diff options
Diffstat (limited to 'newlib/libc/sys/linux/iconv/gconv_dl.c')
| -rw-r--r-- | newlib/libc/sys/linux/iconv/gconv_dl.c | 237 |
1 files changed, 0 insertions, 237 deletions
diff --git a/newlib/libc/sys/linux/iconv/gconv_dl.c b/newlib/libc/sys/linux/iconv/gconv_dl.c deleted file mode 100644 index ee725149f..000000000 --- a/newlib/libc/sys/linux/iconv/gconv_dl.c +++ /dev/null @@ -1,237 +0,0 @@ -/* Handle loading/unloading of shared object for transformation. - Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. - - The GNU C Library 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. - - The GNU C Library 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 the GNU C Library; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -#include <assert.h> -#include <dlfcn.h> -#include <search.h> -#include <stdlib.h> -#include <string.h> -#include <bits/libc-lock.h> -#include <sys/param.h> -#include <ltdl.h> - -#include <gconv_int.h> - - -#ifdef DEBUG -/* For debugging purposes. */ -static void print_all (void); -#endif - - -/* This is a tuning parameter. If a transformation module is not used - anymore it gets not immediately unloaded. Instead we wait a certain - number of load attempts for further modules. If none of the - subsequent load attempts name the same object it finally gets unloaded. - Otherwise it is still available which hopefully is the frequent case. - The following number is the number of unloading attempts we wait - before unloading. */ -#define TRIES_BEFORE_UNLOAD 2 - -/* Array of loaded objects. This is shared by all threads so we have - to use semaphores to access it. */ -static void *loaded; - -/* Comparison function for searching `loaded_object' tree. */ -static int -known_compare (const void *p1, const void *p2) -{ - const struct __gconv_loaded_object *s1 = - (const struct __gconv_loaded_object *) p1; - const struct __gconv_loaded_object *s2 = - (const struct __gconv_loaded_object *) p2; - - return strcmp (s1->name, s2->name); -} - -/* Open the gconv database if necessary. A non-negative return value - means success. */ -struct __gconv_loaded_object * -internal_function -__gconv_find_shlib (const char *name) -{ - struct __gconv_loaded_object *found; - void *keyp; - - - - /* Search the tree of shared objects previously requested. Data in - the tree are `loaded_object' structures, whose first member is a - `const char *', the lookup key. The search returns a pointer to - the tree node structure; the first member of the is a pointer to - our structure (i.e. what will be a `loaded_object'); since the - first member of that is the lookup key string, &FCT_NAME is close - enough to a pointer to our structure to use as a lookup key that - will be passed to `known_compare' (above). */ - - keyp = tfind (&name, &loaded, known_compare); - if (keyp == NULL) - { - /* This name was not known before. */ - size_t namelen = strlen (name) + 1; - - found = malloc (sizeof (struct __gconv_loaded_object) + namelen); - if (found != NULL) - { - /* Point the tree node at this new structure. */ - found->name = (char *) memcpy (found + 1, name, namelen); - found->counter = -TRIES_BEFORE_UNLOAD - 1; - found->handle = NULL; - - if (__builtin_expect (tsearch (found, &loaded, known_compare) - == NULL, 0)) - { - /* Something went wrong while inserting the entry. */ - free (found); - found = NULL; - } - } - } - else - found = *(struct __gconv_loaded_object **) keyp; - - /* Try to load the shared object if the usage count is 0. This - implies that if the shared object is not loadable, the handle is - NULL and the usage count > 0. */ - if (found != NULL) - { - if (found->counter < -TRIES_BEFORE_UNLOAD) - { - assert (found->handle == NULL); - found->handle = __libc_dlopen (found->name); - if (found->handle != NULL) - { - found->fct = __libc_dlsym (found->handle, "gconv"); - if (found->fct == NULL) - { - /* Argh, no conversion function. There is something - wrong here. */ - __gconv_release_shlib (found); - found = NULL; - } - else - { - found->init_fct = __libc_dlsym (found->handle, "gconv_init"); - found->end_fct = __libc_dlsym (found->handle, "gconv_end"); - - /* We have succeeded in loading the shared object. */ - found->counter = 1; - } - } - else - /* Error while loading the shared object. */ - found = NULL; - } - else if (found->handle != NULL) - found->counter = MAX (found->counter + 1, 1); - } - - return found; -} - - -/* This is very ugly but the tsearch functions provide no way to pass - information to the walker function. So we use a global variable. - It is MT safe since we use a lock. */ -static struct __gconv_loaded_object *release_handle; - -static void -do_release_shlib (void *nodep, VISIT value, int level) -{ - struct __gconv_loaded_object *obj = *(struct __gconv_loaded_object **) nodep; - - - - if (value != preorder && value != leaf) - return; - - if (obj == release_handle) - { - /* This is the object we want to unload. Now decrement the - reference counter. */ - assert (obj->counter > 0); - --obj->counter; - } - else if (obj->counter <= 0 && obj->counter >= -TRIES_BEFORE_UNLOAD - && --obj->counter < -TRIES_BEFORE_UNLOAD && obj->handle != NULL) - { - /* Unload the shared object. */ - __libc_dlclose (obj->handle); - obj->handle = NULL; - } -} - - -/* Notify system that a shared object is not longer needed. */ -void -internal_function -__gconv_release_shlib (struct __gconv_loaded_object *handle) -{ - /* Urgh, this is ugly but we have no other possibility. */ - release_handle = handle; - - /* Process all entries. Please note that we also visit entries - with release counts <= 0. This way we can finally unload them - if necessary. */ - twalk (loaded, (void *) do_release_shlib); -} - - -/* We run this if we debug the memory allocation. */ -static void -do_release_all (void *nodep) -{ - struct __gconv_loaded_object *obj = (struct __gconv_loaded_object *) nodep; - - - /* Unload the shared object. */ - if (obj->handle != NULL) - __libc_dlclose (obj->handle); - - free (obj); -} - -static void __attribute__ ((unused)) -free_mem (void) -{ - tdestroy (loaded, do_release_all); -} -text_set_element (__libc_subfreeres, free_mem); - - -#ifdef DEBUG -static void -do_print (const void *nodep, VISIT value, int level) -{ - struct __gconv_loaded_object *obj = *(struct __gconv_loaded_object **) nodep; - - printf ("%10s: \"%s\", %d\n", - value == leaf ? "leaf" : - value == preorder ? "preorder" : - value == postorder ? "postorder" : "endorder", - obj->name, obj->counter); -} - -static void -print_all (void) -{ - __twalk (loaded, do_print); -} -#endif |