--- /dev/null
+/* lt_dlloader.c -- dynamic library loader interface
+
+ Copyright (C) 2004, 2007, 2008 Free Software Foundation, Inc.
+ Written by Gary V. Vaughan, 2004
+
+ NOTE: The canonical source of this file is maintained with the
+ GNU Libtool package. Report bugs to bug-libtool@gnu.org.
+
+GNU Libltdl 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 of the License, or (at your option) any later version.
+
+As a special exception to the GNU Lesser General Public License,
+if you distribute this file as part of a program or library that
+is built using GNU Libtool, you may include this file under the
+same distribution terms that you use for the rest of that program.
+
+GNU Libltdl 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 GNU Libltdl; see the file COPYING.LIB. If not, a
+copy can be downloaded from http://www.gnu.org/licenses/lgpl.html,
+or obtained by writing to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+*/
+
+#include "lt__private.h"
+#include "lt_dlloader.h"
+
+#define RETURN_SUCCESS 0
+#define RETURN_FAILURE 1
+
+static void * loader_callback (SList *item, void *userdata);
+
+/* A list of all the dlloaders we know about, each stored as a boxed
+ SList item: */
+static SList *loaders = 0;
+
+
+/* Return NULL, unless the loader in this ITEM has a matching name,
+ in which case we return the matching item so that its address is
+ passed back out (for possible freeing) by slist_remove. */
+static void *
+loader_callback (SList *item, void *userdata)
+{
+ const lt_dlvtable *vtable = (const lt_dlvtable *) item->userdata;
+ const char * name = (const char *) userdata;
+
+ assert (vtable);
+
+ return streq (vtable->name, name) ? (void *) item : NULL;
+}
+
+
+/* Hook VTABLE into our global LOADERS list according to its own
+ PRIORITY field value. */
+int
+lt_dlloader_add (const lt_dlvtable *vtable)
+{
+ SList *item;
+
+ if ((vtable == 0) /* diagnose invalid vtable fields */
+ || (vtable->module_open == 0)
+ || (vtable->module_close == 0)
+ || (vtable->find_sym == 0)
+ || ((vtable->priority != LT_DLLOADER_PREPEND) &&
+ (vtable->priority != LT_DLLOADER_APPEND)))
+ {
+ LT__SETERROR (INVALID_LOADER);
+ return RETURN_FAILURE;
+ }
+
+ item = slist_box (vtable);
+ if (!item)
+ {
+ (*lt__alloc_die) ();
+
+ /* Let the caller know something went wrong if lt__alloc_die
+ doesn't abort. */
+ return RETURN_FAILURE;
+ }
+
+ if (vtable->priority == LT_DLLOADER_PREPEND)
+ {
+ loaders = slist_cons (item, loaders);
+ }
+ else
+ {
+ assert (vtable->priority == LT_DLLOADER_APPEND);
+ loaders = slist_concat (loaders, item);
+ }
+
+ return RETURN_SUCCESS;
+}
+
+#ifdef LT_DEBUG_LOADERS
+static void *
+loader_dump_callback (SList *item, void *userdata)
+{
+ const lt_dlvtable *vtable = (const lt_dlvtable *) item->userdata;
+ fprintf (stderr, ", %s", (vtable && vtable->name) ? vtable->name : "(null)");
+ return 0;
+}
+
+void
+lt_dlloader_dump (void)
+{
+ fprintf (stderr, "loaders: ");
+ if (!loaders)
+ {
+ fprintf (stderr, "(empty)");
+ }
+ else
+ {
+ const lt_dlvtable *head = (const lt_dlvtable *) loaders->userdata;
+ fprintf (stderr, "%s", (head && head->name) ? head->name : "(null)");
+ if (slist_tail (loaders))
+ slist_foreach (slist_tail (loaders), loader_dump_callback, NULL);
+ }
+ fprintf (stderr, "\n");
+}
+#endif
+
+/* An iterator for the global loader list: if LOADER is NULL, then
+ return the first element, otherwise the following element. */
+lt_dlloader
+lt_dlloader_next (lt_dlloader loader)
+{
+ SList *item = (SList *) loader;
+ return (lt_dlloader) (item ? item->next : loaders);
+}
+
+
+/* Non-destructive unboxing of a loader. */
+const lt_dlvtable *
+lt_dlloader_get (lt_dlloader loader)
+{
+ return (const lt_dlvtable *) (loader ? ((SList *) loader)->userdata : NULL);
+}
+
+
+/* Return the contents of the first item in the global loader list
+ with a matching NAME after removing it from that list. If there
+ was no match, return NULL; if there is an error, return NULL and
+ set an error for lt_dlerror; do not set an error if only resident
+ modules need this loader; in either case, the loader list is not
+ changed if NULL is returned. */
+lt_dlvtable *
+lt_dlloader_remove (char *name)
+{
+ const lt_dlvtable * vtable = lt_dlloader_find (name);
+ static const char id_string[] = "lt_dlloader_remove";
+ lt_dlinterface_id iface;
+ lt_dlhandle handle = 0;
+ int in_use = 0;
+ int in_use_by_resident = 0;
+
+ if (!vtable)
+ {
+ LT__SETERROR (INVALID_LOADER);
+ return 0;
+ }
+
+ /* Fail if there are any open modules which use this loader. */
+ iface = lt_dlinterface_register (id_string, NULL);
+ while ((handle = lt_dlhandle_iterate (iface, handle)))
+ {
+ lt_dlhandle cur = handle;
+ if (cur->vtable == vtable)
+ {
+ in_use = 1;
+ if (lt_dlisresident (handle))
+ in_use_by_resident = 1;
+ }
+ }
+ lt_dlinterface_free (iface);
+ if (in_use)
+ {
+ if (!in_use_by_resident)
+ LT__SETERROR (REMOVE_LOADER);
+ return 0;
+ }
+
+ /* Call the loader finalisation function. */
+ if (vtable && vtable->dlloader_exit)
+ {
+ if ((*vtable->dlloader_exit) (vtable->dlloader_data) != 0)
+ {
+ /* If there is an exit function, and it returns non-zero
+ then it must set an error, and we will not remove it
+ from the list. */
+ return 0;
+ }
+ }
+
+ /* If we got this far, remove the loader from our global list. */
+ return (lt_dlvtable *)
+ slist_unbox ((SList *) slist_remove (&loaders, loader_callback, name));
+}
+
+
+const lt_dlvtable *
+lt_dlloader_find (char *name)
+{
+ return lt_dlloader_get (slist_find (loaders, loader_callback, name));
+}
HCoop / hcoop / debian / courier-authlib.git / blobdiff