void monitorable_actor::bounce(mailbox_element_ptr& what) {
error err;
shared_critical_section([&] {
err = fail_state_;
});
bounce(what, err);
}
void sequencer::enqueue(mailbox_element_ptr what, execution_unit* context) {
auto down_msg_handler = [&](down_msg& dm) {
// quit if either `f` or `g` are no longer available
cleanup(std::move(dm.reason), context);
};
if (handle_system_message(*what, context, false, down_msg_handler))
return;
strong_actor_ptr f;
strong_actor_ptr g;
error err;
shared_critical_section([&] {
f = f_;
g = g_;
err = fail_state_;
});
if (!f) {
// f and g are invalid only after the sequencer terminated
bounce(what, err);
return;
}
// process and forward the non-system message;
// store `f` as the next stage in the forwarding chain
what->stages.push_back(std::move(f));
// forward modified message to `g`
g->enqueue(std::move(what), context);
}
