[FFmpeg-devel] "OPW Qualification Task: Enable daemon mode for FFserver"

[Binathi Bingi]

Hi there,

I see, we need dup2() to redirect the output to logfile. Therefore, I put
it back in the patch.

But, I am not sure if we should definitely use it, because I can't see any
messages on the console as all are being redirected to log file
For instance, when I run ffserver, I can't see the output like"FFserver
started" or when I try to re-run while it is already running as daemon, I
can't see the messages like "bind(port 8090): Address already in use"

So, I did ps -ux to see if ffserver was running as daemon, and it was.
I am not sure if we should use dup2(), as it is redirecting messages from
console.

Regards,
Binathi

On Wed, Nov 5, 2014 at 12:04 AM, Binathi Bingi <binti179 at gmail.com> wrote:

> Hi there,
>
> I am sorry for the indentation errors in the above mail, it was because of
> bad email agent.
>
> In the attached patch, if the config.logfilename is not "-", then stdout
> is closed and then I reopened.
>
> Reynaldo, is right. I don't think it is good idea to use dup2().
> There were problems in running ffserver it couldn't start when I
> redirected the file descriptor to stdin, stdout, stderr using dup2().
> I removed dup2() and just opened something neutral in "/dev/null"
> In this patch, I included error check for return value of open().
>
> Cheers,
> Binathi
>
> On Tue, Nov 4, 2014 at 7:23 AM, Reynaldo H. Verdejo Pinochet <
> reynaldo at osg.samsung.com> wrote:
>
>> Hi
>>
>> On 11/03/2014 04:09 PM, Binathi Bingi wrote:
>> > Hello,
>> >
>> > Inside the child process, I closed the file descriptor and then reopened
>> > and redirected them using dup2() and later closed the opened file. I am
>> not
>> > sure if I understood and used the functionality of dup2() in the right
>> > sense.
>> >
>>
>> Looks about right but see bellow.
>>
>> > [..]
>> >> @@ -3736,10 +3737,42 @@ int main(int argc, char **argv)
>> >>      build_feed_streams();
>> >>
>> >>      compute_bandwidth();
>> >> -
>> >> +
>>
>> Remove trailing withe space
>>
>> >> +    if (config.ffserver_daemon) {
>>
>> What follows needs to be indented
>>
>> >> +    pid_t ffserver_id = 0;
>> >> +    pid_t sid = 0;
>> >> +
>> >> +    ffserver_id = fork();
>> >> +
>> >> +    if (ffserver_id < 0) {
>> >> +            ret = AVERROR(errno);
>> >> +        av_log(NULL, AV_LOG_ERROR, "Impossible to start in daemon
>> mode: %s\n", av_err2str(ret));
>> >> +        exit(1);
>>
>> Fix wrong indentation
>>
>> >> +    }
>> >> +
>> >> +    if (ffserver_id > 0) {
>> >> +        exit(0);
>> >> +    }
>>
>> Drop the braces from single statement ifs blocks like this one.
>>
>> >> +
>> >> +    sid = setsid();
>> >> +    if (sid < 0) {
>> >> +        exit(1);
>> >> +    }
>>
>> Same as above
>>
>> >> +
>> >> +    if (strcmp(config.logfilename, "-") != 0) {
>> >> +            close(0);
>>
>> Drop the != 0. Anything but 0 will evaluate to true anyway. You do this
>> elsewhere on your own code. Be consistent.
>>
>> >> +
>> >> +    fd = open("/dev/null", O_RDWR);
>> >> +    dup2(fd,0);
>> >> +    dup2(fd,1);
>> >> +    dup2(fd,2);
>>
>> You sure you wana dup2() stdin, stdout and stderr on the above
>> condition? Please double check.
>>
>> >> +    close(fd);
>>
>> Above block needs to be re-indented. Also, check for failures in
>> open and dup2() and react accordingly. I think Nicolas mentioned
>> this already.
>>
>> >> +
>> >> +        }
>> >> +    }
>> >>      /* signal init */
>> >>      signal(SIGPIPE, SIG_IGN);
>> >> -
>> >> +
>>
>> Again, drop the trailing white space you introduced here and on
>> multiple lines in this same patch.
>>
>> It's getting there. Congrats ;)
>>
>> Bests,
>>
>> --
>> Reynaldo H. Verdejo Pinochet
>> Open Source Group
>> Samsung Research America / Silicon Valley
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>>
>
>
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