org.jlab.coda.cMsg.RCServerDomain

Class RCServer

java.lang.Object

org.jlab.coda.cMsg.common.cMsgDomainAdapter

org.jlab.coda.cMsg.RCServerDomain.RCServer

All Implemented Interfaces:

cMsgDomainInterface

public class RCServer
extends cMsgDomainAdapter

This class implements the runcontrol server (rcs) domain.

Version:

1.0

Author:

Carl Timmer

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	localUdpPort UDP port on which to receive messages from the rc client.
(package private) java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgGetHelper>	sendAndGets Collection of all of this client's sendAndGet(cMsgMessage, int) calls currently in execution.
(package private) java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgSubscription>	subscribeAndGets Collection of all of this client's subscribeAndGet(String, String, int) calls currently in execution.
(package private) java.util.Set<cMsgSubscription>	subscriptions Collection of all of this client's message subscriptions which are cMsgSubscription objects.

Fields inherited from class org.jlab.coda.cMsg.common.cMsgDomainAdapter

connected, debug, description, domain, host, name, receiving, shutdownHandler, UDL, UDLremainder

Constructor Summary

Constructors

Constructor and Description
RCServer() Constructor.

Method Summary

Modifier and Type	Method and Description
void	close() This method results in this object becoming functionally useless.
void	connect() Method to connect to the rc client from this server.
void	disconnect() Method to close the connection to the rc client.
java.lang.String	getString() Returns a string back to the top level API user indicating the host and port of the client that this server is communicating with.
void	send(cMsgMessage message) Method to send a message/command to the rc client.
cMsgMessage	sendAndGet(cMsgMessage message, int timeout) The message is sent as it would be in the send(org.jlab.coda.cMsg.cMsgMessage) method except that the senderToken and creator are set.
void	setUDL(java.lang.String UDL) Set the UDL of the client which may be a semicolon separated list of (sub)UDLs in this domain.
cMsgSubscriptionHandle	subscribe(java.lang.String subject, java.lang.String type, cMsgCallbackInterface cb, java.lang.Object userObj) This is a method to subscribe to receive messages of a subject and type from the rc client.
cMsgMessage	subscribeAndGet(java.lang.String subject, java.lang.String type, int timeout) This method is like a one-time subscribe.
int	syncSend(cMsgMessage message, int timeout) Method to send a "ping" command to the rc client.
void	unsubscribe(cMsgSubscriptionHandle obj) Method to unsubscribe a previous subscription.

Methods inherited from class org.jlab.coda.cMsg.common.cMsgDomainAdapter

flush, getCurrentUDL, getDebug, getDescription, getDomain, getHost, getInfo, getName, getServerHost, getServerPort, getShutdownHandler, getUDL, getUDLRemainder, isConnected, isReceiving, monitor, setDebug, setDescription, setName, setShutdownHandler, setUDLRemainder, shutdownClients, shutdownServers, start, stop

Methods inherited from class java.lang.Object

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

Field Detail

localUdpPort

int localUdpPort

UDP port on which to receive messages from the rc client.

subscriptions

java.util.Set<cMsgSubscription> subscriptions

Collection of all of this client's message subscriptions which are cMsgSubscription objects. This set is synchronized.

subscribeAndGets

java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgSubscription> subscribeAndGets

Collection of all of this client's subscribeAndGet(String, String, int) calls currently in execution. SubscribeAndGets are very similar to subscriptions and can be thought of as one-shot subscriptions. Key is receiverSubscribeId object, value is cMsgSubscription object.

sendAndGets

java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgGetHelper> sendAndGets

Collection of all of this client's sendAndGet(cMsgMessage, int) calls currently in execution. Key is senderToken object, value is cMsgGetHelper object.

Constructor Detail

RCServer

public RCServer()
         throws cMsgException

Constructor.

Throws:

cMsgException - if cannot find host name.

Method Detail

getString

public java.lang.String getString()

Returns a string back to the top level API user indicating the host and port of the client that this server is communicating with.

Returns:

host:port of client

setUDL

public void setUDL(java.lang.String UDL)
            throws cMsgException

Set the UDL of the client which may be a semicolon separated list of (sub)UDLs in this domain. Bad sub UDLs are ignored, but at least one must be valid.

Specified by:

setUDL in interface cMsgDomainInterface

Overrides:

setUDL in class cMsgDomainAdapter

Parameters:

UDL - UDL of client

Throws:

cMsgException - if UDL is null or no valid UDL exists

connect

public void connect()
             throws cMsgException

Method to connect to the rc client from this server.

Specified by:

connect in interface cMsgDomainInterface

Overrides:

connect in class cMsgDomainAdapter

Throws:

cMsgException - if there are problems parsing the UDL, communication problems with the client, or cannot start up a TCP listening thread

close

public void close()

This method results in this object becoming functionally useless.

disconnect

public void disconnect()

Method to close the connection to the rc client. Keep the listening threads running in case another call to connect() is made.

Specified by:

disconnect in interface cMsgDomainInterface

Overrides:

disconnect in class cMsgDomainAdapter

send

public void send(cMsgMessage message)
          throws cMsgException

Method to send a message/command to the rc client. The command is sent as a string in the message's text field.

Specified by:

send in interface cMsgDomainInterface

Overrides:

send in class cMsgDomainAdapter

Parameters:

message - message to send

Throws:

cMsgException - if there are communication problems with the server; text is null or blank

syncSend

public int syncSend(cMsgMessage message,
                    int timeout)
             throws cMsgException

Method to send a "ping" command to the rc client. It writes a message and returns a zero if no connection to client exists, any other value indicates a valid connection.

Specified by:

syncSend in interface cMsgDomainInterface

Overrides:

syncSend in class cMsgDomainAdapter

Parameters:

message - message to send

timeout - ignored

Returns:

0 if no valid TCP connection to client, 1 if there is a connection.

Throws:

cMsgException - if there is a timeout

subscribe

public cMsgSubscriptionHandle subscribe(java.lang.String subject,
                                        java.lang.String type,
                                        cMsgCallbackInterface cb,
                                        java.lang.Object userObj)
                                 throws cMsgException

This is a method to subscribe to receive messages of a subject and type from the rc client.

Specified by:

subscribe in interface cMsgDomainInterface

Overrides:

subscribe in class cMsgDomainAdapter

Parameters:

subject - message subject

type - message type

cb - callback object whose single method is called upon receiving a message of subject and type

userObj - any user-supplied object to be given to the callback method as an argument

Returns:

handle object to be used for unsubscribing

Throws:

cMsgException - if the subject, type, or callback is null; an identical subscription already exists; if not connected to an rc client

unsubscribe

public void unsubscribe(cMsgSubscriptionHandle obj)
                 throws cMsgException

Method to unsubscribe a previous subscription.

Specified by:

unsubscribe in interface cMsgDomainInterface

Overrides:

unsubscribe in class cMsgDomainAdapter

Parameters:

obj - the object returned from a subscribe call

Throws:

cMsgException - if there is no connection with the rc client; obj is null

subscribeAndGet

public cMsgMessage subscribeAndGet(java.lang.String subject,
                                   java.lang.String type,
                                   int timeout)
                            throws cMsgException,
                                   java.util.concurrent.TimeoutException

This method is like a one-time subscribe. The rc server grabs the first incoming message of the requested subject and type and sends that to the caller. NOTE: Disconnecting when one thread is in the waiting part of a subscribeAndGet may cause that thread to block forever. It is best to always use a timeout with subscribeAndGet so the thread is assured of eventually resuming execution.

Specified by:

subscribeAndGet in interface cMsgDomainInterface

Overrides:

subscribeAndGet in class cMsgDomainAdapter

Parameters:

subject - subject of message desired from server

type - type of message desired from server

timeout - time in milliseconds to wait for a message

Returns:

response message

Throws:

cMsgException - if there are communication problems with rc client; subject and/or type is null or blank

java.util.concurrent.TimeoutException - if timeout occurs

sendAndGet

public cMsgMessage sendAndGet(cMsgMessage message,
                              int timeout)
                       throws cMsgException,
                              java.util.concurrent.TimeoutException

The message is sent as it would be in the send(org.jlab.coda.cMsg.cMsgMessage) method except that the senderToken and creator are set. A marked response can be received from a client regardless of its subject or type. NOTE: Disconnecting when one thread is in the waiting part of a sendAndGet may cause that thread to block forever. It is best to always use a timeout with sendAndGet so the thread is assured of eventually resuming execution.

Specified by:

sendAndGet in interface cMsgDomainInterface

Overrides:

sendAndGet in class cMsgDomainAdapter

Parameters:

message - message sent to client

timeout - time in milliseconds to wait for a response message, zero means wait forever.

Returns:

response message

Throws:

cMsgException - if there are communication problems with the client; subject and/or type is null or blank

java.util.concurrent.TimeoutException - if timeout occurs