spark progress for concurrent jobs

[scottdraves]

import scala.concurrent._
import scala.concurrent.ExecutionContext.Implicits.global


val NUM_SAMPLES = 1000000
var count = 0

Future({
    count += spark.sparkContext.parallelize(1 to NUM_SAMPLES).map{i =>
        Thread.sleep(2)
        val x = Math.random()
        val y = Math.random()
        if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)})

Future({
    count += spark.sparkContext.parallelize(1 to NUM_SAMPLES).map{i =>
        Thread.sleep(2)
        val x = Math.random()
        val y = Math.random()
        if (x*x + y*y < 1) 1 else 0
}.reduce(_ + _)})

OutputCell.HIDDEN

should get 2 progress bars at the same time

[scottdraves]

this looks like it is also fixed by #7415