From 9b1fa1fe414be61696b580cd18ed1ce47dd453d8 Mon Sep 17 00:00:00 2001
From: ntisseyre <ntisseyre@apple.com>
Date: Thu, 10 Aug 2023 10:18:23 -0500
Subject: [PATCH] Returning a copied collection to avoid corrupted iterator by
 multiple threads

Signed-off-by: ntisseyre <ntisseyre@apple.com>
---
 .../addedrelations/AddedRelationsContainer.java    |  4 ++--
 .../addedrelations/ConcurrentAddedRelations.java   | 14 +++++++++++---
 .../addedrelations/EmptyAddedRelations.java        |  2 +-
 .../addedrelations/SimpleAddedRelations.java       |  2 +-
 4 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/AddedRelationsContainer.java b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/AddedRelationsContainer.java
index c0ece092535..52c74de3c46 100644
--- a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/AddedRelationsContainer.java
+++ b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/AddedRelationsContainer.java
@@ -39,7 +39,7 @@ public interface AddedRelationsContainer {
      * of the transaction after there are no additional changes. Otherwise the behavior is non deterministic.
      * @return
      */
-    Collection<InternalRelation> getAll();
+    Collection<InternalRelation> getAllUnsafe();
 
     /**
      * Clears the container which releases allocated memory.
@@ -69,7 +69,7 @@ public boolean isEmpty() {
         }
 
         @Override
-        public Collection<InternalRelation> getAll() {
+        public Collection<InternalRelation> getAllUnsafe() {
             return Collections.emptyList();
         }
 
diff --git a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/ConcurrentAddedRelations.java b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/ConcurrentAddedRelations.java
index 78a8ef75440..32fb69827c1 100644
--- a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/ConcurrentAddedRelations.java
+++ b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/ConcurrentAddedRelations.java
@@ -15,8 +15,10 @@
 package org.janusgraph.graphdb.transaction.addedrelations;
 
 import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
 import org.janusgraph.graphdb.internal.InternalRelation;
 
+import java.util.ArrayList;
 import java.util.Collection;
 
 /**
@@ -37,11 +39,17 @@ public synchronized boolean remove(final InternalRelation relation) {
 
     @Override
     public synchronized Iterable<InternalRelation> getView(final Predicate<InternalRelation> filter) {
-        return super.getView(filter);
+        return copyView(super.getView(filter));
     }
 
     @Override
-    public synchronized Collection<InternalRelation> getAll() {
-        return super.getAll();
+    public synchronized Collection<InternalRelation> getAllUnsafe() {
+        return super.getAllUnsafe();
+    }
+
+    private Iterable<InternalRelation> copyView(Iterable<InternalRelation> currentView) {
+        ArrayList<InternalRelation> view = new ArrayList<>();
+        Iterables.addAll(view, currentView);
+        return view;
     }
 }
diff --git a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/EmptyAddedRelations.java b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/EmptyAddedRelations.java
index c139065120e..0069daa67a6 100644
--- a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/EmptyAddedRelations.java
+++ b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/EmptyAddedRelations.java
@@ -52,7 +52,7 @@ public boolean isEmpty() {
     }
 
     @Override
-    public Collection<InternalRelation> getAll() {
+    public Collection<InternalRelation> getAllUnsafe() {
         return Collections.emptyList();
     }
 
diff --git a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/SimpleAddedRelations.java b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/SimpleAddedRelations.java
index fcc534c9b59..afc2bbeb141 100644
--- a/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/SimpleAddedRelations.java
+++ b/janusgraph-core/src/main/java/org/janusgraph/graphdb/transaction/addedrelations/SimpleAddedRelations.java
@@ -62,7 +62,7 @@ public boolean isEmpty() {
     }
 
     @Override
-    public Collection<InternalRelation> getAll() {
+    public Collection<InternalRelation> getAllUnsafe() {
         return Collections.unmodifiableCollection(new AbstractCollection<InternalRelation>() {
             @Override
             @Nonnull