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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.rng.sampling.distribution;
18  
19  import org.junit.Assert;
20  import org.junit.Test;
21  import org.apache.commons.rng.simple.RandomSource;
22  import org.apache.commons.rng.UniformRandomProvider;
23  
24  /**
25   * Test for {@link ZigguratNormalizedGaussianSampler}.
26   */
27  public class ZigguratNormalizedGaussianSamplerTest {
28      // Cf. RNG-56
29      @Test(expected = StackOverflowError.class)
30      public void testInfiniteLoop() {
31          // A bad implementation whose only purpose is to force access
32          // to the rarest branch.
33          final UniformRandomProvider bad = new UniformRandomProvider() {
34                  public long nextLong(long n) { return 0; }
35                  public long nextLong() { return Long.MAX_VALUE; }
36                  public int nextInt(int n) { return 0; }
37                  public int nextInt() { return Integer.MAX_VALUE; }
38                  public float nextFloat() { return 1; }
39                  public double nextDouble() { return 1;}
40                  public void nextBytes(byte[] bytes, int start, int len) {}
41                  public void nextBytes(byte[] bytes) {}
42                  public boolean nextBoolean() { return false; }
43              };
44  
45          // Infinite loop (in v1.1).
46          new ZigguratNormalizedGaussianSampler(bad).sample();
47      }
48  }