Scala example source code file (InterruptReq.scala)

This example Scala source code file (InterruptReq.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

compiler, failedinterrupt, failedinterrupt, interruptedexception, interruptreq, left, option, r, r, right, some, some, throwable, throwable

The Scala InterruptReq.scala source code

package scala.tools.nsc
package util

/** A class of work items to be used in interrupt requests.
 */
abstract class InterruptReq {
  /** The result type of the operation
   */
  type R
  
  /** The operation to be performed */
  protected val todo: () => R

  /** The result provided */
  private var result: Option[Either[R, Throwable]] = None

  /** To be called from interrupted server to execute demanded task */
  def execute(): Unit = synchronized {
    try {
      result = Some(Left(todo()))
    } catch {
      case t => result = Some(Right(t))
    }
    notify()
  }

  /** To be called from interrupting client to get result for interrupt */
  def getResult(): R = synchronized {
    while (result.isEmpty) {
      try {
        wait()
      } catch { case _ : InterruptedException => () }
    }

    result.get match {
      case Left(res) => res
      case Right(t) => throw new FailedInterrupt(t)
    }
  }
}

class FailedInterrupt(cause: Throwable) extends Exception("Compiler exception during call to 'ask'", cause)