ajanta.server
Class AgentEnv

java.lang.Object
  |
  +--ajanta.server.AgentEnv

public class AgentEnv

extends java.lang.Object

class AgentEnv represents the server's context. A reference to an AgentEnv object is passed to each agent when it is executed. Methods in the AgentEnv class provide the agent with primitive operations like migration, resource binding, etc.

Method Summary

void	createRMIProxy(java.lang.String interf) Create and install an RMI server which has the same interface as the caller agent.
void	createRMIProxy(java.lang.String interf, java.lang.String extension) Create and install an RMI server which has the same interface as the caller agent.
ajanta.naming.URN	createURN(java.lang.String name) Create a URN by appending the given string onto the server's URN
void	deleteResource(ajanta.naming.URN name) Delete registered resource entry whose URN is passed as argument.
ajanta.naming.URN	getAgentServerURN()
ajanta.naming.URN	getAgentURN() Find the name currently executing agent in the same thread group.
ajanta.naming.CascadedCertificate	getCascadedCertificate(int key_length, long duration)
ajanta.agent.Agent	getCurrentAgent() Find the currently executing agent in the same thread group.
ajanta.naming.URN	getHostURN() Return the current host's name
ajanta.server.NRAccess	getNameReg() Return a reference to the name registry access class ( NRAccess ) of the current agent server.
ajanta.util.Resource	getResource(ajanta.naming.URN resName) Return an a proxy for the named resource and if it has not yet been registered then return null.
java.security.PrivateKey	getTemporaryPrivateKey()
java.security.PublicKey	getTemporaryPublicKey()
void	go(ajanta.naming.URN dest) Migrate caller to the specified destination and execute the (parameterless) "run" method
void	go(ajanta.naming.URN dest, ajanta.util.MethodSpec act) Migrate caller to the specified destination and execute the method specified in the MethodSpec
void	go(ajanta.naming.URN dest, java.lang.String method, java.lang.Class[] formals, java.lang.Object[] actuals) Migrate caller agent to a specified destination and execute the named method with the specified formal and actual parameters
void	go(ajanta.naming.URN dest, java.lang.String method, java.lang.Object[] actuals) Migrate caller to the specified destination and execute the named method with the given actual parameters, assuming they exactly match the formal parameter types.
void	launch(ajanta.agent.Agent ag, ajanta.naming.URN dest) Send specified agent to the named destination and execute the (parameterless) "run" method
void	launch(ajanta.agent.Agent ag, ajanta.naming.URN dest, ajanta.util.MethodSpec act) Send specified agent to the named destination and execute the method specified in the MethodSpec
void	launch(ajanta.agent.Agent ag, ajanta.naming.URN dest, java.lang.String method, java.lang.Class[] formals, java.lang.Object[] actuals, boolean first) Launch the given agent to the desired destination, specifying the method to be executed there.
void	launch(ajanta.agent.Agent ag, ajanta.naming.URN dest, java.lang.String method, java.lang.Object[] actuals) Launch agent to the specified destination and execute the named method with the given actual parameters, assuming they exactly match the formal parameter types.
boolean	logEvent(ajanta.logger.Event e)
void	registerAgent(ajanta.agent.Agent ag) Registers an agent with the name registry, If an older entry exists try to rebind.
void	registerResource(ajanta.naming.URN name, ajanta.util.Resource obj) It creates a resource ( RREntry ) in the agent server's resource registry with the given resource name and resource object
void	registerResourceName(ajanta.naming.URN name) It creates a resource ( RREntry) in the agent server's resource registry.
byte[]	sign(byte[] text) Sign an agent with the agent server's private key.
ajanta.util.Resource	waitForResource(ajanta.naming.URN resName) Return an a proxy for the named resource and if it has not yet been registered then wait for it.

Methods inherited from class java.lang.Object

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

Method Detail

getCurrentAgent

public ajanta.agent.Agent getCurrentAgent()

Find the currently executing agent in the same thread group.

Returns:

Reference to if one exists in current thread group and null otherwise

See Also:

Agent

getAgentURN

public ajanta.naming.URN getAgentURN()

Find the name currently executing agent in the same thread group.

Returns:

URN of the agent if one exists in current thread group and null otherwise

See Also:

URN

getNameReg

public ajanta.server.NRAccess getNameReg()

Return a reference to the name registry access class ( NRAccess ) of the current agent server.

Returns:

NRAccess object of the agent server.

See Also:

NRAccess

go

public void go(ajanta.naming.URN dest,
               java.lang.String method,
               java.lang.Class[] formals,
               java.lang.Object[] actuals)
        throws java.net.UnknownHostException,
               LaunchFailedException

Migrate caller agent to a specified destination and execute the named method with the specified formal and actual parameters

Parameters:

dest - URN of the destination

method - name of the method to execute

formals - array of class names of method parametrs

actuals - array of objects i.e. values of the parametrs to the method

java.net.UnknownHostException

LaunchFailedException

go

public void go(ajanta.naming.URN dest,
               java.lang.String method,
               java.lang.Object[] actuals)
        throws java.net.UnknownHostException,
               LaunchFailedException

Migrate caller to the specified destination and execute the named method with the given actual parameters, assuming they exactly match the formal parameter types.

Parameters:

dest - URN of the destination

method - name of the method to execute

actuals - array of objects i.e. values of the parametrs to the method

java.net.UnknownHostException

LaunchFailedException

go

public void go(ajanta.naming.URN dest)
        throws java.net.UnknownHostException,
               LaunchFailedException

Migrate caller to the specified destination and execute the (parameterless) "run" method

Parameters:

dest - URN of the destination

java.net.UnknownHostException

LaunchFailedException

go

public void go(ajanta.naming.URN dest,
               ajanta.util.MethodSpec act)
        throws java.net.UnknownHostException,
               LaunchFailedException

Migrate caller to the specified destination and execute the method specified in the MethodSpec

Parameters:

dest - URN of the destination

act - MethodSpec of the method tb executed at destination

java.net.UnknownHostException

LaunchFailedException

See Also:

MethodSpec

launch

public void launch(ajanta.agent.Agent ag,
                   ajanta.naming.URN dest,
                   java.lang.String method,
                   java.lang.Class[] formals,
                   java.lang.Object[] actuals,
                   boolean first)
            throws LaunchFailedException

Launch the given agent to the desired destination, specifying the method to be executed there. It is internally called by go methods with first = false.

Parameters:

ag - Reference to the agent being launched

dest - URN of the destination

method - name of the method to execute

formals - array of class names of method parametrs

actuals - array of objects i.e. values of the parametrs to the method

first - true indicate very first launch of the agent ( just after creation ) wheras false indicates a luanch at a later stage in the itinerary

LaunchFailedException

See Also:

Agent

launch

public void launch(ajanta.agent.Agent ag,
                   ajanta.naming.URN dest,
                   java.lang.String method,
                   java.lang.Object[] actuals)
            throws java.net.UnknownHostException,
                   LaunchFailedException

Launch agent to the specified destination and execute the named method with the given actual parameters, assuming they exactly match the formal parameter types.

Parameters:

ag - Reference to the agent being launched

dest - URN of the destination

method - name of the method to execute

actuals - array of objects i.e. values of the parametrs to the method

java.net.UnknownHostException

LaunchFailedException

See Also:

Agent

launch

public void launch(ajanta.agent.Agent ag,
                   ajanta.naming.URN dest)
            throws java.net.UnknownHostException,
                   LaunchFailedException

Send specified agent to the named destination and execute the (parameterless) "run" method

Parameters:

ag - Reference to the agent being launched

dest - URN of the destination

java.net.UnknownHostException

LaunchFailedException

See Also:

Agent

launch

public void launch(ajanta.agent.Agent ag,
                   ajanta.naming.URN dest,
                   ajanta.util.MethodSpec act)
            throws java.net.UnknownHostException,
                   LaunchFailedException

Send specified agent to the named destination and execute the method specified in the MethodSpec

Parameters:

ag - Reference to the agent being launched

dest - URN of the destination

act - MethodSpec to be executed

java.net.UnknownHostException

LaunchFailedException

See Also:

ajnata.util.MethodSpec

getHostURN

public ajanta.naming.URN getHostURN()

Return the current host's name

Returns:

URN of the current agent server ( host )

registerResourceName

public void registerResourceName(ajanta.naming.URN name)

It creates a resource ( RREntry) in the agent server's resource registry. It just associate a null entry with the given URN of the resource. It is usefuel when someone has to wait for a resource which will be initialized by second party at a later stage. It helps in synchronizing them.

Parameters:

name - URN of the resource to be created

registerResource

public void registerResource(ajanta.naming.URN name,
                             ajanta.util.Resource obj)

It creates a resource ( RREntry ) in the agent server's resource registry with the given resource name and resource object

Parameters:

name - URN of the resource to be created

obj - Resource object to be registered

See Also:

Resource

deleteResource

public void deleteResource(ajanta.naming.URN name)

Delete registered resource entry whose URN is passed as argument.

Parameters:

name - URN of the resource

waitForResource

public ajanta.util.Resource waitForResource(ajanta.naming.URN resName)

Return an a proxy for the named resource and if it has not yet been registered then wait for it. The proxy to be returned depends on the credentials of the calling agent.Special case - if the resource being requested is this server,return a pointer to the agent server object itself

Parameters:

resName - URN of the resource

Returns:

Resource instance of the proxy for the requested resource.

getResource

public ajanta.util.Resource getResource(ajanta.naming.URN resName)

Return an a proxy for the named resource and if it has not yet been registered then return null. The proxy to be returned depends on the credentials of the calling agent.Special case - if the resource being requested is this server,return a pointer to the agent server object itself

Parameters:

resName - URN of the resource

Returns:

Resource instance of the proxy for the requested resource.

createURN

public ajanta.naming.URN createURN(java.lang.String name)

Create a URN by appending the given string onto the server's URN

Parameters:

name - - string used for urn

Returns:

newly creted URN of the form server urn: name

createRMIProxy

public void createRMIProxy(java.lang.String interf)

Create and install an RMI server which has the same interface as the caller agent. The proxy server has an embedded reference to the agent. It receives the RMI calls and forwards them to the agent. The interface, and the associated proxy class must currently be available on the agent server's classpath. It calls createRMIProxy (String interf,String extension) with extension as "".

Parameters:

interf - name of the "Remote" interface which the agent supports. Extension of the proxy class is "Proxy".

createRMIProxy

public void createRMIProxy(java.lang.String interf,
                           java.lang.String extension)

Create and install an RMI server which has the same interface as the caller agent. The proxy server has an embedded reference to the agent. It receives the RMI calls and forwards them to the agent. The interface, and the associated proxy class must currently be available on the agent server's classpath.

Parameters:

interf - name of the "Remote" interface which the agent supports.

extension - file name extension of the proxy class name, if it is "" then by default "Proxy" is used as extension.

registerAgent

public void registerAgent(ajanta.agent.Agent ag)

Registers an agent with the name registry, If an older entry exists try to rebind.

Parameters:

ag - Agent to be registered

sign

public byte[] sign(byte[] text)
            throws java.security.SignatureException

Sign an agent with the agent server's private key.

Parameters:

text - Content to be signed

java.security.SignatureException

getCascadedCertificate

public ajanta.naming.CascadedCertificate getCascadedCertificate(int key_length,
                                                                long duration)

getTemporaryPrivateKey

public java.security.PrivateKey getTemporaryPrivateKey()

getTemporaryPublicKey

public java.security.PublicKey getTemporaryPublicKey()

logEvent

public boolean logEvent(ajanta.logger.Event e)

getAgentServerURN

public ajanta.naming.URN getAgentServerURN()