Runtime: Test failure: System.MemoryTests.MemoryTests/OwnedMemoryPinLargeArray

[dotnet-mc-bot]

Opened on behalf of @danmosemsft

The test System.MemoryTests.MemoryTests/OwnedMemoryPinLargeArray has failed.

System.OutOfMemoryException : Array dimensions exceeded supported range.

    Stack Trace:

       at System.MemoryTests.MemoryTests.OwnedMemoryPinLargeArray()

Build : Master - 20180314.02 (Full Framework Tests)
Failing configurations:

• Windows.10.Amd64-x86
  
  
  
  • Release
  
  
• Windows.10.Amd64-x64
  
  
  
  • Release
  
  

[ahsonkhan]

cc @GrabYourPitchforks

This test was recently added in https://github.com/dotnet/corefx/pull/28032.

Would using https://github.com/dotnet/corefx/blob/master/src/System.Memory/tests/AllocationHelper.cs help in this case (even though it is used for native memory allocation)?

Or maybe we can use byte, instead of int.

[danmosemsft]

Note it only failed on full framework.

[GrabYourPitchforks]

Can we detect at runtime if large array support is enabled? We can skip the test if this flag is not enabled.

[ahsonkhan]

You could explicitly disable it on full framework, similar to our ToString tests:
https://github.com/dotnet/corefx/blob/a9e68bf3f993a853343fdc1b2c3bb9f7cfd5c411/src/System.Memory/tests/ReadOnlySpan/ToString.cs#L93
[SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework, "Large array support is disabled.")]

[GrabYourPitchforks]

I'd rather not use the target moniker because it _is_ a legitimate test if the proper switch has been enabled. But if we can't detect that switch at runtime then suppressing the test on full framework would be a viable alternative.

[danmosemsft]

You could try catch for OOME specifically. That would have some value

[GrabYourPitchforks]

Looked through the unmanaged side of things and I don't see any place where we expose this switch via a public API. Going to use @ahsonkhan's suggestion of skipping the test on full framework. I'm nervous about swallowing OOMs because they could mask latent issues with the test or with the code under test.

[ahsonkhan]

skipping the test on full framework

Can you please run it locally for TargetGroup=netfx to make sure the test passes (at least once)?

[GrabYourPitchforks]

Manually verified against full framework by setting environment variable COMPLUS_gcallowverylargeobjects=0 and running, observing failure, then setting to 1 and running, observing success.