/interpreter/tags/at2dist220411/src/edu/vub/at/actors/net/OBJNetwork.java

 1/**
 2 * AmbientTalk/2 Project
 3 * OBJNetwork.java created on 24-feb-2007 at 17:38:31
 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;
29
30import java.util.HashMap;
31
32import edu.vub.at.actors.natives.ELVirtualMachine;
33import edu.vub.at.eval.Evaluator;
34import edu.vub.at.exceptions.InterpreterException;
35import edu.vub.at.objects.ATNil;
36import edu.vub.at.objects.ATObject;
37import edu.vub.at.objects.natives.NATByCopy;
38import edu.vub.at.objects.natives.NATText;
39import edu.vub.util.TempFieldGenerator;
40
41/**
42 * This class represents the singleton network object which
43 * provides methods to interface with AT/2's distribution layer.
44 *
45 * @author tvcutsem
46 */
47public final class OBJNetwork extends NATByCopy {
48	
49	/**
50	 * The singleton instance of the network object
51	 */
52	static public final OBJNetwork _INSTANCE_ = new OBJNetwork();
53	
54	/**
55	 * Constructor made private for singleton design pattern
56	 */
57	private OBJNetwork() { }
58	
59	/**
60	 * def online() { make the interpreter go online; return nil }
61	 * After invoking this method, publications and subscriptions can interact
62	 * with those of remote VMs.
63	 */
64	public ATNil base_online() {
65		ELVirtualMachine.currentVM().event_goOnline();
66		return Evaluator.getNil();
67	}
68
69	/**
70	 * def offline() { make the interpreter go offline; return nil }
71	 * Invoking this method causes remote references to become disconnected.
72	 * 
73	 */
74	public ATNil base_offline() {
75		ELVirtualMachine.currentVM().event_goOffline();
76		return Evaluator.getNil();
77	}
78	
79	/**
80	 * After deserialization, ensure that the network object remains unique.
81	 */
82	public ATObject meta_resolve() throws InterpreterException {
83		return OBJNetwork._INSTANCE_;
84	}
85	
86	public NATText meta_print() throws InterpreterException {
87		return NATText.atValue("<native object: network>");
88	}
89	
90	public NATText impl_asCode(TempFieldGenerator objectMap) throws InterpreterException {
91		if (objectMap.contains(this)) {
92			return objectMap.getName(this);
93		}
94		NATText name = objectMap.put(this, NATText.atValue("network"));
95		return name;
96	}
97	
98}