| // Protocol Buffers - Google's data interchange format |
| // Copyright 2008 Google Inc. All rights reserved. |
| // https://developers.google.com/protocol-buffers/ |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef GOOGLE_PROTOBUF_ARENA_H__ |
| #define GOOGLE_PROTOBUF_ARENA_H__ |
| |
| #include <limits> |
| #ifdef max |
| #undef max // Visual Studio defines this macro |
| #endif |
| #if __cplusplus >= 201103L |
| #include <google/protobuf/stubs/type_traits.h> |
| #endif |
| #if defined(_MSC_VER) && !_HAS_EXCEPTIONS |
| // Work around bugs in MSVC <typeinfo> header when _HAS_EXCEPTIONS=0. |
| #include <exception> |
| #include <typeinfo> |
| namespace std { |
| using type_info = ::type_info; |
| } |
| #else |
| #include <typeinfo> |
| #endif |
| |
| #include <google/protobuf/stubs/atomic_sequence_num.h> |
| #include <google/protobuf/stubs/atomicops.h> |
| #include <google/protobuf/stubs/common.h> |
| #include <google/protobuf/stubs/logging.h> |
| #include <google/protobuf/stubs/mutex.h> |
| #include <google/protobuf/stubs/type_traits.h> |
| |
| namespace google { |
| namespace protobuf { |
| |
| class Arena; // defined below |
| class Message; // message.h |
| |
| namespace internal { |
| class ArenaString; // arenastring.h |
| class LazyField; // lazy_field.h |
| |
| template<typename Type> |
| class GenericTypeHandler; // repeated_field.h |
| |
| // Templated cleanup methods. |
| template<typename T> void arena_destruct_object(void* object) { |
| reinterpret_cast<T*>(object)->~T(); |
| } |
| template<typename T> void arena_delete_object(void* object) { |
| delete reinterpret_cast<T*>(object); |
| } |
| inline void arena_free(void* object, size_t size) { |
| free(object); |
| } |
| |
| } // namespace internal |
| |
| // ArenaOptions provides optional additional parameters to arena construction |
| // that control its block-allocation behavior. |
| struct ArenaOptions { |
| // This defines the size of the first block requested from the system malloc. |
| // Subsequent block sizes will increase in a geometric series up to a maximum. |
| size_t start_block_size; |
| |
| // This defines the maximum block size requested from system malloc (unless an |
| // individual arena allocation request occurs with a size larger than this |
| // maximum). Requested block sizes increase up to this value, then remain |
| // here. |
| size_t max_block_size; |
| |
| // An initial block of memory for the arena to use, or NULL for none. If |
| // provided, the block must live at least as long as the arena itself. The |
| // creator of the Arena retains ownership of the block after the Arena is |
| // destroyed. |
| char* initial_block; |
| |
| // The size of the initial block, if provided. |
| size_t initial_block_size; |
| |
| // A function pointer to an alloc method that returns memory blocks of size |
| // requested. By default, it contains a ptr to the malloc function. |
| // |
| // NOTE: block_alloc and dealloc functions are expected to behave like |
| // malloc and free, including Asan poisoning. |
| void* (*block_alloc)(size_t); |
| // A function pointer to a dealloc method that takes ownership of the blocks |
| // from the arena. By default, it contains a ptr to a wrapper function that |
| // calls free. |
| void (*block_dealloc)(void*, size_t); |
| |
| // Hooks for adding external functionality such as user-specific metrics |
| // collection, specific debugging abilities, etc. |
| // Init hook may return a pointer to a cookie to be stored in the arena. |
| // reset and destruction hooks will then be called with the same cookie |
| // pointer. This allows us to save an external object per arena instance and |
| // use it on the other hooks (Note: It is just as legal for init to return |
| // NULL and not use the cookie feature). |
| // on_arena_reset and on_arena_destruction also receive the space used in |
| // the arena just before the reset. |
| void* (*on_arena_init)(Arena* arena); |
| void (*on_arena_reset)(Arena* arena, void* cookie, uint64 space_used); |
| void (*on_arena_destruction)(Arena* arena, void* cookie, uint64 space_used); |
| |
| // type_info is promised to be static - its lifetime extends to |
| // match program's lifetime (It is given by typeid operator). |
| // Note: typeid(void) will be passed as allocated_type every time we |
| // intentionally want to avoid monitoring an allocation. (i.e. internal |
| // allocations for managing the arena) |
| void (*on_arena_allocation)(const std::type_info* allocated_type, |
| uint64 alloc_size, void* cookie); |
| |
| ArenaOptions() |
| : start_block_size(kDefaultStartBlockSize), |
| max_block_size(kDefaultMaxBlockSize), |
| initial_block(NULL), |
| initial_block_size(0), |
| block_alloc(&malloc), |
| block_dealloc(&internal::arena_free), |
| on_arena_init(NULL), |
| on_arena_reset(NULL), |
| on_arena_destruction(NULL), |
| on_arena_allocation(NULL) {} |
| |
| private: |
| // Constants define default starting block size and max block size for |
| // arena allocator behavior -- see descriptions above. |
| static const size_t kDefaultStartBlockSize = 256; |
| static const size_t kDefaultMaxBlockSize = 8192; |
| }; |
| |
| // Support for non-RTTI environments. (The metrics hooks API uses type |
| // information.) |
| #ifndef GOOGLE_PROTOBUF_NO_RTTI |
| #define RTTI_TYPE_ID(type) (&typeid(type)) |
| #else |
| #define RTTI_TYPE_ID(type) (NULL) |
| #endif |
| |
| // Arena allocator. Arena allocation replaces ordinary (heap-based) allocation |
| // with new/delete, and improves performance by aggregating allocations into |
| // larger blocks and freeing allocations all at once. Protocol messages are |
| // allocated on an arena by using Arena::CreateMessage<T>(Arena*), below, and |
| // are automatically freed when the arena is destroyed. |
| // |
| // This is a thread-safe implementation: multiple threads may allocate from the |
| // arena concurrently. Destruction is not thread-safe and the destructing |
| // thread must synchronize with users of the arena first. |
| // |
| // An arena provides two allocation interfaces: CreateMessage<T>, which works |
| // for arena-enabled proto2 message types as well as other types that satisfy |
| // the appropriate protocol (described below), and Create<T>, which works for |
| // any arbitrary type T. CreateMessage<T> is better when the type T supports it, |
| // because this interface (i) passes the arena pointer to the created object so |
| // that its sub-objects and internal allocations can use the arena too, and (ii) |
| // elides the object's destructor call when possible. Create<T> does not place |
| // any special requirements on the type T, and will invoke the object's |
| // destructor when the arena is destroyed. |
| // |
| // The arena message allocation protocol, required by CreateMessage<T>, is as |
| // follows: |
| // |
| // - The type T must have (at least) two constructors: a constructor with no |
| // arguments, called when a T is allocated on the heap; and a constructor with |
| // a google::protobuf::Arena* argument, called when a T is allocated on an arena. If the |
| // second constructor is called with a NULL arena pointer, it must be |
| // equivalent to invoking the first (no-argument) constructor. |
| // |
| // - The type T must have a particular type trait: a nested type |
| // |InternalArenaConstructable_|. This is usually a typedef to |void|. If no |
| // such type trait exists, then the instantiation CreateMessage<T> will fail |
| // to compile. |
| // |
| // - The type T *may* have the type trait |DestructorSkippable_|. If this type |
| // trait is present in the type, then its destructor will not be called if and |
| // only if it was passed a non-NULL arena pointer. If this type trait is not |
| // present on the type, then its destructor is always called when the |
| // containing arena is destroyed. |
| // |
| // - One- and two-user-argument forms of CreateMessage<T>() also exist that |
| // forward these constructor arguments to T's constructor: for example, |
| // CreateMessage<T>(Arena*, arg1, arg2) forwards to a constructor T(Arena*, |
| // arg1, arg2). |
| // |
| // This protocol is implemented by all arena-enabled proto2 message classes as |
| // well as RepeatedPtrField. |
| class LIBPROTOBUF_EXPORT Arena { |
| public: |
| // Arena constructor taking custom options. See ArenaOptions below for |
| // descriptions of the options available. |
| explicit Arena(const ArenaOptions& options) : options_(options) { |
| Init(); |
| } |
| |
| // Default constructor with sensible default options, tuned for average |
| // use-cases. |
| Arena() { |
| Init(); |
| } |
| |
| // Destructor deletes all owned heap allocated objects, and destructs objects |
| // that have non-trivial destructors, except for proto2 message objects whose |
| // destructors can be skipped. Also, frees all blocks except the initial block |
| // if it was passed in. |
| ~Arena(); |
| |
| // API to create proto2 message objects on the arena. If the arena passed in |
| // is NULL, then a heap allocated object is returned. Type T must be a message |
| // defined in a .proto file with cc_enable_arenas set to true, otherwise a |
| // compilation error will occur. |
| // |
| // RepeatedField and RepeatedPtrField may also be instantiated directly on an |
| // arena with this method. |
| // |
| // This function also accepts any type T that satisfies the arena message |
| // allocation protocol, documented above. |
| template <typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* CreateMessage(::google::protobuf::Arena* arena) { |
| if (arena == NULL) { |
| return new T; |
| } else { |
| return arena->CreateMessageInternal<T>(static_cast<T*>(0)); |
| } |
| } |
| |
| // One-argument form of CreateMessage. This is useful for constructing objects |
| // that implement the arena message construction protocol described above but |
| // take additional constructor arguments. |
| template <typename T, typename Arg> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* CreateMessage(::google::protobuf::Arena* arena, const Arg& arg) { |
| if (arena == NULL) { |
| return new T(NULL, arg); |
| } else { |
| return arena->CreateMessageInternal<T>(static_cast<T*>(0), |
| arg); |
| } |
| } |
| |
| // Two-argument form of CreateMessage. This is useful for constructing objects |
| // that implement the arena message construction protocol described above but |
| // take additional constructor arguments. |
| template <typename T, typename Arg1, typename Arg2> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* CreateMessage(::google::protobuf::Arena* arena, |
| const Arg1& arg1, |
| const Arg2& arg2) { |
| if (arena == NULL) { |
| return new T(NULL, arg1, arg2); |
| } else { |
| return arena->CreateMessageInternal<T>(static_cast<T*>(0), |
| arg1, arg2); |
| } |
| } |
| |
| // API to create any objects on the arena. Note that only the object will |
| // be created on the arena; the underlying ptrs (in case of a proto2 message) |
| // will be still heap allocated. Proto messages should usually be allocated |
| // with CreateMessage<T>() instead. |
| // |
| // Note that even if T satisfies the arena message construction protocol |
| // (InternalArenaConstructable_ trait and optional DestructorSkippable_ |
| // trait), as described above, this function does not follow the protocol; |
| // instead, it treats T as a black-box type, just as if it did not have these |
| // traits. Specifically, T's constructor arguments will always be only those |
| // passed to Create<T>() -- no additional arena pointer is implicitly added. |
| // Furthermore, the destructor will always be called at arena destruction time |
| // (unless the destructor is trivial). Hence, from T's point of view, it is as |
| // if the object were allocated on the heap (except that the underlying memory |
| // is obtained from the arena). |
| template <typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* Create(::google::protobuf::Arena* arena) { |
| if (arena == NULL) { |
| return new T(); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value); |
| } |
| } |
| |
| // Version of the above with one constructor argument for the created object. |
| template <typename T, typename Arg> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* Create(::google::protobuf::Arena* arena, const Arg& arg) { |
| if (arena == NULL) { |
| return new T(arg); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg); |
| } |
| } |
| |
| // Version of the above with two constructor arguments for the created object. |
| template <typename T, typename Arg1, typename Arg2> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* Create(::google::protobuf::Arena* arena, const Arg1& arg1, const Arg2& arg2) { |
| if (arena == NULL) { |
| return new T(arg1, arg2); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2); |
| } |
| } |
| |
| // Version of the above with three constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3); |
| } |
| } |
| |
| // Version of the above with four constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3, const Arg4& arg4) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3, arg4); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3, arg4); |
| } |
| } |
| |
| // Version of the above with five constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3, const Arg4& arg4, |
| const Arg5& arg5) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3, arg4, arg5); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3, arg4, arg5); |
| } |
| } |
| |
| // Version of the above with six constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3, const Arg4& arg4, |
| const Arg5& arg5, const Arg6& arg6) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3, arg4, arg5, arg6); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3, arg4, arg5, arg6); |
| } |
| } |
| |
| // Version of the above with seven constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6, typename Arg7> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3, const Arg4& arg4, |
| const Arg5& arg5, const Arg6& arg6, |
| const Arg7& arg7) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3, arg4, arg5, arg6, arg7); |
| } else { |
| return arena->CreateInternal<T>(google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3, arg4, arg5, arg6, arg7); |
| } |
| } |
| |
| // Version of the above with eight constructor arguments for the created |
| // object. |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6, typename Arg7, |
| typename Arg8> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE static T* Create(::google::protobuf::Arena* arena, |
| const Arg1& arg1, const Arg2& arg2, |
| const Arg3& arg3, const Arg4& arg4, |
| const Arg5& arg5, const Arg6& arg6, |
| const Arg7& arg7, const Arg8& arg8) { |
| if (arena == NULL) { |
| return new T(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); |
| } else { |
| return arena->CreateInternal<T>( |
| google::protobuf::internal::has_trivial_destructor<T>::value, |
| arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); |
| } |
| } |
| |
| // Create an array of object type T on the arena *without* invoking the |
| // constructor of T. If `arena` is null, then the return value should be freed |
| // with `delete[] x;` (or `::operator delete[](x);`). |
| // To ensure safe uses, this function checks at compile time |
| // (when compiled as C++11) that T is trivially default-constructible and |
| // trivially destructible. |
| template <typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* CreateArray(::google::protobuf::Arena* arena, size_t num_elements) { |
| GOOGLE_CHECK_LE(num_elements, |
| std::numeric_limits<size_t>::max() / sizeof(T)) |
| << "Requested size is too large to fit into size_t."; |
| if (arena == NULL) { |
| return static_cast<T*>(::operator new[](num_elements * sizeof(T))); |
| } else { |
| return arena->CreateInternalRawArray<T>(num_elements); |
| } |
| } |
| |
| // Returns the total space used by the arena, which is the sums of the sizes |
| // of the underlying blocks. The total space used may not include the new |
| // blocks that are allocated by this arena from other threads concurrently |
| // with the call to this method. |
| GOOGLE_ATTRIBUTE_NOINLINE uint64 SpaceAllocated() const; |
| // As above, but does not include any free space in underlying blocks. |
| GOOGLE_ATTRIBUTE_NOINLINE uint64 SpaceUsed() const; |
| |
| // Frees all storage allocated by this arena after calling destructors |
| // registered with OwnDestructor() and freeing objects registered with Own(). |
| // Any objects allocated on this arena are unusable after this call. It also |
| // returns the total space used by the arena which is the sums of the sizes |
| // of the allocated blocks. This method is not thread-safe. |
| GOOGLE_ATTRIBUTE_NOINLINE uint64 Reset(); |
| |
| // Adds |object| to a list of heap-allocated objects to be freed with |delete| |
| // when the arena is destroyed or reset. |
| template <typename T> GOOGLE_ATTRIBUTE_NOINLINE |
| void Own(T* object) { |
| OwnInternal(object, google::protobuf::internal::is_convertible<T*, ::google::protobuf::Message*>()); |
| } |
| |
| // Adds |object| to a list of objects whose destructors will be manually |
| // called when the arena is destroyed or reset. This differs from Own() in |
| // that it does not free the underlying memory with |delete|; hence, it is |
| // normally only used for objects that are placement-newed into |
| // arena-allocated memory. |
| template <typename T> GOOGLE_ATTRIBUTE_NOINLINE |
| void OwnDestructor(T* object) { |
| if (object != NULL) { |
| AddListNode(object, &internal::arena_destruct_object<T>); |
| } |
| } |
| |
| // Adds a custom member function on an object to the list of destructors that |
| // will be manually called when the arena is destroyed or reset. This differs |
| // from OwnDestructor() in that any member function may be specified, not only |
| // the class destructor. |
| GOOGLE_ATTRIBUTE_NOINLINE void OwnCustomDestructor(void* object, |
| void (*destruct)(void*)) { |
| AddListNode(object, destruct); |
| } |
| |
| // Retrieves the arena associated with |value| if |value| is an arena-capable |
| // message, or NULL otherwise. This differs from value->GetArena() in that the |
| // latter is a virtual call, while this method is a templated call that |
| // resolves at compile-time. |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static ::google::protobuf::Arena* GetArena(const T* value) { |
| return GetArenaInternal(value, static_cast<T*>(0)); |
| } |
| |
| private: |
| struct InternalIsArenaConstructableHelper { |
| template<typename U> |
| static char ArenaConstructable( |
| const typename U::InternalArenaConstructable_*); |
| template<typename U> |
| static double ArenaConstructable(...); |
| }; |
| |
| public: |
| // Helper typetrait that indicates support for arenas in a type T at compile |
| // time. This is public only to allow construction of higher-level templated |
| // utilities. is_arena_constructable<T>::value is true if the message type T |
| // has arena support enabled, and false otherwise. |
| // |
| // This is inside Arena because only Arena has the friend relationships |
| // necessary to see the underlying generated code traits. |
| template<typename T> |
| struct is_arena_constructable : |
| public google::protobuf::internal::integral_constant<bool, |
| sizeof(InternalIsArenaConstructableHelper::ArenaConstructable< |
| const T>(static_cast<const T*>(0))) == sizeof(char)> { |
| }; |
| |
| private: |
| // Blocks are variable length malloc-ed objects. The following structure |
| // describes the common header for all blocks. |
| struct Block { |
| void* owner; // &ThreadCache of thread that owns this block, or |
| // &this->owner if not yet owned by a thread. |
| Block* next; // Next block in arena (may have different owner) |
| // ((char*) &block) + pos is next available byte. It is always |
| // aligned at a multiple of 8 bytes. |
| size_t pos; |
| size_t size; // total size of the block. |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE size_t avail() const { return size - pos; } |
| // data follows |
| }; |
| |
| template<typename Type> friend class ::google::protobuf::internal::GenericTypeHandler; |
| friend class MockArena; // For unit-testing. |
| friend class internal::ArenaString; // For AllocateAligned. |
| friend class internal::LazyField; // For CreateMaybeMessage. |
| |
| struct ThreadCache { |
| // The ThreadCache is considered valid as long as this matches the |
| // lifecycle_id of the arena being used. |
| int64 last_lifecycle_id_seen; |
| Block* last_block_used_; |
| }; |
| |
| static const size_t kHeaderSize = sizeof(Block); |
| static google::protobuf::internal::SequenceNumber lifecycle_id_generator_; |
| #if defined(GOOGLE_PROTOBUF_NO_THREADLOCAL) |
| // Android ndk does not support GOOGLE_THREAD_LOCAL keyword so we use a custom thread |
| // local storage class we implemented. |
| // iOS also does not support the GOOGLE_THREAD_LOCAL keyword. |
| static ThreadCache& thread_cache(); |
| #elif defined(PROTOBUF_USE_DLLS) |
| // Thread local variables cannot be exposed through DLL interface but we can |
| // wrap them in static functions. |
| static ThreadCache& thread_cache(); |
| #else |
| static GOOGLE_THREAD_LOCAL ThreadCache thread_cache_; |
| static ThreadCache& thread_cache() { return thread_cache_; } |
| #endif |
| |
| // SFINAE for skipping addition to delete list for a message type when created |
| // with CreateMessage. This is mainly to skip proto2/proto1 message objects |
| // with cc_enable_arenas=true from being part of the delete list. Also, note, |
| // compiler will optimize out the branch in CreateInternal<T>. |
| template<typename T> |
| static inline bool SkipDeleteList(typename T::DestructorSkippable_*) { |
| return true; |
| } |
| |
| // For message objects that don't have the DestructorSkippable_ trait, we |
| // always add to the delete list. |
| template<typename T> |
| static inline bool SkipDeleteList(...) { |
| return google::protobuf::internal::has_trivial_destructor<T>::value; |
| } |
| |
| private: |
| struct InternalIsDestructorSkippableHelper { |
| template<typename U> |
| static char DestructorSkippable( |
| const typename U::DestructorSkippable_*); |
| template<typename U> |
| static double DestructorSkippable(...); |
| }; |
| |
| public: |
| // Helper typetrait that indicates whether the desctructor of type T should be |
| // called when arena is destroyed at compile time. This is only to allow |
| // construction of higher-level templated utilities. |
| // is_destructor_skippable<T>::value is true if the destructor of the message |
| // type T should not be called when arena is destroyed or false otherwise. |
| // This is inside Arena because only Arena has the friend relationships |
| // necessary to see the underlying generated code traits. |
| template<typename T> |
| struct is_destructor_skippable : |
| public google::protobuf::internal::integral_constant<bool, |
| sizeof(InternalIsDestructorSkippableHelper::DestructorSkippable< |
| const T>(static_cast<const T*>(0))) == |
| sizeof(char) || |
| google::protobuf::internal::has_trivial_destructor<T>::value> { |
| }; |
| |
| |
| // CreateMessage<T> requires that T supports arenas, but this private method |
| // works whether or not T supports arenas. These are not exposed to user code |
| // as it can cause confusing API usages, and end up having double free in |
| // user code. These are used only internally from LazyField and Repeated |
| // fields, since they are designed to work in all mode combinations. |
| template<typename Msg> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static Msg* CreateMaybeMessage( |
| Arena* arena, typename Msg::InternalArenaConstructable_*) { |
| return CreateMessage<Msg>(arena); |
| } |
| |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static T* CreateMaybeMessage(Arena* arena, ...) { |
| return Create<T>(arena); |
| } |
| |
| // Just allocate the required size for the given type assuming the |
| // type has a trivial constructor. |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateInternalRawArray(size_t num_elements) { |
| GOOGLE_CHECK_LE(num_elements, |
| std::numeric_limits<size_t>::max() / sizeof(T)) |
| << "Requested size is too large to fit into size_t."; |
| return static_cast<T*>( |
| AllocateAligned(RTTI_TYPE_ID(T), sizeof(T) * num_elements)); |
| } |
| |
| template <typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateInternal(bool skip_explicit_ownership) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) T(); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateInternal(bool skip_explicit_ownership, const Arg& arg) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) T(arg); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateInternal( |
| bool skip_explicit_ownership, const Arg1& arg1, const Arg2& arg2) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) T(arg1, arg2); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3, |
| const Arg4& arg4) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3, arg4); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3, |
| const Arg4& arg4, |
| const Arg5& arg5) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3, arg4, arg5); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3, |
| const Arg4& arg4, |
| const Arg5& arg5, |
| const Arg6& arg6) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3, arg4, arg5, arg6); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6, typename Arg7> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3, |
| const Arg4& arg4, |
| const Arg5& arg5, |
| const Arg6& arg6, |
| const Arg7& arg7) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3, arg4, arg5, arg6, arg7); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T, typename Arg1, typename Arg2, typename Arg3, |
| typename Arg4, typename Arg5, typename Arg6, typename Arg7, |
| typename Arg8> |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE T* CreateInternal(bool skip_explicit_ownership, |
| const Arg1& arg1, |
| const Arg2& arg2, |
| const Arg3& arg3, |
| const Arg4& arg4, |
| const Arg5& arg5, |
| const Arg6& arg6, |
| const Arg7& arg7, |
| const Arg8& arg8) { |
| T* t = new (AllocateAligned(RTTI_TYPE_ID(T), sizeof(T))) |
| T(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8); |
| if (!skip_explicit_ownership) { |
| AddListNode(t, &internal::arena_destruct_object<T>); |
| } |
| return t; |
| } |
| |
| template <typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateMessageInternal(typename T::InternalArenaConstructable_*) { |
| return CreateInternal<T, Arena*>(SkipDeleteList<T>(static_cast<T*>(0)), |
| this); |
| } |
| |
| template <typename T, typename Arg> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateMessageInternal(typename T::InternalArenaConstructable_*, |
| const Arg& arg) { |
| return CreateInternal<T, Arena*>(SkipDeleteList<T>(static_cast<T*>(0)), |
| this, arg); |
| } |
| |
| template <typename T, typename Arg1, typename Arg2> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| T* CreateMessageInternal(typename T::InternalArenaConstructable_*, |
| const Arg1& arg1, const Arg2& arg2) { |
| return CreateInternal<T, Arena*>(SkipDeleteList<T>(static_cast<T*>(0)), |
| this, arg1, arg2); |
| } |
| |
| // CreateInArenaStorage is used to implement map field. Without it, |
| // google::protobuf::Map need to call generated message's protected arena constructor, |
| // which needs to declare google::protobuf::Map as friend of generated message. |
| template <typename T> |
| static void CreateInArenaStorage(T* ptr, Arena* arena) { |
| CreateInArenaStorageInternal(ptr, arena, |
| typename is_arena_constructable<T>::type()); |
| RegisterDestructorInternal(ptr, arena, |
| typename is_destructor_skippable<T>::type()); |
| } |
| |
| template <typename T> |
| static void CreateInArenaStorageInternal( |
| T* ptr, Arena* arena, google::protobuf::internal::true_type) { |
| new (ptr) T(arena); |
| } |
| template <typename T> |
| static void CreateInArenaStorageInternal( |
| T* ptr, Arena* arena, google::protobuf::internal::false_type) { |
| new (ptr) T; |
| } |
| |
| template <typename T> |
| static void RegisterDestructorInternal( |
| T* ptr, Arena* arena, google::protobuf::internal::true_type) {} |
| template <typename T> |
| static void RegisterDestructorInternal( |
| T* ptr, Arena* arena, google::protobuf::internal::false_type) { |
| arena->OwnDestructor(ptr); |
| } |
| |
| // These implement Own(), which registers an object for deletion (destructor |
| // call and operator delete()). The second parameter has type 'true_type' if T |
| // is a subtype of ::google::protobuf::Message and 'false_type' otherwise. Collapsing |
| // all template instantiations to one for generic Message reduces code size, |
| // using the virtual destructor instead. |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| void OwnInternal(T* object, google::protobuf::internal::true_type) { |
| if (object != NULL) { |
| AddListNode(object, &internal::arena_delete_object< ::google::protobuf::Message >); |
| } |
| } |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| void OwnInternal(T* object, google::protobuf::internal::false_type) { |
| if (object != NULL) { |
| AddListNode(object, &internal::arena_delete_object<T>); |
| } |
| } |
| |
| // Implementation for GetArena(). Only message objects with |
| // InternalArenaConstructable_ tags can be associated with an arena, and such |
| // objects must implement a GetArenaNoVirtual() method. |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static ::google::protobuf::Arena* GetArenaInternal( |
| const T* value, typename T::InternalArenaConstructable_*) { |
| return value->GetArenaNoVirtual(); |
| } |
| |
| template<typename T> GOOGLE_ATTRIBUTE_ALWAYS_INLINE |
| static ::google::protobuf::Arena* GetArenaInternal(const T* value, ...) { |
| return NULL; |
| } |
| |
| // Allocate and also optionally call on_arena_allocation callback with the |
| // allocated type info when the hooks are in place in ArenaOptions and |
| // the cookie is not null. |
| void* AllocateAligned(const std::type_info* allocated, size_t n); |
| |
| // Allocate an internal allocation, avoiding optional typed monitoring. |
| GOOGLE_ATTRIBUTE_ALWAYS_INLINE void* AllocateAligned(size_t n) { |
| return AllocateAligned(NULL, n); |
| } |
| |
| void Init(); |
| |
| // Free all blocks and return the total space used which is the sums of sizes |
| // of the all the allocated blocks. |
| uint64 FreeBlocks(); |
| |
| // Add object pointer and cleanup function pointer to the list. |
| // TODO(rohananil, cfallin): We could pass in a sub-arena into this method |
| // to avoid polluting blocks of this arena with list nodes. This would help in |
| // mixed mode (where many protobufs have cc_enable_arenas=false), and is an |
| // alternative to a chunked linked-list, but with extra overhead of *next. |
| void AddListNode(void* elem, void (*cleanup)(void*)); |
| // Delete or Destruct all objects owned by the arena. |
| void CleanupList(); |
| uint64 ResetInternal(); |
| |
| inline void SetThreadCacheBlock(Block* block) { |
| thread_cache().last_block_used_ = block; |
| thread_cache().last_lifecycle_id_seen = lifecycle_id_; |
| } |
| |
| int64 lifecycle_id_; // Unique for each arena. Changes on Reset(). |
| |
| google::protobuf::internal::AtomicWord blocks_; // Head of linked list of all allocated blocks |
| google::protobuf::internal::AtomicWord hint_; // Fast thread-local block access |
| |
| // Node contains the ptr of the object to be cleaned up and the associated |
| // cleanup function ptr. |
| struct Node { |
| void* elem; // Pointer to the object to be cleaned up. |
| void (*cleanup)(void*); // Function pointer to the destructor or deleter. |
| Node* next; // Next node in the list. |
| }; |
| |
| google::protobuf::internal::AtomicWord cleanup_list_; // Head of a linked list of nodes containing object |
| // ptrs and cleanup methods. |
| |
| bool owns_first_block_; // Indicates that arena owns the first block |
| Mutex blocks_lock_; |
| |
| void AddBlock(Block* b); |
| // Access must be synchronized, either by blocks_lock_ or by being called from |
| // Init()/Reset(). |
| void AddBlockInternal(Block* b); |
| void* SlowAlloc(size_t n); |
| Block* FindBlock(void* me); |
| Block* NewBlock(void* me, Block* my_last_block, size_t n, |
| size_t start_block_size, size_t max_block_size); |
| static void* AllocFromBlock(Block* b, size_t n); |
| template <typename Key, typename T> |
| friend class Map; |
| |
| // The arena may save a cookie it receives from the external on_init hook |
| // and then use it when calling the on_reset and on_destruction hooks. |
| void* hooks_cookie_; |
| |
| ArenaOptions options_; |
| |
| GOOGLE_DISALLOW_EVIL_CONSTRUCTORS(Arena); |
| }; |
| |
| // Defined above for supporting environments without RTTI. |
| #undef RTTI_TYPE_ID |
| |
| } // namespace protobuf |
| |
| } // namespace google |
| #endif // GOOGLE_PROTOBUF_ARENA_H__ |