Unsafe methods and managed code

Dear all,

I am re-designing an image/video processing package that I wrote a while ago to use C# for the GUI part such that development on that end is quicker. However, I want to keep the performance by having the processing run on unmanaged code.

There are of course many ways to do this but the simplest that I have found was to have my interfaces declare an "unsafe" method that processing classes will override.

However, I am not certain and couldn't find any info on it either, if "unsafe" also means that the code will run unmanaged.

Brief code listing:

C#
public interface Processor {
unsafe void doStuff(void*);
}

C++
class MyProcessor : public Processor {
unsafe void doStuff(void*) {
........
.........
}
};

So to sum up, will MyProcessor::doStuff run like or near-like a pure C++ library would

Thanks in advance.

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Unsafe methods and managed code

SpaceDog
Hi Georgios

This is not my area of expertise, so I invite anyone else to comment on this thread.

For objects, Managed C++ (C++/CLI) is probably your best bet. Unless they are COM objects, in which case interop should suffice. In either case, the runtime does the marshalling for you.

Hope that helps

-Chris
Colin Osbaldeston
I recommend P/Invoking into your unmanaged DLLs. As long as there isn't a managed thread running at the same time in the same process, and as long as the machine doesn't run low on memory, the GC shouldn't cause a collection, and your performance should be good.

Hope that helps

-Chris
boss nunya
Hi Georgios

No, the unsafe keyword does not make a method run unmanaged. All unsafe does is allow the use of pointers.

See this MSDN article for more information:

http://msdn.microsoft.com/library/default.asp url=/library/en-us/csref/html/vclrfunsafe.asp

-Chris
Inray
Thanks Chris.

A few questions on that:

- I was hoping the plugin DLLs to contain objects rather than C functions. Will P/Invoke work ok with that

- I will need to pass an unsafe pointer to the DLL, will the data pointed to by the pointer be transfered without marshalling

I hope MS improves the documentation on how unsafe contexts work in managed apps. Unless I'm just making it more complex in my own head.
psygone13
OK, that makes sense.

What do you think would be the best way to interface native plugins with managed code then

Thanks,

Georgios
Unsafe methods and managed code

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