fix for Ryan's issue: we also need to sync when we store a resource.

git-svn-id: file:///humgen/gsa-scr1/gsa-engineering/svn_contents/trunk@3881 348d0f76-0448-11de-a6fe-93d51630548a

java/src/org/broadinstitute/sting/gatk/datasources/simpleDataSources/ResourcePool.java

@@ -67,9 +67,12 @@ abstract class ResourcePool <T,I extends Iterator> {
 
         I iterator = createIteratorFromResource(segment, selectedResource);
 
-        // Make a note of this assignment for proper releasing later.
-        resourceAssignments.put(iterator, selectedResource);
-
+        // also protect the resource assignment
+        synchronized (this) {
+            // Make a note of this assignment for proper releasing later.
+            resourceAssignments.put(iterator, selectedResource);
+        }
+        
         return iterator;
     }