mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/* Register destructors for C++ TLS variables declared with thread_local.
|
|
Copyright (C) 2013-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <stdlib.h>
|
|
#include <ldsodefs.h>
|
|
|
|
typedef void (*dtor_func) (void *);
|
|
|
|
struct dtor_list
|
|
{
|
|
dtor_func func;
|
|
void *obj;
|
|
struct link_map *map;
|
|
struct dtor_list *next;
|
|
};
|
|
|
|
static __thread struct dtor_list *tls_dtor_list;
|
|
static __thread void *dso_symbol_cache;
|
|
static __thread struct link_map *lm_cache;
|
|
|
|
/* Register a destructor for TLS variables declared with the 'thread_local'
|
|
keyword. This function is only called from code generated by the C++
|
|
compiler. FUNC is the destructor function and OBJ is the object to be
|
|
passed to the destructor. DSO_SYMBOL is the __dso_handle symbol that each
|
|
DSO has at a unique address in its map, added from crtbegin.o during the
|
|
linking phase. */
|
|
int
|
|
__cxa_thread_atexit_impl (dtor_func func, void *obj, void *dso_symbol)
|
|
{
|
|
/* Prepend. */
|
|
struct dtor_list *new = calloc (1, sizeof (struct dtor_list));
|
|
new->func = func;
|
|
new->obj = obj;
|
|
new->next = tls_dtor_list;
|
|
tls_dtor_list = new;
|
|
|
|
/* See if we already encountered the DSO. */
|
|
__rtld_lock_lock_recursive (GL(dl_load_lock));
|
|
|
|
if (__glibc_unlikely (dso_symbol_cache != dso_symbol))
|
|
{
|
|
ElfW(Addr) caller = (ElfW(Addr)) dso_symbol;
|
|
|
|
struct link_map *l = _dl_find_dso_for_object (caller);
|
|
|
|
/* If the address is not recognized the call comes from the main
|
|
program (we hope). */
|
|
lm_cache = l ? l : GL(dl_ns)[LM_ID_BASE]._ns_loaded;
|
|
}
|
|
/* A destructor could result in a thread_local construction and the former
|
|
could have cleared the flag. */
|
|
if (lm_cache->l_type == lt_loaded && lm_cache->l_tls_dtor_count == 0)
|
|
lm_cache->l_flags_1 |= DF_1_NODELETE;
|
|
|
|
new->map = lm_cache;
|
|
new->map->l_tls_dtor_count++;
|
|
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Call the destructors. This is called either when a thread returns from the
|
|
initial function or when the process exits via the exit function. */
|
|
void
|
|
__call_tls_dtors (void)
|
|
{
|
|
while (tls_dtor_list)
|
|
{
|
|
struct dtor_list *cur = tls_dtor_list;
|
|
tls_dtor_list = tls_dtor_list->next;
|
|
|
|
cur->func (cur->obj);
|
|
|
|
__rtld_lock_lock_recursive (GL(dl_load_lock));
|
|
|
|
/* Allow DSO unload if count drops to zero. */
|
|
cur->map->l_tls_dtor_count--;
|
|
if (cur->map->l_tls_dtor_count == 0 && cur->map->l_type == lt_loaded)
|
|
cur->map->l_flags_1 &= ~DF_1_NODELETE;
|
|
|
|
__rtld_lock_unlock_recursive (GL(dl_load_lock));
|
|
|
|
free (cur);
|
|
}
|
|
}
|
|
libc_hidden_def (__call_tls_dtors)
|