{
StgTSO *tso, *next;
Capability *cap;
+ Task *task, *saved_task;;
step *step;
+ task = myTask();
+ cap = task->cap;
+
for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
next = tso->global_link;
debugTrace(DEBUG_sched, "performing blocked throwTo to thread %lu", (unsigned long)tso->id);
- cap = tso->cap;
- maybePerformBlockedException(cap, tso);
- }
+ // We must pretend this Capability belongs to the current Task
+ // for the time being, as invariants will be broken otherwise.
+ // In fact the current Task has exclusive access to the systme
+ // at this point, so this is just bookkeeping:
+ task->cap = tso->cap;
+ saved_task = tso->cap->running_task;
+ tso->cap->running_task = task;
+ maybePerformBlockedException(tso->cap, tso);
+ tso->cap->running_task = saved_task;
+ }
+
+ // Restore our original Capability:
+ task->cap = cap;
}