[release/9.0] Backport PR #108311 - Fix statics issue with barriers #108347
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Backport of #108311 to release/9.0
Customer Impact
Applications unexpected crash during startup while attempting to access statics in heavily multithreaded applications. This causes instability for processes which engage in heavily threaded code which has usage of many static variables.
Regression
This was introduced with #99183 , and a previous fix was attempted #105832 . That previous fix was found to be insufficient.
Testing
A new stress test was written by @EgorBo that finally provided a reliable repro case for the failure in #105441 (comment) This reliable repro case was finally found yesterday. Previously we'd only observed the failure in CI, but the manifestation always used a non-live built version of the runtime.
Risk
Medium, additional correctness problems are unexpected, but there may be some performance impact. If this does not fix the issue, further investigation will be needed.
IMPORTANT: If this backport is for a servicing release, please verify that:
The PR target branch is
release/X.0-staging
, notrelease/X.0
.If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.