+#if HAVE_USELOCALE /* glibc or Mac OS X */
+
+/* Simple hash set of strings. We don't want to drag in lots of hash table
+ code here. */
+
+# define SIZE_BITS (sizeof (size_t) * CHAR_BIT)
+
+/* A hash function for NUL-terminated char* strings using
+ the method described by Bruno Haible.
+ See http://www.haible.de/bruno/hashfunc.html. */
+static size_t
+string_hash (const void *x)
+{
+ const char *s = (const char *) x;
+ size_t h = 0;
+
+ for (; *s; s++)
+ h = *s + ((h << 9) | (h >> (SIZE_BITS - 9)));
+
+ return h;
+}
+
+/* A hash table of fixed size. Multiple threads can access it read-only
+ simultaneously, but only one thread can insert into it at the same time. */
+
+/* A node in a hash bucket collision list. */
+struct hash_node
+ {
+ struct hash_node * volatile next;
+ char contents[100]; /* has variable size */
+ };
+
+# define HASH_TABLE_SIZE 257
+static struct hash_node * volatile struniq_hash_table[HASH_TABLE_SIZE]
+ /* = { NULL, ..., NULL } */;
+
+/* This lock protects the struniq_hash_table against multiple simultaneous
+ insertions. */
+gl_lock_define_initialized(static, struniq_lock)
+
+/* Store a copy of the given string in a string pool with indefinite extent.
+ Return a pointer to this copy. */
+static const char *
+struniq (const char *string)
+{
+ size_t hashcode = string_hash (string);
+ size_t slot = hashcode % HASH_TABLE_SIZE;
+ size_t size;
+ struct hash_node *new_node;
+ struct hash_node *p;
+ for (p = struniq_hash_table[slot]; p != NULL; p = p->next)
+ if (strcmp (p->contents, string) == 0)
+ return p->contents;
+ size = strlen (string) + 1;
+ new_node =
+ (struct hash_node *)
+ malloc (offsetof (struct hash_node, contents[0]) + size);
+ if (new_node == NULL)
+ /* Out of memory. Return a statically allocated string. */
+ return "C";
+ memcpy (new_node->contents, string, size);
+ /* Lock while inserting new_node. */
+ gl_lock_lock (struniq_lock);
+ /* Check whether another thread already added the string while we were
+ waiting on the lock. */
+ for (p = struniq_hash_table[slot]; p != NULL; p = p->next)
+ if (strcmp (p->contents, string) == 0)
+ {
+ free (new_node);
+ new_node = p;
+ goto done;
+ }
+ /* Really insert new_node into the hash table. Fill new_node entirely first,
+ because other threads may be iterating over the linked list. */
+ new_node->next = struniq_hash_table[slot];
+ struniq_hash_table[slot] = new_node;
+ done:
+ /* Unlock after new_node is inserted. */
+ gl_lock_unlock (struniq_lock);
+ return new_node->contents;
+}
+
+#endif
+
+
+#if defined IN_LIBINTL || HAVE_USELOCALE
+
+/* Like gl_locale_name_thread, except that the result is not in storage of
+ indefinite extent. */
+# if !defined IN_LIBINTL
+static
+# endif
+const char *
+gl_locale_name_thread_unsafe (int category, const char *categoryname)
+{
+# if HAVE_USELOCALE
+ {
+ locale_t thread_locale = uselocale (NULL);
+ if (thread_locale != LC_GLOBAL_LOCALE)
+ {
+# if __GLIBC__ >= 2 && !defined __UCLIBC__
+ /* Work around an incorrect definition of the _NL_LOCALE_NAME macro in
+ glibc < 2.12.
+ See <http://sourceware.org/bugzilla/show_bug.cgi?id=10968>. */
+ const char *name =
+ nl_langinfo (_NL_ITEM ((category), _NL_ITEM_INDEX (-1)));
+ if (name[0] == '\0')
+ /* Fallback code for glibc < 2.4, which did not implement
+ nl_langinfo (_NL_LOCALE_NAME (category)). */
+ name = thread_locale->__names[category];
+ return name;
+# elif defined __FreeBSD__ || (defined __APPLE__ && defined __MACH__)
+ /* FreeBSD, Mac OS X */
+ int mask;
+
+ switch (category)
+ {
+ case LC_CTYPE:
+ mask = LC_CTYPE_MASK;
+ break;
+ case LC_NUMERIC:
+ mask = LC_NUMERIC_MASK;
+ break;
+ case LC_TIME:
+ mask = LC_TIME_MASK;
+ break;
+ case LC_COLLATE:
+ mask = LC_COLLATE_MASK;
+ break;
+ case LC_MONETARY:
+ mask = LC_MONETARY_MASK;
+ break;
+ case LC_MESSAGES:
+ mask = LC_MESSAGES_MASK;
+ break;
+ default: /* We shouldn't get here. */
+ return "";
+ }
+ return querylocale (mask, thread_locale);
+# endif
+ }
+ }
+# endif
+ return NULL;
+}
+
+#endif
+
+const char *
+gl_locale_name_thread (int category, const char *categoryname)
+{
+#if HAVE_USELOCALE
+ const char *name = gl_locale_name_thread_unsafe (category, categoryname);
+ if (name != NULL)
+ return struniq (name);
+#endif
+ return NULL;
+}
+