/* Copyright (C) 1991-2018 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 <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <sysdep.h>

#include <libc-lock.h>

#include "exit.h"

#include "set-hooks.h"

DEFINE_HOOK (__libc_atexit, (void))

/* Initialize the flag that indicates exit function processing

   is complete. See concurrency notes in stdlib/exit.h where

   __exit_funcs_lock is declared.  */

bool __exit_funcs_done = false;

/* Call all functions registered with `atexit' and `on_exit',

   in the reverse of the order in which they were registered

   perform stdio cleanup, and terminate program execution with STATUS.  */

void

attribute_hidden

__run_exit_handlers (int status, struct exit_function_list **listp,

		     bool run_list_atexit, bool run_dtors)

{

  /* First, call the TLS destructors.  */

#ifndef SHARED

  if (&__call_tls_dtors != NULL)

#endif

    if (run_dtors)

      __call_tls_dtors ();

  /* We do it this way to handle recursive calls to exit () made by

     the functions registered with `atexit' and `on_exit'. We call

     everyone on the list and use the status value in the last

     exit (). */

  while (true)

    {

      struct exit_function_list *cur;

      __libc_lock_lock (__exit_funcs_lock);

    restart:

      cur = *listp;

      if (cur == NULL)

	{

	  /* Exit processing complete.  We will not allow any more

	     atexit/on_exit registrations.  */

	  __exit_funcs_done = true;

	  __libc_lock_unlock (__exit_funcs_lock);

	  break;

	}

      while (cur->idx > 0)

	{

	  struct exit_function *const f = &cur->fns[--cur->idx];

	  const uint64_t new_exitfn_called = __new_exitfn_called;

	  /* Unlock the list while we call a foreign function.  */

	  __libc_lock_unlock (__exit_funcs_lock);

	  switch (f->flavor)

	    {

	      void (*atfct) (void);

	      void (*onfct) (int status, void *arg);

	      void (*cxafct) (void *arg, int status);

	    case ef_free:

	    case ef_us:

	      break;

	    case ef_on:

	      onfct = f->func.on.fn;

#ifdef PTR_DEMANGLE

	      PTR_DEMANGLE (onfct);

#endif

	      onfct (status, f->func.on.arg);

	      break;

	    case ef_at:

	      atfct = f->func.at;

#ifdef PTR_DEMANGLE

	      PTR_DEMANGLE (atfct);

#endif

	      atfct ();

	      break;

	    case ef_cxa:

	      /* To avoid dlclose/exit race calling cxafct twice (BZ 22180),

		 we must mark this function as ef_free.  */

	      f->flavor = ef_free;

	      cxafct = f->func.cxa.fn;

#ifdef PTR_DEMANGLE

	      PTR_DEMANGLE (cxafct);

#endif

	      cxafct (f->func.cxa.arg, status);

	      break;

	    }

	  /* Re-lock again before looking at global state.  */

	  __libc_lock_lock (__exit_funcs_lock);

	  if (__glibc_unlikely (new_exitfn_called != __new_exitfn_called))

	    /* The last exit function, or another thread, has registered

	       more exit functions.  Start the loop over.  */

	    goto restart;

	}

      *listp = cur->next;

      if (*listp != NULL)

	/* Don't free the last element in the chain, this is the statically

	   allocate element.  */

	free (cur);

      __libc_lock_unlock (__exit_funcs_lock);

    }

  if (run_list_atexit)

    RUN_HOOK (__libc_atexit, ());

  _exit (status);

}

void

exit (int status)

{

  __run_exit_handlers (status, &__exit_funcs, true, true);

}

libc_hidden_def (exit)