--- a/src/Pure/Concurrent/task_queue.ML Wed Apr 11 13:37:46 2012 +0200
+++ b/src/Pure/Concurrent/task_queue.ML Wed Apr 11 13:49:09 2012 +0200
@@ -38,7 +38,7 @@
val enqueue_passive: group -> (unit -> bool) -> queue -> task * queue
val enqueue: string -> group -> task list -> int -> (bool -> bool) -> queue -> task * queue
val extend: task -> (bool -> bool) -> queue -> queue option
- val dequeue_passive: Thread.thread -> task -> queue -> bool * queue
+ val dequeue_passive: Thread.thread -> task -> queue -> bool option * queue
val dequeue: Thread.thread -> queue -> (task * (bool -> bool) list) option * queue
val dequeue_deps: Thread.thread -> task list -> queue ->
(((task * (bool -> bool) list) option * task list) * queue)
@@ -317,8 +317,9 @@
(case try (get_job jobs) task of
SOME (Passive _) =>
let val jobs' = set_job task (Running thread) jobs
- in (true, make_queue groups jobs') end
- | _ => (false, queue));
+ in (SOME true, make_queue groups jobs') end
+ | SOME _ => (SOME false, queue)
+ | NONE => (NONE, queue));
fun dequeue thread (queue as Queue {groups, jobs}) =
(case Task_Graph.get_first (uncurry ready_job) jobs of