Experimental Physics and
Industrial Control System

Andy Foster <[email protected]> · Fri, 17 Sep 2004 11:53:56 +0100 (BST)

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 [email protected]
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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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System