CODEWITHSUNDEEP
vb.netc#-to-vb.netlarge-object-heap
Rfrank
Rfrank

Reputation: 51

Managing LOH in vb.net

I have an vb.net application I distribute to my analysts – We assign perhaps 100 200MB images at a time. The app sequentially opens the large jpg image using GDI+ and the image is placed in the LOH. I scan each pixel looking for data. - when done I dispose the image and use GC.collect. But this does not clear the LOH, and as a result the LOH keeps increasing until the app crashes. A work around is to chop the assignment into 25 instance chunks, but this is risky as our analysts often do this late at night – perhaps after a beer or 2.

The C# construct is 

 GCSettings.LargeObjectHeapCompactionMode = GCLargeObjectHeapCompactionMode.CompactOnce

but there is no GCSettings available in vb.net

My vb.net code is 

    loadedImage.Dispose()
    MasterImage.Dispose()

    GC.Collect()
    Finalize()

But I cannot find a vb.net method to force the LOH compaction

When done

Can you help?

Upvotes: -1

Views: 194

Answers (1)

J...
J...

Reputation: 31453

GCSettings.LargeObjectHeapCompactionMode was added in .NET 4.5.1. It exists in VB.NET as well as C#. You're probably targeting a lower version of the .NET runtime. If you want access to this feature you will need to compile against a framework version of 4.5.1 or higher.

This likely won't solve the underlying problem, however. Your leak may not even be where you think it is. Profiling your application with an allocation profiler is the best way to track down resource leaks. Without a Minimal, Complete, and Verifiable example, it is difficult to guess where your application may be going wrong.

Upvotes: 0

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