JMM-safe implementation of memory barriers

JMMBarriers.scala

object JMMBarriers {
  @volatile private var volatile: Int = 0
  /** Enforce a write barrier.
    *
    * Writes before this will not be reordered after this barrier, and will be
    * visible from any other thread which performs a read barrier.
    */
  def writeBarrier() { volatile = 1 }
  /** Enforce a read barrier.
    *
    * Reads after this will not be reordered before this barrier, and will see
    * the effects of any writes from a thread which performed a write barrier
    * before this one.
    */
  def readBarrier() { volatile }
}