--- /dev/null
+/*
+ * Copyright (C) 2014, United States Government, as represented by the
+ * Administrator of the National Aeronautics and Space Administration.
+ * All rights reserved.
+ *
+ * The Java Pathfinder core (jpf-core) platform is 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 gov.nasa.jpf.vm;
+
+/**
+ * interface to abstract the referencing set of threadinfos per object/class
+ * Used to detect shared objects/classes
+ * Instances are created through a configured factory (SharedObjectPolicy)
+ *
+ * We abstract the container so that the way we identify threads is not exposed
+ * to the client, and implementations can use either ThreadInfo references or
+ * global ids.
+ */
+public interface ThreadInfoSet extends Cloneable {
+
+ /**
+ * @return true if the thread wasn't in the set yet and was added
+ */
+ ThreadInfoSet add (ThreadInfo ti);
+
+ ThreadInfoSet remove (ThreadInfo ti);
+
+ boolean contains (ThreadInfo ti);
+
+ boolean isShared (ThreadInfo ti, ElementInfo ei);
+
+
+ boolean hasMultipleLiveThreads ();
+ boolean hasMultipleRunnableThreads ();
+
+ Memento<ThreadInfoSet> getMemento();
+
+ int size();
+}