Fixed some warnings during compilation.

core/src/main/scala/spark/BitTorrentBroadcast.scala

@@ -6,6 +6,7 @@ import java.util.{BitSet, Comparator, Random, Timer, TimerTask, UUID}
 import java.util.concurrent.{Executors, ThreadFactory, ThreadPoolExecutor}
 
 import scala.collection.mutable.{ListBuffer, Map, Set}
+import scala.math
 
 @serializable
 class BitTorrentBroadcast[T] (@transient var value_ : T, isLocal: Boolean) 
@@ -113,7 +114,7 @@ extends Broadcast[T] with Logging {
     }
     
     // In the beginning, this is the only known source to Guide
-    listOfSources = listOfSources + masterSource
+    listOfSources += masterSource
 
     // Register with the Tracker
     BitTorrentBroadcast.registerValue (uuid, 
@@ -203,7 +204,7 @@ extends Broadcast[T] with Logging {
     var blockID = 0
 
     for (i <- 0 until (byteArray.length, blockSize)) {
-      val thisBlockSize = Math.min (blockSize, byteArray.length - i)
+      val thisBlockSize = math.min (blockSize, byteArray.length - i)
       var tempByteArray = new Array[Byte] (thisBlockSize)
       val hasRead = bais.read (tempByteArray, 0, thisBlockSize)
       
@@ -268,7 +269,7 @@ extends Broadcast[T] with Logging {
       if (listOfSources.contains(newSourceInfo)) { 
         listOfSources = listOfSources - newSourceInfo 
       }
-      listOfSources = listOfSources + newSourceInfo
+      listOfSources += newSourceInfo
     }         
   }  
   
@@ -435,7 +436,7 @@ extends Broadcast[T] with Logging {
       
       while (hasBlocks < totalBlocks) {
         var numThreadsToCreate = 
-          Math.min (listOfSources.size, BitTorrentBroadcast.MaxTxPeers) - 
+          math.min (listOfSources.size, BitTorrentBroadcast.MaxTxPeers) - 
           threadPool.getActiveCount
 
         while (hasBlocks < totalBlocks && numThreadsToCreate > 0) {
@@ -446,7 +447,7 @@ extends Broadcast[T] with Logging {
             // Add to peersNowTalking. Remove in the thread. We have to do this 
             // ASAP, otherwise pickPeerToTalkTo picks the same peer more than once
             peersNowTalking.synchronized { 
-              peersNowTalking = peersNowTalking + peerToTalkTo
+              peersNowTalking += peerToTalkTo
             }
           }
           
@@ -936,7 +937,7 @@ extends Broadcast[T] with Logging {
                 i = i - 1
               }
               
-              selectedSources = selectedSources + curPeer
+              selectedSources += curPeer
               
               picksLeft = picksLeft - 1
             }
@@ -1087,7 +1088,10 @@ extends Broadcast[T] with Logging {
 
 class BitTorrentBroadcastFactory 
 extends BroadcastFactory {
-  def initialize (isMaster: Boolean) = BitTorrentBroadcast.initialize (isMaster)
+  def initialize (isMaster: Boolean) = {
+    BitTorrentBroadcast.initialize (isMaster)
+  }
+  
   def newBroadcast[T] (value_ : T, isLocal: Boolean) = 
     new BitTorrentBroadcast[T] (value_, isLocal)
 }