locale/duplocale.c

   1 /* Duplicate handle for selection of locales.
   2    Copyright (C) 1997,2000,2001,2002,2005,2008 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <locale.h>
  22 #include <bits/libc-lock.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include <localeinfo.h>
  27
  28
  29 /* Lock for protecting global data.  */
  30 __libc_rwlock_define (extern , __libc_setlocale_lock attribute_hidden)
  31
  32
  33 __locale_t
  34 __duplocale (__locale_t dataset)
  35 {
  36   /* This static object is returned for newlocale (LC_ALL_MASK, "C").  */
  37   if (dataset == _nl_C_locobj_ptr)
  38     return dataset;
  39
  40   __locale_t result;
  41   int cnt;
  42   size_t names_len = 0;
  43
  44   /* Calculate the total space we need to store all the names.  */
  45   for (cnt = 0; cnt < __LC_LAST; ++cnt)
  46     if (cnt != LC_ALL && dataset->__names[cnt] != _nl_C_name)
  47       names_len += strlen (dataset->__names[cnt]) + 1;
  48
  49   /* Get memory.  */
  50   result = malloc (sizeof (struct __locale_struct) + names_len);
  51
  52   if (result != NULL)
  53     {
  54       char *namep = (char *) (result + 1);
  55
  56       /* We modify global data (the usage counts).  */
  57       __libc_rwlock_wrlock (__libc_setlocale_lock);
  58
  59       for (cnt = 0; cnt < __LC_LAST; ++cnt)
  60         if (cnt != LC_ALL)
  61           {
  62             result->__locales[cnt] = dataset->__locales[cnt];
  63             if (result->__locales[cnt]->usage_count < MAX_USAGE_COUNT)
  64               ++result->__locales[cnt]->usage_count;
  65
  66             if (dataset->__names[cnt] == _nl_C_name)
  67               result->__names[cnt] = _nl_C_name;
  68             else
  69               {
  70                 result->__names[cnt] = namep;
  71                 namep = __stpcpy (namep, dataset->__names[cnt]) + 1;
  72               }
  73           }
  74
  75       /* Update the special members.  */
  76       result->__ctype_b = dataset->__ctype_b;
  77       result->__ctype_tolower = dataset->__ctype_tolower;
  78       result->__ctype_toupper = dataset->__ctype_toupper;
  79
  80       /* It's done.  */
  81       __libc_rwlock_unlock (__libc_setlocale_lock);
  82     }
  83
  84   return result;
  85 }
  86 weak_alias (__duplocale, duplocale)