From: Samuel Lepetit <samuel.lepetit@inria.fr>
Date: Mon, 2 Jul 2012 16:47:55 +0000 (+0200)
Subject: Bugfix in Bittorrent example
X-Git-Tag: v3_9_90~569^2~19^2~22
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/17ac42f75ce20ece3947836ebdd8efb3378b9dce

Bugfix in Bittorrent example
---

diff --git a/examples/bittorrent/Common.java b/examples/bittorrent/Common.java
index 51cb01d77f..e69d3c8c9e 100644
--- a/examples/bittorrent/Common.java
+++ b/examples/bittorrent/Common.java
@@ -3,6 +3,7 @@ package bittorrent;
  * Common constants for use in the simulation
  */
 public class Common {	
+		
 	public static String TRACKER_MAILBOX = "tracker_mailbox";
 	
 	public static int FILE_SIZE = 5120;
@@ -48,7 +49,7 @@ public class Common {
 	/**
 	 * Interval between each update of the choked peers
 	 */
-	public static int UPDATE_CHOKED_INTERVAL = 50;
+	public static int UPDATE_CHOKED_INTERVAL = 30;
 	/**
 	 * Number of pieces the peer asks for simultaneously
 	 */
diff --git a/examples/bittorrent/Connection.java b/examples/bittorrent/Connection.java
index 5cb1b62bba..87ecaccd3b 100644
--- a/examples/bittorrent/Connection.java
+++ b/examples/bittorrent/Connection.java
@@ -1,7 +1,7 @@
 package bittorrent;
 
 import java.util.Arrays;
-
+import org.simgrid.msg.Msg;
 public class Connection {
 	/**
 	 * Remote peer id
@@ -31,7 +31,18 @@ public class Connection {
 	 * Indicates if the peer has choked the current peer
 	 */
 	public boolean chokedDownload = true;
-	
+	/**
+	 * Number of messages we have received from the peer
+	 */
+	public int messagesCount = 0;
+	/**
+	 * Peer speed.
+	 */
+	public double peerSpeed = 0;
+	/**
+	 * Last time the peer was unchoked
+	 */
+	public double lastUnchoke = 0;
 	/**
 	 * Constructor
 	 */
@@ -39,7 +50,14 @@ public class Connection {
 		this.id = id;
 		this.mailbox = Integer.toString(id);
 	}
-
+	/**
+	 * Add a new value to the peer speed average
+	 */
+	public void addSpeedValue(double speed) {
+		peerSpeed = peerSpeed * 0.55 + speed * 0.45;
+		//		peerSpeed = (peerSpeed * messagesCount + speed) / (++messagesCount);		
+	}
+		
 	@Override
 	public String toString() {
 		return "Connection [id=" + id + ", bitfield="
diff --git a/examples/bittorrent/Peer.java b/examples/bittorrent/Peer.java
index 68c694e8e1..981596dec7 100644
--- a/examples/bittorrent/Peer.java
+++ b/examples/bittorrent/Peer.java
@@ -2,6 +2,7 @@ package bittorrent;
 
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map.Entry;
 
@@ -13,12 +14,15 @@ import org.simgrid.msg.RngStream;
 import org.simgrid.msg.Process;
 import org.simgrid.msg.Task;
 
+import bittorrent.Connection;
+
 /**
  * Main class for peers execution
  */
 public class Peer extends Process {
 	protected int round = 0;
 	
+	protected double beginReceiveTime;
 	protected double deadline;
 	
 	protected static RngStream stream = new RngStream();
@@ -70,6 +74,7 @@ public class Peer extends Process {
 		if (getPeersData()) {
 			Msg.debug("Got " + peers.size() + " peers from the tracker");
 			Msg.debug("Here is my current status: " + getStatus());
+			beginReceiveTime = Msg.getClock();			
 			if (hasFinished()) {
 				pieces = Common.FILE_PIECES;
 				sendHandshakeAll();
@@ -351,6 +356,10 @@ public class Peer extends Process {
 				}
 			break;
 		}
+		if (remotePeer != null) {
+			remotePeer.addSpeedValue(1 / (Msg.getClock() - beginReceiveTime));
+		}
+		beginReceiveTime = Msg.getClock();
 	}
 	/**
 	 * Wait for the node to receive interesting bitfield messages (ie: non empty)
@@ -439,33 +448,57 @@ public class Peer extends Process {
 			peerChoked.chokedUpload = true;
 			activePeers.remove(e.getKey());
 		}
-		//Random optimistic unchoking
-		if (round == 0 || true) {
-			int j = 0, i;
-			Connection peerChoosed = null;
-			do {
-				i = 0;
-				int idChosen = stream.randInt(0,peers.size() - 1);
-				for (Connection connection : peers.values()) {
-					if (i == idChosen) {
-						peerChoosed = connection;
-						break;
+		Connection peerChoosed = null;
+		//Separate the case from when the peer is seeding.
+		if (pieces == Common.FILE_PIECES) {
+			//Find the last unchoked peer.
+			double unchokeTime = deadline + 1;
+			for (Connection connection : peers.values()) {
+				if (connection.lastUnchoke < unchokeTime && connection.chokedUpload && connection.interested) {
+					peerChoosed = connection;
+					unchokeTime = connection.lastUnchoke;
+				}
+			}
+		}
+		else {
+			//Random optimistic unchoking
+			if (round == 0) {
+				int j = 0, i;
+				do {
+					i = 0;
+					int idChosen = stream.randInt(0,peers.size() - 1);
+					for (Connection connection : peers.values()) {
+						if (i == idChosen) {
+							peerChoosed = connection;
+							break;
+						}
+						i++;
+					} //TODO: Not really the best way ever
+					if (!peerChoosed.interested) {
+						peerChoosed = null;
+					}
+					j++;
+				} while (peerChoosed == null && j < 
+	Common.MAXIMUM_PEERS);
+			}
+			else {
+				Connection fastest = null;
+				double fastestSpeed = 0;
+				for (Connection c : peers.values()) {
+					if (c.peerSpeed > fastestSpeed && c.chokedUpload && c.interested) {
+						fastest = c;
+						fastestSpeed = c.peerSpeed;
 					}
-					i++;
-				} //TODO: Not really the best way ever
-				if (!peerChoosed.interested) {
-					peerChoosed = null;
 				}
-				j++;
-			} while (peerChoosed == null && j < 
-Common.MAXIMUM_PEERS);
-			if (peerChoosed != null) {
-				activePeers.put(peerChoosed.id,peerChoosed);
-				peerChoosed.chokedUpload = false;
-				sendUnchoked(peerChoosed.mailbox);
+				peerChoosed = fastest;
 			}
 		}
-		//TODO: Use the leecher choke algorithm.
+		if (peerChoosed != null) {
+			activePeers.put(peerChoosed.id,peerChoosed);
+			peerChoosed.chokedUpload = false;
+			peerChoosed.lastUnchoke = Msg.getClock();
+			sendUnchoked(peerChoosed.mailbox);
+		}
 	}
 	/**	
 	 * Updates our "interested" state about peers: send "not interested" to peers
diff --git a/examples/kademlia/Node.java b/examples/kademlia/Node.java
index e8e4e7088f..1655a7dbcd 100644
--- a/examples/kademlia/Node.java
+++ b/examples/kademlia/Node.java
@@ -257,7 +257,7 @@ public class Node extends Process {
 		return destinationFound;
 	}
 	/**
-	 * Sends a "PING" request to a node
+	 * Sends a "PING" reque ast to a node
 	 * @param destination Ping destination id.
 	 */
 	public void ping(int destination) {