From 227cc3a45c15739b16ac91e513c15bc532aec8fa Mon Sep 17 00:00:00 2001 From: yyforyongyu Date: Sat, 2 Nov 2024 11:21:42 +0800 Subject: [PATCH] routing: fix missionControlStore blocks on shutting down --- routing/missioncontrol_store.go | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/routing/missioncontrol_store.go b/routing/missioncontrol_store.go index ceb4740e4..5f4f521f5 100644 --- a/routing/missioncontrol_store.go +++ b/routing/missioncontrol_store.go @@ -50,6 +50,9 @@ type missionControlStore struct { wg sync.WaitGroup db missionControlDB + // TODO(yy): Remove the usage of sync.Cond - we are better off using + // channes than a Cond as suggested in the official godoc. + // // queueCond is signalled when items are put into the queue. queueCond *sync.Cond @@ -347,8 +350,14 @@ func (b *missionControlStore) run() { // Wait for the queue to not be empty. b.queueCond.L.Lock() for b.queue.Front() == nil { - b.queueCond.Wait() - + // To make sure we can properly stop, we must + // read the `done` channel first before + // attempting to call `Wait()`. This is due to + // the fact when `Signal` is called before the + // `Wait` call, the `Wait` call will block + // indefinitely. + // + // TODO(yy): replace this with channels. select { case <-b.done: b.queueCond.L.Unlock() @@ -356,6 +365,8 @@ func (b *missionControlStore) run() { return default: } + + b.queueCond.Wait() } b.queueCond.L.Unlock()