From c2cfe35f121cb88650b4d90c958bcc4214d0ce7f Mon Sep 17 00:00:00 2001 From: tokikuch Date: Mon, 25 Sep 2023 06:35:24 -0700 Subject: [PATCH] core/bloombits: fix deadlock when matcher session hits an error (#28184) When MatcherSession encounters an error, it attempts to close the session. Closing waits for all goroutines to finish, including the 'distributor'. However, the distributor will not exit until all requests have returned. This patch fixes the issue by delivering the (empty) result to the distributor before calling Close(). --- core/bloombits/matcher.go | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/core/bloombits/matcher.go b/core/bloombits/matcher.go index d8f932041..cf799c832 100644 --- a/core/bloombits/matcher.go +++ b/core/bloombits/matcher.go @@ -630,13 +630,16 @@ func (s *MatcherSession) Multiplex(batch int, wait time.Duration, mux chan chan request <- &Retrieval{Bit: bit, Sections: sections, Context: s.ctx} result := <-request + + // Deliver a result before s.Close() to avoid a deadlock + s.deliverSections(result.Bit, result.Sections, result.Bitsets) + if result.Error != nil { s.errLock.Lock() s.err = result.Error s.errLock.Unlock() s.Close() } - s.deliverSections(result.Bit, result.Sections, result.Bitsets) } } }