RE: Understand the EPICS fdmgr functions

["Jeff Hill" <johill@lanl.gov>]

Andy,

Sorry about the delay replying. I created entry 132 in the Mantis bug
tracker. 

Jeff

> -----Original Message-----
> From: Andy Foster [mailto:ajf@observatorysciences.co.uk]
> Sent: Friday, September 17, 2004 4:54 AM
> To: Epics Questions
> Subject: Understand the EPICS fdmgr functions
> 
> 
> Dear All,
> 
> Could someone explain to me why the program below, with the
> call to "ca_add_fd_registration (NULL, NULL), NULL)"
> commented out, produces:
> 
> -----------------------------------------------------
> A call to "assert (epicsThreadOnceCalled)" failed in
> ..../../../src/libCom/osi/os/posix/osdThread.c line 544.
> EPICS Release EPICS R3.14.6GEM9.0 $Tag$ $Date: 2004/07/06 13:38:24 $.
> Current time Fri Sep 17 2004 11:18:49.770291407.
> Please E-mail this message to the author or to tech-talk@aps.anl.gov
> Calling epicsThreadSuspendSelf()
> ------------------------------------------------------
> 
> BUT, if I add in the call, it works OK.
> I'm not sure what the call is really doing since I am passing
> NULL arguments and haven't given it an "fd" to register.
> 
> I don't really want the program to know anything about CA, so I wonder
> why I need this call at all?
> 
> I think what this really shows is that I don't
> understand how to use the "fdmgr" functions and whether they are
> fundamentally linked to using Channel Access in some way.
> 
> Is there any documentation on their use?
> 
> Cheers,
> 
> Andy
> 
> 
> ------------------------------------
> #include <stdio.h>
> #include <math.h>
> 
> #include <X11/Xlib.h>
> 
> #include "fdmgr.h"
> #include "epicsTime.h"
> #include "epicsAssert.h"
> #include "cadef.h"
> 
> static struct timeval polltime = {30, 0};
> static struct timeval tmo      = {2, 0};
> 
> void alarmCB()
> {
>   printf("Inside alarmCB...\n");
> }
> 
> int main (int argc, char **argv)
> {
>     int status;
>     fdmgrAlarmId aid;
>     fdctx *pfdm;
> 
>     pfdm = fdmgr_init ();
>     assert (pfdm);
> /*   SEVCHK (ca_add_fd_registration (NULL, NULL), NULL); */
>     fdmgr_add_fd(pfdm, ConnectionNumber(XOpenDisplay(NULL)), NULL, NULL);
> 
>     aid = fdmgr_add_timeout (pfdm, &tmo, alarmCB, NULL);
>     assert (aid!=fdmgrNoAlarm);
> 
>     while (1) {
>         status = fdmgr_pend_event (pfdm, &polltime);
>         assert (status==0);
>     }
> 
>     return 0;
> }
> ------------------------------------
> 
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