From e49ce483b025c60d11ce36e8d3512384d6b43fea Mon Sep 17 00:00:00 2001
From: gfanton <8671905+gfanton@users.noreply.github.com>
Date: Mon, 20 Nov 2023 17:04:16 +0100
Subject: [PATCH] fix: use 1 as sized channel

Signed-off-by: gfanton <8671905+gfanton@users.noreply.github.com>
---
 tm2/pkg/bft/consensus/common_test.go | 7 ++++++-
 tm2/pkg/bft/consensus/state_test.go  | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/tm2/pkg/bft/consensus/common_test.go b/tm2/pkg/bft/consensus/common_test.go
index 3f5b3a55e95..4acc05c2438 100644
--- a/tm2/pkg/bft/consensus/common_test.go
+++ b/tm2/pkg/bft/consensus/common_test.go
@@ -255,7 +255,12 @@ func subscribeToVoter(cs *ConsensusState, addr crypto.Address) <-chan events.Eve
 		return false
 	})
 
-	testch := make(chan events.Event, 16)
+	// This modification addresses the deadlock issue outlined in issue
+	// #1320. By creating a buffered channel, we ensure that events are
+	// consumed even if the main thread is blocked. This prevents the
+	// deadlock that occurred when eventSwitch.FireEvent was blocked due to
+	// no available consumers for the event.
+	testch := make(chan events.Event, 1)
 	go func() {
 		defer close(testch)
 		for evt := range ch {
diff --git a/tm2/pkg/bft/consensus/state_test.go b/tm2/pkg/bft/consensus/state_test.go
index 262bbbea254..1bcb3ec2128 100644
--- a/tm2/pkg/bft/consensus/state_test.go
+++ b/tm2/pkg/bft/consensus/state_test.go
@@ -1785,7 +1785,12 @@ func subscribe(evsw events.EventSwitch, protoevent events.Event) <-chan events.E
 	listenerID := fmt.Sprintf("%s-%s", testSubscriber, name)
 	ch := events.SubscribeToEvent(evsw, listenerID, protoevent)
 
-	testch := make(chan events.Event, 16)
+	// Similar to the change in common_test.go, this modification introduces
+	// a buffered channel and a separate goroutine for event consumption.
+	// This approach ensures that events are consumed asynchronously,
+	// thereby avoiding the deadlock situation described in the GitHub issue
+	// where the eventSwitch.FireEvent method was blocked.
+	testch := make(chan events.Event, 1)
 	go func() {
 		defer close(testch)
 		for evt := range ch {