VertexBatchTest.Locking failing locally

[Barsonax]

Summary

The VertexBatchTest.Locking is failing for me locally

Expected: False
  But was:  True

   at Duality.Tests.Drawing.VertexBatchTest.Locking() in C:\Git\duality\Test\Core\Drawing\VertexBatchTest.cs:line 90

How to reproduce

• Run the test
• It fails (well or not because it does not fail on the CI)

Workaround

• Ignore it as it only happens locally

Analysis

• Likely happens due to something environment specific. The question is what?

[ilexp]

The specific part of the test that is failing is this:

// Make sure that our locks released properly, i.e. allowing the array to be garbage collected
WeakReference weakRefToLockedData = new WeakReference(typedBatch.Vertices.Data);
Assert.IsTrue(weakRefToLockedData.IsAlive);
typedBatch = null;
abstractBatch = null;
GC.Collect();
Assert.IsFalse(weakRefToLockedData.IsAlive);

Which is dependent on garbage collection behavior, or more specifically the assumption that GC.Collect will free the vertex data array synchronously before returning. Could this be related? Are there ways to ensure this across runtime / GC versions?

[Barsonax]

It does not do it synchronously: https://stackoverflow.com/questions/748777/run-gc-collect-synchronously

Also I think depending on the GC like this is very error prone as it can change between runtime or config settings.

[ilexp]

Also I think depending on the GC like this is very error prone as it can change between runtime or config settings.

It is, but since this part of the test is essentially a GC test, I don't really see a way around relying on GC behavior in some way. The current implementation is flaky though.

It does not do it synchronously: https://stackoverflow.com/questions/748777/run-gc-collect-synchronously

That's probably the issue then. Could be worth a try to use this overload instead and also wait for pending finalizers afterwards.

[ilexp]

Adjusted the test as described above. @Barsonax Can you check whether the issue is fixed on your machine?

[Barsonax]

Will check when iam at my pc

[Barsonax]

It did not fix the issue

[Barsonax]

Only happens in Debug mode, under release mode the test runs succesfully. Debug seems to be keeping instances alive for longer than needed which makes sense as its handy for debugging.

So this error can be fixed by skipping this test in debug mode (no sense in running it if it always fails). In nunit this can be done by making a custom NUnitAttribute and implementing IApplyToTest. Ofcourse a reasonable message should be given explaining that it does not run in debug.

[Barsonax]

Fixed in #719