For transition profiler callbacks, always load the thread

[jkoritzinsky]

Also, add tests for profiler callbacks on a new thread to the runtime

Fixes #105070

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[davmason]

Thanks for the fix, I don't know the details of the interop space enough to comment on the fix but the profiler tests look good to me

[mdh1418]

I don't fully understand all the IL code emitting details, but from #69761, the change to EmitProfilerEndTransitionCallback to have _ASSERTE(SF_IsForwardStub(dwStubFlags)); + defaulting to !fReverseInterop code paths in stubhelpers.cpp seems to suggest that Profiler transitions shouldn't occur during reverse interops, but even if they did, behave the same as forward interops? Am I understanding that correctly?

Could we add asserts that pThread is not null in stubhelpers.cpp ProfilerBeginTransitionCallback/ProfilerEndTransitionCallback?

[jkoritzinsky]

I don't fully understand all the IL code emitting details, but from #69761, the change to EmitProfilerEndTransitionCallback to have _ASSERTE(SF_IsForwardStub(dwStubFlags)); + defaulting to !fReverseInterop code paths in stubhelpers.cpp seems to suggest that Profiler transitions shouldn't occur during reverse interops, but even if they did, behave the same as forward interops? Am I understanding that correctly?

Could we add asserts that pThread is not null in stubhelpers.cpp ProfilerBeginTransitionCallback/ProfilerEndTransitionCallback?

The profiler transitions for "reverse interop" are done as part of the JIT code emit now for these scenarios, so we don't handle them in the IL stub (which is what #69761 was fixing).

I can add the assert.

[mdh1418]

Looks good to me!

[gbalykov]

@jkoritzinsky thanks! Does this need to be backported to .net 7 and .net 8?

[jkoritzinsky]

I'll backport this to .NET 8. 7 is EOL so I can't backport there.

[jkoritzinsky]

/backport to release/8.0-staging

[github-actions]

Started backporting to release/8.0-staging: https://github.com/dotnet/runtime/actions/runs/10029358160