/** Connect to PVs */
public void start() throws Exception {
if (pv_basename == null) return;
jumper_pv = PVPool.getPV(pv_basename + "_sw_jump_status");
jumper_pv.addListener(jumper_pv_listener);
mask_pv = PVPool.getPV(pv_basename + "_swmask");
mask_pv.addListener(mask_pv_listener);
}
/** Start archiving this channel. */
final void start() throws Exception {
is_running = true;
need_first_sample = true;
final PV pv = PVPool.getPV(name);
pv.addListener(this);
synchronized (this) {
if (this.pv != null) throw new Exception(name + " started twice");
this.pv = pv;
}
}
/** Stop archiving this channel */
final void stop() {
if (!is_running) return;
is_running = false;
final PV safe_pv;
synchronized (this) {
safe_pv = pv;
pv = null;
}
safe_pv.removeListener(this);
PVPool.releasePV(safe_pv);
addInfoToBuffer(ValueButcher.createOff());
}
// ChannelPutRequester
@Override
public void putDone(final Status status, final ChannelPut channelPut) {
if (status.isSuccess())
logger.log(Level.FINE, "Write {0} = {1} completed", new Object[] {pv.getName(), new_value});
else {
error =
new Exception(
"Write " + pv.getName() + " = " + new_value + " failed, " + status.toString());
logger.log(Level.WARNING, "", error);
}
updates.countDown();
channelPut.destroy();
}
/** Disconnect PVs */
public void stop() {
if (pv_basename == null) return;
mask_pv.removeListener(mask_pv_listener);
jumper_pv.removeListener(jumper_pv_listener);
PVPool.releasePV(jumper_pv);
PVPool.releasePV(mask_pv);
state = BypassState.Disconnected;
// Does NOT notify listener
// because the way this is used the listener
// will soon see a different list of bypasses
// or close down.
// Either way, no update needed.
}
// Future
@Override
public Object get(final long timeout, final TimeUnit unit)
throws InterruptedException, ExecutionException, TimeoutException {
if (!updates.await(timeout, unit)) throw new TimeoutException(pv.getName() + " write timeout");
if (error != null) throw new ExecutionException(error);
return null;
}
// ChannelPutRequester
@Override
public void channelPutConnect(
final Status status, final ChannelPut channelPut, final Structure structure) {
if (!status.isSuccess()) {
error = new Exception("Failed to connect 'put' for " + pv.getName() + ": " + status);
updates.countDown();
return;
}
try {
final PVStructure write_structure =
PVDataFactory.getPVDataCreate().createPVStructure(structure);
final BitSet bit_set = new BitSet(write_structure.getNumberFields());
// Locate the value field at deepest level in structure
PVField field = null;
PVStructure search = write_structure;
while (search != null) {
final PVField[] fields = search.getPVFields();
if (fields.length != 1)
throw new Exception(
"Can only write to simple struct.element.value path, got " + structure);
if (fields[0].getFieldName().equals("value")) {
field = fields[0];
break;
} else if (fields[0] instanceof PVStructure) search = (PVStructure) fields[0];
else search = null;
}
if (field == null) throw new Exception("Cannot locate 'value' to write in " + structure);
// Enumerated? Write to value.index
if (field instanceof PVStructure && "enum_t".equals(field.getField().getID()))
field = ((PVStructure) field).getSubField("index");
// Indicate what's changed & change it
bit_set.set(field.getFieldOffset());
PVStructureHelper.setField(field, new_value);
// Perform write
channelPut.put(write_structure, bit_set);
} catch (Exception ex) {
logger.log(Level.WARNING, "Failed to write " + pv.getName() + " = " + new_value, ex);
error = new Exception("Failed to write " + pv.getName() + " = " + new_value, ex);
updates.countDown();
}
}
/** @return Human-readable info on internal state of PV */
public synchronized String getInternalState() {
if (pv == null) return "Not initialized";
return pv.read() != null ? "Connected" : "Disconnected";
}
/** @return <code>true</code> if connected */
public final synchronized boolean isConnected() {
return pv != null && pv.read() != null;
}
@Override
public void disconnected(PV pv) {
logger.log(Level.WARNING, "Mask PV Disconnected: " + pv.getName());
updateState(jumper, null);
}
@Override
public void disconnected(PV pv) {
logger.log(Level.WARNING, "Jumper PV Disconnected: " + pv.getName());
updateState(null, mask);
}
/** @return Name of the Mask PV, for example "Ring_Vac:SGV_AB:FPL_Ring_swmask" */
public String getMaskPVName() {
return mask_pv.getName();
}
/** @return Name of the Jumper PV, for example "Ring_Vac:SGV_AB:FPL_Ring_sw_jump_status" */
public String getJumperPVName() {
return jumper_pv.getName();
}
