madkit.kernel

Class Activator<A extends AbstractAgent>

java.lang.Object

madkit.kernel.Activator<A>

Direct Known Subclasses:

GenericBehaviorActivator

public abstract class Activator<A extends AbstractAgent>
extends Object

This class defines a tool for scheduling mechanism. An activator is configured according to a community, a group and a role. It could be used to activate a group of agents on a particular behavior (a method of the agent's class) Subclasses should override execute(List, Object...) for defining how a sequential execution of a list of agents take place. By default, this list corresponds to all the agents in a single core mode or to partial views of the entire list when the multicore mode is used. The multicore mode is set to false by default.

Since:

MaDKit 2.0

Version:

5.0

Author:

Fabien Michel, Olivier Gutknecht

See Also:

Scheduler, GenericBehaviorActivator

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Activator(String community, String group, String role) Builds a new Activator on the given CGR location of the artificial society with multicore mode set to false.

Method Summary

Modifier and Type	Method and Description
protected void	adding(A agent) This method is automatically called when an agent joins the corresponding group and role.
protected void	adding(List<A> agents) Called when a list of agents joins the corresponding group and role.
void	allAgentsLeaveRole() Makes all the agents leave the corresponding role at once.
abstract void	execute(List<A> agentsList, Object... args) This should define what has to be done on the agents for a simulation step.
void	execute(Object... args) Call #execute(List agentsList) on all the agents, i.e. using Overlooker.getCurrentAgentsList().
void	executeBehaviorOf(AbstractAgent agent, String behaviorName, Object... args) Executes a specific method on a targeted agent.
static <T> Method	findMethodOn(Class<T> agentClass, String methodName, Class<?>... parameterTypes) Returns the agent's method named methodName considering a given agentClass.
static <T> Method	findMethodOnFromArgsSample(Class<T> agentClass, String methodName, Object... argsSample) Returns the agent's method named methodName considering a given agentClass and a sample of the arguments which could be passed to it.
String	getCommunity() Gets the community to which this activator/probe is binded to.
List<A>	getCurrentAgentsList() Returns a snapshot at moment t of the agents handling the group/role couple
String	getGroup() Gets the group to which this activator/probe is binded to.
static ExecutorService	getMadkitServiceExecutor() Returns the MDK ExecutorService that executes task in parallel
Integer	getPriority() The priority of this activator when conflicting with another Activator.
String	getRole() Gets the role to which this activator/probe is binded to.
List<A>	getShuffledList() Returns a ListIterator over the agents which is shuffled
Scheduler.SimulationTime	getSimulationTime() Get the Scheduler.SimulationTime associated with the simulation
void	initialize() Called by the MaDKit kernel when the Activator or Probe is first added.
boolean	isMulticoreModeOn()
void	killAgents() Kills all the agents which are monitored.
protected void	multicoreExecute(Object... args) Executes the behavior on all the agents in a concurrent way, using several processor cores if available.
int	nbOfParallelTasks() Returns the number of tasks that will be created by this activator in order to benefit from multicore platforms.
protected void	removing(A agent) This method is automatically called when an agent leaves the corresponding group and role.
protected void	removing(List<A> agents) This method is automatically called when a list of agents has leaved the corresponding group and role.
int	size() Returns the number of the agents handling the group/role couple
String	toString() returns a string containing the CGR location and the number of monitored agents.
void	useMulticore(int nbOfParallelTasks) Sets the number of tasks which will be used on a multicore architecture.

Methods inherited from class java.lang.Object

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

Constructor Detail

Activator

protected Activator(String community,
                    String group,
                    String role)

Builds a new Activator on the given CGR location of the artificial society with multicore mode set to false. This has the same effect as Activator(community, group, role, false).

Parameters:

community -

group -

role -

See Also:

Scheduler

Method Detail

getPriority

public Integer getPriority()

The priority of this activator when conflicting with another Activator. A lesser priority means that the activator will be triggered first. When the activator's priority is not set, a default priority is defined using the order in which the activators are added to the simulation engine using Scheduler.addActivator(Activator), that is the first activator has priority 0, the second has 1, and so on. Setting the activator's priority should be done using Scheduler.setActivatorPriority(Activator, int) so that the scheduler can maintain the ordering coherence of the activators list. By default, when two activators have the same priority, the order of activation is undefined.

Returns:

the priority of this scheduler.

execute

public void execute(Object... args)

Call #execute(List agentsList) on all the agents, i.e. using Overlooker.getCurrentAgentsList(). By default, this is automatically called by the default scheduler's loop once the activator is added.

Parameters:

args - arguments that could be used by the scheduler to pass information to this activator for an activation

See Also:

Scheduler.doSimulationStep()

executeBehaviorOf

public void executeBehaviorOf(AbstractAgent agent,
                              String behaviorName,
                              Object... args)

Executes a specific method on a targeted agent.

Parameters:

agent - the targeted agent.

behaviorName - the name of a method belonging to the agents (even private or inherited ones)

args - parameters to be passed for the invocation

adding

protected void adding(A agent)

This method is automatically called when an agent joins the corresponding group and role. This method is empty by default. Override this method when you want to do some initialization when an agent enters the group/role.

Parameters:

agent - which has been added to this group/role

execute

public abstract void execute(List<A> agentsList,
                             Object... args)

This should define what has to be done on the agents for a simulation step. By default, this calls is automatically made using a list containing all the agents for this CGR, i.e. Overlooker.getCurrentAgentsList() is used by default. When the multicore mode is on, the list is only a portion and this method will automatically be distributed over several threads. So, one has to take care about how the activator's fields are used here to avoid a ConcurrentModificationException for instance.

Parameters:

agentsList -

multicoreExecute

protected void multicoreExecute(Object... args)

Executes the behavior on all the agents in a concurrent way, using several processor cores if available. This call decomposes the execution of the activator in nbOfParallelTasks() tasks so that there are independently performed by the available core of the host.

Default implementation Beware that using this call will produce different outputs for each run unless a concurrent simulation model is used. That is to say, a model supporting concurrent phases in the simulation execution such as the IRM4S model

toString

public String toString()

returns a string containing the CGR location and the number of monitored agents.

Returns:

a string representation of this tool.

isMulticoreModeOn

public boolean isMulticoreModeOn()

Returns:

true if the multicore mode is on. I.e. nbOfParallelTasks() > 1. This method could be used by the default behavior of scheduler agents as they test in which mode each activator has to be used.

useMulticore

public void useMulticore(int nbOfParallelTasks)

Sets the number of tasks which will be used on a multicore architecture. If set to a number greater than 1, the scheduler will automatically use multicoreExecute(Object...) on this activator when execute(Object...) is called. If set to 1, the agents are sequentially activated. Beware that this is the only way to do exact replication of simulations, unless you have clear specifications for your model, see multicoreExecute(Object...).

Parameters:

nbOfParallelTasks - the number of simultaneous tasks that this activator will use to make a step. Default is 1 upon creation, so that isMulticoreModeOn() returns false.

nbOfParallelTasks

public int nbOfParallelTasks()

Returns the number of tasks that will be created by this activator in order to benefit from multicore platforms.

Returns:

the number of tasks that will be created.

getMadkitServiceExecutor

public static ExecutorService getMadkitServiceExecutor()

Returns the MDK ExecutorService that executes task in parallel

Returns:

an ExecutorService running task in parallel

findMethodOn

public static <T> Method findMethodOn(Class<T> agentClass,
                                      String methodName,
                                      Class<?>... parameterTypes)
                               throws NoSuchMethodException

Returns the agent's method named methodName considering a given agentClass. This also works for private and inherited methods.

Parameters:

agentClass - the class wherein the search has to be made

methodName - the name of the method

parameterTypes - the parameter types of the targeted method

Returns:

the agent's method named methodName

Throws:

NoSuchMethodException

findMethodOnFromArgsSample

public static <T> Method findMethodOnFromArgsSample(Class<T> agentClass,
                                                    String methodName,
                                                    Object... argsSample)
                                             throws NoSuchMethodException

Returns the agent's method named methodName considering a given agentClass and a sample of the arguments which could be passed to it. The purpose of this method is restricted to a limited number of use cases since findMethodOn(Class, String, Class...) should be preferred if the exact signature of the searched method is known. A typical use case of this method is when the only information available is the arguments which are passed, for instance when overriding the execute(List, Object...) method and the like in Activator subclasses. This also works for private and inherited methods.

Parameters:

agentClass - the class wherein the search has to be made

methodName - the name of the method

argsSample - a sample of the args which can be passed to the method

Returns:

the agent's method named methodName

Throws:

NoSuchMethodException - if a matching method cannot be found

getSimulationTime

public Scheduler.SimulationTime getSimulationTime()

Get the Scheduler.SimulationTime associated with the simulation

Returns:

the simulationTime associated with the simulation

getCommunity

public String getCommunity()

Gets the community to which this activator/probe is binded to.

Returns:

a string representing the community's name

getGroup

public String getGroup()

Gets the group to which this activator/probe is binded to.

Returns:

a string representing the group's name

getRole

public String getRole()

Gets the role to which this activator/probe is binded to.

Returns:

a string representing the role's name

initialize

public void initialize()

Called by the MaDKit kernel when the Activator or Probe is first added. Default behavior is: adding(getCurrentAgentsList());

adding

protected void adding(List<A> agents)

Called when a list of agents joins the corresponding group and role. This method is automatically called by the MaDKit kernel when agents enter a role due to the use of AbstractAgent.launchAgentBucket(String, int, String...). Override this method when you want to do some initialization on the agents that enter the group/role. Default implementation is:

 protected void adding(final List<A> agents) {
        for (A agent : agents) {
                adding(agent);
        }
 }
 

Parameters:

agents - the list of agents which have been added to this group/role at once.

removing

protected void removing(List<A> agents)

This method is automatically called when a list of agents has leaved the corresponding group and role. This method is empty by default. Override this method when you want to do some initialization on the agents that enter the group/role. Default implementation is:

 protected void removing(final List<A> agents) {
        for (A agent : agents) {
                removing(agent);
        }
 }
 

Parameters:

agents - the list of agents which have been removed from this group/role

removing

protected void removing(A agent)

This method is automatically called when an agent leaves the corresponding group and role. This method is empty by default. Override this method when you want to do some work when an agent leaves the group/role. Note that the role is still handled by the agent when invoked.

Parameters:

agent - the agent which is being removed from this group/role

size

public int size()

Returns the number of the agents handling the group/role couple

Returns:

the number of the agents that handle the group/role couple

getCurrentAgentsList

public List<A> getCurrentAgentsList()

Returns a snapshot at moment t of the agents handling the group/role couple

Returns:

a list view (a snapshot at moment t) of the agents that handle the group/role couple (in proper sequence)

Since:

MaDKit 3.0

getShuffledList

public List<A> getShuffledList()

Returns a ListIterator over the agents which is shuffled

Returns:

a ListIterator which has been previously shuffled

Since:

MaDKit 3.0

killAgents

public void killAgents()

Kills all the agents which are monitored.

allAgentsLeaveRole

public void allAgentsLeaveRole()

Makes all the agents leave the corresponding role at once.