From 88b716cb3bcd2dd54f3f022b46f4212b9746e555 Mon Sep 17 00:00:00 2001
From: Atsushi Watanabe <atsushi.w@ieee.org>
Date: Sun, 3 May 2020 11:54:38 +0900
Subject: [PATCH] Don't run agent task after close

Fix send on closed channel panic.
---
 agent.go | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/agent.go b/agent.go
index fb24dc3..ea32c9c 100644
--- a/agent.go
+++ b/agent.go
@@ -191,10 +191,16 @@ func (a *Agent) run(t func(*Agent)) error {
 	case <-a.done:
 		return a.getErr()
 	case a.muChan <- struct{}{}:
-		t(a)
-
+		var err error
+		select {
+		case <-a.done:
+			// Ensure the agent is not closed
+			err = a.getErr()
+		default:
+			t(a)
+		}
 		<-a.muChan
-		return nil
+		return err
 	}
 }