+ // NB. keep cap->lock held while we call boundTaskExiting(). This
+ // is necessary during shutdown, where we want the invariant that
+ // after shutdownCapability(), all the Tasks associated with the
+ // Capability have completed their shutdown too. Otherwise we
+ // could have boundTaskExiting()/workerTaskStop() running at some
+ // random point in the future, which causes problems for
+ // freeTaskManager().
+ ACQUIRE_LOCK(&cap->lock);
+ releaseCapability_(cap,rtsFalse);