Scala example source code file (Channel.scala)

This example Scala source code file (Channel.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to scala-lang.org; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

a, channel, concurrent, fifo, linkedlist

The Channel.scala Scala example source code

/*                     __                                               *\
**     ________ ___   / /  ___     Scala API                            **
**    / __/ __// _ | / /  / _ |    (c) 2003-2013, LAMP/EPFL             **
**  __\ \/ /__/ __ |/ /__/ __ |    http://scala-lang.org/               **
** /____/\___/_/ |_/____/_/ | |                                         **
**                          |/                                          **
\*                                                                      */



package scala.concurrent

/** This class ...
 *
 *  @author  Martin Odersky
 *  @version 1.0, 10/03/2003
 */
class Channel[A] {
  class LinkedList[A] {
    var elem: A = _
    var next: LinkedList[A] = null
  }
  private var written = new LinkedList[A] // FIFO buffer, realized through
  private var lastWritten = written       // aliasing of a linked list
  private var nreaders = 0

  /**
   */
  def write(x: A) = synchronized {
    lastWritten.elem = x
    lastWritten.next = new LinkedList[A]
    lastWritten = lastWritten.next
    if (nreaders > 0) notify()
  }

  def read: A = synchronized {
    while (written.next == null) {
      try {
        nreaders += 1
        wait()
      }
      finally nreaders -= 1
    }
    val x = written.elem
    written = written.next
    x
  }

}