Re: Differing results in calling same program from different environments

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hi Pete,

I haven't used the signals technique from a CGI program.  So I don't 
know what I'm talking about, I'm just going to guess!

I suspect that when Apache spawns the CGI jobs, it's specifying a signal 
mask that tells them to block the alarm signal (SIGALRM) that gets sent 
when the alarm() API's time limit expires?

That would explain the result you're seeing.

My suggestion is to eliminate the signal logic and replace it with (more 
complex, but also more robust) non-blocking socket logic.

HTH


On 6/22/2011 12:42 PM, Pete Helgren wrote:
> I have an ILE RPG program is pretty simple: It checks to see if the port
> at a certain host is online or not. It was written to demonstrate how to
> call an RPG program from Java.  It works fine  when called from Java.  I
> wrote an ILE RPG 5250 program that calls the same program (CHK_PORT).
> It works well in that ILE RPG program as well.  So I am now using it in
> a CGIDEV2 program and it works well if the host/port is online but if
> the host is offline, the call times out rather than returns which causes
> the CGIDEV2 program to fail.
>
> The CHK_PORT program is based on some code from Scott Klements Sockets
> programming tutorial (I think).  The challenge in writing the program in
> the first place was coding for the the failure of the connection when
> the host or port was offline.  I solved it using the following code:
>
>        C*************************************************
>        C* Connect to the requested host
>        C*************************************************
>        C/FREE
>              init_signals();
>
>              alarm(5);
>              if connect(sock: p_connto: addrlen)<  0;
>                     msg = 'unable to connect to server!';
>                   //  dsply  msg;
>                     callp close(sock);
>                     alarm(0);
>                     port_status = '0';
>                     return;
>              else;
>                     msg = 'Host is online!';
>                     port_status = '1';
>                    // dsply msg;
>              endif;
>         /end-free
>
> Again, the code works great when I call it from Java or from the ILE RPG
> 5250 program I wrote, but the CGIDEV2 program which calls the program
> never seems to time out when the connection fails.  This *seems* like an
> activation group issue (?) but I can't quite figure out why an offline
> host/port causes it to fail ONLY in the CGIDEV2 program call.  In fact,
> the code used in the CGIDEV2 program was a cut and paste from the 5250
> program with slight modifications to accommodate the CGIDEV2  methods of
> reading/writing to the output.
>
> Any ideas on where to start tracking down the issue?