reliable multicast: Timeout

2 files changed, 38 insertions, 13 deletions

diff --git a/src/main/java/derms/net/rmulticast/ReliableMulticast.java b/src/main/java/derms/net/rmulticast/ReliableMulticast.java
index 22e16a2..85d4f31 100644
--- a/src/main/java/derms/net/rmulticast/ReliableMulticast.java
+++ b/src/main/java/derms/net/rmulticast/ReliableMulticast.java
@@ -61,7 +61,7 @@ public class ReliableMulticast<T extends Serializable & Hashable> {
         DatagramPacket pkt = Packet.encode(msg, group);
         outSock.send(pkt);
         positiveAcks.clear();
-        (new Thread(new Timeout(msg.id()))).start();
+        (new Thread(new Timeout<T>(msg, positiveAcks, retransmissions))).start();
         lastSend.set(Instant.now());
     }
 
@@ -72,16 +72,4 @@ public class ReliableMulticast<T extends Serializable & Hashable> {
         }
     }
 
-    private class Timeout implements Runnable {
-        MessageID mid;
-
-        private Timeout(MessageID mid) {
-            this.mid = mid;
-        }
-
-        @Override
-        public void run() {
-            // TODO
-        }
-    }
 }
diff --git a/src/main/java/derms/net/rmulticast/Timeout.java b/src/main/java/derms/net/rmulticast/Timeout.java
new file mode 100644
index 0000000..7eaac3e
--- /dev/null
+++ b/src/main/java/derms/net/rmulticast/Timeout.java
@@ -0,0 +1,37 @@
+package derms.net.rmulticast;
+
+import java.io.Serializable;
+import java.time.Duration;
+import java.util.Set;
+import java.util.concurrent.BlockingQueue;
+import java.util.logging.Logger;
+
+/** If a message is not positively acknowledged after some time, Timeout puts it in the retransmissions list. */
+class Timeout<T extends Serializable & Hashable> implements Runnable {
+    private static final Duration timeout = Duration.ofSeconds(1);
+
+    private final Message<T> msg;
+    private final Set<MessageID> positiveAcks;
+    private final BlockingQueue<Message<T>> retransmissions;
+    private final Logger log;
+
+    Timeout(Message<T> msg, Set<MessageID> positiveAcks, BlockingQueue<Message<T>> retransmissions) {
+        this.msg = msg;
+        this.positiveAcks = positiveAcks;
+        this.retransmissions = retransmissions;
+        this.log = Logger.getLogger(this.getClass().getName());
+    }
+
+    @Override
+    public void run() {
+        try {
+            Thread.sleep(timeout.toMillis());
+            if (!positiveAcks.contains(msg.id())) {
+                log.info("Message "+msg.id()+" not ack'ed after "+timeout+"; retransmitting.");
+                retransmissions.put(msg);
+            }
+        } catch (InterruptedException e) {
+            log.info("Timeout thread interrupted: " + e.getMessage());
+        }
+    }
+}