reliable multicast: javadoc

1 files changed, 15 insertions, 2 deletions

diff --git a/src/main/java/derms/net/rmulticast/ReliableMulticast.java b/src/main/java/derms/net/rmulticast/ReliableMulticast.java
index 2b9d9aa..1632351 100644
--- a/src/main/java/derms/net/rmulticast/ReliableMulticast.java
+++ b/src/main/java/derms/net/rmulticast/ReliableMulticast.java
@@ -13,7 +13,12 @@ import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 
-/** TODO */
+/**
+ * A reliable multicast protocol that guarantees delivery of messages in the event of a fail-stop.
+ *
+ * An implementation of the Trans protocol over IP multicast. Melliar-Smith, et al. "Broadcast Protocols for
+ * Distributed Systems" in IEEE Transactions on Parallel and Distributed Systems, vol. 1, no. 1, 1990.
+ */
 public class ReliableMulticast<T extends MessagePayload> {
     private final SocketAddress group;
     private final InetAddress laddr; // Local address.
@@ -27,6 +32,12 @@ public class ReliableMulticast<T extends MessagePayload> {
     private final BlockingQueue<Message<T>> delivered;
     private final Logger log;
 
+    /**
+     * Join the specified multicast group.
+     *
+     * @param group The IP address and port of the multicast group.
+     * @param laddr The IP address of the local process.
+     */
     public ReliableMulticast(InetSocketAddress group, InetAddress laddr) throws IOException {
         this.group = group;
         this.laddr = laddr;
@@ -61,6 +72,7 @@ public class ReliableMulticast<T extends MessagePayload> {
         }
     }
 
+    /** Send a message to the group. */
     public void send(T payload) throws IOException {
         Message<T> msg = new Message<T>(
                 payload,
@@ -74,8 +86,9 @@ public class ReliableMulticast<T extends MessagePayload> {
         lastSend.set(Instant.now());
     }
 
+    /** Receive a message from the group, blocking if necessary until a message arrives. */
     public T receive() throws InterruptedException {
-        Message<T> msg = delivered.take();
+        Message<T> msg = delivered.take(); // Blocks until a message becomes available.
         return msg.payload;
     }
 }