From: Sebastian Huber <sebastian.huber@embedded-brains.de>
To: newlib@sourceware.org
Subject: Re: [PATCH] Fix __fp_lock_all() and __fp_unlock_all()
Date: Thu, 19 May 2022 19:08:33 +0200 [thread overview]
Message-ID: <d14ac8c3-7832-12c8-b26e-8ac13d3f7be3@embedded-brains.de> (raw)
In-Reply-To: <YoYx6ZcIBvg+xvPQ@calimero.vinschen.de>
On 19/05/2022 14:02, Corinna Vinschen wrote:
> 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?
This patch was a preparation for this proposal:
https://sourceware.org/pipermail/newlib/2022/019735.html
It is a behaviour change for the default Newlib configuration, however,
from my point of view it is more or less a bug fix.
--
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prev parent reply other threads:[~2022-05-19 17:08 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 17:13 Sebastian Huber
2022-05-18 17:13 ` [PATCH] Fix __sFILE::_lock initialization Sebastian Huber
2022-05-19 12:04 ` Corinna Vinschen
2022-05-18 17:13 ` [PATCH] Use weak reference for _REENT_SMALL Sebastian Huber
2022-05-19 12:05 ` Corinna Vinschen
2022-05-19 12:02 ` [PATCH] Fix __fp_lock_all() and __fp_unlock_all() Corinna Vinschen
2022-05-19 17:08 ` Sebastian Huber [this message]
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