Files
epics-base/modules/ca/src/client/caEventRate.cpp
Andrew Johnson 3c99391d93 Added SPDX License ID to all EPICS-original source files
In some cases the license-identification header was missing,
so I added that as well. Replaced the remaining headers that
specifically identified "Versions 3.13.7 and higher".

Makefiles and the build system were deliberately excluded.
2020-08-03 11:53:01 -05:00

140 lines
3.8 KiB
C++

/*************************************************************************\
* Copyright (c) 2002 The University of Chicago, as Operator of Argonne
* National Laboratory.
* Copyright (c) 2002 The Regents of the University of California, as
* Operator of Los Alamos National Laboratory.
* SPDX-License-Identifier: EPICS
* EPICS BASE is distributed subject to a Software License Agreement found
* in file LICENSE that is included with this distribution.
\*************************************************************************/
#include <stdio.h>
#include <limits.h>
#include <math.h>
#include "cadef.h"
#include "dbDefs.h"
#include "epicsTime.h"
#include "errlog.h"
/*
* event_handler()
*/
extern "C" void eventCallBack ( struct event_handler_args args )
{
unsigned *pCount = static_cast < unsigned * > ( args.usr );
(*pCount)++;
}
/*
* caEventRate ()
*/
void caEventRate ( const char *pName, unsigned count )
{
static const double initialSamplePeriod = 1.0;
static const double maxSamplePeriod = 60.0 * 5.0;
unsigned eventCount = 0u;
chid * pChidTable = new chid [ count ];
{
printf ( "Connecting to CA Channel \"%s\" %u times.",
pName, count );
fflush ( stdout );
epicsTime begin = epicsTime::getCurrent ();
for ( unsigned i = 0u; i < count; i++ ) {
int status = ca_search ( pName, & pChidTable[i] );
SEVCHK ( status, NULL );
}
int status = ca_pend_io ( 10000.0 );
if ( status != ECA_NORMAL ) {
fprintf ( stderr, " not found.\n" );
return;
}
epicsTime end = epicsTime::getCurrent ();
printf ( " done(%f sec).\n", end - begin );
}
{
printf ( "Subscribing %u times.", count );
fflush ( stdout );
epicsTime begin = epicsTime::getCurrent ();
for ( unsigned i = 0u; i < count; i++ ) {
int addEventStatus = ca_add_event ( DBR_FLOAT,
pChidTable[i], eventCallBack, &eventCount, NULL);
SEVCHK ( addEventStatus, __FILE__ );
}
int status = ca_flush_io ();
SEVCHK ( status, __FILE__ );
epicsTime end = epicsTime::getCurrent ();
printf ( " done(%f sec).\n", end - begin );
}
{
printf ( "Waiting for initial value events." );
fflush ( stdout );
// let the first one go by
epicsTime begin = epicsTime::getCurrent ();
while ( eventCount < count ) {
int status = ca_pend_event ( 0.01 );
if ( status != ECA_TIMEOUT ) {
SEVCHK ( status, NULL );
}
}
epicsTime end = epicsTime::getCurrent ();
printf ( " done(%f sec).\n", end - begin );
}
double samplePeriod = initialSamplePeriod;
double X = 0.0;
double XX = 0.0;
unsigned N = 0u;
while ( true ) {
unsigned nEvents, lastEventCount, curEventCount;
epicsTime beginPend = epicsTime::getCurrent ();
lastEventCount = eventCount;
int status = ca_pend_event ( samplePeriod );
curEventCount = eventCount;
epicsTime endPend = epicsTime::getCurrent ();
if ( status != ECA_TIMEOUT ) {
SEVCHK ( status, NULL );
}
if ( curEventCount >= lastEventCount ) {
nEvents = curEventCount - lastEventCount;
}
else {
nEvents = ( UINT_MAX - lastEventCount ) + curEventCount + 1u;
}
N++;
double period = endPend - beginPend;
double Hz = nEvents / period;
X += Hz;
XX += Hz * Hz;
double mean = X / N;
double stdDev = sqrt ( XX / N - mean * mean );
printf ( "CA Event Rate (Hz): current %g mean %g std dev %g\n",
Hz, mean, stdDev );
if ( samplePeriod < maxSamplePeriod ) {
samplePeriod += samplePeriod;
}
}
}