+ //
+ // What can we do here? There are a bunch of worker threads, it
+ // might be nice to let them exit cleanly. There may be some main
+ // threads in the run queue; we should let them return to their
+ // callers with an Interrupted state. We can't in general wait
+ // for all the running Tasks to stop, because some might be off in
+ // a C call that is blocked.
+ //
+ // Letting the run queue drain is the safest thing. That lets any
+ // main threads return that can return, and cleans up all the
+ // runnable threads. Then we grab all the Capabilities to stop
+ // anything unexpected happening while we shut down.
+ //
+ // ToDo: this doesn't let us get the time stats from the worker
+ // tasks, because they haven't called taskStop().
+ //
+ ACQUIRE_LOCK(&sched_mutex);
+ {
+ nat i;
+ for (i = 1000; i > 0; i--) {
+ if (EMPTY_RUN_QUEUE()) {
+ IF_DEBUG(scheduler, sched_belch("run queue is empty"));
+ break;
+ }
+ IF_DEBUG(scheduler, sched_belch("yielding"));
+ RELEASE_LOCK(&sched_mutex);
+ prodWorker();
+ yieldThread();
+ ACQUIRE_LOCK(&sched_mutex);
+ }
+ }
+
+#ifdef SMP
+ {
+ Capability *cap;
+ int n_capabilities = RtsFlags.ParFlags.nNodes;
+ Capability *caps[n_capabilities];
+ nat i;
+
+ while (n_capabilities > 0) {
+ IF_DEBUG(scheduler, sched_belch("exitScheduler: grabbing all the capabilies (%d left)", n_capabilities));
+ waitForReturnCapability(&sched_mutex, &cap);
+ n_capabilities--;
+ caps[n_capabilities] = cap;
+ }
+ }
+#else
+ {
+ Capability *cap;
+ waitForReturnCapability(&sched_mutex, &cap);
+ }
+#endif