--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/main/gov/nasa/jpf/vm/SingleLockThresholdFli.java	Fri Jan 23 10:14:01 2015 -0800
@@ -0,0 +1,86 @@
+/*
+ * 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;
+
+/**
+ * a threshold FieldLockInfo with a single lock candidate
+ * This is the base version that does destructive updates. Override singleLockThresholdFli for a persistent version
+ */
+public class SingleLockThresholdFli extends ThresholdFieldLockInfo {
+    protected int lockRef;
+    
+    SingleLockThresholdFli (ThreadInfo ti, int lockRef, int remainingChecks) {
+      super( remainingChecks);
+      
+      tiLastCheck = ti;
+      this.lockRef = lockRef;
+    }
+
+    @Override
+	protected int[] getCandidateLockSet() {
+      int[] set = { lockRef };
+      return set;
+    }
+
+    /**
+     * override this for path local flis
+     */
+    protected SingleLockThresholdFli singleLockThresholdFli (ThreadInfo ti, int lockRef, int remainingChecks){
+      this.lockRef = lockRef;
+      this.tiLastCheck = ti;
+      this.remainingChecks = remainingChecks;
+
+      return this;
+    }
+    
+    @Override
+	public FieldLockInfo checkProtection (ThreadInfo ti, ElementInfo ei, FieldInfo fi) {
+      int[] currentLockRefs = ti.getLockedObjectReferences();
+      int nLocks = currentLockRefs.length;
+      int nRemaining = Math.max(0, remainingChecks--);
+            
+      for (int i=0; i<nLocks; i++) {
+        if (currentLockRefs[i] == lockRef) {
+          return singleLockThresholdFli( ti, lockRef, nRemaining);
+        }
+      }
+      
+      checkFailedLockAssumption(ti, ei, fi);
+      return empty;
+    }
+
+    /**
+     * only called at the end of the gc on all live objects. The recycled ones
+     * are either already nulled in the heap, or are not marked as live
+     */
+    @Override
+	public FieldLockInfo cleanUp (Heap heap) {
+      ElementInfo ei = heap.get(lockRef);
+      if (!heap.isAlive(ei)) {
+        return FieldLockInfo.empty;
+      } else {
+        return this;
+      }
+    }
+
+    @Override
+	public String toString() {
+      return ("SingleLockThresholdFli {remainingChecks="+remainingChecks+",lock="+lockRef + '}');
+    }  
+
+}