locale/duplocale.c

   1 /* Duplicate handle for selection of locales.
   2    Copyright (C) 1997,2000-2002,2005,2008,2009 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   /* Handle a special value.  */
  41   if (dataset == LC_GLOBAL_LOCALE)
  42     dataset = &_nl_global_locale;
  43
  44   __locale_t result;
  45   int cnt;
  46   size_t names_len = 0;
  47
  48   /* Calculate the total space we need to store all the names.  */
  49   for (cnt = 0; cnt < __LC_LAST; ++cnt)
  50     if (cnt != LC_ALL && dataset->__names[cnt] != _nl_C_name)
  51       names_len += strlen (dataset->__names[cnt]) + 1;
  52
  53   /* Get memory.  */
  54   result = malloc (sizeof (struct __locale_struct) + names_len);
  55
  56   if (result != NULL)
  57     {
  58       char *namep = (char *) (result + 1);
  59
  60       /* We modify global data (the usage counts).  */
  61       __libc_rwlock_wrlock (__libc_setlocale_lock);
  62
  63       for (cnt = 0; cnt < __LC_LAST; ++cnt)
  64         if (cnt != LC_ALL)
  65           {
  66             result->__locales[cnt] = dataset->__locales[cnt];
  67             if (result->__locales[cnt]->usage_count < MAX_USAGE_COUNT)
  68               ++result->__locales[cnt]->usage_count;
  69
  70             if (dataset->__names[cnt] == _nl_C_name)
  71               result->__names[cnt] = _nl_C_name;
  72             else
  73               {
  74                 result->__names[cnt] = namep;
  75                 namep = __stpcpy (namep, dataset->__names[cnt]) + 1;
  76               }
  77           }
  78
  79       /* Update the special members.  */
  80       result->__ctype_b = dataset->__ctype_b;
  81       result->__ctype_tolower = dataset->__ctype_tolower;
  82       result->__ctype_toupper = dataset->__ctype_toupper;
  83
  84       /* It's done.  */
  85       __libc_rwlock_unlock (__libc_setlocale_lock);
  86     }
  87
  88   return result;
  89 }
  90 weak_alias (__duplocale, duplocale)