From 23a380cd5aa3654204b7e08bda842495fa112aab Mon Sep 17 00:00:00 2001
From: Skons <k.temming@gmail.com>
Date: Tue, 20 Feb 2018 20:29:36 +0100
Subject: [PATCH] OPFService now cleanly closes the socket upon exiting

---
 OPFService/NetworkService.cs | 39 +++++++++++++++++++++++++++++++-----
 OPFService/Program.cs        | 11 +++++++++-
 2 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/OPFService/NetworkService.cs b/OPFService/NetworkService.cs
index 454d8e5..9e97bac 100644
--- a/OPFService/NetworkService.cs
+++ b/OPFService/NetworkService.cs
@@ -26,6 +26,8 @@
 namespace OPFService {
     class NetworkService {
         OPFDictionary dict;
+        Socket listener;
+        int restarted = 0;
 
         public NetworkService(OPFDictionary d) {
             dict = d;
@@ -34,17 +36,32 @@ public NetworkService(OPFDictionary d) {
         public void main() {
             IPAddress ip = IPAddress.Parse("127.0.0.1");
             IPEndPoint local = new IPEndPoint(ip, 5999);
-            Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+            listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
 
-            try {
+            try
+            {
                 listener.Bind(local);
                 listener.Listen(64);
-                while (true) {
+                while (true)
+                {
                     Socket client = listener.Accept();
                     new Thread(() => handle(client)).Start();
                 }
-            } catch (Exception e) {
-                // don't know what to do here
+            }
+            catch (Exception e)
+            {
+                String exception = e.ToString();
+                //On a not sane restart, the Socket keeps the connection up for 30 seconds
+                //try a restart by calling main() again
+                if (exception.Contains("Only one usage of each socket address") && restarted < 4)
+                {
+                    restarted++;
+                    System.Threading.Thread.Sleep(30000);
+                    main();
+                }
+                else {
+                    throw; //shut the service down
+                }
             }
         }
 
@@ -68,5 +85,17 @@ public void handle(Socket client) {
             }
             client.Close();
         }
+
+        public void Close()
+        {
+            restarted = 0; //reset the counter
+            try
+            {
+                listener.Close();
+            }
+            catch (Exception e)
+            {
+            }
+        }
     }
 }
diff --git a/OPFService/Program.cs b/OPFService/Program.cs
index 15bc417..bfacb9c 100644
--- a/OPFService/Program.cs
+++ b/OPFService/Program.cs
@@ -24,6 +24,7 @@
 namespace OPFService {
     class OPFService : ServiceBase {
         Thread worker;
+        NetworkService svc;
 
         public OPFService() {
         }
@@ -36,13 +37,21 @@ protected override void OnStart(string[] args) {
             base.OnStart(args);
             OPFDictionary d = new OPFDictionary(AppDomain.CurrentDomain.BaseDirectory + "\\opfmatch.txt", AppDomain.CurrentDomain.BaseDirectory + "opfcont.txt");
             // OPFDictionary d = new OPFDictionary("c:\\windows\\system32\\opfmatch.txt", "c:\\windows\\system32\\opfcont.txt");
-            NetworkService svc = new NetworkService(d);
+            svc = new NetworkService(d);
             worker = new Thread(() => svc.main());
             worker.Start();
         }
 
         protected override void OnShutdown() {
             base.OnShutdown();
+            svc.Close();
+            worker.Abort();
+        }
+
+        protected override void OnStop()
+        {
+            base.OnStop();
+            svc.Close();
             worker.Abort();
         }