api for specifying update state for activate() and voteToHalt()
diff --git a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
index a42b411..8135479 100644
--- a/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
+++ b/pregelix/pregelix-api/src/main/java/edu/uci/ics/pregelix/api/graph/Vertex.java
@@ -234,19 +234,44 @@
     /**
      * Vote to halt. Once all vertex vote to halt and no more messages, a
      * Pregelix job will terminate.
+     * 
+     * The state of the current vertex value is saved.
      */
     public final void voteToHalt() {
         halt = true;
         updated = true;
     }
+    
+    /**
+     * Vote to halt. Once all vertex vote to halt and no more messages, a
+     * Pregelix job will terminate.
+     * 
+     * @param update whether or not to save the vertex value
+     */
+    public final void voteToHalt(boolean update) {
+        halt = true;
+        updated = update;
+    }
 
     /**
      * Activate a halted vertex such that it is alive again.
+     * 
+     * The state of the current vertex value is saved.
      */
     public final void activate() {
         halt = false;
         updated = true;
     }
+    
+    /**
+     * Activate a halted vertex such that it is alive again.
+     * 
+     * @param update whether or not to save the vertex value
+     */
+    public final void activate(boolean update) {
+        halt = false;
+        updated = update;
+    }
 
     /**
      * @return the vertex is halted (true) or not (false)