From 05c6b9379ad74ffcb937eb577a16728c049c3266 Mon Sep 17 00:00:00 2001
From: "Quentin McGaw (desktop)" <quentin.mcgaw@gmail.com>
Date: Thu, 10 Jun 2021 14:13:08 +0000
Subject: [PATCH] Maintenance: prevent exit race condition for loops

---
 internal/dns/loop.go         | 5 +++++
 internal/openvpn/loop.go     | 8 ++++++++
 internal/shadowsocks/loop.go | 3 +++
 3 files changed, 16 insertions(+)

diff --git a/internal/dns/loop.go b/internal/dns/loop.go
index ef1d6546..531d30b0 100644
--- a/internal/dns/loop.go
+++ b/internal/dns/loop.go
@@ -159,6 +159,11 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
 				stayHere = false
 			case err := <-waitError: // unexpected error
 				unboundCancel()
+				if ctx.Err() != nil {
+					close(waitError)
+					closeStreams()
+					return
+				}
 				l.state.setStatusWithLock(constants.Crashed)
 				const fallback = true
 				l.useUnencryptedDNS(fallback)
diff --git a/internal/openvpn/loop.go b/internal/openvpn/loop.go
index 20d30384..77cbeea5 100644
--- a/internal/openvpn/loop.go
+++ b/internal/openvpn/loop.go
@@ -211,6 +211,14 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) { //nolint:gocog
 				stayHere = false
 			case err := <-waitError: // unexpected error
 				openvpnCancel()
+				if ctx.Err() != nil {
+					close(waitError)
+					close(stdoutLines)
+					close(stderrLines)
+					<-lineCollectionDone
+					<-portForwardDone
+					return
+				}
 				l.state.setStatusWithLock(constants.Crashed)
 				l.logAndWait(ctx, err)
 				l.crashed = true
diff --git a/internal/shadowsocks/loop.go b/internal/shadowsocks/loop.go
index cb0acb0b..246c7def 100644
--- a/internal/shadowsocks/loop.go
+++ b/internal/shadowsocks/loop.go
@@ -139,6 +139,9 @@ func (l *looper) Run(ctx context.Context, done chan<- struct{}) {
 			case err := <-waitError: // unexpected error
 				shadowsocksCancel()
 				close(waitError)
+				if ctx.Err() != nil {
+					return
+				}
 				l.state.setStatusWithLock(constants.Crashed)
 				l.logAndWait(ctx, err)
 				crashed = true