#include <locale.h>
#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <errno.h>
#include <stdlib.h>
#include <math.h>

/* Run this program with LC_ALL=fr_FR.utf-8 (or some other locale with
 * "," as the decimal point) to demonstrate that c_strtod will affect
 * other threads on platforms without strtod_l.
 *
 * Compile with the -pthread flag if using GCC.
 */

double c_strtod (char const *nptr, char **endptr)
{
  double r;
  char *saved_locale = setlocale (LC_NUMERIC, NULL);

  if (saved_locale)
    {
      saved_locale = strdup (saved_locale);
      if (!saved_locale) abort();
      setlocale (LC_NUMERIC, "C");
    }

  r = strtod(nptr, endptr);

  if (saved_locale)
    {
      setlocale (LC_NUMERIC, saved_locale);
      free (saved_locale);
    }

  return r;
}

void *strtod_thread(void *arg)
{
  int i, use_c_strtod = *((int*)arg);
  for (i=0; ; ++i)
    {
      char *str = use_c_strtod ? "1234.567" : "1234,567";
      double val = (use_c_strtod ? c_strtod : strtod)(str, NULL);

      if (!(fabs(val - 1234.567) < 0.1))
        printf("fail val=%f use_c_strtod=%d i=%d\n",
                val, use_c_strtod, i);
    }
}

int main(int argc, char **argv)
{
  pthread_t th[2];
  int i, arg[2] = {0, 1};

  setlocale(LC_ALL, "");
  for (i = 0; i < 2; ++i)
    {
      if (pthread_create(&th[i], NULL, strtod_thread, &arg[i]))
        printf("thread creation failed, i=%d\n", i);
    }
  pthread_join(th[0], NULL);
  return 0;
}