Memory Leak in C++ CallBack Function

Question

I am beginner to C++, Currently i Writing Code for CallBack Function to Getting Bytes array continuously from CLI Wrapper. My code

    C++
        **Declaration:**
        void ReceivedSensor1ByteArray(unsigned char values[], int length);

        **Calling:**
         GetSensor1ColorsFromCsharp(&ReceivedSensor1ByteArray);


        **Definition:**
         byte* sensor1bytevalues;
         void ReceivedSensor1ByteArray(unsigned char values[], int length)
        {
            if(length > 0)
             {
        sensor1bytevalues=new byte[length];

        for(int i = 0; i < length; i++)
        {
            sensor1bytevalues[i]=values[i];
        }
            }
        }

    **CLI Wrapper**

        **Decalration:**

            public ref class SampleWrapper
                {
                    SampleWrapper(void)
                    {   
            kinectSocketwrapperObj->ReadBytesValues+=gcnew CLIWrapperClass::ByteValuesReady(this,&Wrapper::SampleWrapper::ByteArrayReadyMethod);
                }
        public:

             CLIWrapperClass ^ kinectSocketwrapperObj;
            static SampleWrapper ^ Instance = gcnew SampleWrapper();
            void ByteArrayReadyMethod(array<Byte> ^ values);
    **Definition:**

      GetByteArrayCallback byteArrayCallback;
    __declspec(dllexport) void GetSensor1ColorsFromCsharp(GetByteArrayCallback cb)
    {
            byteArrayCallback = cb;
            CLIWrapperClass ^KinectServerWrapper = SampleWrapper::Instance->kinectSocketwrapperObj;
            KinectServerWrapper->ReceiveSensor1colors();
    }

 void SampleWrapper::ByteArrayReadyMethod(array<Byte> ^ values)
   {
      Byte *nativeValues = new Byte[values->Length];
      copyManagedByteToUnfloatArray(nativeValues, values);
      byteArrayCallback(nativeValues, values->Length);

   }

void copyManagedByteToUnfloatArray(Byte target[], array<Byte> ^ values)
   {
      int maxSize = values->Length;
      if ( maxSize > 0) 
      {
         for (int index = 0; index < maxSize; index++ ) 
         {
            target[index] = (float)values[index];
         }
      }
   }

Actually I Receiving Bytes Data from C# through CLI Wrapper Class and Passed to C++ Application in order to DisplayImageFrame. When i call GetSensor1VerticesFromCSharp function continuesly the system Memory increased after 10 minutes the system gets hanged. please suggest me to solve this issue.

Thanks, Kirubha

Answer 1

What's the lifetime of sensor1camevalues? It's not clear if it's part of a class or if you're copying into a global array, which can make managing it's lifetime difficult at best.

Either switch to using a container like std::vector, which will handle allocating memory for the sensor values for you, or use shared pointers like std::unique_ptr<float []> to initialise the dynamic array. It's important to read up on RAII / memory management and how this works, as this is a key concept of C++.

Answer 2

You should free with "delete" each chunk of memory allocated with "new", if you are about "true" c++, not .Net one.

I.e.:

sensor1camevalues=new float[length]; // memory allocation
delete[] sensor1camevalues; // deallocation