// Copyright 2011 the V8 project authors. All rights reserved. // 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 V8_SMART_POINTERS_H_ #define V8_SMART_POINTERS_H_ namespace v8 { namespace internal { template<typename Deallocator, typename T> class SmartPointerBase { public: // Default constructor. Constructs an empty scoped pointer. inline SmartPointerBase() : p_(NULL) {} // Constructs a scoped pointer from a plain one. explicit inline SmartPointerBase(T* ptr) : p_(ptr) {} // Copy constructor removes the pointer from the original to avoid double // freeing. inline SmartPointerBase(const SmartPointerBase<Deallocator, T>& rhs) : p_(rhs.p_) { const_cast<SmartPointerBase<Deallocator, T>&>(rhs).p_ = NULL; } // When the destructor of the scoped pointer is executed the plain pointer // is deleted using DeleteArray. This implies that you must allocate with // NewArray. inline ~SmartPointerBase() { if (p_) Deallocator::Delete(p_); } inline T* operator->() const { return p_; } // You can get the underlying pointer out with the * operator. inline T* operator*() { return p_; } // You can use [n] to index as if it was a plain pointer. inline T& operator[](size_t i) { return p_[i]; } // You can use [n] to index as if it was a plain pointer. const inline T& operator[](size_t i) const { return p_[i]; } // We don't have implicit conversion to a T* since that hinders migration: // You would not be able to change a method from returning a T* to // returning an SmartArrayPointer<T> and then get errors wherever it is used. // If you want to take out the plain pointer and don't want it automatically // deleted then call Detach(). Afterwards, the smart pointer is empty // (NULL). inline T* Detach() { T* temp = p_; p_ = NULL; return temp; } inline void Reset(T* new_value) { if (p_) Deallocator::Delete(p_); p_ = new_value; } // Assignment requires an empty (NULL) SmartArrayPointer as the receiver. Like // the copy constructor it removes the pointer in the original to avoid // double freeing. inline SmartPointerBase<Deallocator, T>& operator=( const SmartPointerBase<Deallocator, T>& rhs) { ASSERT(is_empty()); T* tmp = rhs.p_; // swap to handle self-assignment const_cast<SmartPointerBase<Deallocator, T>&>(rhs).p_ = NULL; p_ = tmp; return *this; } inline bool is_empty() { return p_ == NULL; } private: T* p_; }; // A 'scoped array pointer' that calls DeleteArray on its pointer when the // destructor is called. template<typename T> struct ArrayDeallocator { static void Delete(T* array) { DeleteArray(array); } }; template<typename T> class SmartArrayPointer: public SmartPointerBase<ArrayDeallocator<T>, T> { public: inline SmartArrayPointer() { } explicit inline SmartArrayPointer(T* ptr) : SmartPointerBase<ArrayDeallocator<T>, T>(ptr) { } inline SmartArrayPointer(const SmartArrayPointer<T>& rhs) : SmartPointerBase<ArrayDeallocator<T>, T>(rhs) { } }; template<typename T> struct ObjectDeallocator { static void Delete(T* object) { delete object; } }; template<typename T> class SmartPointer: public SmartPointerBase<ObjectDeallocator<T>, T> { public: inline SmartPointer() { } explicit inline SmartPointer(T* ptr) : SmartPointerBase<ObjectDeallocator<T>, T>(ptr) { } inline SmartPointer(const SmartPointer<T>& rhs) : SmartPointerBase<ObjectDeallocator<T>, T>(rhs) { } }; } } // namespace v8::internal #endif // V8_SMART_POINTERS_H_