Fixing jvm 1.5 support for parallel collections.

Special cased with thread pool executor scheduling. Fixed an ugly
concurrency bug where futures returned by a thread pool executor didn't
remove the task from the queue when cancel was called. Note to self and
others: don't cancel futures returned by thread pool executors, it might
lead to unexpected behaviour. Modified the executor to add new threads
if all the active threads are syncing, in order to avoid deadlocks.

Fixed a hidden bug in AdaptiveWorkStealingTasks, where correct behaviour
depended on the execution order of the tasks. This didn't fail before
with ForkJoinTasks, since there the execution order is well-defined.

Scalachecked 1.5 & 1.6 support.

No review.

1 files changed, 5 insertions, 2 deletions

diff --git a/src/library/scala/collection/parallel/mutable/ParArray.scala b/src/library/scala/collection/parallel/mutable/ParArray.scala
index a1164b7b80..909b8eb5d7 100644
--- a/src/library/scala/collection/parallel/mutable/ParArray.scala
+++ b/src/library/scala/collection/parallel/mutable/ParArray.scala
@@ -102,8 +102,11 @@ self =>
       val left = remaining
       if (left >= 2) {
         val splitpoint = left / 2
-        Seq(new ParArrayIterator(i, i + splitpoint, arr) with SCPI,
-            new ParArrayIterator(i + splitpoint, until, arr) with SCPI)
+        val sq = Seq(
+          new ParArrayIterator(i, i + splitpoint, arr) with SCPI,
+          new ParArrayIterator(i + splitpoint, until, arr) with SCPI)
+        i = until
+        sq
       } else {
         Seq(this)
       }