Every thread is a daemon thread => Program shuts down ASAP once its done.

Some log messages added to blank exception handlers.

src/scala/spark/Broadcast.scala

@@ -6,7 +6,7 @@ import java.util.{BitSet, Comparator, Random, Timer, TimerTask, UUID}
 
 import com.google.common.collect.MapMaker
 
-import java.util.concurrent.{Executors, ExecutorService, ThreadPoolExecutor}
+import java.util.concurrent.{Executors, ThreadFactory, ThreadPoolExecutor}
 
 import scala.collection.mutable.{ListBuffer, Map, Set}
 
@@ -374,7 +374,9 @@ extends BroadcastRecipe  with Logging {
         oosTracker.flush
         gInfo = oisTracker.readObject.asInstanceOf[SourceInfo]
       } catch {
-        case e: Exception => { }
+        case e: Exception => { 
+          logInfo ("getGuideInfo had a " + e)
+        }
       } finally {   
         if (oisTracker != null) { 
           oisTracker.close 
@@ -454,8 +456,7 @@ extends BroadcastRecipe  with Logging {
 
     override def run = {
       var threadPool = 
-        Executors.newFixedThreadPool(
-          BroadcastBT.MaxTxPeers).asInstanceOf[ThreadPoolExecutor]
+        BroadcastBT.newDaemonFixedThreadPool (BroadcastBT.MaxTxPeers)
       
       while (hasBlocks < totalBlocks) {
         var numThreadsToCreate = 
@@ -636,8 +637,7 @@ extends BroadcastRecipe  with Logging {
     private var setOfCompletedSources = Set[SourceInfo] ()
   
     override def run = {
-      // TODO: Cached threadpool has 60s keep alive timer
-      var threadPool = Executors.newCachedThreadPool
+      var threadPool = BroadcastBT.newDaemonCachedThreadPool
       var serverSocket: ServerSocket = null
 
       serverSocket = new ServerSocket (0)
@@ -722,7 +722,9 @@ extends BroadcastRecipe  with Logging {
                 SourceInfo.UnusedParam, SourceInfo.UnusedParam))
             gosSource.flush
           } catch {
-            case e: Exception => { }
+            case e: Exception => { 
+              logInfo ("sendStopBroadcastNotifications had a " + e)
+            }
           } finally {
             if (gisSource != null) {
               gisSource.close
@@ -816,7 +818,7 @@ extends BroadcastRecipe  with Logging {
       // TODO: Not sure if this will be able to fix the number of outgoing links
       // We should have a timeout mechanism on the receiver side
       var threadPool = 
-        Executors.newFixedThreadPool(BroadcastBT.MaxRxPeers)
+        BroadcastBT.newDaemonFixedThreadPool(BroadcastBT.MaxRxPeers)
     
       var serverSocket = new ServerSocket (0) 
       listenPort = serverSocket.getLocalPort
@@ -959,7 +961,9 @@ extends BroadcastRecipe  with Logging {
             oos.writeObject (arrayOfBlocks(blockIndex))
             oos.flush
           } catch { 
-            case e: Exception => { }
+            case e: Exception => { 
+              logInfo ("pickAndSendBlock had a " + e)
+            }
           }
           logInfo ("Sent block: " + blockIndex + " to " + clientSocket)
         }
@@ -1225,12 +1229,51 @@ extends Logging {
     }
   }
   
+  // Returns a standard ThreadFactory except all threads are daemons
+  private def newDaemonThreadFactory: ThreadFactory = {
+    new ThreadFactory {
+      def newThread(r: Runnable): Thread = {
+        var t = Executors.defaultThreadFactory.newThread(r)
+        t.setDaemon(true)
+        return t
+      }
+    }  
+  }
+  
+  // Wrapper over newCachedThreadPool
+  def newDaemonCachedThreadPool: ThreadPoolExecutor = {
+    var threadPool = 
+      Executors.newCachedThreadPool.asInstanceOf[ThreadPoolExecutor]
+  
+    threadPool.setThreadFactory (newDaemonThreadFactory)
+    
+    return threadPool
+  }
+  
+  // Wrapper over newFixedThreadPool
+  def newDaemonFixedThreadPool (nThreads: Int): ThreadPoolExecutor = {
+    var threadPool = 
+      Executors.newFixedThreadPool (nThreads).asInstanceOf[ThreadPoolExecutor]
+  
+    threadPool.setThreadFactory (newDaemonThreadFactory)
+    
+    return threadPool
+  }
+
   class TrackMultipleValues
   extends Thread with Logging {
     var stopTracker = false
     
     override def run = {
-      var threadPool = Executors.newCachedThreadPool
+      var myThreadFactory = new ThreadFactory {
+        def newThread(r: Runnable): Thread = {
+          var t = Executors.defaultThreadFactory.newThread(r)
+          t.setDaemon(true)
+          return t
+        }
+      }
+    
+      var threadPool = BroadcastBT.newDaemonCachedThreadPool
       var serverSocket: ServerSocket = null
       
       serverSocket = new ServerSocket (BroadcastBT.MasterTrackerPort)
@@ -1246,7 +1289,6 @@ extends Logging {
           } catch {
             case e: Exception => {
               logInfo ("TrackMultipleValues Timeout. Stopping listening...") 
-              // TODO: Tracking should be explicitly stopped by the SparkContext
               stopTracker = true 
             }
           }
@@ -1265,10 +1307,12 @@ extends Logging {
                         valueToGuideMap (uuid)
                       } else SourceInfo ("", SourceInfo.TxNotStartedRetry,
                           SourceInfo.UnusedParam, SourceInfo.UnusedParam)
-                    logInfo ("TrackMultipleValues:Got new request: " + clientSocket + " for " + uuid + " : " + gInfo.listenPort)
+                    logInfo ("TrackMultipleValues: Got new request: " + clientSocket + " for " + uuid + " : " + gInfo.listenPort)
                     oos.writeObject (gInfo)
                   } catch {
-                    case e: Exception => { }
+                    case e: Exception => { 
+                      logInfo ("TrackMultipleValues had a " + e)
+                    }
                   } finally {
                     ois.close
                     oos.close