/interpreter/tags/at_build150307/src/edu/vub/at/actors/net/cmd/CMDInitRequireServices.java

 1/**
 2 * AmbientTalk/2 Project
 3 * VMInitialDiscovery.java created on 22-feb-2007 at 13:20:13
 4 * (c) Programming Technology Lab, 2006 - 2007
 5 * Authors: Tom Van Cutsem & Stijn Mostinckx
 6 * 
 7 * Permission is hereby granted, free of charge, to any person
 8 * obtaining a copy of this software and associated documentation
 9 * files (the "Software"), to deal in the Software without
10 * restriction, including without limitation the rights to use,
11 * copy, modify, merge, publish, distribute, sublicense, and/or
12 * sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following
14 * conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
27 */
28package edu.vub.at.actors.net.cmd;
29
30import edu.vub.at.actors.natives.ELVirtualMachine;
31import edu.vub.at.actors.net.Logging;
32
33import java.util.Set;
34
35import org.jgroups.Address;
36import org.jgroups.Message;
37import org.jgroups.SuspectedException;
38import org.jgroups.TimeoutException;
39import org.jgroups.blocks.MessageDispatcher;
40
41/**
42 * A CMDInitRequireServices message is sent asynchronously to any VM just discovered in the environment
43 * if thhe discovering VM has some open subscriptions. This command is sent to the discovered VM to ask
44 * it whether it has any publications matching the outstanding subscriptions at the sender VM.
45 * 
46 * SENDER: the discovering VM
47 * RECEIVER: the discovered VM
48 * MODE: ASYNCHRONOUS, UNICAST
49 * PROPERTIES: outstanding subscription topics of sender
50 * REPLY: potential CMDJoinServices
51 * 
52 * @author tvcutsem
53 */
54
55public class CMDInitRequireServices extends VMCommand {
56
57	/**
58	 * A Set of Packet objects representing serialized ATStripe topics.
59	 */
60	private final Set topics_;
61	
62	public CMDInitRequireServices(Set topics) {
63		super("initRequireServices");
64		topics_ = topics;
65	}
66	
67	public void send(MessageDispatcher dispatcher, Address recipientVM) {
68		try {
69			super.sendAsyncUnicast(dispatcher, recipientVM);
70		} catch (TimeoutException e) {
71			Logging.VirtualMachine_LOG.warn(this + ": timeout while trying to transmit discovery query, dropping");
72		} catch (SuspectedException e) {
73			Logging.VirtualMachine_LOG.warn(this + ": remote VM suspected while sending discovery query");
74		}
75	}
76	
77	public Object uponReceiptBy(ELVirtualMachine remoteHost, Message wrapper) throws Exception {
78		// query local discoverymanager for matching topics
79		remoteHost.discoveryActor_.event_receiveNewSubscriptionsFrom(topics_, wrapper.getSrc());
80    	return null;
81	}
82	
83}