1 // The libMesh Finite Element Library. 2 // Copyright (C) 2002-2020 Benjamin S. Kirk, John W. Peterson, Roy H. Stogner 3 4 // This library is free software; you can redistribute it and/or 5 // modify it under the terms of the GNU Lesser General Public 6 // License as published by the Free Software Foundation; either 7 // version 2.1 of the License, or (at your option) any later version. 8 9 // This library is distributed in the hope that it will be useful, 10 // but WITHOUT ANY WARRANTY; without even the implied warranty of 11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 // Lesser General Public License for more details. 13 14 // You should have received a copy of the GNU Lesser General Public 15 // License along with this library; if not, write to the Free Software 16 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 17 18 19 20 #ifndef LIBMESH_REFERENCE_COUNTED_OBJECT_H 21 #define LIBMESH_REFERENCE_COUNTED_OBJECT_H 22 23 // Local includes 24 #include "libmesh/reference_counter.h" 25 26 // C++ includes 27 #include <typeinfo> 28 29 namespace libMesh 30 { 31 32 /** 33 * This class implements reference counting. Any class that 34 * is properly derived from this class will get reference counted, provided 35 * that the library is configured with \p --enable-reference-counting 36 * and you are compiling with \p DEBUG defined. 37 * For example, the following is sufficient to define the class \p Foo 38 * as a reference counted class: 39 * 40 * \code 41 * class Foo : public ReferenceCountedObject<Foo> 42 * { 43 * public: 44 * 45 * Foo () {} 46 * 47 * ~Foo () {} 48 * 49 * void bar (); 50 * 51 * private: 52 * }; 53 * 54 * \endcode 55 * 56 * \par 57 * If the library is configured with \p --disable-reference-counting 58 * or \p DEBUG is not defined then this class does nothing. 59 * All members are inlined and empty, so they should effectively disappear. 60 * 61 * \author Benjamin S. Kirk 62 * \date 2002-2007 63 */ 64 template <typename T> 65 class ReferenceCountedObject : public ReferenceCounter 66 { 67 protected: 68 69 /** 70 * Constructor. Protected so that you cannot 71 * instantiate a \p ReferenceCountedObject, only derive 72 * from it. 73 */ ReferenceCountedObject()74 ReferenceCountedObject () 75 { 76 #if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG) 77 78 increment_constructor_count(typeid(T).name()); 79 80 #endif 81 } 82 83 /** 84 * Also, increment the counter if the copy-constructor is called. 85 */ ReferenceCountedObject(const ReferenceCountedObject & other)86 ReferenceCountedObject (const ReferenceCountedObject & other) 87 : ReferenceCounter(other) 88 { 89 #if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG) 90 91 increment_constructor_count(typeid(T).name()); 92 93 #endif 94 } 95 96 /** 97 * Move constructor, must be declared noexcept. 98 */ ReferenceCountedObject(ReferenceCountedObject && other)99 ReferenceCountedObject(ReferenceCountedObject && other) noexcept 100 : ReferenceCounter(std::move(other)) 101 { 102 #if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG) 103 104 increment_constructor_count(typeid(T).name()); 105 106 #endif 107 } 108 109 /** 110 * Copy assignment operator does nothing - we're copying an 111 * already-allocated object over an already-allocated object, so the 112 * counts for this class shouldn't change. There are also no non-static 113 * members in this or the base class to copy, so there is nothing 114 * for us to actually do. 115 */ 116 ReferenceCountedObject & operator= (const ReferenceCountedObject & /*other*/) 117 { 118 return *this; 119 } 120 121 122 public: 123 124 /** 125 * Destructor. 126 */ ~ReferenceCountedObject()127 ~ReferenceCountedObject () 128 { 129 #if defined(LIBMESH_ENABLE_REFERENCE_COUNTING) && defined(DEBUG) 130 131 increment_destructor_count(typeid(T).name()); 132 133 #endif 134 } 135 }; 136 137 138 } // namespace libMesh 139 140 141 #endif // LIBMESH_REFERENCE_COUNTED_OBJECT_H 142