/* Copyright (C) 1999, 2001, 2002, 2005 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include <assert.h> #include <stdlib.h> #include <bits/libc-lock.h> #include "exit.h" #include <atomic.h> #include <sysdep.h> #undef __cxa_atexit /* Register a function to be called by exit or when a shared library is unloaded. This function is only called from code generated by the C++ compiler. */ int __cxa_atexit (void (*func) (void *), void *arg, void *d) { struct exit_function *new = __new_exitfn (); if (new == NULL) return -1; #ifdef PTR_MANGLE PTR_MANGLE (func); #endif new->func.cxa.fn = (void (*) (void *, int)) func; new->func.cxa.arg = arg; new->func.cxa.dso_handle = d; atomic_write_barrier (); new->flavor = ef_cxa; return 0; } INTDEF(__cxa_atexit) /* We change global data, so we need locking. */ __libc_lock_define_initialized (static, lock) static struct exit_function_list initial; struct exit_function_list *__exit_funcs = &initial; struct exit_function * __new_exitfn (void) { struct exit_function_list *p = NULL; struct exit_function_list *l; struct exit_function *r = NULL; size_t i = 0; __libc_lock_lock (lock); for (l = __exit_funcs; l != NULL; p = l, l = l->next) { for (i = l->idx; i > 0; --i) if (l->fns[i - 1].flavor != ef_free) break; if (i > 0) break; /* This block is completely unused. */ l->idx = 0; } if (l == NULL || i == sizeof (l->fns) / sizeof (l->fns[0])) { /* The last entry in a block is used. Use the first entry in the previous block if it exists. Otherwise create a new one. */ if (p == NULL) { assert (l != NULL); p = (struct exit_function_list *) calloc (1, sizeof (struct exit_function_list)); if (p != NULL) { p->next = __exit_funcs; __exit_funcs = p; } } if (p != NULL) { r = &p->fns[0]; p->idx = 1; } } else { /* There is more room in the block. */ r = &l->fns[i]; l->idx = i + 1; } /* Mark entry as used, but we don't know the flavor now. */ if (r != NULL) r->flavor = ef_us; __libc_lock_unlock (lock); return r; }