src/gromacs/random/tests/seed.cpp

   1 /*
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   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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  35 /*! \internal \file
  36  * \brief Tests for random seed functions
  37  *
  38  * \author Erik Lindahl <erik.lindahl@gmail.com>
  39  * \ingroup module_random
  40  */
  41 #include "gmxpre.h"
  42
  43 #include "gromacs/random/seed.h"
  44
  45 #include <gtest/gtest.h>
  46
  47 namespace gmx
  48 {
  49
  50 namespace
  51 {
  52
  53 // Test the random device call
  54 TEST(SeedTest, makeRandomSeed)
  55 {
  56     // Unlike Sony, we do not use "4" as a constant random value, so the only
  57     // thing we can check for the random device is that multiple calls to
  58     // it produce different results.
  59     // We choose to ignore the 2^-64 probability this will happen by chance;
  60     // if you execute the unit tests once per second you might have to run them
  61     // an extra time rougly once per 300 billion years - apologies in advance!
  62
  63     uint64_t i0 = makeRandomSeed();
  64     uint64_t i1 = makeRandomSeed();
  65
  66     EXPECT_NE(i0, i1);
  67 }
  68
  69 }      // namespace anonymous
  70
  71 }      // namespace gmx