localename: Fine-tune support for per-thread locales on Solaris 11.4.

* lib/localename-table.h: New file, extracted from lib/localename.c.
* lib/localename-table.c: Likewise.
* lib/localename.c: Include localename-table.h.
(get_locale_t_name, newlocale, duplocale, freelocale): Invoke
locale_hash_function instead of pointer_hash.
* modules/localename (Files): Add lib/localename-table.h,
lib/localename-table.c.
(lib_SOURCES): Add localename-table.c.
* m4/intlsolaris.m4 (gt_INTL_SOLARIS): Require AC_CANONICAL_HOST. Test
for Solaris 11.4 locale system only on Solaris. Test for it
independently whether getlocalename_l exists.
* m4/intl.m4 (gt_INTL_SUBDIR_CORE): Don't test for 'uselocale' and
'getlocalename_l'. Instead, invoke gt_INTL_SOLARIS. Set
HAVE_NAMELESS_LOCALES.
* modules/gettext (Files): Add m4/intlsolaris.m4.

1 files changed, 73 insertions, 0 deletions

diff --git a/lib/localename-table.h b/lib/localename-table.h
new file mode 100644
index 0000000000..0d204d6d14
--- /dev/null
+++ b/lib/localename-table.h
@@ -0,0 +1,73 @@
+/* Table that maps a locale object to the names of the locale categories.
+   Copyright (C) 2018 Free Software Foundation, Inc.
+
+   This program 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 program 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 Bruno Haible <bruno@clisp.org>, 2018.  */
+
+#if HAVE_USELOCALE && HAVE_NAMELESS_LOCALES /* Solaris >= 11.4 */
+
+# include <stddef.h>
+# include <locale.h>
+
+# ifdef IN_LIBINTL
+#  include "lock.h"
+# else
+#  include "glthread/lock.h"
+# endif
+
+struct locale_categories_names
+  {
+    /* Locale category -> name (allocated with indefinite extent).  */
+    const char *category_name[6];
+  };
+
+/* A hash table of fixed size.  Multiple threads can access it read-only
+   simultaneously, but only one thread can insert into it or remove from it
+   at the same time.
+   This hash table has global scope, so that when an application uses both
+   GNU libintl and gnulib, the application sees only one hash table.  (When
+   linking statically with libintl, the fact that localename-table.c is a
+   separate compilation unit resolves the duplicate symbol conflict.  When
+   linking with libintl as a shared library, we rely on ELF and the symbol
+   conflict resolution implemented in the ELF dynamic loader here.)
+   Both the libintl overrides and the gnulib overrides of the functions
+   newlocale, duplocale, freelocale see the same hash table (and the same lock).
+   For this reason, the internal layout of the hash table and the hash function
+   MUST NEVER CHANGE.  If you need to change the internal layout or the hash
+   function, introduce versioning by appending a version suffix to the symbols
+   at the linker level.  */
+# define locale_hash_function libintl_locale_hash_function
+# define locale_hash_table libintl_locale_hash_table
+# define locale_lock libintl_locale_lock
+
+extern size_t _GL_ATTRIBUTE_CONST locale_hash_function (locale_t x);
+
+/* A node in a hash bucket collision list.  */
+struct locale_hash_node
+  {
+    struct locale_hash_node *next;
+    locale_t locale;
+    struct locale_categories_names names;
+  };
+
+# define LOCALE_HASH_TABLE_SIZE 101
+extern struct locale_hash_node * locale_hash_table[LOCALE_HASH_TABLE_SIZE];
+
+/* This lock protects the locale_hash_table against multiple simultaneous
+   accesses (except that multiple simultaneous read accesses are allowed).  */
+
+gl_rwlock_define(extern, locale_lock)
+
+#endif