Merge "Return a copy of the "real" set in AssociationStore" into tm-dev
diff --git a/services/companion/java/com/android/server/companion/AssociationStoreImpl.java b/services/companion/java/com/android/server/companion/AssociationStoreImpl.java
index 21a677b8..cb28254 100644
--- a/services/companion/java/com/android/server/companion/AssociationStoreImpl.java
+++ b/services/companion/java/com/android/server/companion/AssociationStoreImpl.java
@@ -171,12 +171,20 @@
broadcastChange(CHANGE_TYPE_REMOVED, association);
}
+ /**
+ * @return a "snapshot" of the current state of the existing associations.
+ */
public @NonNull Collection<AssociationInfo> getAssociations() {
- final Collection<AssociationInfo> allAssociations;
synchronized (mLock) {
- allAssociations = mIdMap.values();
+ // IMPORTANT: make and return a COPY of the mIdMap.values(), NOT a "direct" reference.
+ // The HashMap.values() returns a collection which is backed by the HashMap, so changes
+ // to the HashMap are reflected in this collection.
+ // For us this means that if mIdMap is modified while the iteration over mIdMap.values()
+ // is in progress it may lead to "undefined results" (according to the HashMap's
+ // documentation) or cause ConcurrentModificationExceptions in the iterator (according
+ // to the bugreports...).
+ return List.copyOf(mIdMap.values());
}
- return Collections.unmodifiableCollection(allAssociations);
}
public @NonNull List<AssociationInfo> getAssociationsForUser(@UserIdInt int userId) {