SI-7938 - parallel collections should use default ExecutionContext

Parallel collections now use `scala.concurrent.ExecutionContext`
by default.

The `ExecutionContextTaskSupport` is optimized to use the
`ForkJoinPool` underlying the `ExecutionContext` if possible.
Otherwise, a fallback `TaskSupport` that creates a reduction tree and
execute an operation through `Future`s is used.

1 files changed, 4 insertions, 1 deletions

diff --git a/test/files/scalacheck/parallel-collections/ParallelArrayCheck.scala b/test/files/scalacheck/parallel-collections/ParallelArrayCheck.scala
index 255c04498e..691a3e961e 100644
--- a/test/files/scalacheck/parallel-collections/ParallelArrayCheck.scala
+++ b/test/files/scalacheck/parallel-collections/ParallelArrayCheck.scala
@@ -24,6 +24,8 @@ abstract class ParallelArrayCheck[T](tp: String) extends ParallelSeqCheck[T]("Pa
 
   def hasStrictOrder = true
 
+  def tasksupport: TaskSupport
+
   def ofSize(vals: Seq[Gen[T]], sz: Int) = {
     val a = new mutable.ArrayBuffer[T](sz)
     val gen = vals(rnd.nextInt(vals.size))
@@ -33,6 +35,7 @@ abstract class ParallelArrayCheck[T](tp: String) extends ParallelSeqCheck[T]("Pa
 
   def fromSeq(a: Seq[T]) = {
     val pa = new ParArray[T](a.size)
+    pa.tasksupport = tasksupport
     var i = 0
     for (elem <- a.toList) {
       pa(i) = elem
@@ -50,7 +53,7 @@ abstract class ParallelArrayCheck[T](tp: String) extends ParallelSeqCheck[T]("Pa
 }
 
 
-object IntParallelArrayCheck extends ParallelArrayCheck[Int]("Int") with IntSeqOperators with IntValues {
+class IntParallelArrayCheck(val tasksupport: TaskSupport) extends ParallelArrayCheck[Int]("Int") with IntSeqOperators with IntValues {
   override def instances(vals: Seq[Gen[Int]]) = oneOf(super.instances(vals), sized { sz =>
     (0 until sz).toArray.toSeq
   }, sized { sz =>