From 1cf44b9d6d0f7905a453c268708a952007652e2b Mon Sep 17 00:00:00 2001 From: Toshihito Kikuchi Date: Mon, 25 Sep 2023 16:34:46 -0700 Subject: [PATCH] core/bloombits: fix deadlock when matcher session hits an error 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 81c6b06645..12fd0ace82 100644 --- a/core/bloombits/matcher.go +++ b/core/bloombits/matcher.go @@ -640,13 +640,16 @@ 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) } } }