lib/time_r.c

/* Reentrant time functions like localtime_r.

   Copyright (C) 2003, 2006-2007, 2010-2026 Free Software Foundation, Inc.

   This file is free software: you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   This file is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Paul Eggert.  */

#include <config.h>

#include <time.h>

/* The replacement functions in this file are only used on native Windows.
   They are multithread-safe, because the gmtime() and localtime() functions
   on native Windows — both in the ucrt and in the older MSVCRT — return a
   pointer to a 'struct tm' in thread-local memory.  */

static struct tm *
copy_tm_result (struct tm *dest, struct tm const *src)
{
  if (! src)
    return 0;
  *dest = *src;
  return dest;
}


struct tm *
gmtime_r (time_t const * restrict t, struct tm * restrict tp)
{
  return copy_tm_result (tp, gmtime (t));
}

struct tm *
localtime_r (time_t const * restrict t, struct tm * restrict tp)
{
  return copy_tm_result (tp, localtime (t));
}