Package org.epics.archiverappliance.engine.pv

Class PVContext

java.lang.Object

org.epics.archiverappliance.engine.pv.PVContext

public class PVContext
extends Object

Handle PV context, pool PVs by name. When using the pure java CA client implementation, it returns the same 'channel' when trying to access the same PV name multiple times. That's good, but I don't know how to determine if the channel for this EPICS_V3_PV is actually shared. Calling destroy() on such a shared channel creates problems.
The PVContext adds its own hash map of channels and keeps a reference count.

Version:

4-Jun-2012, Luofeng Li:added codes to support for the new archiver

Author:

Kay Kasemir s@version Initial version:CSS

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PVContext.MonitorMask

Constructor Summary

Constructors

Constructor	Description
PVContext()

Method Summary

Modifier and Type	Method	Description
static RefCountedChannel	getChannel(String name, int jcaCommandThreadId, gov.aps.jca.event.ConnectionListener conn_callback)	Get a new channel, or a reference to an existing one.
static int	getChannelCount()	Return the channel count as this class sees it.
static void	scheduleCommand(String pvName, int jcaCommandThreadId, RefCountedChannel channel_ref, String msg, Runnable command)	Add a command to the JCACommandThread.
static void	setConfigservice(ConfigService configservice)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PVContext

public PVContext()

Method Detail

setConfigservice

public static void setConfigservice(ConfigService configservice)

getChannel

public static RefCountedChannel getChannel(String name,
                                           int jcaCommandThreadId,
                                           gov.aps.jca.event.ConnectionListener conn_callback)
                                    throws Exception

Get a new channel, or a reference to an existing one.

Parameters:

name - Channel name

jcaCommandThreadId - The JCA Command thread.

conn_callback -  

Returns:

reference to channel

Throws:

Exception - on error

See Also:

releaseChannel(org.epics.archiverappliance.engine.pv.RefCountedChannel, gov.aps.jca.event.ConnectionListener)

scheduleCommand

public static void scheduleCommand(String pvName,
                                   int jcaCommandThreadId,
                                   RefCountedChannel channel_ref,
                                   String msg,
                                   Runnable command)

Add a command to the JCACommandThread.

Parameters:

pvName - The name of the PV that this applies to

jcaCommandThreadId - The JCA Command thread for this PV.

channel_ref - this can be null

msg -  

command - The runnable that will run in the specified command thread

getChannelCount

public static int getChannelCount()

Return the channel count as this class sees it.

Returns:

int channels size