ModuleManager angefangen; libltdl zum Projekt hinzugefuegt

1 files changed, 210 insertions, 0 deletions

diff --git a/libltdl/lt_dlloader.c b/libltdl/lt_dlloader.c
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+/* 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));
+}