i#6938 sched migrate: Make replay record_index atomic #6995
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PR #6985 removed the global sched_lock_ which used to synchronize access to other output's record_index field, leaving a data race. Since only the index and not the recorded contents need synchronization, we use an atomic rather than a mutex to coordinate. Tested by running an internal test under ThreadSanitizer where a race is reported without this fix and no race with the fix. Issue: #6938
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OSX is #6992 |
brettcoon
approved these changes
Sep 20, 2024
It could only affect the rough timing across outputs as they try to align with each others' timestamps: you're right that it does not affect actual content of the real records played back. |
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PR #6985 removed the global sched_lock_ which used to synchronize
access to other output's record_index field, leaving a data
race (affecting only the rough timing across outputs where an output
waits if gets ahead of other outputs' timestamps).
Since only the index and not the recorded contents need
synchronization, we use an atomic rather than a mutex to coordinate.
Tested by running an internal test under ThreadSanitizer where a race
is reported without this fix and no race with the fix.
Issue: #6938