Don't hold the wait subsystem lock when acquiring the shared memory process-level lock #123162
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…rocess-level lock For the no-pthreads shared memory implementation, we can dispose an unnamed Mutex object when disposing a named Mutex. When we dispose a named Mutex, we'll acquire the shared memory process-level lock to do so. Then when we dispose the unnamed mutex, we'll acquire the Wait Subsystem lock to be able to handle cleanup. When we lock a named mutex, currently we acquire the process-level lock for the shared memory manager while we still hold the wait subsystem lock (inverse order of lock aquisition -> deadlock). This is not necessary (we aren't going to touch any of the WaitSubsystem data structures at this point) so reorder the locks so we don't lock the wait subsystem lock when acquiring the shared memory lock.
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wtgodbe
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Jan 14, 2026
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For the no-pthreads shared memory implementation, we can dispose an unnamed Mutex object when disposing a named Mutex.
When we dispose a named Mutex, we'll acquire the shared memory process-level lock to do so. Then when we dispose the unnamed mutex, we'll acquire the Wait Subsystem lock to be able to handle cleanup. When we lock a named mutex, currently we acquire the process-level lock for the shared memory manager while we still hold the wait subsystem lock (inverse order of lock aquisition -> deadlock). This is not necessary (we aren't going to touch any of the WaitSubsystem data structures at this point) so reorder the locks so we don't lock the wait subsystem lock when acquiring the shared memory lock.
Unblocks dotnet/aspnetcore#65006