fix: add mutex to LocalRepositoryCache to prevent concurrent map panic (rebase of #6055) - #6138
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louzt wants to merge 1 commit into
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fix: add mutex to LocalRepositoryCache to prevent concurrent map panic (rebase of #6055)#6138louzt wants to merge 1 commit into
louzt wants to merge 1 commit into
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LocalRepositoryCache.CacheDirCache is a plain map[string]string
accessed concurrently by Fetch (write) and GetTarArchive (read)
when multiple matrix jobs resolve --local-repository actions in
parallel. This causes:
fatal error: concurrent map read and map write
goroutine ... [running]:
LocalRepositoryCache.GetTarArchive(...)
local_repository_cache.go:47
Add a sync.RWMutex to serialize access to CacheDirCache:
- Fetch: write lock when updating the cache
- GetTarArchive: read lock when looking up cached paths
LocalRepositories is set at initialization and only read after,
so it does not need synchronization.
This is the same class of bug as nektos#6028 (fixed in nektos#6029 for
GoGitActionCache), but in the --local-repository code path.
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Summary
Fix concurrent map panic in
LocalRepositoryCachewhen multiple goroutines callFetch()simultaneously with overlapping cacheDir keys.What
cacheDirMu sync.RWMutexfield onLocalRepositoryCacheFetch()holds write lock when updatingCacheDirCacheGetTarArchive()holds read lock when readingRebase status
Rebased against current master (4f41128). Zero conflicts. Builds clean. Unit tests pass under
-race -short.Note
PR #6109 from @aruneshdwivedi0 overlaps with this fix (same concern, different mutex name) — closing in favor of this PR for the narrower scope. The
install.shdefault BINDIR change in #6109 can be a separate PR if desired.