[syslog-ng] [Bug 135] pipe() source missing follow_freq() option

[Sandor Geller]

Hi,

The pipe / file code is almost the same within syslog-ng. For files
there is no point to use select() as it would always indicate
readability that's why regular files have to get stat()-ed
periodically, this is what happens when follow-freq isn't 0. For pipes
there is no point to use stat() (other than detecting that the pipe
was replaced by another) however select()/poll()/epoll() indicates
that there is content to read. Syslog-ng from version 2 to 3.2.x
doesn't do this on its own but uses glib which uses select() under the
hood to monitor fds.

Of course I could be wrong so feel free to correct me :)

Regards,

Sandor

On Wed, Sep 28, 2011 at 3:57 PM, Patrick H. <syslogng at feystorm.net> wrote:
> I havent looked at the code, but whats the behavior that is used when
> reading from pipes? There's 2 ways of seeing if theres data on a pipe, doing
> a periodic non-blocking read, and doing a select. From the documentation it
> sounded like doing a non-blocking read was the default behavior to check if
> theres data on the pipe, and that setting follow-freq to 0 changed it to a
> select() call. So without having this option available, which does it use?
>
> -Patrick
>
> Sent: Wed Sep 28 2011 01:22:39 GMT-0600 (MST)
> From: bugzilla at bugzilla.balabit.com
> To: syslog-ng at lists.balabit.hu
> Subject: [syslog-ng] [Bug 135] pipe() source missing follow_freq() option
>
> https://bugzilla.balabit.com/show_bug.cgi?id=135
>
>
> Balazs Scheidler <bazsi at balabit.hu> changed:
>
>            What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                  CC|                            |frobert at balabit.hu
>
>
>
>
> --- Comment #1 from Balazs Scheidler <bazsi at balabit.hu>  2011-09-28 09:22:39
> ---
> No point in allowing follow-freq() for pipe sources, so this is a
> documentation bug and should be removed from there.
>
>
>
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>