Avoid useless reallocation of empty TreeMaps and map iterators

[simantics/platform.git] / bundles / org.simantics.acorn / src / org / simantics / acorn / MainProgram.java

diff --git a/bundles/org.simantics.acorn/src/org/simantics/acorn/MainProgram.java b/bundles/org.simantics.acorn/src/org/simantics/acorn/MainProgram.java
index 1e4b5cbac508623fff9fd9d5017043818ce1ee42..52be328eb87ea5de7d9b58fed20e1fe53439f727 100644 (file)
--- a/bundles/org.simantics.acorn/src/org/simantics/acorn/MainProgram.java
+++ b/bundles/org.simantics.acorn/src/org/simantics/acorn/MainProgram.java
@@ -70,7 +70,7 @@ public class MainProgram implements Runnable, Closeable {
                this.updateSchedules = new ArrayList[CLUSTER_THREADS];
                for(int i=0;i<clusterUpdateThreads.length;i++) {
                        clusterUpdateThreads[i] = Executors.newSingleThreadExecutor(new ClusterThreadFactory("Cluster Updater " + (i+1), false));
-                       updateSchedules[i] = new ArrayList<ClusterUpdateOperation>();
+                       updateSchedules[i] = new ArrayList<>();
                }
        }
 
@@ -93,11 +93,13 @@ public class MainProgram implements Runnable, Closeable {
 
                try {
 
+                       TreeMap<ClusterUID, List<ClusterUpdateOperation>> updates = new TreeMap<>(clusterComparator);
+
                        main:
                        while(alive) {
 
-                               TreeMap<ClusterUID, List<ClusterUpdateOperation>> updates = new TreeMap<ClusterUID, List<ClusterUpdateOperation>>(clusterComparator);
-
+                               if (!updates.isEmpty())
+                                       updates.clear();
                                operationQueue.pumpUpdates(updates);
 
                                if(updates.isEmpty()) {
@@ -165,6 +167,9 @@ public class MainProgram implements Runnable, Closeable {
                for(int i=0;i<CLUSTER_THREADS;i++)
                        updateSchedules[i].clear();
 
+               if (updates.isEmpty())
+                       return;
+
                final Semaphore s = new Semaphore(0);
 
                for(Map.Entry<ClusterUID, List<ClusterUpdateOperation>> entry : updates.entrySet()) {