fix: Avoid deadlock in AgentReportStats Close during agent Close #5415
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Since AgentReportStats takes a stats function which was doing mutex locking on agent shutdown, it was possible for there to be a deadlock depending on how the AgentReportsStats Close function is implemented. This mostly seems to happen on Windows test runners as it's pretty hard to hit this edge case. The bug currently only exists in the test implementation of AgentReportStats, however, this was refactored to be more robust in case of future changes.
mafredri
commented
Dec 14, 2022
| _ = cl.Close() | ||
| }); err != nil { | ||
| a.logger.Error(ctx, "report stats goroutine", slog.Error(err)) | ||
| _ = cl.Close() |
There was a problem hiding this comment.
Review: Is stats reporter startup failure fatal? I.e. do we return an error or not?
mafredri
commented
Dec 14, 2022
| @@ -561,28 +580,6 @@ func (a *agent) init(ctx context.Context) { | |||
| } | |||
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| go a.runLoop(ctx) | |||
| cl, err := a.client.AgentReportStats(ctx, a.logger, func() *codersdk.AgentStats { | |||
| stats := map[netlogtype.Connection]netlogtype.Counts{} | |||
| a.closeMutex.Lock() | |||
kylecarbs
approved these changes
Dec 14, 2022
mtojek
reviewed
Dec 14, 2022
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Since AgentReportStats takes a stats function which was doing mutex
locking on agent shutdown, it was possible for there to be a deadlock
depending on how the AgentReportsStats Close function is implemented.
This mostly seems to happen on Windows test runners as it's pretty hard
to hit this edge case. The bug currently only exists in the test
implementation of AgentReportStats, however, this was refactored to be
more robust in case of future changes.