Re: [PATCH] Fix __fp_lock_all() and __fp_unlock_all()

[Corinna Vinschen <vinschen@redhat.com>]

On May 18 19:13, Sebastian Huber wrote:
> For _REENT_GLOBAL_STDIO_STREAMS, lock/unlock all FILE objects.  In the
> repository, this function is only used by Cygwin during process forks.  Since
> Cygwin enabled _REENT_GLOBAL_STDIO_STREAMS recently, without this fix no FILE
> object at all was locked.
> ---
>  newlib/libc/stdio/findfp.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
> index 6933ff1db..a39082387 100644
> --- a/newlib/libc/stdio/findfp.c
> +++ b/newlib/libc/stdio/findfp.c
> @@ -333,6 +333,8 @@ __fp_lock_all (void)
>  #ifndef _REENT_GLOBAL_STDIO_STREAMS
>    ptr = _REENT;
>    (void) _fwalk_sglue (ptr, __fp_lock, &ptr->__sglue);
> +#else
> +  (void) _fwalk_sglue (NULL, __fp_lock, &__sglue);
>  #endif

The resulting __fp_lock_all/__fp_unlock_all functions look a bit weird
to me, codewise. Counter-proposal:

diff --git a/newlib/libc/stdio/findfp.c b/newlib/libc/stdio/findfp.c
index 118637a18f5b..ebfbf0976de5 100644
--- a/newlib/libc/stdio/findfp.c
+++ b/newlib/libc/stdio/findfp.c
@@ -329,31 +329,24 @@ __fp_unlock (struct _reent * ptr __unused, FILE * fp)
   return 0;
 }
 
+#ifdef _REENT_GLOBAL_STDIO_STREAMS
+# define _PTR NULL
+# define _GLUE __sglue
+#else
+# define _PTR _REENT
+# define _GLUE _PTR->__sglue
+#endif
+
 void
 __fp_lock_all (void)
 {
-#ifndef _REENT_GLOBAL_STDIO_STREAMS
-  struct _reent *ptr;
-#endif
-
-  __sfp_lock_acquire ();
-
-#ifndef _REENT_GLOBAL_STDIO_STREAMS
-  ptr = _REENT;
-  (void) _fwalk_sglue (ptr, __fp_lock, &ptr->__sglue);
-#endif
+  _fwalk_sglue (_PTR, __fp_lock, &_GLUE);
 }
 
 void
 __fp_unlock_all (void)
 {
-#ifndef _REENT_GLOBAL_STDIO_STREAMS
-  struct _reent *ptr;
-
-  ptr = _REENT;
-  (void) _fwalk_sglue (ptr, __fp_unlock, &ptr->__sglue);
-#endif
-
+  _fwalk_sglue (_PTR, __fp_unlock, &_GLUE);
   __sfp_lock_release ();
 }
 #endif

What do you think?


Thanks,
Corinna