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/** |
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* @test 1.1 03/11/06 |
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* @test %I% %E% |
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* @bug 4949279 |
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* @summary Independent instantiations of Random() have distinct seeds. |
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*/ |
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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/licenses/publicdomain |
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*/ |
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import java.util.Random; |
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public class DistinctSeeds { |
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public static void main(String[] args) throws Exception { |
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// Strictly speaking, it is possible for these to be equal, |
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// but the likelihood should be *extremely* small. |
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if (new Random().nextLong() == new Random().nextLong()) |
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throw new RuntimeException("Random seeds not unique."); |
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// Strictly speaking, it is possible for these to randomly fail, |
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// but the probability should be *extremely* small (< 2**-63). |
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if (new Random().nextLong() == new Random().nextLong() || |
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new Random().nextLong() == new Random().nextLong()) |
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throw new RuntimeException("Random() seeds not unique."); |
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} |
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} |
