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2000-10-24  Ulrich Drepper  <drepper@redhat.com>

	Complete revamp of the reference counter handling.
	* include/link.h (struct link_map): Add l_idx field.
	* elf/dl-close.c: Handle decrementing of reference counters more
	correctly. If necessary decrement reference counters of dependencies
	of dependencies.
	* elf/dl-lookup.c (add_dependency): Only increment reference counter
	of the object itself and not also its dependencies.
	* elf/dl-open.c: Increment reference counters here.
	* elf/dl-deps.c: Remove reference counter handling here.
	* elf/dl-load.c: Likewise.
	* elf/rtld.c: Adjust for _dl_map_deps not handling reference counters.

	* elf/loadtest.c: Print loaded objects at the beginning.
This commit is contained in:
Ulrich Drepper 2000-10-24 07:36:55 +00:00
parent 69c3325490
commit 42c4f32a44
8 changed files with 91 additions and 58 deletions
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16
ChangeLog
View File

@ -1,3 +1,19 @@
2000-10-24 Ulrich Drepper <drepper@redhat.com>
Complete revamp of the reference counter handling.
* include/link.h (struct link_map): Add l_idx field.
* elf/dl-close.c: Handle decrementing of reference counters more
correctly. If necessary decrement reference counters of dependencies
of dependencies.
* elf/dl-lookup.c (add_dependency): Only increment reference counter
of the object itself and not also its dependencies.
* elf/dl-open.c: Increment reference counters here.
* elf/dl-deps.c: Remove reference counter handling here.
* elf/dl-load.c: Likewise.
* elf/rtld.c: Adjust for _dl_map_deps not handling reference counters.
* elf/loadtest.c: Print loaded objects at the beginning.
2000-10-24 Andreas Jaeger <aj@suse.de>
* sysdeps/mips/dl-machine.h: Partly revert patch from 2000-10-18.

56
elf/dl-close.c
View File

@ -49,6 +49,7 @@ _dl_close (void *_map)
unsigned int nsearchlist;
unsigned int nrellist;
unsigned int i;
unsigned int *new_opencount;
/* First see whether we can remove the object at all. */
if (map->l_flags_1 & DF_1_NODELETE)
@ -61,9 +62,6 @@ _dl_close (void *_map)
/* Acquire the lock. */
__libc_lock_lock (_dl_load_lock);
list = map->l_searchlist.r_list;
nsearchlist = map->l_searchlist.r_nlist;
/* Decrement the reference count. */
if (map->l_opencount > 1 || map->l_type != lt_loaded)
{
@ -81,14 +79,46 @@ _dl_close (void *_map)
"\n", NULL);
}
for (i = 0; i < nsearchlist; ++i)
if (! (list[i]->l_flags_1 & DF_1_NODELETE))
--list[i]->l_opencount;
/* One decrement the object itself, not the dependencies. */
--map->l_opencount;
__libc_lock_unlock (_dl_load_lock);
return;
}
list = map->l_searchlist.r_list;
nsearchlist = map->l_searchlist.r_nlist;
/* Compute the new l_opencount values. */
new_opencount = (unsigned int *) alloca (nsearchlist
* sizeof (unsigned int));
for (i = 0; i < nsearchlist; ++i)
{
list[i]->l_idx = i;
new_opencount[i] = list[i]->l_opencount;
}
--new_opencount[0];
for (i = 1; i < nsearchlist; ++i)
if (! (list[i]->l_flags_1 & DF_1_NODELETE)
/* Decrement counter. */
&& --new_opencount[i] == 0
/* Test whether this object was also loaded directly. */
&& list[i]->l_searchlist.r_list != NULL)
{
/* In this case we have the decrement all the dependencies of
this object. They are all in MAP's dependency list. */
unsigned int j;
struct link_map **dep_list = list[i]->l_searchlist.r_list;
for (j = 1; j < list[i]->l_searchlist.r_nlist; ++j)
if (! (dep_list[j]->l_flags_1 & DF_1_NODELETE))
{
assert (dep_list[j]->l_idx < nsearchlist);
--new_opencount[dep_list[j]->l_idx];
}
}
assert (new_opencount[0] == 0);
rellist = map->l_reldeps;
nrellist = map->l_reldepsact;
@ -96,7 +126,7 @@ _dl_close (void *_map)
for (i = 0; i < nsearchlist; ++i)
{
struct link_map *imap = map->l_initfini[i];
if (imap->l_opencount == 1 && imap->l_type == lt_loaded
if (new_opencount[i] == 0 && imap->l_type == lt_loaded
&& (imap->l_info[DT_FINI] || imap->l_info[DT_FINI_ARRAY])
&& ! (imap->l_flags_1 & DF_1_NODELETE)
/* Skip any half-cooked objects that were never initialized. */
@ -126,19 +156,17 @@ _dl_close (void *_map)
(*(void (*) (void)) ((void *) imap->l_addr
+ imap->l_info[DT_FINI]->d_un.d_ptr)) ();
}
/* Store the new l_opencount value. */
imap->l_opencount = new_opencount[i];
/* Just a sanity check. */
assert (imap->l_type == lt_loaded || imap->l_opencount > 0);
}
/* Notify the debugger we are about to remove some loaded objects. */
_r_debug.r_state = RT_DELETE;
_dl_debug_state ();
/* The search list contains a counted reference to each object it
points to, the 0th elt being MAP itself. Decrement the reference
counts on all the objects MAP depends on. */
for (i = 0; i < nsearchlist; ++i)
if (! (list[i]->l_flags_1 & DF_1_NODELETE))
--list[i]->l_opencount;
/* Check each element of the search list to see if all references to
it are gone. */
for (i = 0; i < nsearchlist; ++i)

21
elf/dl-deps.c
View File

@ -243,18 +243,7 @@ _dl_map_object_deps (struct link_map *map,
dtail = newp;
++nduplist;
if (dep->l_reserved)
{
/* This object is already in the search list we are
building. Don't add a duplicate pointer.
Release the reference just added by
_dl_map_object. */
if (dep->l_initfini != NULL)
for (i = 1; dep->l_initfini[i] != NULL; ++i)
--dep->l_initfini[i]->l_opencount;
--dep->l_opencount;
}
else
if (! dep->l_reserved)
{
/* Append DEP to the unique list. */
newp->done = 0;
@ -363,13 +352,7 @@ _dl_map_object_deps (struct link_map *map,
/* This object is already in the search list we
are building. Don't add a duplicate pointer.
Release the reference just added by
_dl_map_object. */
if (args.aux->l_initfini != NULL)
for (i = 1; args.aux->l_initfini[i] != NULL; ++i)
--args.aux->l_initfini[i]->l_opencount;
--args.aux->l_opencount;
Just added by _dl_map_object. */
for (late = newp; late->unique; late = late->unique)
if (late->unique->map == args.aux)
break;

15
elf/dl-load.c
View File

@ -785,10 +785,6 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
free (realname);
add_name_to_object (l, name);
if (l->l_initfini != NULL)
for (i = 1; l->l_initfini[i] != NULL; ++i)
++l->l_initfini[i]->l_opencount;
++l->l_opencount;
return l;
}
@ -821,7 +817,6 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
l = _dl_new_object (realname, name, l_type, loader);
if (__builtin_expect (! l, 0))
LOSE (ENOMEM, N_("cannot create shared object descriptor"));
l->l_opencount = 1;
/* Extract the remaining details we need from the ELF header
and then read in the program header table. */
@ -1467,7 +1462,9 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
/* If the requested name matches the soname of a loaded object,
use that object. Elide this check for names that have not
yet been opened. */
if (l->l_opencount <= 0)
/* XXX Is this test still correct after the reference counter
handling rewrite? */
if (l->l_opencount == 0)
continue;
if (!_dl_name_match_p (name, l))
{
@ -1487,11 +1484,7 @@ _dl_map_object (struct link_map *loader, const char *name, int preloaded,
l->l_soname_added = 1;
}
/* We have a match -- bump the reference count and return it. */
if (l->l_initfini != NULL)
for (i = 1; l->l_initfini[i] != NULL; ++i)
++l->l_initfini[i]->l_opencount;
++l->l_opencount;
/* We have a match. */
return l;
}

6
elf/dl-lookup.c
View File

@ -160,11 +160,7 @@ add_dependency (struct link_map *undef_map, struct link_map *map)
if (__builtin_expect (act < undef_map->l_reldepsmax, 1))
undef_map->l_reldeps[undef_map->l_reldepsact++] = map;
/* And increment the counter in the referenced object
and its dependencies. */
if (map->l_initfini != NULL)
for (j = 1; map->l_initfini[j] != NULL; ++j)
++map->l_initfini[j]->l_opencount;
/* And increment the counter in the referenced object. */
++map->l_opencount;
/* Display information if we are debugging. */

11
elf/dl-open.c
View File

@ -238,7 +238,8 @@ dl_open_worker (void *a)
return;
}
if (new->l_searchlist.r_list)
/* It was already open. */
if (new->l_searchlist.r_list != NULL)
{
/* Let the user know about the opencount. */
if (__builtin_expect (_dl_debug_files, 0))
@ -259,13 +260,19 @@ dl_open_worker (void *a)
if ((mode & RTLD_GLOBAL) && new->l_global == 0)
(void) add_to_global (new);
/* It was already open. */
/* Increment just the reference counter of the object. */
++new->l_opencount;
return;
}
/* Load that object's dependencies. */
_dl_map_object_deps (new, NULL, 0, 0);
/* Increment the open count for all dependencies. */
for (i = 0; i < new->l_searchlist.r_nlist; ++i)
++new->l_searchlist.r_list[i]->l_opencount;
/* So far, so good. Now check the versions. */
for (i = 0; i < new->l_searchlist.r_nlist; ++i)
if (new->l_searchlist.r_list[i]->l_versions == NULL)

8
elf/loadtest.c
View File

@ -83,17 +83,23 @@ main (int argc, char *argv[])
int debug = argc > 1 && argv[1][0] != '\0';
int count = TEST_ROUNDS;
int result = 0;
struct link_map *map;
mtrace ();
/* Just a seed. */
srandom (TEST_ROUNDS);
if (debug)
{
puts ("in the beginning");
OUT;
}
while (count--)
{
int nr = random () % NTESTS;
int index = tests[nr].index;
struct link_map *map;
printf ("%4d: %4d: ", count + 1, nr);
fflush (stdout);

16
elf/rtld.c
View File

@ -550,7 +550,6 @@ of this helper program; chances are you did not intend to run this program.\n\
_dl_loaded->l_phdr = phdr;
_dl_loaded->l_phnum = phent;
_dl_loaded->l_entry = *user_entry;
_dl_loaded->l_opencount = 1;
/* At this point we are in a bit of trouble. We would have to
fill in the values for l_dev and l_ino. But in general we
@ -707,7 +706,7 @@ of this helper program; chances are you did not intend to run this program.\n\
{
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
lt_library, 0, 0);
if (new_map->l_opencount == 1)
if (++new_map->l_opencount == 1)
/* It is no duplicate. */
++npreloads;
}
@ -775,7 +774,7 @@ of this helper program; chances are you did not intend to run this program.\n\
{
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
lt_library, 0, 0);
if (new_map->l_opencount == 1)
if (++new_map->l_opencount == 1)
/* It is no duplicate. */
++npreloads;
}
@ -786,7 +785,7 @@ of this helper program; chances are you did not intend to run this program.\n\
char *p = strndupa (problem, file_size - (problem - file));
struct link_map *new_map = _dl_map_object (_dl_loaded, p, 1,
lt_library, 0, 0);
if (new_map->l_opencount == 1)
if (++new_map->l_opencount == 1)
/* It is no duplicate. */
++npreloads;
}
@ -823,9 +822,14 @@ of this helper program; chances are you did not intend to run this program.\n\
HP_TIMING_DIFF (diff, start, stop);
HP_TIMING_ACCUM_NT (load_time, diff);
/* Mark all objects as being in the global scope. */
/* Mark all objects as being in the global scope and set the open
counter. */
for (i = _dl_loaded->l_searchlist.r_nlist; i > 0; )
_dl_loaded->l_searchlist.r_list[--i]->l_global = 1;
{
--i;
_dl_loaded->l_searchlist.r_list[i]->l_global = 1;
++_dl_loaded->l_searchlist.r_list[i]->l_opencount;
}
#ifndef MAP_ANON
/* We are done mapping things, so close the zero-fill descriptor. */