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/*
* 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_H_
#define ART_RUNTIME_CLASS_TABLE_H_
#include <string>
#include <utility>
#include <vector>
#include "base/allocator.h"
#include "base/hash_set.h"
#include "base/macros.h"
#include "base/mutex.h"
#include "dex_file.h"
#include "gc_root.h"
#include "object_callbacks.h"
#include "runtime.h"
namespace art {
namespace mirror {
class ClassLoader;
} // namespace mirror
class ClassVisitor {
public:
virtual ~ClassVisitor() {}
// Return true to continue visiting.
virtual bool Visit(mirror::Class* klass) = 0;
};
// Each loader has a ClassTable
class ClassTable {
public:
ClassTable();
// Used by image writer for checking.
bool Contains(mirror::Class* klass)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
// Freeze the current class tables by allocating a new table and never updating or modifying the
// existing table. This helps prevents dirty pages after caused by inserting after zygote fork.
void FreezeSnapshot()
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
// Returns the number of classes in previous snapshots.
size_t NumZygoteClasses() const SHARED_REQUIRES(Locks::classlinker_classes_lock_);
// Returns all off the classes in the lastest snapshot.
size_t NumNonZygoteClasses() const SHARED_REQUIRES(Locks::classlinker_classes_lock_);
// Update a class in the table with the new class. Returns the existing class which was replaced.
mirror::Class* UpdateClass(const char* descriptor, mirror::Class* new_klass, size_t hash)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
// NO_THREAD_SAFETY_ANALYSIS for object marking requiring heap bitmap lock.
template<class Visitor>
void VisitRoots(Visitor& visitor)
NO_THREAD_SAFETY_ANALYSIS
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
template<class Visitor>
void VisitRoots(const Visitor& visitor)
NO_THREAD_SAFETY_ANALYSIS
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
// Return false if the callback told us to exit.
bool Visit(ClassVisitor* visitor)
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
mirror::Class* Lookup(const char* descriptor, size_t hash)
SHARED_REQUIRES(Locks::classlinker_classes_lock_, Locks::mutator_lock_);
void Insert(mirror::Class* klass)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
void InsertWithHash(mirror::Class* klass, size_t hash)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
// Returns true if the class was found and removed, false otherwise.
bool Remove(const char* descriptor)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
// Return true if we inserted the dex file, false if it already exists.
bool InsertDexFile(mirror::Object* dex_file)
REQUIRES(Locks::classlinker_classes_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
private:
class ClassDescriptorHashEquals {
public:
// Same class loader and descriptor.
std::size_t operator()(const GcRoot<mirror::Class>& root) const NO_THREAD_SAFETY_ANALYSIS;
bool operator()(const GcRoot<mirror::Class>& a, const GcRoot<mirror::Class>& b) const
NO_THREAD_SAFETY_ANALYSIS;;
// Same descriptor.
bool operator()(const GcRoot<mirror::Class>& a, const char* descriptor) const
NO_THREAD_SAFETY_ANALYSIS;
std::size_t operator()(const char* descriptor) const NO_THREAD_SAFETY_ANALYSIS;
};
class GcRootEmptyFn {
public:
void MakeEmpty(GcRoot<mirror::Class>& item) const {
item = GcRoot<mirror::Class>();
}
bool IsEmpty(const GcRoot<mirror::Class>& item) const {
return item.IsNull();
}
};
// hash set which hashes class descriptor, and compares descriptors and class loaders. Results
// should be compared for a matching Class descriptor and class loader.
typedef HashSet<GcRoot<mirror::Class>, GcRootEmptyFn, ClassDescriptorHashEquals,
ClassDescriptorHashEquals, TrackingAllocator<GcRoot<mirror::Class>, kAllocatorTagClassTable>>
ClassSet;
// TODO: shard lock to have one per class loader.
// We have a vector to help prevent dirty pages after the zygote forks by calling FreezeSnapshot.
std::vector<ClassSet> classes_ GUARDED_BY(Locks::classlinker_classes_lock_);
// Dex files used by the class loader which may not be owned by the class loader. We keep these
// live so that we do not have issues closing any of the dex files.
std::vector<GcRoot<mirror::Object>> dex_files_ GUARDED_BY(Locks::classlinker_classes_lock_);
};
} // namespace art
#endif // ART_RUNTIME_CLASS_TABLE_H_