From f15f48f499c55b6c8b724d2c3fc67d8082a9bb98 Mon Sep 17 00:00:00 2001
From: marecabo <23156476+marecabo@users.noreply.github.com>
Date: Tue, 4 Jun 2024 09:42:17 +0200
Subject: [PATCH] Parallelize DynActivityEngine.doSimStep()

---
 .../dynagent/run/DynActivityEngine.java       | 46 +++++++++++--------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/contribs/dvrp/src/main/java/org/matsim/contrib/dynagent/run/DynActivityEngine.java b/contribs/dvrp/src/main/java/org/matsim/contrib/dynagent/run/DynActivityEngine.java
index 729c4e87ff9..cfb0958c0c8 100644
--- a/contribs/dvrp/src/main/java/org/matsim/contrib/dynagent/run/DynActivityEngine.java
+++ b/contribs/dvrp/src/main/java/org/matsim/contrib/dynagent/run/DynActivityEngine.java
@@ -20,9 +20,9 @@
 package org.matsim.contrib.dynagent.run;
 
 import java.util.ArrayList;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Objects;
 
 import org.matsim.api.core.v01.Id;
 import org.matsim.api.core.v01.network.Link;
@@ -56,25 +56,31 @@ public void doSimStep(double time) {
 		dynAgents.addAll(newDynAgents);
 		newDynAgents.clear();
 
-		Iterator<DynAgent> dynAgentIter = dynAgents.iterator();
-		while (dynAgentIter.hasNext()) {
-			DynAgent agent = dynAgentIter.next();
-			Preconditions.checkState(agent.getState() == State.ACTIVITY);
-			agent.doSimStep(time);
-			// ask agents about the current activity end time;
-			double currentEndTime = agent.getActivityEndTime();
-
-			if (currentEndTime == Double.POSITIVE_INFINITY) { // agent says: stop simulating me
-				unregisterAgentAtActivityLocation(agent);
-				internalInterface.getMobsim().getAgentCounter().decLiving();
-				dynAgentIter.remove();
-			} else if (currentEndTime <= time) { // the agent wants to end the activity NOW
-				unregisterAgentAtActivityLocation(agent);
-				agent.endActivityAndComputeNextState(time);
-				internalInterface.arrangeNextAgentState(agent);
-				dynAgentIter.remove();
-			}
-		}
+		List<DynAgent> agentsToRemove = dynAgents.parallelStream()
+				.map(agent -> {
+
+					Preconditions.checkState(agent.getState() == State.ACTIVITY);
+					agent.doSimStep(time);
+					// ask agents about the current activity end time;
+					double currentEndTime = agent.getActivityEndTime();
+
+					if (currentEndTime == Double.POSITIVE_INFINITY) { // agent says: stop simulating me
+						unregisterAgentAtActivityLocation(agent);
+						internalInterface.getMobsim().getAgentCounter().decLiving();
+						return agent;
+					} else if (currentEndTime <= time) { // the agent wants to end the activity NOW
+						unregisterAgentAtActivityLocation(agent);
+						agent.endActivityAndComputeNextState(time);
+						internalInterface.arrangeNextAgentState(agent);
+						return agent;
+					}
+
+					return null;
+				})
+				.filter(Objects::nonNull)
+				.toList();
+
+		dynAgents.removeAll(agentsToRemove);
 	}
 
 	@Override