[Info-vax] Timeout in a write using QUIW.

[Bob Gezelter]

On Thursday, June 22, 2023 at 2:54:18 AM UTC-4, Jan-Erik Söderholm wrote:
> Den 2023-06-22 kl. 00:19, skrev Stephen Hoffman: 
> > On 2023-06-21 21:39:19 +0000, Jan-Erik S derholm said: 
> >> 
> >> My thought was to just queue the I/O, wait a sec or two using $WAIT and 
> >> then check the IOSB. If not completed OK, CANCEL and return an error to 
> >> the application... 
> >> 
> >> We'll see. Hopefully we can convince them to install wired connections 
> >> instead of using Wifi... 
> > 
> > Yeah. I tried that in the 1980s. Learned that ASTs and threads and 
> > completion routines avoided a whole lot of the mess that the inevitable 
> > errors within sync I/O and networking involves. You're headed for some 
> > races here, too. 
> > 
> >
> Yes, there are some "unknowns" in this. :-) 
> Equipment gets restarted or powered off. Network is "flaky". 
> 
> Most of the reconnect issues are handled by the telnet driver 
> by creating TNA devices that are used for the communication. 
> 
> The connections are reconnected after a equipment restart or 
> network autage automatically with no application involvment. 
> 
> And the programming is easier by just pretending that all network 
> equipment are "terminals" having a TNA device. 
> 
> Thanks for your input! 
> 
> Jan-Erik.
Jan-Erik,

Definition of "network": Connections are subject to random/non-random interference.

Otherwise, I concur with Hoff. Use a Timer AST and cancel; with the "cancel pending" bit to avoid race conditions. The IO completion will occur, with the appropriate IO completion code in the IOSB.

- Bob Gezelter, http://www.rlgsc.com