/* main program */
int main( int argc, char *argv[] ) {
/* system and variable names */
const char *sysNam = ( argc > 1 ) ? argv[1] : "ca";
const char *varNam = ( argc > 2 ) ? argv[2] : "demo:voltage";
void *sys;
void *var;
int status;
/* create system */
status = pvSysCreate( sysNam, 0, &sys );
if ( status ) {
printf( "pvSysCreate( %s ) failure\n", sysNam );
return -1;
}
/* create variable */
status = pvVarCreate( sys, varNam, NULL, NULL, 0, &var );
if ( status ) {
printf( "pvVarCreate( %s, %s ) failure\n", sysNam, varNam );
return -1;
}
/* monitor variable as double (assume scalar) */
status = pvVarMonitorOn( var, pvTypeDOUBLE, 1, event, NULL, NULL );
if ( status ) {
printf( "pvVarMonitorOn( %s ) failure\n", varNam );
}
/* shouldn't need this! */
pvSysPend( sys, 1, FALSE );
/* block for 10 seconds */
pvSysPend( sys, 10, TRUE );
/* tidy up */
pvVarDestroy( var );
pvSysDestroy( sys );
return 0;
}
/*
* Assign/Connect to a channel.
* Assign to a zero-length string ("") disconnects/de-assigns,
* in safe mode, creates an anonymous PV.
*/
epicsShareFunc pvStat seq_pvAssign(SS_ID ss, CH_ID chId, const char *pvName)
{
PROG *sp = ss->prog;
CHAN *ch = sp->chan + chId;
pvStat status = pvStatOK;
DBCHAN *dbch;
if (!pvName) pvName = "";
DEBUG("Assign %s to \"%s\"\n", ch->varName, pvName);
epicsMutexMustLock(sp->lock);
dbch = ch->dbch;
if (dbch) /* was assigned to a named PV */
{
ch->dbch = 0;
epicsMutexUnlock(sp->lock);
status = pvVarDestroy(&dbch->pvid);
epicsMutexMustLock(sp->lock);
sp->assignCount--;
if (dbch->connected) /* see connection handler */
{
dbch->connected = FALSE;
sp->connectCount--;
/* Must not call seq_camonitor(ch, FALSE), it would give an
error because channel is already dead. pvVarDestroy takes
care that the monid inside the pvid gets invalidated. */
/* Note ch->monitored remains on because it is a configuration
value that belongs to the variable and newly created channels
for the same variable should inherit this configuration. */
}
if (status != pvStatOK)
{
errlogSevPrintf(errlogFatal, "pvAssign(var %s, pv %s): pvVarDestroy() failure: "
"%s\n", ch->varName, dbch->dbName, pvVarGetMess(dbch->pvid));
}
free(dbch->dbName);
}
if (pvName[0] == 0) /* new name is empty -> free resources */
{
if (dbch) {
free(dbch);
}
}
else /* new name is non-empty -> create resources */
{
if (!dbch)
{
dbch = new(DBCHAN);
if (!dbch)
{
errlogSevPrintf(errlogFatal, "pvAssign: calloc failed\n");
epicsMutexUnlock(sp->lock);
return pvStatERROR;
}
}
dbch->dbName = epicsStrDup(pvName);
if (!dbch->dbName)
{
errlogSevPrintf(errlogFatal, "pvAssign: epicsStrDup failed\n");
free(dbch);
epicsMutexUnlock(sp->lock);
return pvStatERROR;
}
ch->dbch = dbch;
status = pvVarCreate(
sp->pvSys, /* PV system context */
dbch->dbName, /* DB channel name */
seq_conn_handler, /* connection handler routine */
seq_event_handler, /* event handler routine */
ch, /* user ptr is CHAN structure */
&dbch->pvid); /* ptr to pvid */
if (status != pvStatOK)
{
errlogSevPrintf(errlogFatal, "pvAssign(var %s, pv %s): pvVarCreate() failure: "
"%s\n", ch->varName, dbch->dbName, pvVarGetMess(dbch->pvid));
free(ch->dbch->dbName);
free(ch->dbch);
}
else
{
sp->assignCount++;
}
}
epicsMutexUnlock(sp->lock);
return status;
}
/*
* Assign/Connect to a channel.
* Assign to a zero-length string ("") disconnects/de-assigns,
* in safe mode, creates an anonymous PV.
*/
epicsShareFunc pvStat epicsShareAPI seq_pvAssign(SS_ID ss, VAR_ID varId, const char *pvName)
{
SPROG *sp = ss->sprog;
CHAN *ch = sp->chan + varId;
pvStat status = pvStatOK;
DBCHAN *dbch = ch->dbch;
if (!pvName) pvName = "";
DEBUG("Assign %s to \"%s\"\n", ch->varName, pvName);
epicsMutexMustLock(sp->programLock);
if (dbch) /* was assigned to a named PV */
{
status = pvVarDestroy(dbch->pvid);
dbch->pvid = NULL;
sp->assignCount -= 1;
if (dbch->connected) /* see connection handler */
{
dbch->connected = FALSE;
sp->connectCount--;
/* Must not call seq_monitor(ch, FALSE), it would give an
error because channel is already dead. Instead mark that no
subscriptions are active so when seq_monitor gets called when
we re-create the channel, it actually does something. */
dbch->monid = NULL;
/* Note ch->monitored remains on because it is a configuration
value that belongs to the variable and newly created channels
for the same variable should inherit this configuration. */
}
if (status != pvStatOK)
{
errlogSevPrintf(errlogFatal, "pvAssign(var %s, pv %s): pvVarDestroy() failure: "
"%s\n", ch->varName, dbch->dbName, pvVarGetMess(dbch->pvid));
}
free(dbch->dbName);
}
if (pvName == NULL || pvName[0] == 0) /* new name is empty -> free resources */
{
if (dbch) {
free(ch->dbch->ssMetaData);
free(ch->dbch);
}
}
else /* new name is non-empty -> create resources */
{
if (!dbch)
{
dbch = new(DBCHAN);
if (!dbch)
{
errlogSevPrintf(errlogFatal, "pvAssign: calloc failed\n");
return pvStatERROR;
}
}
dbch->dbName = epicsStrDup(pvName);
if (!dbch->dbName)
{
errlogSevPrintf(errlogFatal, "pvAssign: epicsStrDup failed\n");
free(dbch);
return pvStatERROR;
}
if ((sp->options & OPT_SAFE) && sp->numSS > 0)
{
dbch->ssMetaData = newArray(PVMETA, sp->numSS);
if (!dbch->ssMetaData)
{
errlogSevPrintf(errlogFatal, "pvAssign: calloc failed\n");
free(dbch->dbName);
free(dbch);
return pvStatERROR;
}
}
ch->dbch = dbch;
sp->assignCount++;
status = pvVarCreate(
sp->pvSys, /* PV system context */
dbch->dbName, /* DB channel name */
seq_conn_handler, /* connection handler routine */
ch, /* user ptr is CHAN structure */
sp->debug, /* debug level (inherited) */
&dbch->pvid); /* ptr to pvid */
if (status != pvStatOK)
{
errlogSevPrintf(errlogFatal, "pvAssign(var %s, pv %s): pvVarCreate() failure: "
"%s\n", ch->varName, dbch->dbName, pvVarGetMess(dbch->pvid));
if (ch->dbch->ssMetaData)
free(ch->dbch->ssMetaData);
free(ch->dbch->dbName);
free(ch->dbch);
}
}
epicsMutexUnlock(sp->programLock);
return status;
}
