From 2d8008abf68460cc89541fff87d4b4d68545c7a1 Mon Sep 17 00:00:00 2001
From: senft-desktop <senftt@gmail.com>
Date: Fri, 30 Nov 2012 15:12:05 +0100
Subject: [PATCH] Added max. retries for ack

---
 ws2012/P2P/uebungen/4/src/node/Ack.java | 46 +++++++++++--------------
 1 file changed, 20 insertions(+), 26 deletions(-)

diff --git a/ws2012/P2P/uebungen/4/src/node/Ack.java b/ws2012/P2P/uebungen/4/src/node/Ack.java
index 4ffc8cf8..83afb02c 100644
--- a/ws2012/P2P/uebungen/4/src/node/Ack.java
+++ b/ws2012/P2P/uebungen/4/src/node/Ack.java
@@ -13,6 +13,12 @@ public class Ack {
     // timeout in seconds
     private final int TIMEOUT = 1000;
 
+    private final int MAX_RETRIES = 5;
+
+    // the number of times we already sent this ack (IRGENDWANN IST AUCH MAL
+    // SCHLUSS!)
+    private int retries = 1;
+
     private int id;
     private SocketAddress address;
     private ByteBuffer buf;
@@ -73,6 +79,7 @@ public class Ack {
 
         @Override
         public void run() {
+            retries++;
             while (notReceived && System.currentTimeMillis() < timeToStop) {
                 try {
                     Thread.sleep(10);
@@ -83,32 +90,19 @@ public class Ack {
 
             // Timeout hit -> re-send
             if (notReceived) {
-                try {
-                    LOGGER.log(Level.INFO, "Absent ack #{0}. Resending to {1}",
-                            new Object[] { id, address.toString() });
-
-                    /**
-                     * TODO: This would be the intuitive order (first re-send,
-                     * then start the new TimeoutThread), right? Unfortunately
-                     * this gives ugly log outputs, because the re-sent message
-                     * arrives before the new thread is constructed, so we get:
-                     * 
-                     * <pre>
-                     * [2012-11-28 07:53:05 PM] node.Node INFO:  Initialized node /127.0.0.1:37179 
-                     * a spawn b
-                     * [2012-11-28 07:53:15 PM] node.Node INFO:  Initialized node /127.0.0.1:35358
-                     * [2012-11-28 07:53:15 PM] node.Ack INFO:  Starting timeout thread for ack #-1276001492 
-                     * [2012-11-28 07:53:15 PM] node.Node INFO:  /127.0.0.1:35358 received invite from /127.0.0.1:37179 
-                     * [2012-11-28 07:53:20 PM] node.Ack INFO:  Absent ack #-1276001492). Resending to /127.0.0.1:35358
-                     * </pre>
-                     * 
-                     * No big deal, and we could just swap the statements, but
-                     * meh...
-                     */
-                    channel.send(buf, address);
-                    startThread();
-                } catch (IOException e) {
-                    e.printStackTrace();
+                if (retries < MAX_RETRIES) {
+                    try {
+                        LOGGER.log(Level.INFO,
+                                "Absent ack #{0}. Resending to {1}",
+                                new Object[] { id, address.toString() });
+                        channel.send(buf, address);
+                        startThread();
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                } else {
+                    LOGGER.log(Level.SEVERE, "Dropping ack #{0}",
+                            new Object[] { id });
                 }
             }
         }