put conf at 3rd position, modify suite class, add comments

Author: WangTaoTheTonic

core/src/main/scala/org/apache/spark/HttpServer.scala

@@ -57,7 +57,7 @@ private[spark] class HttpServer(
     } else {
       logInfo("Starting HTTP Server")
       val (actualServer, actualPort) =
-        Utils.startServiceOnPort[Server](requestedPort, doStart, serverName, new SparkConf())
+        Utils.startServiceOnPort[Server](requestedPort, doStart, new SparkConf(), serverName)
       server = actualServer
       port = actualPort
     }

core/src/main/scala/org/apache/spark/network/nio/ConnectionManager.scala

@@ -174,7 +174,7 @@ private[nio] class ConnectionManager(
     serverChannel.socket.bind(new InetSocketAddress(port))
     (serverChannel, serverChannel.socket.getLocalPort)
   }
-  Utils.startServiceOnPort[ServerSocketChannel](port, startService, name, conf)
+  Utils.startServiceOnPort[ServerSocketChannel](port, startService, conf, name)
   serverChannel.register(selector, SelectionKey.OP_ACCEPT)
 
   val id = new ConnectionManagerId(Utils.localHostName, serverChannel.socket.getLocalPort)

core/src/main/scala/org/apache/spark/ui/JettyUtils.scala

@@ -201,7 +201,7 @@ private[spark] object JettyUtils extends Logging {
       }
     }
 
-    val (server, boundPort) = Utils.startServiceOnPort[Server](port, connect, serverName, conf)
+    val (server, boundPort) = Utils.startServiceOnPort[Server](port, connect, conf, serverName)
     ServerInfo(server, boundPort, collection)
   }
 

core/src/main/scala/org/apache/spark/util/AkkaUtils.scala

@@ -53,7 +53,7 @@ private[spark] object AkkaUtils extends Logging {
     val startService: Int => (ActorSystem, Int) = { actualPort =>
       doCreateActorSystem(name, host, actualPort, conf, securityManager)
     }
-    Utils.startServiceOnPort(port, startService, name, conf)
+    Utils.startServiceOnPort(port, startService, conf, name)
   }
 
   private def doCreateActorSystem(

core/src/main/scala/org/apache/spark/util/Utils.scala

@@ -1706,16 +1706,17 @@ private[spark] object Utils extends Logging {
    * Each subsequent attempt uses 1 + the port used in the previous attempt (unless the port is 0).
    *
    * @param startPort The initial port to start the service on.
-   * @param maxRetries Maximum number of retries to attempt.
-   *                   A value of 3 means attempting ports n, n+1, n+2, and n+3, for example.
    * @param startService Function to start service on a given port.
    *                     This is expected to throw java.net.BindException on port collision.
+   * @param conf Used to get maximum number of retries.
+   * @param serviceName Name of the service.
    */
   def startServiceOnPort[T](
       startPort: Int,
       startService: Int => (T, Int),
-      serviceName: String = "",
-      conf: SparkConf): (T, Int) = {
+      conf: SparkConf,
+      serviceName: String = ""
+      ): (T, Int) = {
     val serviceString = if (serviceName.isEmpty) "" else s" '$serviceName'"
     val maxRetries = portMaxRetries(conf)
     logInfo(s"Starting service$serviceString on port $startPort with maximum $maxRetries retries. ")

external/flume/src/test/scala/org/apache/spark/streaming/flume/FlumeStreamSuite.scala

@@ -80,7 +80,7 @@ class FlumeStreamSuite extends FunSuite with BeforeAndAfter with Matchers with L
       val socket = new ServerSocket(trialPort)
       socket.close()
       (null, trialPort)
-    })._2
+    }, conf)._2
   }
 
   /** Setup and start the streaming context */

external/mqtt/src/test/scala/org/apache/spark/streaming/mqtt/MQTTStreamSuite.scala

@@ -29,6 +29,7 @@ import org.apache.spark.storage.StorageLevel
 import org.apache.spark.streaming.dstream.ReceiverInputDStream
 import org.eclipse.paho.client.mqttv3._
 import org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence
+import org.apache.spark.SparkConf
 
 class MQTTStreamSuite extends FunSuite with Eventually with BeforeAndAfter {
 
@@ -101,7 +102,7 @@ class MQTTStreamSuite extends FunSuite with Eventually with BeforeAndAfter {
       val socket = new ServerSocket(trialPort)
       socket.close()
       (null, trialPort)
-    })._2
+    }, new SparkConf())._2
   }
 
   def publishData(data: String): Unit = {