Hi all -- I sent this last week but it never showed up in my inbox, so I'm assuming you haven't seen it...
On Fri, Sep 22, 2017 at 5:54 PM, C Smith <[email protected]> wrote: > Hi all -- > > Thanks to your help, I am now using XDDP sockets for communication between > non-RT processes and a single RT process. It is generally working -- I > start the RT task first, and it opens several sockets. It starts doing > non-blocking reads and writes, and since no process is on the other end, > they return immediately. > > Then I start one or more non-RT processes that connect, either O_RDONLY or > O_WRONLY, to several of the non-RT ends of the sockets (via /dev/rtpXX). > That works well, now the RT and non-RT processes are exchanging data. > > The problem comes if I run one of the non-RT processes in a debugger and > halt it (after it has connected). The evidence is ambiguous, but usually > it seems the RT task just hangs. Then if I continue the non-RT process, > everything becomes healthy again and messages flow. Or, if I kill the > non-RT process, at least the RT task doesn't hang. > > I haven't been able to figure out anything about the RT process when it is > "hung". The first time I saw this today, it appeared that a socket > sendto() operation in the RT process was returning errno = ENOMEM, but I > wasn't able to reproduce it. If I attach to the RT process in a debugger > while it is hung, I'm not able to get it to continue. And if I start the > RT process in a debugger, then break when it hangs, I can single step > through the entire infinite loop of the RT process without problem; but > then when I continue it goes back to the hang behavior. (One thing the > infinite loop does is increment a counter in shared memory -- I can see > this happen when I'm single stepping, but then when I continue I see from > non-RT processes that the counter in shared memory stops incrementing.) > > Any ideas, either what is expected when the process on one end of an XDDP > socket is suspended, or how I could figure out what's going on in the RT > process? > > Thanks for all you help so far! > Bob > _______________________________________________ Xenomai mailing list [email protected] https://xenomai.org/mailman/listinfo/xenomai
