/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2016 - ROLI Ltd.

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

   -----------------------------------------------------------------------------

   To release a closed-source product which uses other parts of JUCE not
   licensed under the ISC terms, commercial licenses are available: visit
   www.juce.com for more information.

  ==============================================================================
*/

#ifndef JUCE_LEAKEDOBJECTDETECTOR_H_INCLUDED
#define JUCE_LEAKEDOBJECTDETECTOR_H_INCLUDED


//==============================================================================
/**
    Embedding an instance of this class inside another class can be used as a low-overhead
    way of detecting leaked instances.

    This class keeps an internal static count of the number of instances that are
    active, so that when the app is shutdown and the static destructors are called,
    it can check whether there are any left-over instances that may have been leaked.

    To use it, use the JUCE_LEAK_DETECTOR macro as a simple way to put one in your
    class declaration. Have a look through the juce codebase for examples, it's used
    in most of the classes.
*/
template <class OwnerClass>
class LeakedObjectDetector
{
public:
    //==============================================================================
    LeakedObjectDetector() noexcept                                 { ++(getCounter().numObjects); }
    LeakedObjectDetector (const LeakedObjectDetector&) noexcept     { ++(getCounter().numObjects); }

    ~LeakedObjectDetector()
    {
        if (--(getCounter().numObjects) < 0)
        {
            DBG ("*** Dangling pointer deletion! Class: " << getLeakedObjectClassName());

            /** If you hit this, then you've managed to delete more instances of this class than you've
                created.. That indicates that you're deleting some dangling pointers.

                Note that although this assertion will have been triggered during a destructor, it might
                not be this particular deletion that's at fault - the incorrect one may have happened
                at an earlier point in the program, and simply not been detected until now.

                Most errors like this are caused by using old-fashioned, non-RAII techniques for
                your object management. Tut, tut. Always, always use ScopedPointers, OwnedArrays,
                ReferenceCountedObjects, etc, and avoid the 'delete' operator at all costs!
            */
            jassertfalse;
        }
    }

private:
    //==============================================================================
    class LeakCounter
    {
    public:
        LeakCounter() noexcept {}

        ~LeakCounter()
        {
            if (numObjects.value > 0)
            {
                DBG ("*** Leaked objects detected: " << numObjects.value << " instance(s) of class " << getLeakedObjectClassName());

                /** If you hit this, then you've leaked one or more objects of the type specified by
                    the 'OwnerClass' template parameter - the name should have been printed by the line above.

                    If you're leaking, it's probably because you're using old-fashioned, non-RAII techniques for
                    your object management. Tut, tut. Always, always use ScopedPointers, OwnedArrays,
                    ReferenceCountedObjects, etc, and avoid the 'delete' operator at all costs!
                */
                jassertfalse;
            }
        }

        Atomic<int> numObjects;
    };

    static const char* getLeakedObjectClassName()
    {
        return OwnerClass::getLeakedObjectClassName();
    }

    static LeakCounter& getCounter() noexcept
    {
        static LeakCounter counter;
        return counter;
    }
};

//==============================================================================
#if DOXYGEN || ! defined (JUCE_LEAK_DETECTOR)
 #if (DOXYGEN || JUCE_CHECK_MEMORY_LEAKS)
  /** This macro lets you embed a leak-detecting object inside a class.

      To use it, simply declare a JUCE_LEAK_DETECTOR(YourClassName) inside a private section
      of the class declaration. E.g.

      @code
      class MyClass
      {
      public:
          MyClass();
          void blahBlah();

      private:
          JUCE_LEAK_DETECTOR (MyClass)
      };
      @endcode

      @see JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR, LeakedObjectDetector
  */
  #define JUCE_LEAK_DETECTOR(OwnerClass) \
        friend class juce::LeakedObjectDetector<OwnerClass>; \
        static const char* getLeakedObjectClassName() noexcept { return #OwnerClass; } \
        juce::LeakedObjectDetector<OwnerClass> JUCE_JOIN_MACRO (leakDetector, __LINE__);
 #else
  #define JUCE_LEAK_DETECTOR(OwnerClass)
 #endif
#endif


#endif   // JUCE_LEAKEDOBJECTDETECTOR_H_INCLUDED
