#include <pthread.h>
#include <stdlib.h>

#include "MiscSupport.h"

#include "Random.h"


static __thread drand48_data *buffer = NULL;

static void initBuffer()
{
  if (buffer) return;
  buffer = new drand48_data;
  long seedval = TimeVal(true).asMicroseconds() ^ pthread_self();
  srand48_r(seedval, buffer);  
}

int32_t getRandom31()
{ 
  initBuffer();
  // A long is 64 bits, but the result is only 31 bits.
  long int result;
  lrand48_r(buffer, &result);
  return result;
}

uint64_t getRandom64()
{
  initBuffer();
  long int a, b, c;
  lrand48_r(buffer, &a);
  lrand48_r(buffer, &b);
  lrand48_r(buffer, &c);
  return a ^ (b << 33) ^ (c << 16);
}

double getRandomD()
{
  initBuffer();
  double result;
  drand48_r(buffer, &result);
  return result;
}