From 0e3ba93dbad5b44b8e53f3c22f86b30ef9e4cd40 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 d8f932041b..cf799c8324 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) } } }