#1 Burning Software

After burning files with the UDFDataBurner we are releasing the file tree with UDFDataburner.Files.Clear() but it is not releasing the files (Trying to delete a file gives a error that the file is locked).

We are using C# (.net 3.5) on Windows 7 64bit.

In the DataBurner9.sln sample app supplied with the SDK we switched the DataBurner object to a UDFDataBurner object and experienced that same problem after burning a CD and clicking the Clear button.
This did not release the file handle.

Jason

What version of SDK do you use? Please supply complete log with version header uncut. Thanks!

Here are the logs and the versions
Starburn.dll is 12.0.0.272 with product version v12 Trident II Build 20100110
StarburnX12.dll is 12.0.0.0

If you need anything else let me know.

OK, got the log, checking the issue on our side.

Just wondering what the status of this issue is.

Hello, Jason

You should release the DataBurner(UDFDataBurner) object to release all locked files! The calling of the "Files.Clear" function makes sense until your disc is not burned!!


Regards,

Dmitry

We are still unable to free the files after burning.

I've included your sample app Databurner9.sln which I've modified to use the UDFDataburner. Nothing that I've add to the Clear button event unlocks the files. Only closing the app does this.

Could you please show me what I need to change to free the files.

Jason

Hello, Jason

You should also release all local IDataFile/IDataFolder objects:

m_crossThreadParam_CurFolder = null;
m_crossThreadParam_AddedFolder = null;


Regards,

Dmitry

I've add the two lines of code you suggested to the btnClear_Click event.

Again this did not release the file lock.

This is getting really frustrating as we are unable to use your burning library without a fix to this problem.

Could you please look at your modified sample app that I have attached and reply with a working solution.

Thanks
Jason

Hello,

Jason I will check this issue today!

Thanx,

Dmitry

Hello, Jason

It seems this is the 'C# example' issue! The C++ example release all used files!

Dmitry

This is not a solution for us. Our project is written in C# so we need a C# solution. Please let me know when I can expect a fix for this issue. We would like to use your solution but with pending deadlines we may have to consider other vendors.

Jason

Hello, Jason

I will redesign the DataBurner C# example today and send it to you today.

Regards,

Dmitry

Hello, Jason

When you set the COM interface object to null you make the interface object eligible for garbage collection, but the object doesn't get garbage collected right then and there!!! The .Net Garbage Collector tries to minimize overhead by running in the background which means you can never be sure when any particular object will be finalized!!
So, you should release your Burning object manually by calling the System.Runtime.InteropServices.Marshal.ReleaseComObject(your_burning_object) method;

private void OnStopBurningProgress()
{
...

// Now, we should release the current DataBurner object
System.Runtime.InteropServices.Marshal.ReleaseComObject(m_udfDataBurner);

// Create new DataBurner object
m_udfDataBurner = new UDFDataBurnerClass();

...
}

You should be very careful when using this approach ( ReleaseComObject ). Since this basically force the COM reference count to zero, this can have the effect of deactivating the COM server even when the server should not be deactivated - for example when other references to the COM object still exist. So, you should set the all DataBurner, DataFolder and DataFile members(variables) to null before calling the ReleaseComObject method.


Regards,

Dmitry

Thanks for your support. I finally got the file locks to be released. Your code sent us on the right path to fixing our issue.
I did however have to add a force garbage collection to finally get the file locks released.

//Final working sample
private void OnStopBurningProgress()
{
...

// FinalReleaseComObject sets the reference count to 0; ReleaseComObject decrements it by 1;
System.Runtime.InteropServices.Marshal.FinalReleaseComObject(m_udfDataBurner);
GC.Collect();

// Create new DataBurner object
m_udfDataBurner = new UDFDataBurnerClass();

...
}


Thanks again for the timely support,
Jason