1 /* 2 * DISTRHO Plugin Framework (DPF) 3 * Copyright (C) 2012-2016 Filipe Coelho <falktx@falktx.com> 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any purpose with 6 * or without fee is hereby granted, provided that the above copyright notice and this 7 * permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD 10 * TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN 11 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER 13 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 14 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15 */ 16 17 #ifndef DISTRHO_LEAK_DETECTOR_HPP_INCLUDED 18 #define DISTRHO_LEAK_DETECTOR_HPP_INCLUDED 19 20 #include "../DistrhoUtils.hpp" 21 22 START_NAMESPACE_DISTRHO 23 24 // ----------------------------------------------------------------------- 25 // The following code was based from juce-core LeakDetector class 26 // Copyright (C) 2013 Raw Material Software Ltd. 27 28 /** A good old-fashioned C macro concatenation helper. 29 This combines two items (which may themselves be macros) into a single string, 30 avoiding the pitfalls of the ## macro operator. 31 */ 32 #define DISTRHO_JOIN_MACRO_HELPER(a, b) a ## b 33 #define DISTRHO_JOIN_MACRO(item1, item2) DISTRHO_JOIN_MACRO_HELPER(item1, item2) 34 35 #ifdef DEBUG 36 /** This macro lets you embed a leak-detecting object inside a class.\n 37 To use it, simply declare a DISTRHO_LEAK_DETECTOR(YourClassName) inside a private section 38 of the class declaration. E.g. 39 \code 40 class MyClass 41 { 42 public: 43 MyClass(); 44 void blahBlah(); 45 46 private: 47 DISTRHO_LEAK_DETECTOR(MyClass) 48 }; 49 \endcode 50 */ 51 # define DISTRHO_LEAK_DETECTOR(ClassName) \ 52 friend class DISTRHO_NAMESPACE::LeakedObjectDetector<ClassName>; \ 53 static const char* getLeakedObjectClassName() noexcept { return #ClassName; } \ 54 DISTRHO_NAMESPACE::LeakedObjectDetector<ClassName> DISTRHO_JOIN_MACRO(leakDetector_, ClassName); 55 56 # define DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(ClassName) \ 57 DISTRHO_DECLARE_NON_COPY_CLASS(ClassName) \ 58 DISTRHO_LEAK_DETECTOR(ClassName) 59 #else 60 /** Don't use leak detection on release builds. */ 61 # define DISTRHO_LEAK_DETECTOR(ClassName) 62 # define DISTRHO_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(ClassName) \ 63 DISTRHO_DECLARE_NON_COPY_CLASS(ClassName) 64 #endif 65 66 //============================================================================== 67 /** 68 Embedding an instance of this class inside another class can be used as a low-overhead 69 way of detecting leaked instances. 70 71 This class keeps an internal static count of the number of instances that are 72 active, so that when the app is shutdown and the static destructors are called, 73 it can check whether there are any left-over instances that may have been leaked. 74 75 To use it, use the DISTRHO_LEAK_DETECTOR macro as a simple way to put one in your 76 class declaration. 77 */ 78 template<class OwnerClass> 79 class LeakedObjectDetector 80 { 81 public: 82 //============================================================================== LeakedObjectDetector()83 LeakedObjectDetector() noexcept { ++(getCounter().numObjects); } LeakedObjectDetector(const LeakedObjectDetector &)84 LeakedObjectDetector(const LeakedObjectDetector&) noexcept { ++(getCounter().numObjects); } 85 ~LeakedObjectDetector()86 ~LeakedObjectDetector() noexcept 87 { 88 if (--(getCounter().numObjects) < 0) 89 { 90 /** If you hit this, then you've managed to delete more instances of this class than you've 91 created.. That indicates that you're deleting some dangling pointers. 92 93 Note that although this assertion will have been triggered during a destructor, it might 94 not be this particular deletion that's at fault - the incorrect one may have happened 95 at an earlier point in the program, and simply not been detected until now. 96 97 Most errors like this are caused by using old-fashioned, non-RAII techniques for 98 your object management. Tut, tut. Always, always use ScopedPointers, OwnedArrays, 99 ReferenceCountedObjects, etc, and avoid the 'delete' operator at all costs! 100 */ 101 d_stderr2("*** Dangling pointer deletion! Class: '%s', Count: %i", getLeakedObjectClassName(), getCounter().numObjects); 102 } 103 } 104 105 private: 106 //============================================================================== 107 class LeakCounter 108 { 109 public: LeakCounter()110 LeakCounter() noexcept 111 : numObjects(0) {} 112 ~LeakCounter()113 ~LeakCounter() noexcept 114 { 115 if (numObjects > 0) 116 { 117 /** If you hit this, then you've leaked one or more objects of the type specified by 118 the 'OwnerClass' template parameter - the name should have been printed by the line above. 119 120 If you're leaking, it's probably because you're using old-fashioned, non-RAII techniques for 121 your object management. Tut, tut. Always, always use ScopedPointers, OwnedArrays, 122 ReferenceCountedObjects, etc, and avoid the 'delete' operator at all costs! 123 */ 124 d_stderr2("*** Leaked objects detected: %i instance(s) of class '%s'", numObjects, getLeakedObjectClassName()); 125 } 126 } 127 128 // this should be an atomic... 129 volatile int numObjects; 130 }; 131 getLeakedObjectClassName()132 static const char* getLeakedObjectClassName() noexcept 133 { 134 return OwnerClass::getLeakedObjectClassName(); 135 } 136 getCounter()137 static LeakCounter& getCounter() noexcept 138 { 139 static LeakCounter counter; 140 return counter; 141 } 142 }; 143 144 // ----------------------------------------------------------------------- 145 146 END_NAMESPACE_DISTRHO 147 148 #endif // DISTRHO_LEAK_DETECTOR_HPP_INCLUDED 149