special CancelException support during tabulation

git-svn-id: https://wala.svn.sourceforge.net/svnroot/wala/trunk@2058 f5eafffb-2e1d-0410-98e4-8ec43c5233c4

com.ibm.wala.core/src/com/ibm/wala/dataflow/IFDS/TabulationCancelException.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2007 IBM Corporation.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package com.ibm.wala.dataflow.IFDS;
+
+import com.ibm.wala.dataflow.IFDS.TabulationSolver.Result;
+import com.ibm.wala.eclipse.util.CancelException;
+
+/**
+ * A {@link CancelException} thrown during tabulation; holds a pointer to a partial {@link Result}.
+ * Use with care, this can hold on to a lot of memory.
+ * 
+ * @author sjfink
+ */
+public class TabulationCancelException extends CancelException {
+  
+  private final Result result;
+
+  protected TabulationCancelException(CancelException cause, Result r) {
+    super(cause);
+    this.result = r;
+  }
+
+  public Result getResult() {
+    return result;
+  }
+
+}

com.ibm.wala.core/src/com/ibm/wala/dataflow/IFDS/TabulationSolver.java

@@ -209,10 +209,16 @@ public class TabulationSolver<T, P> {
    */
   public TabulationResult<T, P> solve() throws CancelException {
 
-    initialize();
-    forwardTabulateSLRPs();
-    Result r = new Result();
-    return r;
+    try {
+      initialize();
+      forwardTabulateSLRPs();
+      Result r = new Result();
+      return r;
+    } catch (CancelException e) {
+      // store a partially-tabulated result in the thrown exception.
+      Result r = new Result();
+      throw new TabulationCancelException(e, r);
+    }
   }
 
   /**

com.ibm.wala.core/src/com/ibm/wala/eclipse/util/CancelException.java

@@ -18,9 +18,13 @@ package com.ibm.wala.eclipse.util;
  */
 public class CancelException extends Exception {
 
-  private CancelException(String msg) {
+  protected CancelException(String msg) {
     super(msg);
   }
+  
+  protected CancelException(Exception cause) {
+    super(cause);
+  }
 
   public static CancelException make(String msg) {
     return new CancelException(msg);