Re: How to destroy _reent structure

[Sebastian Huber <sebastian dot huber at embedded-brains dot de>]

Hello Corinna,

On 04/24/2013 12:26 PM, Corinna Vinschen wrote:
> On Apr 24 10:04, Sebastian Huber wrote:
> > Hello,
> >
> > there is _REENT_INIT_PTR() for initialization, but how can I destroy
> > a _reent structure.  Is this _wrapup_reent()?
>
> Try _reclaim_reent.  But it's not the same as _REENT_INIT_PTR since
> _REENT_INIT_PTR does not allocate any memory.
>
>
> Corinna

so for initialization we can use:

struct _reent *p = malloc(sizeof(*p));
if (p != NULL) {
  _REENT_INIT_PTR(p);
}

For destruction we can use:

_reclaim_reent(p);
free(p);

What is the purpose of _wrapup_reent()?  Its not called from within Newlib and 
I don't find a function that can register an atexit handler in a non-global 
_reent structure.  There is also no public header file for this function.

In RTEMS we currently use this:

static int newlib_free_buffers(
  FILE *fp
)
{
  switch ( fileno(fp) ) {
    case 0:
    case 1:
    case 2:
      if (fp->_flags & __SMBF) {
        free( fp->_bf._base );
        fp->_flags &= ~__SMBF;
        fp->_bf._base = fp->_p = (unsigned char *) NULL;
      }
      break;
    default:
     fclose(fp);
  }
  return 0;
}

void newlib_delete_hook(
  rtems_tcb *current_task,
  rtems_tcb *deleted_task
)
{
  struct _reent *ptr;

  ptr = deleted_task->libc_reent;
  deleted_task->libc_reent = NULL;

  /*
   *  Just in case there are some buffers lying around.
   */
  _fwalk(ptr, newlib_free_buffers);

  _Workspace_Free(ptr);
}

So this looks pretty wrong.

--
Sebastian Huber, embedded brains GmbH

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