[6.0 preview 5] Fix assertion failure / crash in multi-core JIT

[kouvel]

• Port of Fix assertion failure / crash in multi-core JIT #53573 to Preview 5
• When the recorder times out it doesn't actually stop profiling, but writes out the profile
• The app may later stop profiling, and then it tries to write the profile again
• PR Multicorejit unification #48326 fairly expected that the profile is only written once (some state is mutated)
• The timer is being stopped in the recorder's destructor
• Fixes [.NET 6 Preview 5] dnSpy stopped working while decompiling assembly #53014

Customer impact

• By default, the multi-core JIT timeout time for the recorder is 12 seconds. The timer is only used on Windows.
• After a timeout, if the application exits, stops a profile, or starts another profile, the app crashes
• Affects any Windows app that enables multi-core JIT

Regression?

• Yes, from 6.0 preview 4

Testing

• Manual test with a repro, added test to coreclr tests
• PAL, coreclr, and libraries tests

Risk

Low:

• The change stops profiling on timeout in the same way that it is stopped in all other cases
• I'm not aware of any significant risks

[jkotas]

Thanks

[mmitche]

I don't think this will make p5. We're past the point of new changes unless they are ship stoppers at this point.

[mmitche]

@kouvel @jkotas, @adityapatwardhan is blocked by this (pulling preview 5 into powershell). Is there a workaround?

[adityapatwardhan]

@rjmholt as FYI.

[jkotas]

Is there a workaround?

Avoid using multicore JIT temporily.

[adityapatwardhan]

@jkotas How can we disable that?

[daxian-dbw]

@jkotas I presume that means we should avoid using ProfileOptimization.StartProfile in PowerShell, right? Anything else?

[jkotas]

Right. Also, AssemblyLoadContext.StartProfileOptimization.