Re: [PATCH 1/2] Replace _fwalk() calls with _fwalk_reent()

[Jeff Johnston <jjohnstn@redhat.com>]

Looks fine.

-- Jeff J.

On Wed, Mar 30, 2022 at 5:58 AM Sebastian Huber <
sebastian.huber@embedded-brains.de> wrote:

> Remove the _fwalk() implementation to avoid duplicated code with
> _fwalk_reent().
> ---
>  newlib/libc/stdio/findfp.c | 16 ++++++++--------
>  newlib/libc/stdio/fwalk.c  | 26 --------------------------
>  newlib/libc/stdio/local.h  |  1 -
>  newlib/libc/stdio/refill.c |  8 ++++----
>  winsup/cygwin/syscalls.cc  |  6 +++---
>  5 files changed, 15 insertions(+), 42 deletions(-)
>
> diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
> index 9877c1f2c..7bb48e014 100644
> --- a/newlib/libc/stdio/findfp.c
> +++ b/newlib/libc/stdio/findfp.c
> @@ -323,20 +323,20 @@ __sinit_lock_release (void)
>
>  /* Walkable file locking routine.  */
>  static int
> -__fp_lock (FILE * ptr)
> +__fp_lock (struct _reent * ptr __unused, FILE * fp)
>  {
> -  if (!(ptr->_flags2 & __SNLK))
> -    _flockfile (ptr);
> +  if (!(fp->_flags2 & __SNLK))
> +    _flockfile (fp);
>
>    return 0;
>  }
>
>  /* Walkable file unlocking routine.  */
>  static int
> -__fp_unlock (FILE * ptr)
> +__fp_unlock (struct _reent * ptr __unused, FILE * fp)
>  {
> -  if (!(ptr->_flags2 & __SNLK))
> -    _funlockfile (ptr);
> +  if (!(fp->_flags2 & __SNLK))
> +    _funlockfile (fp);
>
>    return 0;
>  }
> @@ -346,13 +346,13 @@ __fp_lock_all (void)
>  {
>    __sfp_lock_acquire ();
>
> -  (void) _fwalk (_REENT, __fp_lock);
> +  (void) _fwalk_reent (_REENT, __fp_lock);
>  }
>
>  void
>  __fp_unlock_all (void)
>  {
> -  (void) _fwalk (_REENT, __fp_unlock);
> +  (void) _fwalk_reent (_REENT, __fp_unlock);
>
>    __sfp_lock_release ();
>  }
> diff --git a/newlib/libc/stdio/fwalk.c b/newlib/libc/stdio/fwalk.c
> index 8040d5718..2cefcc40e 100644
> --- a/newlib/libc/stdio/fwalk.c
> +++ b/newlib/libc/stdio/fwalk.c
> @@ -27,32 +27,6 @@ static char sccsid[] = "%W% (Berkeley) %G%";
>  #include <errno.h>
>  #include "local.h"
>
> -int
> -_fwalk (struct _reent *ptr,
> -       register int (*function) (FILE *))
> -{
> -  register FILE *fp;
> -  register int n, ret = 0;
> -  register struct _glue *g;
> -
> -  /*
> -   * It should be safe to walk the list without locking it;
> -   * new nodes are only added to the end and none are ever
> -   * removed.
> -   *
> -   * Avoid locking this list while walking it or else you will
> -   * introduce a potential deadlock in [at least] refill.c.
> -   */
> -  for (g = &ptr->__sglue; g != NULL; g = g->_next)
> -    for (fp = g->_iobs, n = g->_niobs; --n >= 0; fp++)
> -      if (fp->_flags != 0 && fp->_flags != 1 && fp->_file != -1)
> -       ret |= (*function) (fp);
> -
> -  return ret;
> -}
> -
> -/* Special version of __fwalk where the function pointer is a reentrant
> -   I/O function (e.g. _fclose_r).  */
>  int
>  _fwalk_reent (struct _reent *ptr,
>         register int (*reent_function) (struct _reent *, FILE *))
> diff --git a/newlib/libc/stdio/local.h b/newlib/libc/stdio/local.h
> index f63c5fb10..09ccd6407 100644
> --- a/newlib/libc/stdio/local.h
> +++ b/newlib/libc/stdio/local.h
> @@ -183,7 +183,6 @@ extern void   __sinit (struct _reent *);
>  extern void   _cleanup_r (struct _reent *);
>  extern void   __smakebuf_r (struct _reent *, FILE *);
>  extern int    __swhatbuf_r (struct _reent *, FILE *, size_t *, int *);
> -extern int    _fwalk (struct _reent *, int (*)(FILE *));
>  extern int    _fwalk_reent (struct _reent *, int (*)(struct _reent *,
> FILE *));
>  struct _glue * __sfmoreglue (struct _reent *,int n);
>  extern int __submore (struct _reent *, FILE *);
> diff --git a/newlib/libc/stdio/refill.c b/newlib/libc/stdio/refill.c
> index ccedc7af7..31665bcd9 100644
> --- a/newlib/libc/stdio/refill.c
> +++ b/newlib/libc/stdio/refill.c
> @@ -23,10 +23,10 @@
>  #include "local.h"
>
>  static int
> -lflush (FILE *fp)
> +lflush (struct _reent * ptr __unused, FILE *fp)
>  {
>    if ((fp->_flags & (__SLBF | __SWR)) == (__SLBF | __SWR))
> -    return fflush (fp);
> +    return _fflush_r (_REENT, fp);
>    return 0;
>  }
>
> @@ -102,10 +102,10 @@ __srefill_r (struct _reent * ptr,
>     */
>    if (fp->_flags & (__SLBF | __SNBF))
>      {
> -      /* Ignore this file in _fwalk to avoid potential deadlock. */
> +      /* Ignore this file in _fwalk_reent to avoid potential deadlock. */
>        short orig_flags = fp->_flags;
>        fp->_flags = 1;
> -      (void) _fwalk (_GLOBAL_REENT, lflush);
> +      (void) _fwalk_reent (_GLOBAL_REENT, lflush);
>        fp->_flags = orig_flags;
>
>        /* Now flush this file without locking it. */
> diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
> index 24ec01da8..1cecaa017 100644
> --- a/winsup/cygwin/syscalls.cc
> +++ b/winsup/cygwin/syscalls.cc
> @@ -3058,10 +3058,10 @@ _cygwin_istext_for_stdio (int fd)
>  }
>
>  /* internal newlib function */
> -extern "C" int _fwalk (struct _reent *ptr, int (*function) (FILE *));
> +extern "C" int _fwalk_reent (struct _reent *ptr, int (*function) (struct
> _reent *, FILE *));
>
>  static int
> -setmode_helper (FILE *f)
> +setmode_helper (struct _reent *ptr __unused, FILE *f)
>  {
>    if (fileno (f) != _my_tls.locals.setmode_file)
>      {
> @@ -3137,7 +3137,7 @@ cygwin_setmode (int fd, int mode)
>         _my_tls.locals.setmode_mode = O_TEXT;
>        else
>         _my_tls.locals.setmode_mode = O_BINARY;
> -      _fwalk (_GLOBAL_REENT, setmode_helper);
> +      _fwalk_reent (_GLOBAL_REENT, setmode_helper);
>      }
>    return res;
>  }
> --
> 2.34.1
>
>