a4/tcp/tester/learner/NonDeterminismCheckingSUL.java

   1 package learner;
   2
   3 import java.util.ArrayList;
   4 import java.util.List;
   5
   6 import de.learnlib.api.SUL;
   7 import de.learnlib.api.SULException;
   8
   9 /**
  10  * SUL-wrapper to check for non-determinism, by use of an observation tree.
  11  *
  12  * @author Ramon Janssen
  13  *
  14  * @param <I>
  15  * @param <O>
  16  */
  17 public class NonDeterminismCheckingSUL<I,O> implements SUL<I,O> {
  18         private final SUL<I,O> sul;
  19         private final ObservationTree<I,O> root = new ObservationTree<I,O>();
  20         private final List<I> inputs = new ArrayList<>();
  21         private final List<O> outputs = new ArrayList<>();
  22
  23         public NonDeterminismCheckingSUL(SUL<I,O> sul) {
  24                 this.sul = sul;
  25         }
  26
  27         @Override
  28         public void post() {
  29                 sul.post();
  30                 // check for non-determinism: crashes if outputs are inconsistent with previous ones
  31                 root.addObservation(inputs, outputs);
  32                 inputs.clear();
  33                 outputs.clear();
  34         }
  35
  36         @Override
  37         public void pre() {
  38                 sul.pre();
  39         }
  40
  41         @Override
  42         public O step(I input) throws SULException {
  43                 O result = sul.step(input);
  44                 inputs.add(input);
  45                 outputs.add(result);
  46                 return result;
  47         }
  48 }