read<kWithoutReadBarrier>());
	if (before_ptr != after_ptr) {
	// If another thread raced and updated the reference, do not store the read barrier updated
	// one.
	data_.CompareAndSetStrongRelease(before, Encode(after_ptr, MaskHash(before)));
	}
	}

	inline ObjPtr<mirror::Class> ClassTable::TableSlot::ExtractPtr(uint32_t data) {
	return reinterpret_cast<mirror::Class*>(data & ~kHashMask);
	}

	inline uint32_t ClassTable::TableSlot::Encode(ObjPtr<mirror::Class> klass, uint32_t hash_bits) {
	DCHECK_LE(hash_bits, kHashMask);
	return reinterpret_cast<uintptr_t>(klass.Ptr()) \| hash_bits;
	}

	inline ClassTable::TableSlot::TableSlot(ObjPtr<mirror::Class> klass, uint32_t descriptor_hash)
	: data_(Encode(klass, MaskHash(descriptor_hash))) {
	DCHECK_EQ(descriptor_hash, klass->DescriptorHash());
	}

	inline ClassTable::TableSlot::TableSlot(uint32_t ptr, uint32_t descriptor_hash)
	: data_(ptr \| MaskHash(descriptor_hash)) {
	DCHECK_ALIGNED(ptr, kObjectAlignment);
	}

	template <typename Filter>
	inline void ClassTable::RemoveStrongRoots(const Filter& filter) {
	WriterMutexLock mu(Thread::Current(), lock_);
	strong_roots_.erase(std::remove_if(strong_roots_.begin(), strong_roots_.end(), filter),
	strong_roots_.end());
	}

	inline ObjPtr<mirror::Class> ClassTable::LookupByDescriptor(ObjPtr<mirror::Class> klass) {
	uint32_t hash = klass->DescriptorHash();
	std::string temp;
	const char* descriptor = klass->GetDescriptor(&temp);
	return Lookup(descriptor, hash);
	}

	inline size_t ClassTable::Size() const {
	ReaderMutexLock mu(Thread::Current(), lock_);
	return classes_.size();
	}

	} // namespace art

	#endif // ART_RUNTIME_CLASS_TABLE_INL_H_