Scala example source code file (t2417.scala)

This example Scala source code file (t2417.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Scala tags/keywords

exception, exception, hashmap, hashmap, hashset, hashset, int, int, map, set, test, thread, throwable, unit

The Scala t2417.scala source code

// #2417
object Test {
  
  def parallel(numThreads: Int)(block: => Unit) {
    var failure: Throwable = null
    val threads = Array.fromFunction(i => new Thread {
      override def run {
        try {
          block
          } catch {
            case x => failure = x
          }
        }
      })(numThreads)
      for (t <- threads) t.start
      for (t <- threads) t.join
      if (failure != null) println("FAILURE: " + failure)
    }
  
    def testSet(initialSize: Int, numThreads: Int, passes: Int) {
      val orig = Set.empty ++ (1 to initialSize)
      parallel(numThreads) {
        for (pass <- 0 until passes) {
          var s = orig
          for (e <- (initialSize to 1 by -1)) {
            s -= e
            val obs = s.size
            if (obs != e - 1) {
              throw new Exception("removed e=" + e + ", size was " + obs + ", s=" + s)
            }
          }
        }
      }
    }
  
    def testMap(initialSize: Int, numThreads: Int, passes: Int) {
      val orig = Map.empty ++ ((1 to initialSize) map ((_,"v")))
      parallel(numThreads) {
        for (pass <- 0 until passes) {
          var m = orig
          for (e <- (initialSize to 1 by -1)) {
            m -= e
            val obs = m.size
            if (obs != e - 1) {
              throw new Exception("removed e=" + e + ", size was " + obs + ", m=" + m)
            }
          }
        }
      }
    }
  
    def main(args: Array[String]) {
      println("testing small Map that doesn't promote to HashMap...")
      testMap(4, 2, 1000000)
      println()
  
      println("testing single-threaded HashMap use...")
      testMap(5, 1, 1000000)
      println()
  
      println("testing HashMap.size from multiple threads...")
      testMap(5, 2, 1000000)
      println()
  
      println("testing small Set that doesn't promote to HashSet...")
      testSet(4, 2, 1000000)
      println()
  
      println("testing single-threaded HashSet use...")
      testSet(5, 1, 1000000)
      println()
  
      println("testing HashSet.size from multiple threads...")
      testSet(5, 2, 1000000)
      println()
    }
}