Experimental Physics and
Industrial Control System

Eric Norum <[email protected]> · Mon, 26 Jul 2004 14:29:31 -0500

Robert Soliday wrote:
> int sigint=0;
.
.
.

/* wrapper for ca_pend_event that allows breaking out early if the
   flag is set from a signal handler. Unlike ca_pend_event, a timeout
   of zero will not be converted to infinity. */
long oag_ca_pend_event(double timeout, int *flag) {
  long status=ECA_NORMAL;
  if (timeout <= 0)
    ca_poll();
  while (timeout > 0) {
    if (*flag)
      return(status);
    if (timeout > 1) {
      status = ca_pend_event(1);
      timeout -= 1;
    } else {
      status = ca_pend_event(timeout);
      timeout = 0;
    }
  }
  return(status);
}


I'm not completely up to speed on the latest 'alias/noalias' state of C
pointers, but I think that it would be safer to add some 'volatile' keywords
to protect yourself from overzealous optimizers:
volatile int sigint = 0;
.
.
long oag_ca_pend_event(double timeout, volatile int *flag) {
.
.
--
Eric Norum                                 [email protected]
Advanced Photon Source                     Phone: (630) 252-4793
Argonne National Laboratory

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System