Subject: Re: [PATCH v3 1/9] compat/mingw.c: expand MinGW support for sigaction

From: Johannes Sixt <[email-masked]>
Date: Mon, 02 Jun 2014 07:57:35 +0200

Am 6/1/2014 20:10, schrieb Jeremiah Mahler:
> Due to portability issues across UNIX versions sigaction(2) should be used
> instead of signal(2).
> 
>>>From the signal(2) man page:
> 
>   The behavior of signal() varies across UNIX versions, and has also var‐
>   ied historically across different versions of Linux.   Avoid  its  use:
>   use sigaction(2) instead.
> 
> Unfortunately MinGW under Windows has limited support for signal and no
> support for sigaction.  And this prevents sigaction from being used across
> the entire Git project.
> 
> In compat/mingw.c there is a faux sigaction function but it only supports
> SIGALARM.  Hence the need for continuing to use signal() in other cases.
> 
> This patch expands the faux sigaction function so that it calls signal in
> cases other than SIGALRM.  Now sigaction can be used across the entire Git
> project and MinGW will still work with signal as it did before.
> 
> Signed-off-by: Jeremiah Mahler <[email-masked]>
> ---
>  compat/mingw.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/compat/mingw.c b/compat/mingw.c
> index e9892f8..e504cef 100644
> --- a/compat/mingw.c
> +++ b/compat/mingw.c
> @@ -1651,14 +1651,15 @@ int setitimer(int type, struct itimerval *in, struct itimerval *out)
>  
>  int sigaction(int sig, struct sigaction *in, struct sigaction *out)
>  {
> -	if (sig != SIGALRM)
> -		return errno = EINVAL,
> -			error("sigaction only implemented for SIGALRM");
>  	if (out != NULL)
>  		return errno = EINVAL,
>  			error("sigaction: param 3 != NULL not implemented");

A fix for this missing implementation is needed before patch 9/9 can be
applied.

>  
> -	timer_fn = in->sa_handler;
> +	if (sig == SIGALRM)
> +		timer_fn = in->sa_handler;
> +	else
> +		signal(sig, in->sa_handler);
> +
>  	return 0;
>  }
>  
> 

-- Hannes