org.jlab.coda.cMsg.cMsgDomain.client

Class cMsgServerClient

java.lang.Object

org.jlab.coda.cMsg.common.cMsgDomainAdapter

org.jlab.coda.cMsg.cMsgDomain.client.cMsg

org.jlab.coda.cMsg.cMsgDomain.client.cMsgServerClient

All Implemented Interfaces:

cMsgDomainInterface

public class cMsgServerClient
extends cMsg

This class implements a cMsg client which is created in a cMsg server for the purpose of communicating with other cMsg servers in the cMsg domain.

Version:

1.0

Author:

Carl Timmer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) class	cMsgServerClient.RejectHandler Class for telling a thread pool what to do for rejected requests to start a new thread (when the pool already is using its maximum number of threads.

Nested classes/interfaces inherited from class org.jlab.coda.cMsg.cMsgDomain.client.cMsg

cMsg.KeepAlive, cMsg.Multicaster, cMsg.ParsedUDL, cMsg.UdpReceiver, cMsg.UpdateServer

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.String[]	clientNamesAndNamespaces String array filled in by calling getClientNamesAndNamespaces().
(package private) cMsgGetHelper	clientNamesHelper Helper object used in getClientNamesAndNamespaces().
(package private) cMsgGetHelper	cloudLockHelper Helper object used in cloudLock(int).
(package private) java.util.concurrent.atomic.AtomicBoolean	gotCloudLock Did we successfully grab the cloud-joining lock of the server in the cloud we are trying to join?
(package private) java.util.concurrent.atomic.AtomicBoolean	gotRegistrationLock Did we successfully grab the client-joining lock of the server in the cloud we are trying to join? This lock is necessary to ensure that each client joining a server that is part of a cloud has a unique name.
(package private) cMsgGetHelper	registrationLockHelper Helper object used in registrationLock(int).
(package private) java.util.concurrent.ConcurrentHashMap<java.lang.Integer,java.util.concurrent.Future<java.lang.Boolean>>	serverSendAndGetCancel Collection of all Future objects from this server client's serverSendAndGet(org.jlab.coda.cMsg.cMsgMessage, java.lang.String, org.jlab.coda.cMsg.cMsgCallbackInterface) calls.
(package private) java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgSendAndGetCallbackThread>	serverSendAndGets Collection of all of this server client's cMsgSendAndGetCallbackThread objects which are threads waiting for results of a serverSendAndGet(org.jlab.coda.cMsg.cMsgMessage, java.lang.String, org.jlab.coda.cMsg.cMsgCallbackInterface) on a connected server.

Fields inherited from class org.jlab.coda.cMsg.cMsgDomain.client.cMsg

broadList, connectLock, currentParsedUDL, domainOut, domainOutSocket, domainServerHost, domainServerPort, hasSend, hasSendAndGet, hasShutdown, hasSubscribe, hasSubscribeAndGet, hasSyncSend, hasUnsubscribe, ipList, keepAliveSocket, keepAliveThread, listeningThread, monitorXML, notConnectLock, sendAndGets, socketLock, subscribeAndGets, subscribeLock, subscriptions, syncSends, uniqueClientKey, uniqueId, updateServerThread, useFailovers

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
cMsgServerClient(cMsgNameServer nameServer) Constructor.

Method Summary

Modifier and Type	Method and Description
void	cleanup() Method to clean up after this object.
boolean	cloudLock(int delay) Lock the server (in cMsg subdomain) so that no other servers may simultaneously join the cMsg subdomain server cloud or register a client.
void	cloudUnlock() Unlock the server enabling other servers to join the cMsg subdomain server cloud or register a client.
java.util.HashSet<java.lang.String>	connect(int fromNsTcpPort, int fromNsMulticastPort, boolean isOriginator, java.lang.String cloudPassword, java.lang.String clientPassword, boolean multicasting) Method to connect to the domain server from a cMsg server acting as a bridge.
java.lang.String[]	getClientNamesAndNamespaces() This method gets the names and namespaces of all the local clients (not servers) of another cMsg domain server.
void	printSizes() This method prints sizes of maps for debugging purposes.
boolean	registrationLock(int delay) Grab the registration lock (for adding a client) of another cMsg domain server.
void	registrationUnlock() Release the registration lock (when adding a client) of another cMsg domain server.
int	serverSendAndGet(cMsgMessage message, java.lang.String namespace, cMsgCallbackInterface cb) The message is sent by a server client to another server as it would be in the cMsg.send(org.jlab.coda.cMsg.cMsgMessage) method.
void	serverShutdown() Method to shutdown the server connected to.
void	serverShutdownClients(java.lang.String client, boolean includeMe) Method to shutdown the given clients.
void	serverSubscribe(java.lang.String subject, java.lang.String type, java.lang.String namespace, cMsgCallbackInterface cb, java.lang.Object userObj) Method for a server to subscribe to receive messages of a subject and type from another domain server.
void	serverUnSendAndGet(int id) Method to remove a previous serverSendAndGet.
void	serverUnsubscribe(java.lang.String subject, java.lang.String type, java.lang.String namespace, cMsgCallbackInterface cb, java.lang.Object userObj) Method for a server to unsubscribe a previous subscription to receive messages of a subject and type from another domain server.
(package private) java.util.HashSet<java.lang.String>	talkToNameServerFromServer(java.net.Socket socket, int cloudStatus, int fromNSTcpPort, int fromNSMulticastPort, boolean isOriginator, java.lang.String cloudPassword, java.lang.String clientPassword) This method gets the host and port of the domain server from the name server.
void	thisServerCloudStatus(int status) This method tells the server this server is connected to, what cloud status this server has.

Methods inherited from class org.jlab.coda.cMsg.cMsgDomain.client.cMsg

connect, connectWithMulticast, disconnect, flush, getCurrentUDL, getInfo, getServerHost, getServerPort, monitor, parseUDL, send, sendAndGet, setUDL, shutdownClients, shutdownServers, subscribe, subscribeAndGet, syncSend, talkToNameServerFromClient, unsubscribe

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

getDebug, getDescription, getDomain, getHost, getName, getShutdownHandler, getUDL, getUDLRemainder, isConnected, isReceiving, setDebug, setDescription, setName, setShutdownHandler, setUDLRemainder, start, stop

Methods inherited from class java.lang.Object

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

Field Detail

serverSendAndGets

java.util.concurrent.ConcurrentHashMap<java.lang.Integer,cMsgSendAndGetCallbackThread> serverSendAndGets

Collection of all of this server client's cMsgSendAndGetCallbackThread objects which are threads waiting for results of a serverSendAndGet(org.jlab.coda.cMsg.cMsgMessage, java.lang.String, org.jlab.coda.cMsg.cMsgCallbackInterface) on a connected server. Key is senderToken object, value is cMsgSendAndGetCallbackThread object.

serverSendAndGetCancel

java.util.concurrent.ConcurrentHashMap<java.lang.Integer,java.util.concurrent.Future<java.lang.Boolean>> serverSendAndGetCancel

Collection of all Future objects from this server client's serverSendAndGet(org.jlab.coda.cMsg.cMsgMessage, java.lang.String, org.jlab.coda.cMsg.cMsgCallbackInterface) calls. These objects allow the cancellation of such a call currently in execution. Interrupting these threads directly seems to cause problems with the thread pool executor. Key is senderToken object, value is Future object.

clientNamesHelper

cMsgGetHelper clientNamesHelper

Helper object used in getClientNamesAndNamespaces().

clientNamesAndNamespaces

java.lang.String[] clientNamesAndNamespaces

String array filled in by calling getClientNamesAndNamespaces().

cloudLockHelper

cMsgGetHelper cloudLockHelper

Helper object used in cloudLock(int).

gotCloudLock

java.util.concurrent.atomic.AtomicBoolean gotCloudLock

Did we successfully grab the cloud-joining lock of the server in the cloud we are trying to join?

registrationLockHelper

cMsgGetHelper registrationLockHelper

Helper object used in registrationLock(int).

gotRegistrationLock

java.util.concurrent.atomic.AtomicBoolean gotRegistrationLock

Did we successfully grab the client-joining lock of the server in the cloud we are trying to join? This lock is necessary to ensure that each client joining a server that is part of a cloud has a unique name.

Constructor Detail

cMsgServerClient

public cMsgServerClient(cMsgNameServer nameServer)
                 throws cMsgException

Constructor.

Parameters:

nameServer - nameServer this client is running in

Throws:

cMsgException - if local host name cannot be found

Method Detail

printSizes

public void printSizes()

This method prints sizes of maps for debugging purposes.

cleanup

public void cleanup()

Method to clean up after this object.

connect

public java.util.HashSet<java.lang.String> connect(int fromNsTcpPort,
                                                   int fromNsMulticastPort,
                                                   boolean isOriginator,
                                                   java.lang.String cloudPassword,
                                                   java.lang.String clientPassword,
                                                   boolean multicasting)
                                            throws cMsgException

Method to connect to the domain server from a cMsg server acting as a bridge. This method is only called by the cMsgDomain.server.cMsgServerBridge object.

Parameters:

fromNsTcpPort - TCP listening port of name server calling this method

fromNsMulticastPort - UDP multicast listening port of name server calling this method

isOriginator - true if originating the connection between the 2 servers and false if this is the response or reciprocal connection

cloudPassword - password for connecting to a server in a particular cloud

clientPassword - password for a client connecting to this server

multicasting - true if multicasting to find server since host unknown

Returns:

set of servers (names of form "host:port") that the server we're connecting to is already connected with

Throws:

cMsgException - if there are problems parsing the UDL or communication problems with the server

serverSendAndGet

public int serverSendAndGet(cMsgMessage message,
                            java.lang.String namespace,
                            cMsgCallbackInterface cb)
                     throws java.io.IOException

The message is sent by a server client to another server as it would be in the cMsg.send(org.jlab.coda.cMsg.cMsgMessage) method. The receiving server notes the fact that a response to it is expected, and sends it to all subscribed to its subject and type. When a marked response is received from a client, it sends that first response back to the original sender regardless of its subject or type.

Parameters:

message - message sent to server

namespace - namespace of message sent

cb - callback to run on receipt of response message

Returns:

the receiverSubscribe id number of the sendAndGet

Throws:

java.io.IOException - if there are communication problems with the server

serverUnSendAndGet

public void serverUnSendAndGet(int id)
                        throws java.io.IOException

Method to remove a previous serverSendAndGet. This method is only called when a serverSendAndGet times out and the server must be told to forget about the serverSendAndGet.

Parameters:

id - unique id of serverSendAndGet request to delete

Throws:

java.io.IOException - if there are communication problems with the server

serverSubscribe

public void serverSubscribe(java.lang.String subject,
                            java.lang.String type,
                            java.lang.String namespace,
                            cMsgCallbackInterface cb,
                            java.lang.Object userObj)
                     throws java.io.IOException

Method for a server to subscribe to receive messages of a subject and type from another domain server. The combination of arguments must be unique. In other words, only 1 subscription is allowed for a given set of subject, type, callback, and userObj.

Parameters:

subject - message subject

type - message type

namespace - message namespace

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

Throws:

java.io.IOException - there are communication problems with the server

serverUnsubscribe

public void serverUnsubscribe(java.lang.String subject,
                              java.lang.String type,
                              java.lang.String namespace,
                              cMsgCallbackInterface cb,
                              java.lang.Object userObj)
                       throws java.io.IOException

Method for a server to unsubscribe a previous subscription to receive messages of a subject and type from another domain server. Since many subscriptions may be made to the same subject and type values, but with different callbacks and user objects, the callback and user object must be specified so the correct subscription can be removed.

Parameters:

subject - message subject

type - message type

namespace - message namespace

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

Throws:

java.io.IOException - there are communication problems with the server

serverShutdownClients

public void serverShutdownClients(java.lang.String client,
                                  boolean includeMe)
                           throws java.io.IOException

Method to shutdown the given clients. Wildcards used to match client names with the given string.

Parameters:

client - client(s) to be shutdown

includeMe - if true, it is permissible to shutdown calling client

Throws:

java.io.IOException - if there are communication problems with the server

serverShutdown

public void serverShutdown()
                    throws java.io.IOException

Method to shutdown the server connected to.

Throws:

java.io.IOException - if there are communication problems with the server

talkToNameServerFromServer

java.util.HashSet<java.lang.String> talkToNameServerFromServer(java.net.Socket socket,
                                                               int cloudStatus,
                                                               int fromNSTcpPort,
                                                               int fromNSMulticastPort,
                                                               boolean isOriginator,
                                                               java.lang.String cloudPassword,
                                                               java.lang.String clientPassword)
                                                        throws java.io.IOException,
                                                               cMsgException

This method gets the host and port of the domain server from the name server. It also gets information about the subdomain handler object. Note to those who would make changes in the protocol, keep the first three ints the same. That way the server can reliably check for mismatched versions.

Parameters:

socket - socket communication to server

cloudStatus - relationship this server has to server cloud. Can be INCLOUD, NONCLOUD, or BECOMINGCLOUD.

fromNSTcpPort - TCP listening port of name server calling this method

fromNSMulticastPort - UDP multicast listening port of name server calling this method

isOriginator - true if originating the connection between the 2 servers and false if this is the response or reciprocal connection.

cloudPassword - password for connecting to a server in a particular cloud

clientPassword - password for a client connecting to this server

Returns:

list of servers.

Throws:

cMsgException - error returned from server

java.io.IOException - if there are communication problems with the name server

cloudLock

public boolean cloudLock(int delay)
                  throws java.io.IOException

Lock the server (in cMsg subdomain) so that no other servers may simultaneously join the cMsg subdomain server cloud or register a client.

Parameters:

delay - time in milliseconds to wait for locked to be grabbed before timing out

Returns:

true if successful, else false

Throws:

java.io.IOException - if there are communication problems with the name server

cloudUnlock

public void cloudUnlock()
                 throws java.io.IOException

Unlock the server enabling other servers to join the cMsg subdomain server cloud or register a client.

Throws:

java.io.IOException - if there are communication problems with the name server

registrationLock

public boolean registrationLock(int delay)
                         throws java.io.IOException

Grab the registration lock (for adding a client) of another cMsg domain server.

Parameters:

delay - time in milliseconds to wait for the lock before timing out

Returns:

true if successful, else false

Throws:

java.io.IOException - if there are communication problems with the name server

registrationUnlock

public void registrationUnlock()
                        throws java.io.IOException

Release the registration lock (when adding a client) of another cMsg domain server.

Throws:

java.io.IOException - if communication error with server

thisServerCloudStatus

public void thisServerCloudStatus(int status)
                           throws java.io.IOException

This method tells the server this server is connected to, what cloud status this server has.

Parameters:

status - cMsgNameServer.INCLOUD, .NONCLOUD, or .BECOMINGCLOUD

Throws:

java.io.IOException - if communication error with server

getClientNamesAndNamespaces

public java.lang.String[] getClientNamesAndNamespaces()
                                               throws java.io.IOException

This method gets the names and namespaces of all the local clients (not servers) of another cMsg domain server.

Returns:

array of client names and namespaces

Throws:

java.io.IOException - if communication error with server