import scala.actors.{Future, Futures}
object Test {
def main(args:Array[String]) : Unit = {
//scala.actors.Debug.level = 3
val size = /*if (args.length > 0) Integer.parseInt(args(0)) else*/ 8
val (m,n) = (size, size)
def random = (for (i <- 0 until m*n) yield java.lang.Math.random).toArray
val A = Matrix(m, n, random)
val B = Matrix(m, n, random)
val format = new java.text.DecimalFormat("000.00'ms'");
var iter = 1
val done = 21
while (iter < done) {
val start = System.nanoTime()
val result = A * B
val time = System.nanoTime() - start
result match {
case Some(result) => {
printf(" Iteration %2d succeeded %n", iter/*, format.format(time / 1e6)*/)
iter += 1
}
case None => {
printf(">>>> Iteration %2d failed after %s <<<<< %n", iter, format.format(time / 1e6))
iter = done
}
}
}
println("Test done with no deadlock. Try again, it will not occur...")
}
}
case class Matrix(numRows: Int, numCols: Int, values: Array[Double]) {
def this(m:Int, n:Int) = this(m, n, new Array[Double](m*n))
def offset(i:Int, j:Int) = i * numCols + j
def apply(i:Int, j:Int) = values( offset(i,j) )
def update(i:Int, j:Int, value:Double) = values(offset(i, j)) = value;
def *(by:Matrix) = {
val aM = numRows
val aN = numCols
assert(aM == by.numCols)
assert(aN == by.numRows)
val resultMatrix = new Matrix(aM, aM)
val m = aM.asInstanceOf[Int]
val n = aN.asInstanceOf[Int]
val rows = for (j <- 0 until m) yield {
Futures.future {
val b_j = new Array[Double](n)
var k = 0
while (k < n) { // sadly, while loops are still faster than for loops
b_j(k) = by(k,j)
k += 1
}
var i = 0
while (i < m) {
var s = 0.0d;
k = 0
while (k < n) {
s += Matrix.this(i,k) * b_j(k)
k += 1
}
resultMatrix(i,j) = s
i += 1
}
//printf("future %d of %d completed.%n", j, m)
j
}
}
// rows.foreach { x=> x() } // This appears to force sequential execution, so use:
// timeout is 10 years; see http://lampsvn.epfl.ch/trac/scala/ticket/2515
val done = Futures.awaitAll(10*365*24*60*60*1000, rows.toArray : _*) // list to array, as varargs.
if (done.contains(None))
None
else
Some(resultMatrix)
}
}
