BasicRandom.cc

//FJSTARTHEADER
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// Copyright (c) 2005-2023, Matteo Cacciari, Gavin P. Salam and Gregory Soyez
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//   nlo includes
#include "fastjet/internal/BasicRandom.hh"
 
FASTJET_BEGIN_NAMESPACE      // defined in fastjet/internal/base.hh
 
#ifdef FASTJET_HAVE_LIMITED_THREAD_SAFETY
std::mutex BasicRandom<double>::_multiple_number_generation_mutex;
#endif
 
//
//                   random number generator
//  uses method of L'Ecuyer, (via F.James, comp. phys. comm. 60(1990)329)
//
int __default_random_generator(int *__iseed) 
{
  int __k = __iseed[0]/53668;
  __iseed[0] = (__iseed[0] - __k*53668)*40014 - __k*12211;
  if(__iseed[0] < 0) __iseed[0] += 2147483563;
  
  __k = __iseed[1]/52774;
  __iseed[1] = (__iseed[1] - __k*52774)*40692 - __k*3791;
  if(__iseed[1] < 0) __iseed[1] += 2147483399;
  
  int __iz = __iseed[0] - __iseed[1];
  if(__iz < 1) __iz += 2147483562;
  
  return __iz;
}
 
//   global defined random number generator
BasicRandom<int>     _G_random_int;
BasicRandom<double>  _G_random_double;
 
 
FASTJET_END_NAMESPACE