+bool Mailbox::listen() const
+{
+ return not pimpl_->empty() || (pimpl_->is_permanent() && pimpl_->has_some_done_comm());
+}
+
+aid_t Mailbox::listen_from() const
+{
+ kernel::activity::CommImplPtr comm = front();
+ if (comm && comm->src_actor_)
+ return comm->src_actor_->get_pid();
+ else
+ return -1;
+}
+
+bool Mailbox::ready() const