elf/unload2.c

   1 #include <dlfcn.h>
   2 #include <elf.h>
   3 #include <errno.h>
   4 #include <error.h>
   5 #include <link.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 #define OUT \
  10   for (map = _r_debug.r_map; map != NULL; map = map->l_next)                  \
  11     if (map->l_type == lt_loaded)                                             \
  12       printf ("name = \"%s\", direct_opencount = %d\n",                       \
  13               map->l_name, (int) map->l_direct_opencount);                    \
  14   fflush (stdout)
  15
  16 int
  17 main (void)
  18 {
  19   void *h[3];
  20   struct link_map *map;
  21   void (*fp) (void);
  22
  23   h[0] = dlopen ("unload2mod.so", RTLD_LAZY);
  24   h[1] = dlopen ("unload2mod.so", RTLD_LAZY);
  25   if (h[0] == NULL || h[1] == NULL)
  26     error (EXIT_FAILURE, errno, "cannot load \"unload2mod.so\"");
  27   h[2] = dlopen ("unload2dep.so", RTLD_LAZY);
  28   if (h[2] == NULL)
  29     error (EXIT_FAILURE, errno, "cannot load \"unload2dep.so\"");
  30
  31   puts ("\nAfter loading everything:");
  32   OUT;
  33
  34   dlclose (h[0]);
  35
  36   puts ("\nAfter unloading \"unload2mod.so\" once:");
  37   OUT;
  38
  39   dlclose (h[1]);
  40
  41   puts ("\nAfter unloading \"unload2mod.so\" twice:");
  42   OUT;
  43
  44   fp = dlsym (h[2], "foo");
  45   puts ("\nnow calling `foo'");
  46   fflush (stdout);
  47   fp ();
  48   puts ("managed to call `foo'");
  49   fflush (stdout);
  50
  51   dlclose (h[2]);
  52
  53   puts ("\nAfter unloading \"unload2dep.so\":");
  54   OUT;
  55
  56   return 0;
  57 }