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Diffstat (limited to 'runtime/intern_table.h')
-rw-r--r-- | runtime/intern_table.h | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/runtime/intern_table.h b/runtime/intern_table.h new file mode 100644 index 0000000..1ff4f6d --- /dev/null +++ b/runtime/intern_table.h @@ -0,0 +1,98 @@ +/* + * 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_SRC_INTERN_TABLE_H_ +#define ART_SRC_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_); + + // Register a String trusting that it is safe to intern. + // Used when reinitializing InternTable from an image. + void RegisterStrong(mirror::String* s) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); + + void SweepInternTableWeaks(IsMarkedTester is_marked, void* arg) + SHARED_LOCKS_REQUIRED(Locks::heap_bitmap_lock_); + + bool ContainsWeak(mirror::String* s) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); + + size_t Size() const; + + void VisitRoots(RootVisitor* visitor, void* arg, bool clean_dirty); + + void DumpForSigQuit(std::ostream& os) const; + + bool IsDirty() const { return is_dirty_; } + void Dirty() { + is_dirty_ = true; + } + + 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_; + Table image_strong_interns_ 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_SRC_CLASS_LINKER_H_ |