RE: Process Delay -- RPG400-L

On Mon, 16 Jan 2006, Scott Klement wrote:

Actually I coded up an example that uses setitimer() and also avoids the
problem discussed in the paragraph above.  My example also uses signals to
terminate the program gracefully.  My example is in C but you could call
RPG subprocedures from the C code to do what you want.  My example is
here:
http://archive.midrange.com/c400-l/200511/msg00007.html


I don't see how your code solves the problems I discussed (aside from the
fact that all it does is print a message, and there's no way that could
take that long.

The problem it solves is that it will call the action() every time thetimer goes off, even if action() takes longer to execute than the timerwait period. The action() function is where you would put your usefulcode.

Also, your code doesn't run on the iSeries -- at least not on my V5R3
system.  It crashes immediately with a floating point error, and never
even gets to the point of calling setitimer().

As the disclaimer said at the bottom of the example, "This has only beentested on linux, but should be cross platform..." I guess it isn't ascross platform as I hoped. Still, it is quite valuable as an example, andthat is the whole point of posting it.

It also uses the signal() API which is slow because it saves the program
stack when it receives a signal and restores it when the signal handler
exits.  This behavior is annoying because it also means you can't use
global variables to communicate with your signal handler.

When you use the setitimer() function you can't help but use signals.setitimer uses signals as a trigger. I simply added another signal toshut down gracefully. If you use setitimer() at all, you will bynecessity use signals (at least this is true on linux - if this isn'ttrue on OS/400 then just say so).

I don't understand why you think a Linux C solution is an appropriate
answer for an iSeries RPG question.

Because the example is relevant to the post that setitimer() could solvethe problem.


James Rich

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