com.goldencode.p2j.util

Class AgentPool

java.lang.Object

com.goldencode.p2j.util.AgentPool

Direct Known Subclasses:

AgentPool.BoundPool, AgentPool.UnboundPool

abstract class AgentPool
extends java.lang.Object

The main class for agent pooling. Based on the appserver's operating mode, the newConnection() call will return a:

• AgentPool.BoundPool for State-reset and State-aware modes.
• AgentPool.UnboundPool for State-free and Stateless modes.

Agents are extracted from mainPool as connection or procedure requests are incoming and put back in the pool only after the connection terminates or it becomes unbound.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) static class	AgentPool.BoundPool Class implementing the behavior for STATE-RESET and STATE-AWARE operating modes.
(package private) static class	AgentPool.UnboundPool Class implementing the behavior for STATE-FREE and STATELESS operating modes.

Field Summary

Fields

Modifier and Type	Field and Description
private int	agentIdGenerator The generator for Agent IDs.
private java.util.Map<java.lang.Integer,Agent>	agents The map of agents.
private java.util.Set<Agent>	all All started agents.
private AppServerDefinition	appDef The appserver definition.
private java.util.Set<java.lang.String>	disabledLegacyErrors Set of connection IDs which can't throw legacy OO errors on the remote side.
private java.lang.String	exports The EXPORTS for this appserver.
private static java.util.Map<java.lang.String,java.lang.String>	idsToAppserver Map of connection IDs to appserver name.
private static CentralLogger	LOG Logger.
private java.util.Set<Agent>	mainPool The pool of agents.
protected java.util.Map<java.lang.Object,Agent>	persistentProcedures The remote persistent procedures exposed as proxy procedures to the requester.
private java.util.Map<java.lang.String,java.lang.String>	serverConnectionContext The value of SESSSION:SERVER-CONNECTION-CONTEXT set for each connection.

Constructor Summary

Constructors

Modifier	Constructor and Description
private	AgentPool(AppServerDefinition def) Build a new agent pool, for the specified appserver.

Method Summary

Modifier and Type	Method and Description
(package private) Agent	acquireAgent(java.lang.String id) Acquire a new agent from the pool to handle requests incoming via the given connection ID.
(package private) abstract Agent	acquireAgent(java.lang.String id, java.lang.String code, int agentId) Acquire a new agent from the pool to handle requests incoming via the given connection ID.
(package private) void	addProcedure(java.lang.Object referent, Agent agent) Register the given persistent procedure with the Agent which created it.
(package private) int	available() Get the number of available agents, waiting for work, in mainPool.
(package private) AppServerInvocationResult	connect(java.util.concurrent.atomic.AtomicBoolean sessionTerminated, java.lang.String subjectId, boolean sessionFree, java.lang.String user, java.lang.String pwd, java.lang.String serverInfo, java.lang.Object[] requestInfo) Establish a new appserver connection.
(package private) abstract boolean	deactivateAgentOnRemoveProcedure(java.lang.String id, java.lang.Object referent) Determine if the agent must be unbound and deactivate procedure invoked, when there are no more persistent procedures bound to it.
(package private) void	disableLegacyErrors(java.lang.String id) Disable legacy OO errors thrown on this connection.
(package private) void	disconnect(java.lang.String id) Disconnect the appserver connection, with the given ID.
(package private) java.lang.String	getActivate() Get the activate procedure for the appserver handled by this pool.
(package private) Agent	getAgent(int agentId) Get the agent for the given ID.
(package private) static java.lang.String	getAppserver(java.lang.String connectionId) Get the appserver name used to established the given connection.
(package private) java.lang.String	getDeactivate() Get the deactivate procedure for the appserver handled by this pool.
(package private) AppServerDefinition	getDef() Get the definition of this appserver.
(package private) character	getExports() Get the exports for this appserver.
(package private) Agent	getFromMainPool() Extract an agent from the main pool; if non available, attempt to start one.
(package private) java.lang.String	getName() Get the name of the appserver handled by this pool.
(package private) AppServerOperatingMode	getOperatingMode() Get the operating mode for this appserver.
(package private) java.lang.String	getPropath() Get the appserver's propath.
(package private) java.lang.String	getServerConnectionContext(java.lang.String connectionID) Get the SERVER-CONNECTION-CONTEXT attribute of the specified connection.
(package private) java.lang.String	getShutdown() Get the shutdown procedure for the appserver handled by this pool.
(package private) java.lang.String	getStartup() Get the startup procedure for the appserver handled by this pool.
(package private) java.lang.String	getStartupParameter() Get the startup parameters for the appserver handled by this pool.
(package private) boolean	hasProcedure(java.lang.Object referent) Check if the given persistent procedure was started as a remote procedure with the appserver associated with this pool.
(package private) boolean	isDisabledLegacyErrors(java.lang.String id) Check if the given connection ID should suppress legacy OO errors.
(package private) boolean	isEmpty() Check if this pool is empty.
(package private) boolean	isPasoe() Check if this appserver definition is for PASOE.
(package private) abstract java.lang.String	newConnection() Establish a new connection.
(package private) static AgentPool	newPool(java.lang.String appServer) Instantiate a new agent pool for the given appserver, based on the operating mode.
(package private) java.lang.String	nextId() Get the next connection ID.
(package private) void	poolAgent(Agent agent, boolean newlyCreated) Add an agent back to the mainPool.
(package private) abstract void	releaseAgent(java.lang.String id, Agent agent) Release the given agent and place it back in the pool.
(package private) void	removeAgent(Agent agent) Remove the given agent entirely from the pool.
(package private) void	removeProcedure(java.lang.String id, java.lang.Object referent) De-register the persistent procedure from persistentProcedures.
(package private) void	restartAgents() Terminate all running agents and start the same number of agents, to refresh their context.
(package private) void	setExports(character exports) Set the exports for this appserver.
(package private) void	setServerConnectionContext(java.lang.String connectionID, java.lang.String serverConnectionContext) Set the SERVER-CONNECTION-CONTEXT attribute of the specified connection.
(package private) int	size() Get the pool size.
(package private) void	start() Start listening for appserver-related commands.
(package private) void	terminateAll() Send the terminate command to all agents in this pool.
(package private) void	terminateConnection(java.lang.String id, boolean running) Terminate the connection with the given ID.
(package private) void	trimAgents() Trim the running agents so the pool size is as close to AppServerDefinition.getMinAgents() as possible.

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final CentralLogger LOG

Logger.

idsToAppserver

private static final java.util.Map<java.lang.String,java.lang.String> idsToAppserver

Map of connection IDs to appserver name.

mainPool

private final java.util.Set<Agent> mainPool

The pool of agents.

agents

private final java.util.Map<java.lang.Integer,Agent> agents

The map of agents.

serverConnectionContext

private final java.util.Map<java.lang.String,java.lang.String> serverConnectionContext

The value of SESSSION:SERVER-CONNECTION-CONTEXT set for each connection.

persistentProcedures

protected final java.util.Map<java.lang.Object,Agent> persistentProcedures

The remote persistent procedures exposed as proxy procedures to the requester. This map is also used on the agent side to determine if a procedure was ran remote or not.

all

private final java.util.Set<Agent> all

All started agents.

disabledLegacyErrors

private final java.util.Set<java.lang.String> disabledLegacyErrors

Set of connection IDs which can't throw legacy OO errors on the remote side.

appDef

private final AppServerDefinition appDef

The appserver definition.

exports

private java.lang.String exports

The EXPORTS for this appserver.

agentIdGenerator

private int agentIdGenerator

The generator for Agent IDs.

Constructor Detail

AgentPool

private AgentPool(AppServerDefinition def)

Build a new agent pool, for the specified appserver.

Parameters:

def - The appserver definition.

Method Detail

getAppserver

static java.lang.String getAppserver(java.lang.String connectionId)

Get the appserver name used to established the given connection.

Parameters:

connectionId - The connection ID.

Returns:

See above.

newPool

static AgentPool newPool(java.lang.String appServer)

Instantiate a new agent pool for the given appserver, based on the operating mode.

Parameters:

appServer - The appserver's name.

Returns:

A new pool instance.

Throws:

java.lang.IllegalArgumentException - If the operating mode can not be resolved to one of AppServerOperatingMode constants.

acquireAgent

abstract Agent acquireAgent(java.lang.String id,
                            java.lang.String code,
                            int agentId)
                     throws NumberedException

Acquire a new agent from the pool to handle requests incoming via the given connection ID.

Parameters:

id - The connection ID.

code - The code of a persistent external procedure to which the agent is associated. May be null.

agentId - The agent ID which created the given procedure code, a negative number means the procedure code will not be used.

Returns:

See above.

Throws:

NumberedException - If there was no agent available.

releaseAgent

abstract void releaseAgent(java.lang.String id,
                           Agent agent)

Release the given agent and place it back in the pool. This will handle any bound-related constraints.

Parameters:

id - The connection ID.

agent - The agent which needs to be released.

newConnection

abstract java.lang.String newConnection()
                                 throws NumberedException

Establish a new connection.

Returns:

The connection ID.

Throws:

NumberedException - If the connection could not be established.

deactivateAgentOnRemoveProcedure

abstract boolean deactivateAgentOnRemoveProcedure(java.lang.String id,
                                                  java.lang.Object referent)

Determine if the agent must be unbound and deactivate procedure invoked, when there are no more persistent procedures bound to it.

Parameters:

id - The connection ID.

referent - The persistent procedure.

Returns:

true if the deactivate can be invoked and the agent unbound.

disableLegacyErrors

void disableLegacyErrors(java.lang.String id)

Disable legacy OO errors thrown on this connection.

Parameters:

id - The appserver connection id.

isDisabledLegacyErrors

boolean isDisabledLegacyErrors(java.lang.String id)

Check if the given connection ID should suppress legacy OO errors.

Parameters:

id - The appserver connection id.

Returns:

See above.

acquireAgent

Agent acquireAgent(java.lang.String id)
            throws NumberedException

Acquire a new agent from the pool to handle requests incoming via the given connection ID.

Parameters:

id - The connection ID.

Returns:

See above.

Throws:

NumberedException - If there was no agent available.

getAgent

Agent getAgent(int agentId)

Get the agent for the given ID.

Parameters:

agentId - The agent ID.

nextId

java.lang.String nextId()

Get the next connection ID.

Returns:

See above.

getExports

character getExports()

Get the exports for this appserver. If set, only the external procedures which match these exports will be available for invocation.

Returns:

See above.

setExports

void setExports(character exports)

Set the exports for this appserver.

Parameters:

exports - The appserver's exports.

getName

java.lang.String getName()

Get the name of the appserver handled by this pool.

Returns:

See above.

getPropath

java.lang.String getPropath()

Get the appserver's propath.

Returns:

See above.

getStartup

java.lang.String getStartup()

Get the startup procedure for the appserver handled by this pool.

Returns:

See above.

getStartupParameter

java.lang.String getStartupParameter()

Get the startup parameters for the appserver handled by this pool.

Returns:

See above.

getShutdown

java.lang.String getShutdown()

Get the shutdown procedure for the appserver handled by this pool.

Returns:

See above.

getActivate

java.lang.String getActivate()

Get the activate procedure for the appserver handled by this pool.

Returns:

See above.

getDeactivate

java.lang.String getDeactivate()

Get the deactivate procedure for the appserver handled by this pool.

Returns:

See above.

connect

AppServerInvocationResult connect(java.util.concurrent.atomic.AtomicBoolean sessionTerminated,
                                  java.lang.String subjectId,
                                  boolean sessionFree,
                                  java.lang.String user,
                                  java.lang.String pwd,
                                  java.lang.String serverInfo,
                                  java.lang.Object[] requestInfo)

Establish a new appserver connection. This will invoke any connect procedure for this appserver, to which the given user, pwd and serverInfo parameters will be passed.

The appserver connection must be configured to start under the given P2J-level subject ID.

Parameters:

sessionTerminated - A special var to inform us if the session has been terminated. The session state can't be invoked directly from here, as a deadlock might occur.

subjectId - The subject ID associated with this appserver.

sessionFree - Flag indicating if the connection request is for a session-free operating mode.

user - The first parameter to pass to the connect procedure, if any.

pwd - The second parameter to pass to the connect procedure, if any.

serverInfo - The third parameter to pass to the connect procedure, if any.

requestInfo - The remote OerequestInfo details, as set by OerequestInfo.toArray().

Returns:

An AppServerInvocationResult instance with any result or caught errors.

disconnect

void disconnect(java.lang.String id)

Disconnect the appserver connection, with the given ID. It will invoke any configured disconnect procedure, but will not return any errors or values to the caller.

Parameters:

id - The connection ID to disconnect.

start

void start()

Start listening for appserver-related commands.

terminateAll

void terminateAll()

Send the terminate command to all agents in this pool.

terminateConnection

void terminateConnection(java.lang.String id,
                         boolean running)

Terminate the connection with the given ID.

Parameters:

id - The connection ID.

running - Flag indicating the Agent is already processing a command.

getOperatingMode

AppServerOperatingMode getOperatingMode()

Get the operating mode for this appserver.

Returns:

See above.

isPasoe

boolean isPasoe()

Check if this appserver definition is for PASOE.

Returns:

See above.

poolAgent

void poolAgent(Agent agent,
               boolean newlyCreated)

Add an agent back to the mainPool.

Parameters:

agent - The agent to add back to the pool.

newlyCreated - When this flag is true, the agent is added to the global pool too.

isEmpty

boolean isEmpty()

Check if this pool is empty.

Returns:

true if the pool is empty, false otherwise.

removeAgent

void removeAgent(Agent agent)

Remove the given agent entirely from the pool.

Parameters:

agent - The agent which was terminated and needs to be removed.

size

int size()

Get the pool size.

Returns:

See above.

available

int available()

Get the number of available agents, waiting for work, in mainPool.

Returns:

See above.

hasProcedure

boolean hasProcedure(java.lang.Object referent)

Check if the given persistent procedure was started as a remote procedure with the appserver associated with this pool.

Parameters:

referent - The persistent procedure.

Returns:

See above.

addProcedure

void addProcedure(java.lang.Object referent,
                  Agent agent)

Register the given persistent procedure with the Agent which created it.

Parameters:

referent - The persistent procedure.

agent - The agent which created the persistent procedure.

removeProcedure

final void removeProcedure(java.lang.String id,
                           java.lang.Object referent)

De-register the persistent procedure from persistentProcedures.

Parameters:

id - The connection ID.

referent - The persistent procedure.

getDef

AppServerDefinition getDef()

Get the definition of this appserver.

Returns:

The appserver definition.

restartAgents

void restartAgents()

Terminate all running agents and start the same number of agents, to refresh their context.

trimAgents

void trimAgents()

Trim the running agents so the pool size is as close to AppServerDefinition.getMinAgents() as possible.

getFromMainPool

Agent getFromMainPool()

Extract an agent from the main pool; if non available, attempt to start one. If the max number of running agents is reached and all agents are busy, return null.

Returns:

The extracted agent or null if all agents are busy.

getServerConnectionContext

java.lang.String getServerConnectionContext(java.lang.String connectionID)

Get the SERVER-CONNECTION-CONTEXT attribute of the specified connection.

Parameters:

connectionID - The connection ID for this appserver.

Returns:

See above.

setServerConnectionContext

void setServerConnectionContext(java.lang.String connectionID,
                                java.lang.String serverConnectionContext)

Set the SERVER-CONNECTION-CONTEXT attribute of the specified connection.

Parameters:

connectionID - The connection ID for this appserver.

serverConnectionContext - The attribute's value.