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/*
* 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_INTERN_TABLE_H_
#define ART_RUNTIME_INTERN_TABLE_H_
#include "base/mutex.h"
#include "root_visitor.h"
#include <map>
namespace art {
namespace mirror {
class String;
} // namespace mirror
/**
* Used to intern strings.
*
* There are actually two tables: one that holds strong references to its strings, and one that
* holds weak references. The former is used for string literals, for which there is an effective
* reference from the constant pool. The latter is used for strings interned at runtime via
* String.intern. Some code (XML parsers being a prime example) relies on being able to intern
* arbitrarily many strings for the duration of a parse without permanently increasing the memory
* footprint.
*/
class InternTable {
public:
InternTable();
// Interns a potentially new string in the 'strong' table. (See above.)
mirror::String* InternStrong(int32_t utf16_length, const char* utf8_data)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Interns a potentially new string in the 'strong' table. (See above.)
mirror::String* InternStrong(const char* utf8_data)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Interns a potentially new string in the 'strong' table. (See above.)
mirror::String* InternStrong(mirror::String* s) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
// Interns a potentially new string in the 'weak' table. (See above.)
mirror::String* InternWeak(mirror::String* s) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
void SweepInternTableWeaks(RootVisitor visitor, void* arg);
bool ContainsWeak(mirror::String* s) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
size_t Size() const;
void VisitRoots(RootVisitor* visitor, void* arg, bool only_dirty, bool clean_dirty);
void DumpForSigQuit(std::ostream& os) const;
void DisallowNewInterns() EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_);
void AllowNewInterns() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
private:
typedef std::multimap<int32_t, mirror::String*> Table;
mirror::String* Insert(mirror::String* s, bool is_strong)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
mirror::String* Lookup(Table& table, mirror::String* s, uint32_t hash_code)
SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
mirror::String* Insert(Table& table, mirror::String* s, uint32_t hash_code);
void Remove(Table& table, const mirror::String* s, uint32_t hash_code);
mutable Mutex intern_table_lock_;
bool is_dirty_ GUARDED_BY(intern_table_lock_);
bool allow_new_interns_ GUARDED_BY(intern_table_lock_);
ConditionVariable new_intern_condition_ GUARDED_BY(intern_table_lock_);
Table strong_interns_ GUARDED_BY(intern_table_lock_);
Table weak_interns_ GUARDED_BY(intern_table_lock_);
};
} // namespace art
#endif // ART_RUNTIME_INTERN_TABLE_H_
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