#if !defined(__OBJECT_H) #define __OBJECT_H #include #include "constructor_stats.h" /// Reference counted object base class class Object { public: /// Default constructor Object() { print_default_created(this); } /// Copy constructor Object(const Object &) : m_refCount(0) { print_copy_created(this); } /// Return the current reference count int getRefCount() const { return m_refCount; }; /// Increase the object's reference count by one void incRef() const { ++m_refCount; } /** \brief Decrease the reference count of * the object and possibly deallocate it. * * The object will automatically be deallocated once * the reference count reaches zero. */ void decRef(bool dealloc = true) const { --m_refCount; if (m_refCount == 0 && dealloc) delete this; else if (m_refCount < 0) throw std::runtime_error("Internal error: reference count < 0!"); } virtual std::string toString() const = 0; protected: /** \brief Virtual protected deconstructor. * (Will only be called by \ref ref) */ virtual ~Object() { print_destroyed(this); } private: mutable std::atomic m_refCount { 0 }; }; // Tag class used to track constructions of ref objects. When we track constructors, below, we // track and print out the actual class (e.g. ref), and *also* add a fake tracker for // ref_tag. This lets us check that the total number of ref constructors/destructors is // correct without having to check each individual ref type individually. class ref_tag {}; /** * \brief Reference counting helper * * The \a ref refeference template is a simple wrapper to store a * pointer to an object. It takes care of increasing and decreasing * the reference count of the object. When the last reference goes * out of scope, the associated object will be deallocated. * * \ingroup libcore */ template class ref { public: /// Create a nullptr reference ref() : m_ptr(nullptr) { print_default_created(this); track_default_created((ref_tag*) this); } /// Construct a reference from a pointer explicit ref(T *ptr) : m_ptr(ptr) { if (m_ptr) ((Object *) m_ptr)->incRef(); print_created(this, "from pointer", m_ptr); track_created((ref_tag*) this, "from pointer"); } /// Copy constructor ref(const ref &r) : m_ptr(r.m_ptr) { if (m_ptr) ((Object *) m_ptr)->incRef(); print_copy_created(this, "with pointer", m_ptr); track_copy_created((ref_tag*) this); } /// Move constructor ref(ref &&r) noexcept : m_ptr(r.m_ptr) { r.m_ptr = nullptr; print_move_created(this, "with pointer", m_ptr); track_move_created((ref_tag*) this); } /// Destroy this reference ~ref() { if (m_ptr) ((Object *) m_ptr)->decRef(); print_destroyed(this); track_destroyed((ref_tag*) this); } /// Move another reference into the current one ref &operator=(ref &&r) noexcept { print_move_assigned(this, "pointer", r.m_ptr); track_move_assigned((ref_tag*) this); if (*this == r) return *this; if (m_ptr) ((Object *) m_ptr)->decRef(); m_ptr = r.m_ptr; r.m_ptr = nullptr; return *this; } /// Overwrite this reference with another reference ref& operator=(const ref& r) { if (this == &r) { return *this; } print_copy_assigned(this, "pointer", r.m_ptr); track_copy_assigned((ref_tag *) this); if (m_ptr == r.m_ptr) return *this; if (m_ptr) ((Object *) m_ptr)->decRef(); m_ptr = r.m_ptr; if (m_ptr) ((Object *) m_ptr)->incRef(); return *this; } /// Overwrite this reference with a pointer to another object ref& operator=(T *ptr) { print_values(this, "assigned pointer"); track_values((ref_tag*) this, "assigned pointer"); if (m_ptr == ptr) return *this; if (m_ptr) ((Object *) m_ptr)->decRef(); m_ptr = ptr; if (m_ptr) ((Object *) m_ptr)->incRef(); return *this; } /// Compare this reference with another reference bool operator==(const ref &r) const { return m_ptr == r.m_ptr; } /// Compare this reference with another reference bool operator!=(const ref &r) const { return m_ptr != r.m_ptr; } /// Compare this reference with a pointer bool operator==(const T* ptr) const { return m_ptr == ptr; } /// Compare this reference with a pointer bool operator!=(const T* ptr) const { return m_ptr != ptr; } /// Access the object referenced by this reference T* operator->() { return m_ptr; } /// Access the object referenced by this reference const T* operator->() const { return m_ptr; } /// Return a C++ reference to the referenced object T& operator*() { return *m_ptr; } /// Return a const C++ reference to the referenced object const T& operator*() const { return *m_ptr; } /// Return a pointer to the referenced object explicit operator T* () { return m_ptr; } /// Return a const pointer to the referenced object T* get_ptr() { return m_ptr; } /// Return a pointer to the referenced object const T* get_ptr() const { return m_ptr; } private: T *m_ptr; }; #endif /* __OBJECT_H */