Re: [tarantool-patches] [PATCH v2] Fix O_NONBLOCK flag loss

[Vladimir Davydov <vdavydov.dev@gmail.com>]

Please prefix the subject line with a subsystem name ("say: " in your
case).

On Mon, Aug 13, 2018 at 09:37:58AM +0300, Olga Arkhangelskaia wrote:
> During syslog reconnect we lose nonblock flag. This leads to misbehavior
> while logging. Tarantool hangs forever.

> Test for this fix will be available in 1.10.

Please explain why (in the commit message).

> 
> Closes #3615
> ---
> https://github.com/tarantool/tarantool/issues/3615
> https://github.com/tarantool/tarantool/tree/OKriw/gh-3615-loss-nonblock-1.9
> 
> v1:
> https://www.freelists.org/post/tarantool-patches/PATCH-Fix-O-NONBLOCK-flag-loss
> 
> Changes in v2:
> -rebased on 1.9
> -changed set_nonblock arg
> -set flag in one more place
> 
>  src/say.c | 34 +++++++++++++++++++++-------------
>  1 file changed, 21 insertions(+), 13 deletions(-)
> 
> diff --git a/src/say.c b/src/say.c
> index 063e0295c..9c1066efc 100644
> --- a/src/say.c
> +++ b/src/say.c
> @@ -238,6 +238,23 @@ write_to_file(struct log *log, int total);
>  static void
>  write_to_syslog(struct log *log, int total);
>  
> +/**
> + * Sets O_NONBLOCK flag in case if lognonblock is set.
> + */
> +static void
> +set_nonblock(struct log *log)

Please prefix this function with 'log_' (log_set_nonblock), because this
function is a method of 'log' object.

> +{
> +	if (!log->nonblock)
> +		return;
> +	else {

'else' is pointless.

> +		int flags;
> +		if ((flags = fcntl(log->fd, F_GETFL, 0)) < 0 ||
> +				fcntl(log->fd, F_SETFL, flags | O_NONBLOCK) < 0) {

Malformed indentation. Please align the next line to 'if (', as we do
everywhere else.

> +			say_syserror("fcntl, fd=%i", log->fd);
> +		}
> +	}
> +}