1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
8 *
9 * Alternatively, the contents of this file may be used under the terms of
10 * either the GNU Lesser General Public License Version 2.1 or later (the
11 * "LGPL"), in which case the provisions of the LGPL are applicable instead
12 * of those above. If you wish to allow use of your version of this file only
13 * under the terms of the LGPL, and not to allow others to use your version of
14 * this file under the terms of the EPL, indicate your decision by deleting
15 * the provisions above and replace them with the notice and other provisions
16 * required by the LGPL. If you do not delete the provisions above, a recipient
17 * may use your version of this file under the terms of the EPL or the LGPL.
18 *
19 * Based on the original MiniSat specification from:
20 *
21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
22 * Sixth International Conference on Theory and Applications of Satisfiability
23 * Testing, LNCS 2919, pp 502-518, 2003.
24 *
25 * See www.minisat.se for the original solver in C++.
26 *
27 * Contributors:
28 * CRIL - initial API and implementation
29 *******************************************************************************/
30 package org.sat4j.minisat.core;
31
32 import java.io.Serializable;
33
34 /**
35 * Abstraction allowing to choose various restarts strategies.
36 *
37 * @author leberre
38 *
39 */
40 public interface RestartStrategy extends Serializable, ConflictTimer {
41
42 /**
43 * Hook method called just before the search starts.
44 *
45 * @param params
46 * the user's search parameters.
47 *
48 */
49 void init(SearchParams params);
50
51 /**
52 * Ask for the next restart in number of conflicts. Deprecated since 2.3.2
53 *
54 * @return the delay in conflicts before the next restart.
55 */
56 @Deprecated
57 long nextRestartNumberOfConflict();
58
59 /**
60 * Ask the strategy if the solver should restart.
61 *
62 * @return true if the solver should restart, else false.
63 */
64 boolean shouldRestart();
65
66 /**
67 * Hook method called when a restart occurs (once the solver has backtracked
68 * to top decision level).
69 *
70 */
71 void onRestart();
72
73 /**
74 * Called when the solver backjumps to the root level.
75 *
76 * @since 2.3.2
77 */
78 void onBackjumpToRootLevel();
79
80 SearchParams getSearchParams();
81
82 void newLearnedClause(Constr learned, int trailLevel);
83 }