Does C# PXCMSenseManager.Dispose() call PXCMSenseManager.Close()?

[Niels_Dekker]

Is the PXCMSenseManager.Close() call in the following code necessary, or is it redundant?

  using ( PXCMSenseManager myManager = session.CreateSenseManager() )
  {
      // Usually some more code here...
      // ...

      myManager.Close();
  }

As you probably know, C#'s 'using' statement does internally call Dispose() when the declared object (myManager) goes out of scope. Will this Dispose() call indirectly call PXCMSenseManager.Close()? Or will it do something equivalent?

Kind regards, Niels
--
Niels Dekker
Scientific programmer at LKEB
Leiden University Medical Center

[AndreCarlucci]

Hi Niels,

Excellent question. Usually with the .net framework that's the case, but I'm not sure looking at the source code of the libpxcclr.cs.dll.

When we create a PXCMSenseManager, an object called handlerDIR (internal class) is also created. It implements IDisposable.

public pxcmStatus Init(Handler handler) {
        if (handler == null) {
            return PXCMSenseManager_Init(instance, IntPtr.Zero);
        }
        if (handlerDIR != null) {
            handlerDIR.Dispose();
        }
        handlerDIR = new HandlerDIR(this, handler);
        return PXCMSenseManager_Init(instance, handlerDIR.dirUnmanaged);
}

// Calling Close will dispose the handleDIR

public void Close() {
        PXCMSenseManager_Close(instance);
        if (handlerDIR == null) {
            return;
        }
        handlerDIR.Dispose();
}

[DllImport("libpxccpp2c")]
internal static extern void PXCMSenseManager_Close(IntPtr putil);

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

PXCMSenseManager inheriteds from PXCMBase (IDisposable). This is the Dispose method:

public virtual void Dispose() {
        int num;
        lock (this) {
            num = refcount;
            if (refcount > 0) {
                --refcount;
            }
        }
        if (num > 0 && instance != IntPtr.Zero) {
            PXCMBase_Release(instance);
        }
        else {
            orig = this;
        }
}

[DllImport("libpxccpp2c")]
internal static extern void PXCMBase_Release(IntPtr pbase);

Instance is a pointer to the unmanaged object.

I can't tell you for sure because I don't have access to the  unmanaged code, but It seems that calling Close disposes this handlerDIR and calling Dispose don't, so it sounds like a good idea to call them both.

Maybe someone from Intel can help us with that :)

[Niels_Dekker]

Thank you for your very informative reply, Andre Carlucci! I did not realize before that the C# source code of those RealSense SDK classes is already part of my installation, at "C:\Program Files (x86)\Intel\RSSDK\framework\common\pxcclr.cs\src". Now I see, the implementation of PXCMSenseManager is partially at pxcclr.cs\src\pxcmsensemanager.cs and partially at pxcclr.cs\src\native\pxcmsensemanager.cs  But it seems like PXCMSenseManager does not have a Dispose() override.

So do you think PXCMSenseManager should have a Dispose() override, in order to dispose its handlerDIR data member?

If you think this is a bug, can you please report it to Intel? (Or otherwise, can you tell me where to report the bug?)

Note that calling both myManager.Close() and myManager.Dispose(), triggers a Code Analysis warning from Visual Studio:

warning CA2202: Microsoft.Usage : Object 'myManager' can be disposed more than once in method '...'. To avoid generating a System.ObjectDisposedException you should not call Dispose more than one time on an object.

This warning even appears when the Dispose() call is done implicitly, by using 'using'.

Kind regards, Niels

[AndreCarlucci]

Oh man, I didn't realize the code was there in the installation all the time.

I went up to the pxclr.cs directory and stopped there, since my eyes didn't catch that was the same name without the "lib" part.

That source code I posted above came from my decompiled version that is on github: https://github.com/SharpSenses

I'll update github (and SharpSenses) to use the original code as soon as I have the time.

It's funny that I asked in this forum a lot about this source and nobody could tell me where it was or even if it was available. So thanks :)

---

About the error, you can easily override the Dispose and call Close and the parent Dispose now that you have the source-code. Go ahead and compile the dll to be AnyCpu too and be happy :)

I'm not sure if this is really a bug or if it's intended for some reason though. I'll ask around :)

Cheers!

[Niels_Dekker]

Thanks again for your feedback, André!

FYI, I just posted a similar C++ question: Does Release() call Close(), for a C++ pointer to a PXCSenseManager?

Kind regards, Niels