Adding management of ParticipantLeft and ParticipantJoined, and utnin…

…g sequencing system events

Closes: #72
Closes: #941 adding scope from ParticipantLeft/Joined,
MemberJoined/Left, and ContextJoined/Left. SpaceCreated/Destroyed are
not impacted beacause not sent by agents but spaces. AgentSpawned/Killed
was already scoped

main/apiplugins/io.sarl.util/src/io/sarl/util/Events.sarl

@@ -0,0 +1,85 @@
+/*
+ * $Id$
+ *
+ * SARL is an general-purpose agent programming language.
+ * More details on http://www.sarl.io
+ *
+ * Copyright (C) 2014-2019 the original authors or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.sarl.util
+
+import io.sarl.lang.core.Address
+import io.sarl.lang.core.SpaceID
+import java.util.UUID
+
+/** Notifies other participants the member with agentID has effectively 
+ * integrated the space.
+ * The event is fired within the default space of the context in which the agent entered a new space.
+ * The joining agent does not receive this event.
+ * The source of the event is the entering agent.
+ */
+final event ParticipantJoined {
+
+	/** The identifier of the space in which the agent is entering.
+	 */
+	val spaceID : SpaceID
+
+	/** The identifier of the agent that has entered the space.
+	 */
+	val agentID : UUID
+
+	/** Construct the event.
+	 * 
+	 * @param source the address of the emitter.
+	 * @param spaceID the identifier of the space.
+	 * @param agentID the identifier of the agent.
+	 */
+	new (source : Address, spaceID : SpaceID, agentID : UUID) {
+		setSource(source)
+		this.spaceID = spaceID
+		this.agentID = agentID
+	}
+
+}
+
+/** Notifies other participants the member with agentID has effectively 
+ * left the space.
+ * The event is fired within the default space of the context in which the agent left the space.
+ * The leaving agent does not receive this event.
+ * The source of the event is the leaving agent.
+ */
+final event ParticipantLeft {
+
+	/** The identifier of the space the agent just left.
+	 */
+	val spaceID : SpaceID
+
+	/** The identifier of the agent that has left the space.
+	 */
+	val agentID : UUID
+
+	/** Construct the event.
+	 * 
+	 * @param source the address of the emitter.
+	 * @param spaceID the identifier of the space.
+	 * @param agentID the identifier of the agent.
+	 */
+	new (source : Address, spaceID : SpaceID, agentID : UUID) {
+		setSource(source)
+		this.spaceID = spaceID
+		this.agentID = agentID
+	}
+
+}

main/apiplugins/io.sarl.util/src/io/sarl/util/OpenEventSpace.sarl

@@ -25,8 +25,6 @@ import io.sarl.lang.core.Address
 import io.sarl.lang.core.EventListener
 import io.sarl.lang.core.EventSpace
 
-
-
 /**
  * Event driven interaction space where agent are free register and unregister themselves.
  * Agents should only register once in this type of space.
@@ -47,8 +45,9 @@ interface OpenEventSpace extends EventSpace {
 	 *
 	 * @param entity the entity to register.
 	 * @return the entity's address in this space
+	 * @fires ParticipantJoined in its enclosing Context default space.
 	 */
-	def register(entity : EventListener) : Address
+	def register(entity : EventListener) : Address fires ParticipantJoined
 
 	/**
 	 * Unregisters the entity inside this space.
@@ -57,8 +56,9 @@ interface OpenEventSpace extends EventSpace {
 	 *
 	 * @param entity the entity to unregister.
 	 * @return the former entity's address
+	 * @fires ParticipantJoined in its enclosing Context default space.
 	 */
-	def unregister(entity : EventListener) : Address
+	def unregister(entity : EventListener) : Address fires ParticipantLeft
 
 }
 

sre/io.janusproject/io.janusproject.plugin/src/io/janusproject/kernel/bic/ExternalContextAccessSkill.java

@@ -74,25 +74,30 @@ public class ExternalContextAccessSkill extends BuiltinSkill implements External
 
 	private ClearableReference<Skill> skillBufferBehaviors;
 
-	/** Constructor.
+	/**
+	 * Constructor.
+	 *
 	 * @param agent owner of the skill.
 	 */
 	ExternalContextAccessSkill(Agent agent) {
 		super(agent);
 	}
 
-	/** Replies the InternalEventBusCapacity skill as fast as possible.
+	/**
+	 * Replies the InternalEventBusCapacity skill as fast as possible.
 	 *
 	 * @return the skill
 	 */
 	protected final InternalEventBusCapacity getInternalEventBusCapacitySkill() {
-		if (this.skillBufferInternalEventBusCapacity == null || this.skillBufferInternalEventBusCapacity.get() == null) {
+		if (this.skillBufferInternalEventBusCapacity == null
+				|| this.skillBufferInternalEventBusCapacity.get() == null) {
 			this.skillBufferInternalEventBusCapacity = $getSkill(InternalEventBusCapacity.class);
 		}
 		return $castSkill(InternalEventBusCapacity.class, this.skillBufferInternalEventBusCapacity);
 	}
 
-	/** Replies the Behaviors skill as fast as possible.
+	/**
+	 * Replies the Behaviors skill as fast as possible.
 	 *
 	 * @return the skill
 	 */
@@ -103,7 +108,8 @@ protected final Behaviors getBehaviorsSkill() {
 		return $castSkill(Behaviors.class, this.skillBufferBehaviors);
 	}
 
-	/** {@inheritDoc}
+	/**
+	 * {@inheritDoc}
 	 *
 	 * @deprecated since 0.10
 	 */
@@ -181,38 +187,43 @@ public boolean join(UUID futureContext, UUID futureContextDefaultSpaceID) {
 		}
 
 		this.contexts.add(futureContext);
+		fireContextJoined(futureContext, futureContextDefaultSpaceID);
+		fireMemberJoined(ac);
 
 		((OpenEventSpace) ac.getDefaultSpace()).register(getInternalEventBusCapacitySkill().asEventListener());
 
-		fireContextJoined(futureContext, futureContextDefaultSpaceID);
-		fireMemberJoined(ac);
 		return true;
 	}
 
 	/**
-	 * Fires an {@link ContextJoined} event into the Inner Context default space of the owner agent to notify behaviors/members
-	 * that a new context has been joined.
+	 * Fires an {@link ContextJoined} event into the Inner Context default space of
+	 * the owner agent to notify behaviors/members that a new context has been
+	 * joined.
 	 *
-	 * @param futureContext ID of the newly joined context
-	 * @param futureContextDefaultSpaceID ID of the default space of the newly joined context
+	 * @param futureContext               ID of the newly joined context
+	 * @param futureContextDefaultSpaceID ID of the default space of the newly
+	 *                                    joined context
 	 */
 	protected final void fireContextJoined(UUID futureContext, UUID futureContextDefaultSpaceID) {
-		getBehaviorsSkill().wake(new ContextJoined(futureContext, futureContextDefaultSpaceID));
+		getBehaviorsSkill().wake(new ContextJoined(futureContext, futureContextDefaultSpaceID),
+				it -> it.getUUID() != getOwner().getID());
 	}
 
 	/**
-	 * Fires an {@link MemberJoined} event into the newly joined parent Context default space to notify other context's members
-	 * that a new agent joined this context.
+	 * Fires an {@link MemberJoined} event into the newly joined parent Context
+	 * default space to notify other context's members that a new agent joined this
+	 * context.
 	 *
 	 * @param newJoinedContext the newly joined context to notify its members
 	 */
 	protected final void fireMemberJoined(AgentContext newJoinedContext) {
 		final EventSpace defSpace = newJoinedContext.getDefaultSpace();
 		defSpace.emit(
-				// No need to give an event source because the event's source is explicitly set below.
-				null,
-				new MemberJoined(defSpace.getAddress(getOwner().getID()), newJoinedContext.getID(), getOwner().getID(),
-				getOwner().getClass().getName()));
+				// No need to give an event source because the event's source is explicitly set
+				// below.
+				null, new MemberJoined(new Address(defSpace.getSpaceID(), getOwner().getID()), newJoinedContext.getID(),
+						getOwner().getID(), getOwner().getClass().getName()),
+				it -> it.getUUID() != getOwner().getID());
 	}
 
 	@Override
@@ -226,38 +237,40 @@ public boolean leave(UUID contextID) {
 		if (!this.contexts.contains(contextID)) {
 			return false;
 		}
-
-		// To send this event the agent must still be inside the context and its default space
-		fireContextLeft(contextID);
-		fireMemberLeft(ac);
-
 		((OpenEventSpace) ac.getDefaultSpace()).unregister(getInternalEventBusCapacitySkill().asEventListener());
-
-		return this.contexts.remove(contextID);
+		final boolean b = this.contexts.remove(contextID);
+		fireMemberLeft(ac);
+		fireContextLeft(contextID);
+		return b;
 	}
 
 	/**
-	 * Fires an {@link ContextLeft} event into the Inner Context Default space of the owner agent to notify behaviors/members that
-	 * the specified context has been left.
+	 * Fires an {@link ContextLeft} event into the Inner Context Default space of
+	 * the owner agent to notify behaviors/members that the specified context has
+	 * been left.
 	 *
 	 * @param contextID the ID of context that will be left
 	 */
 	protected final void fireContextLeft(UUID contextID) {
-		getBehaviorsSkill().wake(new ContextLeft(contextID));
+		getBehaviorsSkill().wake(new ContextLeft(contextID),
+								it -> it.getUUID() != getOwner().getID());
 	}
 
 	/**
-	 * Fires an {@link MemberLeft} event into the default space of the Context that will be left to notify other context's members
-	 * that an agent has left this context.
+	 * Fires an {@link MemberLeft} event into the default space of the Context that
+	 * will be left to notify other context's members that an agent has left this
+	 * context.
 	 *
 	 * @param leftContext the context that will be left
 	 */
 	protected final void fireMemberLeft(AgentContext leftContext) {
 		final EventSpace defSpace = leftContext.getDefaultSpace();
 		defSpace.emit(
-				// No need to give an event source because the event's source is explicitly set below.
-				null,
-				new MemberLeft(defSpace.getAddress(getOwner().getID()), getOwner().getID(), getOwner().getClass().getName()));
+				// No need to give an event source because the event's source is explicitly set
+				// below.
+				null, new MemberLeft(new Address(defSpace.getSpaceID(), getOwner().getID()), getOwner().getID(),
+									getOwner().getClass().getName()),
+									it -> it.getUUID() != getOwner().getID());
 	}
 
 	@Override

sre/io.janusproject/io.janusproject.plugin/src/io/janusproject/kernel/space/EventSpaceImpl.java

@@ -23,14 +23,19 @@
 
 import java.util.concurrent.locks.ReadWriteLock;
 
+import com.google.inject.Inject;
 import com.google.inject.Provider;
 
+import io.janusproject.services.contextspace.ContextSpaceService;
 import io.janusproject.services.distributeddata.DistributedDataStructureService;
-
 import io.sarl.lang.core.Address;
+import io.sarl.lang.core.AgentContext;
 import io.sarl.lang.core.EventListener;
+import io.sarl.lang.core.EventSpace;
 import io.sarl.lang.core.SpaceID;
 import io.sarl.util.OpenEventSpace;
+import io.sarl.util.ParticipantJoined;
+import io.sarl.util.ParticipantLeft;
 
 /**
  * Default implementation of an event space.
@@ -44,6 +49,9 @@
  */
 public class EventSpaceImpl extends AbstractEventSpace implements OpenEventSpace {
 
+	@Inject
+	private ContextSpaceService contextRepository;
+
 	/**
 	 * Constructs an event space.
 	 *
@@ -57,12 +65,49 @@ public EventSpaceImpl(SpaceID id, DistributedDataStructureService factory, Provi
 
 	@Override
 	public Address register(EventListener entity) {
-		return getParticipantInternalDataStructure().registerParticipant(new Address(getSpaceID(), entity.getID()), entity);
+		final Address a = getParticipantInternalDataStructure().registerParticipant(new Address(getSpaceID(), entity.getID()), entity);
+		fireParticipantJoined(a);
+		return a;
 	}
 
 	@Override
 	public Address unregister(EventListener entity) {
-		return getParticipantInternalDataStructure().unregisterParticipant(entity);
+		final Address a = getParticipantInternalDataStructure().unregisterParticipant(entity);
+		fireParticipantLeft(a);
+		return a;
+	}
+
+	/**
+	 * Fires an {@link ParticipantJoined} event into the default space of the current Context to notify other context's members
+	 * that a new agent joined this space.
+	 * @param newAgentAddress - the address of the agent.
+	 */
+	protected final void fireParticipantJoined(Address newAgentAddress) {
+		final AgentContext enclosingContext = this.contextRepository.getContext(newAgentAddress.getSpaceID().getContextID());
+		final EventSpace defSpace = enclosingContext.getDefaultSpace();
+		defSpace.emit(
+				// No need to give an event source because the event's source is explicitly set below.
+				null,
+				new ParticipantJoined(defSpace.getAddress(newAgentAddress.getUUID()), newAgentAddress.getSpaceID(), newAgentAddress.getUUID()),
+									  it -> it.getUUID() != newAgentAddress.getUUID());
+	}
+
+	/**
+	 * Fires an {@link ParticipantLeft} event into the default space of the current Context to notify other context's members
+	 * that an agent left this space.
+	 * @param agentAddress - address of the agent leaving the space.
+	 */
+	protected final void fireParticipantLeft(Address agentAddress) {
+		final AgentContext enclosingContext = this.contextRepository.getContext(agentAddress.getSpaceID().getContextID());
+		final EventSpace defSpace = enclosingContext.getDefaultSpace();
+		//Since this agent may already have quit the default space at the moment this event is sent,
+		//it is mandatory to recreate an address to be sure the event has a source
+		defSpace.emit(
+				// No need to give an event source because the event's source is explicitly set below.
+				null,
+				new ParticipantLeft(new Address(defSpace.getSpaceID(), agentAddress.getUUID()),
+									agentAddress.getSpaceID(), agentAddress.getUUID()),
+									it -> it.getUUID() != agentAddress.getUUID());
 	}
 
 }