.gitlab-ci.yml

@@ -25,7 +25,7 @@ grade:
   tags:
     - cs206
   image:
-    name: smarter3/moocs:parprog1-scalashop-2020-02-17
+    name: smarter3/moocs:reactive-actorbintree-2020-04-15
     entrypoint: [""]
   allow_failure: true
   before_script:

assignment.sbt

@@ -1,9 +1,4 @@
 // Student tasks (i.e. submit, packageSubmission)
 enablePlugins(StudentTasks)
 
-courseraId := ch.epfl.lamp.CourseraId(
+
-  key = "OpSNmtC1EeWvXAr2bF16EQ",
-  itemId = "MhXvy",
-  premiumItemId = Some("NeGTv"),
-  partId = "Q2e1P"
-)

build.sbt

@@ -1,13 +1,24 @@
-course := "parprog1"
+course := "reactive"
-assignment := "scalashop"
+assignment := "actorbintree"
-
-scalaVersion := "0.23.0-bin-20200211-5b006fb-NIGHTLY"
-scalacOptions ++= Seq("-language:implicitConversions", "-deprecation")
-libraryDependencies ++= Seq(
-  "com.storm-enroute" %% "scalameter-core" % "0.19",
-  "org.scala-lang.modules" %% "scala-parallel-collections" % "0.2.0",
-  "com.novocode" % "junit-interface" % "0.11" % Test
-).map(_.withDottyCompat(scalaVersion.value))
 
 testOptions in Test += Tests.Argument(TestFrameworks.JUnit, "-a", "-v", "-s")
-testSuite := "scalashop.BlurSuite"
+parallelExecution in Test := false
+
+val akkaVersion = "2.6.0"
+
+scalaVersion := "0.23.0-bin-20200211-5b006fb-NIGHTLY"
+
+scalacOptions ++= Seq(
+  "-feature",
+  "-deprecation",
+  "-encoding", "UTF-8",
+  "-unchecked",
+  "-language:implicitConversions"
+)
+
+libraryDependencies ++= Seq(
+  "com.typesafe.akka"        %% "akka-actor"         % akkaVersion,
+  "com.typesafe.akka"        %% "akka-testkit"       % akkaVersion % Test,
+  "com.novocode"             % "junit-interface"     % "0.11"      % Test
+).map(_.withDottyCompat(scalaVersion.value))
+testSuite := "actorbintree.BinaryTreeSuite"

src/main/scala/actorbintree/BinaryTreeSet.scala

@@ -0,0 +1,189 @@
+/**
+ * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
+ */
+package actorbintree
+
+import akka.actor._
+import scala.collection.immutable.Queue
+
+object BinaryTreeSet {
+
+  trait Operation {
+    def requester: ActorRef
+    def id: Int
+    def elem: Int
+  }
+
+  trait OperationReply {
+    def id: Int
+  }
+
+  /** Request with identifier `id` to insert an element `elem` into the tree.
+    * The actor at reference `requester` should be notified when this operation
+    * is completed.
+    */
+  case class Insert(requester: ActorRef, id: Int, elem: Int) extends Operation
+
+  /** Request with identifier `id` to check whether an element `elem` is present
+    * in the tree. The actor at reference `requester` should be notified when
+    * this operation is completed.
+    */
+  case class Contains(requester: ActorRef, id: Int, elem: Int) extends Operation
+
+  /** Request with identifier `id` to remove the element `elem` from the tree.
+    * The actor at reference `requester` should be notified when this operation
+    * is completed.
+    */
+  case class Remove(requester: ActorRef, id: Int, elem: Int) extends Operation
+
+  /** Request to perform garbage collection */
+  case object GC
+
+  /** Holds the answer to the Contains request with identifier `id`.
+    * `result` is true if and only if the element is present in the tree.
+    */
+  case class ContainsResult(id: Int, result: Boolean) extends OperationReply
+
+  /** Message to signal successful completion of an insert or remove operation. */
+  case class OperationFinished(id: Int) extends OperationReply
+
+}
+
+
+class BinaryTreeSet extends Actor {
+  import BinaryTreeSet._
+  import BinaryTreeNode._
+
+  def createRoot: ActorRef = context.actorOf(BinaryTreeNode.props(0, initiallyRemoved = true))
+
+  var root = createRoot
+
+  // optional
+  var pendingQueue = Queue.empty[Operation]
+
+  // optional
+  def receive = normal
+
+  // optional
+  /** Accepts `Operation` and `GC` messages. */
+  val normal: Receive = {
+    case op:Operation => root ! op
+    case GC => {
+      val newRoot = createRoot;
+      root ! CopyTo(newRoot)
+      context.become(garbageCollecting(newRoot))
+    }
+   }
+
+  // optional
+  /** Handles messages while garbage collection is performed.
+    * `newRoot` is the root of the new binary tree where we want to copy
+    * all non-removed elements into.
+    */
+  def garbageCollecting(newRoot: ActorRef): Receive = {
+    case op:Operation => pendingQueue = pendingQueue.enqueue(op)
+    case CopyFinished =>
+      pendingQueue.foreach(newRoot ! _) //foreach preserves order of a queue (same as dequeueing)
+      root ! PoisonPill //Will also stop all of its children
+      pendingQueue = Queue.empty
+      root = newRoot;
+      context.become(normal)
+    //Ignore GC messages here
+  }
+}
+
+object BinaryTreeNode {
+  trait Position
+
+  case object Left extends Position
+  case object Right extends Position
+
+  case class CopyTo(treeNode: ActorRef)
+  case object CopyFinished
+
+  def props(elem: Int, initiallyRemoved: Boolean) = Props(classOf[BinaryTreeNode],  elem, initiallyRemoved)
+}
+
+class BinaryTreeNode(val elem: Int, initiallyRemoved: Boolean) extends Actor {
+  import BinaryTreeNode._
+  import BinaryTreeSet._
+
+  var subtrees = Map[Position, ActorRef]()
+  var removed = initiallyRemoved
+
+  // optional
+  def receive = normal
+
+  def goDownTo(elem : Int) : Position = if(elem < this.elem) Left else Right
+  // optional
+  /** Handles `Operation` messages and `CopyTo` requests. */
+  val normal: Receive = {
+    case Insert  (requester, id, elem) =>
+      if(elem == this.elem && !removed){
+        requester ! OperationFinished(id)
+      }else{
+        val nextPos = goDownTo(elem)
+        
+        subtrees get nextPos match{
+          case Some(node) => node ! Insert(requester, id, elem)
+          case None => {
+              val newActorSubtree = (nextPos, context.actorOf(BinaryTreeNode.props(elem, false)))
+              subtrees = subtrees + newActorSubtree
+              requester ! OperationFinished(id);
+          }
+        }
+      }
+    case Contains(requester, id, elem) =>
+      if(elem == this.elem && !removed)
+        requester ! ContainsResult(id, true)
+      else{
+        //Need to search subtrees
+        subtrees get goDownTo(elem) match{
+          case Some(node) => node ! Contains(requester, id, elem)
+          case None => requester ! ContainsResult(id, false)
+        }
+      }
+        
+    case Remove  (requester, id, elem) => 
+      if(elem == this.elem && !removed){
+        removed = true
+        requester ! OperationFinished(id)
+      }else{
+        subtrees get goDownTo(elem) match{
+          case Some(node) => node ! Remove(requester, id, elem)
+          case None => requester ! OperationFinished(id) // (elem isn't in the tree)
+        }
+      }
+
+    case CopyTo(newRoot) =>
+      //We are already done, nothing to do
+      if(removed && subtrees.isEmpty) context.parent ! CopyFinished
+      else{
+        if(!removed) newRoot ! Insert(self, elem, elem)
+        subtrees.values foreach(_ ! CopyTo(newRoot)) //Copy subtrees elems
+        //val insertConfirmed = if(removed) true else false, hence we can simply pass removed
+        context.become(copying(subtrees.values.toSet, removed))
+      }
+  }
+
+  // optional
+  /** `expected` is the set of ActorRefs whose replies we are waiting for,
+    * `insertConfirmed` tracks whether the copy of this node to the new tree has been confirmed.
+    */
+  def copying(expected: Set[ActorRef], insertConfirmed: Boolean): Receive = {
+    //To catch the insert of this node into the new tree beeing finished
+    case OperationFinished(_) => {
+      if(expected.isEmpty) context.parent ! CopyFinished
+      else context.become(copying(expected, true))
+    }
+    
+    case CopyFinished => {
+      val newExp = expected-sender
+      if(insertConfirmed && newExp.isEmpty){
+        context.parent ! CopyFinished
+      }else{
+        context.become(copying(newExp, insertConfirmed))
+      }
+    }
+  }
+}

src/main/scala/scalashop/HorizontalBoxBlur.scala

@@ -1,65 +0,0 @@
-package scalashop
-
-import org.scalameter._
-
-object HorizontalBoxBlurRunner {
-
-  val standardConfig = config(
-    Key.exec.minWarmupRuns -> 5,
-    Key.exec.maxWarmupRuns -> 10,
-    Key.exec.benchRuns -> 10,
-    Key.verbose -> true
-  ) withWarmer(new Warmer.Default)
-
-  def main(args: Array[String]): Unit = {
-    val radius = 3
-    val width = 1920
-    val height = 1080
-    val src = new Img(width, height)
-    val dst = new Img(width, height)
-    val seqtime = standardConfig measure {
-      HorizontalBoxBlur.blur(src, dst, 0, height, radius)
-    }
-    println(s"sequential blur time: $seqtime")
-
-    val numTasks = 32
-    val partime = standardConfig measure {
-      HorizontalBoxBlur.parBlur(src, dst, numTasks, radius)
-    }
-    println(s"fork/join blur time: $partime")
-    println(s"speedup: ${seqtime.value / partime.value}")
-  }
-}
-
-/** A simple, trivially parallelizable computation. */
-object HorizontalBoxBlur extends HorizontalBoxBlurInterface {
-
-  /** Blurs the rows of the source image `src` into the destination image `dst`,
-   *  starting with `from` and ending with `end` (non-inclusive).
-   *
-   *  Within each row, `blur` traverses the pixels by going from left to right.
-   */
-  def blur(src: Img, dst: Img, from: Int, end: Int, radius: Int): Unit = {
-  // TODO implement this method using the `boxBlurKernel` method
-  for(y <- from until end){
-      for(x <- 0 until src.width){
-        dst(x,y) = boxBlurKernel(src, x, y, radius)
-      }
-    }
-  }
-
-  /** Blurs the rows of the source image in parallel using `numTasks` tasks.
-   *
-   *  Parallelization is done by stripping the source image `src` into
-   *  `numTasks` separate strips, where each strip is composed of some number of
-   *  rows.
-   */
-  def parBlur(src: Img, dst: Img, numTasks: Int, radius: Int): Unit = {
-  // TODO implement using the `task` construct and the `blur` method
-  val r = 0 to src.height by (src.height/(Math.min(numTasks, src.height)))
-  var ranges = r zip r.tail
-  val tasks = ranges.map( { case (from, to) => task(blur(src, dst, from, to, radius)) } )
-  tasks foreach {_.join}
-  }
-
-}

src/main/scala/scalashop/Interfaces.scala

@@ -1,18 +0,0 @@
-package scalashop
-
-// Interfaces used by the grading infrastructure. Do not change signatures
-// or your submission will fail with a NoSuchMethodError.
-
-trait HorizontalBoxBlurInterface {
-  def blur(src: Img, dst: Img, from: Int, end: Int, radius: Int): Unit
-  def parBlur(src: Img, dst: Img, numTasks: Int, radius: Int): Unit
-}
-
-trait VerticalBoxBlurInterface {
-  def blur(src: Img, dst: Img, from: Int, end: Int, radius: Int): Unit
-  def parBlur(src: Img, dst: Img, numTasks: Int, radius: Int): Unit
-}
-
-trait BoxBlurKernelInterface {
-  def boxBlurKernel(src: Img, x: Int, y: Int, radius: Int): RGBA
-}

src/main/scala/scalashop/PhotoCanvas.scala

@@ -1,85 +0,0 @@
-package scalashop
-
-import java.awt._
-import java.awt.event._
-import java.awt.image._
-import java.io._
-import javax.imageio._
-import javax.swing._
-import javax.swing.event._
-
-class PhotoCanvas extends JComponent {
-
-  var imagePath: Option[String] = None
-
-  var image = loadScalaImage()
-
-  override def getPreferredSize = {
-    new Dimension(image.width, image.height)
-  }
-
-  private def loadScalaImage(): Img = {
-    val stream = this.getClass.getResourceAsStream("/scalashop/scala.jpg")
-    try {
-      loadImage(stream)
-    } finally {
-      stream.close()
-    }
-  }
-
-  private def loadFileImage(path: String): Img = {
-    val stream = new FileInputStream(path)
-    try {
-      loadImage(stream)
-    } finally {
-      stream.close()
-    }
-  }
-
-  private def loadImage(inputStream: InputStream): Img = {
-    val bufferedImage = ImageIO.read(inputStream)
-    val width = bufferedImage.getWidth
-    val height = bufferedImage.getHeight
-    val img = new Img(width, height)
-    for (x <- 0 until width; y <- 0 until height) img(x, y) = bufferedImage.getRGB(x, y)
-    img
-  }
-
-  def reload(): Unit = {
-    image = imagePath match {
-      case Some(path) => loadFileImage(path)
-      case None => loadScalaImage()
-    }
-    repaint()
-  }
-
-  def loadFile(path: String): Unit = {
-    imagePath = Some(path)
-    reload()
-  }
-
-  def applyFilter(filterName: String, numTasks: Int, radius: Int): Unit = {
-    val dst = new Img(image.width, image.height)
-    filterName match {
-      case "horizontal-box-blur" =>
-        HorizontalBoxBlur.parBlur(image, dst, numTasks, radius)
-      case "vertical-box-blur" =>
-        VerticalBoxBlur.parBlur(image, dst, numTasks, radius)
-      case "" =>
-    }
-    image = dst
-    repaint()
-  }
-
-  override def paintComponent(gcan: Graphics) = {
-    super.paintComponent(gcan)
-
-    val width = image.width
-    val height = image.height
-    val bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB)
-    for (x <- 0 until width; y <- 0 until height) bufferedImage.setRGB(x, y, image(x, y))
-
-    gcan.drawImage(bufferedImage, 0, 0, null)
-  }
-
-}

src/main/scala/scalashop/ScalaShop.scala

@@ -1,140 +0,0 @@
-package scalashop
-
-import org.scalameter._
-import java.awt._
-import java.awt.event._
-import javax.swing._
-import javax.swing.event._
-import scala.collection.mutable.ArrayBuffer
-import scala.reflect.ClassTag
-
-object ScalaShop {
-
-  class ScalaShopFrame extends JFrame("ScalaShop\u2122") {
-    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE)
-    setSize(1024, 600)
-    setLayout(new BorderLayout)
-
-    val rightpanel = new JPanel
-    rightpanel.setBorder(BorderFactory.createEtchedBorder(border.EtchedBorder.LOWERED))
-    rightpanel.setLayout(new BorderLayout)
-    add(rightpanel, BorderLayout.EAST)
-
-    val controls = new JPanel
-    controls.setLayout(new GridLayout(0, 2))
-    rightpanel.add(controls, BorderLayout.NORTH)
-
-    val filterLabel = new JLabel("Filter")
-    controls.add(filterLabel)
-
-    val filterCombo = new JComboBox(Array(
-      "horizontal-box-blur",
-      "vertical-box-blur"
-    ))
-    controls.add(filterCombo)
-
-    val radiusLabel = new JLabel("Radius")
-    controls.add(radiusLabel)
-
-    val radiusSpinner = new JSpinner(new SpinnerNumberModel(3, 1, 16, 1))
-    controls.add(radiusSpinner)
-
-    val tasksLabel = new JLabel("Tasks")
-    controls.add(tasksLabel)
-
-    val tasksSpinner = new JSpinner(new SpinnerNumberModel(32, 1, 128, 1))
-    controls.add(tasksSpinner)
-
-    val stepbutton = new JButton("Apply filter")
-    stepbutton.addActionListener(new ActionListener {
-      def actionPerformed(e: ActionEvent): Unit = {
-        val time = measure {
-          canvas.applyFilter(getFilterName, getNumTasks, getRadius)
-        }
-        updateInformationBox(time.value)
-      }
-    })
-    controls.add(stepbutton)
-
-    val clearButton = new JButton("Reload")
-    clearButton.addActionListener(new ActionListener {
-      def actionPerformed(e: ActionEvent): Unit = {
-        canvas.reload()
-      }
-    })
-    controls.add(clearButton)
-
-    val info = new JTextArea("   ")
-    info.setBorder(BorderFactory.createLoweredBevelBorder)
-    rightpanel.add(info, BorderLayout.SOUTH)
-
-    val mainMenuBar = new JMenuBar()
-
-    val fileMenu = new JMenu("File")
-    val openMenuItem = new JMenuItem("Open...")
-    openMenuItem.addActionListener(new ActionListener {
-      def actionPerformed(e: ActionEvent): Unit = {
-        val fc = new JFileChooser()
-        if (fc.showOpenDialog(ScalaShopFrame.this) == JFileChooser.APPROVE_OPTION) {
-          canvas.loadFile(fc.getSelectedFile.getPath)
-        }
-      }
-    })
-    fileMenu.add(openMenuItem)
-    val exitMenuItem = new JMenuItem("Exit")
-    exitMenuItem.addActionListener(new ActionListener {
-      def actionPerformed(e: ActionEvent): Unit = {
-        sys.exit(0)
-      }
-    })
-    fileMenu.add(exitMenuItem)
-
-    mainMenuBar.add(fileMenu)
-
-    val helpMenu = new JMenu("Help")
-    val aboutMenuItem = new JMenuItem("About")
-    aboutMenuItem.addActionListener(new ActionListener {
-      def actionPerformed(e: ActionEvent): Unit = {
-        JOptionPane.showMessageDialog(null, "ScalaShop, the ultimate image manipulation tool\nBrought to you by EPFL, 2015")
-      }
-    })
-    helpMenu.add(aboutMenuItem)
-
-    mainMenuBar.add(helpMenu)
-
-    setJMenuBar(mainMenuBar)
-
-    val canvas = new PhotoCanvas
-
-    val scrollPane = new JScrollPane(canvas)
-
-    add(scrollPane, BorderLayout.CENTER)
-    setVisible(true)
-
-    def updateInformationBox(time: Double): Unit = {
-      info.setText(s"Time: $time")
-    }
-
-    def getNumTasks: Int = tasksSpinner.getValue.asInstanceOf[Int]
-
-    def getRadius: Int = radiusSpinner.getValue.asInstanceOf[Int]
-
-    def getFilterName: String = {
-      filterCombo.getSelectedItem.asInstanceOf[String]
-    }
-
-  }
-
-  try {
-    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName())
-  } catch {
-    case _: Exception => println("Cannot set look and feel, using the default one.")
-  }
-
-  val frame = new ScalaShopFrame
-
-  def main(args: Array[String]): Unit = {
-    frame.repaint()
-  }
-
-}

src/main/scala/scalashop/VerticalBoxBlur.scala

@@ -1,67 +0,0 @@
-package scalashop
-
-import org.scalameter._
-
-object VerticalBoxBlurRunner {
-
-  val standardConfig = config(
-    Key.exec.minWarmupRuns -> 5,
-    Key.exec.maxWarmupRuns -> 10,
-    Key.exec.benchRuns -> 10,
-    Key.verbose -> true
-  ) withWarmer(new Warmer.Default)
-
-  def main(args: Array[String]): Unit = {
-    val radius = 3
-    val width = 1920
-    val height = 1080
-    val src = new Img(width, height)
-    val dst = new Img(width, height)
-    val seqtime = standardConfig measure {
-      VerticalBoxBlur.blur(src, dst, 0, width, radius)
-    }
-    println(s"sequential blur time: $seqtime")
-
-    val numTasks = 32
-    val partime = standardConfig measure {
-      VerticalBoxBlur.parBlur(src, dst, numTasks, radius)
-    }
-    println(s"fork/join blur time: $partime")
-    println(s"speedup: ${seqtime.value / partime.value}")
-  }
-
-}
-
-/** A simple, trivially parallelizable computation. */
-object VerticalBoxBlur extends VerticalBoxBlurInterface {
-
-  /** Blurs the columns of the source image `src` into the destination image
-   *  `dst`, starting with `from` and ending with `end` (non-inclusive).
-   *
-   *  Within each column, `blur` traverses the pixels by going from top to
-   *  bottom.
-   */
-  def blur(src: Img, dst: Img, from: Int, end: Int, radius: Int): Unit = {
-    // TODO implement this method using the `boxBlurKernel` method
-    for(x <- from until end){
-      for(y <- 0 until src.height){
-        dst(x,y) = boxBlurKernel(src, x, y, radius)
-      }
-    }
-  }
-
-  /** Blurs the columns of the source image in parallel using `numTasks` tasks.
-   *
-   *  Parallelization is done by stripping the source image `src` into
-   *  `numTasks` separate strips, where each strip is composed of some number of
-   *  columns.
-   */
-  def parBlur(src: Img, dst: Img, numTasks: Int, radius: Int): Unit = {
-    // TODO implement using the `task` construct and the `blur` method
-    val r = 0 to src.width by (src.width/(Math.min(numTasks, src.width)))
-    var ranges = r zip r.tail
-    val tasks = ranges.map( { case (from, to) => task(blur(src, dst, from, to, radius)) } )
-    tasks foreach {_.join}
-  }
-
-}

src/main/scala/scalashop/package.scala

@@ -1,121 +0,0 @@
-import java.util.concurrent._
-import scala.util.DynamicVariable
-
-import org.scalameter._
-
-package object scalashop extends BoxBlurKernelInterface {
-
-  /** The value of every pixel is represented as a 32 bit integer. */
-  type RGBA = Int
-
-  /** Returns the red component. */
-  def red(c: RGBA): Int = (0xff000000 & c) >>> 24
-
-  /** Returns the green component. */
-  def green(c: RGBA): Int = (0x00ff0000 & c) >>> 16
-
-  /** Returns the blue component. */
-  def blue(c: RGBA): Int = (0x0000ff00 & c) >>> 8
-
-  /** Returns the alpha component. */
-  def alpha(c: RGBA): Int = (0x000000ff & c) >>> 0
-
-  /** Used to create an RGBA value from separate components. */
-  def rgba(r: Int, g: Int, b: Int, a: Int): RGBA = {
-    (r << 24) | (g << 16) | (b << 8) | (a << 0)
-  }
-
-  /** Restricts the integer into the specified range. */
-  def clamp(v: Int, min: Int, max: Int): Int = {
-    if (v < min) min
-    else if (v > max) max
-    else v
-  }
-
-  /** Image is a two-dimensional matrix of pixel values. */
-  class Img(val width: Int, val height: Int, private val data: Array[RGBA]) {
-    def this(w: Int, h: Int) = this(w, h, new Array(w * h))
-    def apply(x: Int, y: Int): RGBA = data(y * width + x)
-    def update(x: Int, y: Int, c: RGBA): Unit = data(y * width + x) = c
-  }
-
-  /** Computes the blurred RGBA value of a single pixel of the input image. */
-  def boxBlurKernel(src: Img, x: Int, y: Int, radius: Int): RGBA = {
-
-    // TODO implement using while loops
-    var r = 0
-    var g = 0
-    var b = 0
-    var a = 0
-
-    var count = 0
-
-    var xi = clamp(x-radius, 0, src.width-1)
-    while(xi<=clamp(x+radius, 0, src.width-1)) {
-      var yi = clamp(y-radius, 0, src.height-1)
-      while(yi<=clamp(y+radius, 0, src.height-1)) {
-        r = r + red(src(xi, yi))
-        g = g + green(src(xi, yi))
-        b = b + blue(src(xi, yi))
-        a = a + alpha(src(xi, yi))
-        count = count + 1
-        yi = yi + 1
-      }
-      xi = xi + 1
-    }
-
-    rgba(r/count, g/count, b/count, a/count)
-  }
-
-  val forkJoinPool = new ForkJoinPool
-
-  abstract class TaskScheduler {
-    def schedule[T](body: => T): ForkJoinTask[T]
-    def parallel[A, B](taskA: => A, taskB: => B): (A, B) = {
-      val right = task {
-        taskB
-      }
-      val left = taskA
-      (left, right.join())
-    }
-  }
-
-  class DefaultTaskScheduler extends TaskScheduler {
-    def schedule[T](body: => T): ForkJoinTask[T] = {
-      val t = new RecursiveTask[T] {
-        def compute = body
-      }
-      Thread.currentThread match {
-        case wt: ForkJoinWorkerThread =>
-          t.fork()
-        case _ =>
-          forkJoinPool.execute(t)
-      }
-      t
-    }
-  }
-
-  val scheduler =
-    new DynamicVariable[TaskScheduler](new DefaultTaskScheduler)
-
-  def task[T](body: => T): ForkJoinTask[T] = {
-    scheduler.value.schedule(body)
-  }
-
-  def parallel[A, B](taskA: => A, taskB: => B): (A, B) = {
-    scheduler.value.parallel(taskA, taskB)
-  }
-
-  def parallel[A, B, C, D](taskA: => A, taskB: => B, taskC: => C, taskD: => D): (A, B, C, D) = {
-    val ta = task { taskA }
-    val tb = task { taskB }
-    val tc = task { taskC }
-    val td = taskD
-    (ta.join(), tb.join(), tc.join(), td)
-  }
-
-  // Workaround Dotty's handling of the existential type KeyValue
-  implicit def keyValueCoerce[T](kv: (Key[T], T)): KeyValue = {
-    kv.asInstanceOf[KeyValue]
-  }
-}

src/test/scala/actorbintree/BinaryTreeSuite.scala

@@ -0,0 +1,126 @@
+/**
+ * Copyright (C) 2009-2015 Typesafe Inc. <http://www.typesafe.com>
+ */
+package actorbintree
+
+import akka.actor.{ActorRef, ActorSystem, Props, actorRef2Scala, scala2ActorRef}
+import akka.testkit.{ImplicitSender, TestKit, TestProbe}
+import org.junit.Test
+import org.junit.Assert._
+
+import scala.util.Random
+import scala.concurrent.duration._
+
+class BinaryTreeSuite extends TestKit(ActorSystem("BinaryTreeSuite")) with ImplicitSender {
+
+  import actorbintree.BinaryTreeSet._
+
+  def receiveN(requester: TestProbe, ops: Seq[Operation], expectedReplies: Seq[OperationReply]): Unit =
+    requester.within(5.seconds) {
+      val repliesUnsorted = for (i <- 1 to ops.size) yield try {
+        requester.expectMsgType[OperationReply]
+      } catch {
+        case ex: Throwable if ops.size > 10 => sys.error(s"failure to receive confirmation $i/${ops.size}\n$ex")
+        case ex: Throwable                  => sys.error(s"failure to receive confirmation $i/${ops.size}\nRequests:" + ops.mkString("\n    ", "\n     ", "") + s"\n$ex")
+      }
+      val replies = repliesUnsorted.sortBy(_.id)
+      if (replies != expectedReplies) {
+        val pairs = (replies zip expectedReplies).zipWithIndex filter (x => x._1._1 != x._1._2)
+        fail("unexpected replies:" + pairs.map(x => s"at index ${x._2}: got ${x._1._1}, expected ${x._1._2}").mkString("\n    ", "\n    ", ""))
+      }
+    }
+
+  def verify(probe: TestProbe, ops: Seq[Operation], expected: Seq[OperationReply]): Unit = {
+    val topNode = system.actorOf(Props[BinaryTreeSet])
+
+    ops foreach { op =>
+      topNode ! op
+    }
+
+    receiveN(probe, ops, expected)
+    // the grader also verifies that enough actors are created
+  }
+
+  @Test def `proper inserts and lookups (5pts)`(): Unit = {
+    val topNode = system.actorOf(Props[BinaryTreeSet])
+
+    topNode ! Contains(testActor, id = 1, 1)
+    expectMsg(ContainsResult(1, false))
+
+    topNode ! Insert(testActor, id = 2, 1)
+    topNode ! Contains(testActor, id = 3, 1)
+
+    expectMsg(OperationFinished(2))
+    expectMsg(ContainsResult(3, true))
+    ()
+  }
+
+  @Test def `instruction example (5pts)`(): Unit = {
+    val requester = TestProbe()
+    val requesterRef = requester.ref
+    val ops = List(
+      Insert(requesterRef, id=100, 1),
+      Contains(requesterRef, id=50, 2),
+      Remove(requesterRef, id=10, 1),
+      Insert(requesterRef, id=20, 2),
+      Contains(requesterRef, id=80, 1),
+      Contains(requesterRef, id=70, 2)
+    )
+
+    val expectedReplies = List(
+      OperationFinished(id=10),
+      OperationFinished(id=20),
+      ContainsResult(id=50, false),
+      ContainsResult(id=70, true),
+      ContainsResult(id=80, false),
+      OperationFinished(id=100)
+    )
+
+    verify(requester, ops, expectedReplies)
+  }
+
+
+  @Test def `behave identically to built-in set (includes GC) (40pts)`(): Unit = {
+    val rnd = new Random()
+    def randomOperations(requester: ActorRef, count: Int): Seq[Operation] = {
+      def randomElement: Int = rnd.nextInt(100)
+      def randomOperation(requester: ActorRef, id: Int): Operation = rnd.nextInt(4) match {
+        case 0 => Insert(requester, id, randomElement)
+        case 1 => Insert(requester, id, randomElement)
+        case 2 => Contains(requester, id, randomElement)
+        case 3 => Remove(requester, id, randomElement)
+      }
+
+      for (seq <- 0 until count) yield randomOperation(requester, seq)
+    }
+
+    def referenceReplies(operations: Seq[Operation]): Seq[OperationReply] = {
+      var referenceSet = Set.empty[Int]
+      def replyFor(op: Operation): OperationReply = op match {
+        case Insert(_, seq, elem) =>
+          referenceSet = referenceSet + elem
+          OperationFinished(seq)
+        case Remove(_, seq, elem) =>
+          referenceSet = referenceSet - elem
+          OperationFinished(seq)
+        case Contains(_, seq, elem) =>
+          ContainsResult(seq, referenceSet(elem))
+      }
+
+      for (op <- operations) yield replyFor(op)
+    }
+
+    val requester = TestProbe()
+    val topNode = system.actorOf(Props[BinaryTreeSet])
+    val count = 1000
+
+    val ops = randomOperations(requester.ref, count)
+    val expectedReplies = referenceReplies(ops)
+
+    ops foreach { op =>
+      topNode ! op
+      if (rnd.nextDouble() < 0.1) topNode ! GC
+    }
+    receiveN(requester, ops, expectedReplies)
+  }
+}

src/test/scala/scalashop/BlurSuite.scala

@@ -1,11 +0,0 @@
-package scalashop
-
-import java.util.concurrent._
-import scala.collection._
-import org.junit._
-import org.junit.Assert.assertEquals
-
-class BlurSuite {
-
-  @Rule def individualTestTimeout = new org.junit.rules.Timeout(10 * 1000)
-}