release-22.2: sql: Make tochar.FormatCache thread safe #108078
Merged
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Backport 1/1 commits from #108032 on behalf of @ecwall.
/cc @cockroachdb/release
Fixes #95424
FormatCache.lookup()
previously wrapped calls tocache.UnorderedCache.Get()
inRWMutex.RLock()
/RWMutex.RUnlock()
which allowed for data races becauseUnorderedCache.Get()
can modify the state of its LRU cache.This PR fixes the race condition by changing the
RWMutex
to aMutex
to handle cases where the LRU cache is modified.Release note (bug fix): Fix nil pointer dereference caused by race condition when using to_char builtin.
Release justification: to_char race condition fix.