/**
* Forcefully shuts down the connection to this tablet server and fails all the outstanding RPCs.
* Only use when shutting down a client.
*
* @return deferred object to use to track the shutting down of this connection
*/
public Deferred<Void> shutdown() {
// First, check whether we have RPCs in flight and cancel them.
for (Iterator<KuduRpc<?>> ite = rpcs_inflight.values().iterator(); ite.hasNext(); ) {
KuduRpc<?> rpc = ite.next();
rpc.errback(new ConnectionResetException(null));
ite.remove();
}
// Same for the pending RPCs.
synchronized (this) {
if (pending_rpcs != null) {
for (Iterator<KuduRpc<?>> ite = pending_rpcs.iterator(); ite.hasNext(); ) {
ite.next().errback(new ConnectionResetException(null));
ite.remove();
}
}
}
final Channel chancopy = chan;
if (chancopy == null) {
return Deferred.fromResult(null);
}
if (chancopy.isConnected()) {
Channels.disconnect(chancopy); // ... this is going to set it to null.
// At this point, all in-flight RPCs are going to be failed.
}
if (chancopy.isBound()) {
Channels.unbind(chancopy);
}
// It's OK to call close() on a Channel if it's already closed.
final ChannelFuture future = Channels.close(chancopy);
// Now wrap the ChannelFuture in a Deferred.
final Deferred<Void> d = new Deferred<Void>();
// Opportunistically check if it's already completed successfully.
if (future.isSuccess()) {
d.callback(null);
} else {
// If we get here, either the future failed (yeah, that sounds weird)
// or the future hasn't completed yet (heh).
future.addListener(
new ChannelFutureListener() {
public void operationComplete(final ChannelFuture future) {
if (future.isSuccess()) {
d.callback(null);
return;
}
final Throwable t = future.getCause();
if (t instanceof Exception) {
d.callback(t);
} else {
// Wrap the Throwable because Deferred doesn't handle Throwables,
// it only uses Exception.
d.callback(
new NonRecoverableException("Failed to shutdown: " + TabletClient.this, t));
}
}
});
}
return d;
}
/** Quick and dirty way to close a connection to a tablet server, if it wasn't already closed. */
@VisibleForTesting
void disconnect() {
Channel chancopy = chan;
if (chancopy != null && chancopy.isConnected()) {
Channels.disconnect(chancopy);
}
}