From 83def0a52be8abc5b60a579698bca1a27c21853f Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Mon, 24 Sep 2018 03:08:18 +0200
Subject: [PATCH] Prevent signal and wait from racing

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 WireGuardNetworkExtension/PacketTunnelProvider.swift | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/WireGuardNetworkExtension/PacketTunnelProvider.swift b/WireGuardNetworkExtension/PacketTunnelProvider.swift
index 9959dec..e884b8f 100644
--- a/WireGuardNetworkExtension/PacketTunnelProvider.swift
+++ b/WireGuardNetworkExtension/PacketTunnelProvider.swift
@@ -181,7 +181,7 @@ class WireGuardContext {
     private var packetFlow: NEPacketTunnelFlow
     private var outboundPackets: [NEPacket] = []
     private var isTunnelClosed: Bool = false
-    private let readPacketCondition = NSCondition()
+    private var readPacketCondition = NSCondition()
 
     init(packetFlow: NEPacketTunnelFlow) {
         self.packetFlow = packetFlow
@@ -193,7 +193,9 @@ class WireGuardContext {
     }
 
     func packetsRead(packets: [NEPacket]) {
+        readPacketCondition.lock()
         outboundPackets.append(contentsOf: packets)
+        readPacketCondition.unlock()
         readPacketCondition.signal()
     }