STM revisited: add Scala

Some time ago I compared F# and Haskell STM implementation performance. Today I'm adding Scala into it:

	import scala.concurrent.stm._
	object Test {
	def run(n: Int) = {
	val x = Ref(0)
	val y = Ref(0)
	(1 to n) foreach { i =>
	atomic { implicit tx =>
	val x1 = x()
	val y1 = y()
	if (x() != y()) retry
	x() = x1 + 1
	y() = y1 + 1
	}
	}
	}
	def time(block: => Unit) = {
	val beginTime=System.currentTimeMillis
	block
	val endTime=System.currentTimeMillis
	println(endTime-beginTime)
	}
	time(run(1000000))
	}
	// scala> time(run(1000000))
	// 401

view raw stm.scala hosted with ❤ by GitHub

So, it's more than two times slower than Haskell, but more than 3 times faster than F#. Interesting.