MappedByteBuffer.java: (forceImpl...

* java/nio/MappedByteBuffer.java: (forceImpl, isLoadedImpl, loadImpl,
	unmapImpl):  New dummy methods, to be overridden by subclass.
	(finalize, isLoaded, load, force):  New methods.
	* java/nio/MappedByteBufferImpl.java:  More-or-less rewrite.
	Now works, at least for read mapping.

From-SVN: r78662

libjava/java/nio/MappedByteBuffer.java

@@ -44,28 +44,46 @@ package java.nio;
  */
 public abstract class MappedByteBuffer extends ByteBuffer
 {
-  private boolean loaded = false;
-  
   MappedByteBuffer (int capacity, int limit, int position, int mark)
   {
     super (capacity, limit, position, mark);
   }
   
+  void forceImpl()
+  {
+  }
+
   public final MappedByteBuffer force ()
   {
-    // FIXME: Flush to disk here.
+    forceImpl();
     return this;
   }
     
+  boolean isLoadedImpl()
+  {
+    load();
+    return true;
+  }
+
   public final boolean isLoaded ()
   {
-    return loaded;
+    return isLoadedImpl();
   }
     
+  void loadImpl()
+  {
+  }
+
   public final MappedByteBuffer load ()
   {
-    // FIXME: Try to load all pages into memory.
-    loaded = true;
+    loadImpl();
     return this;
   }
+
+  void unmapImpl ()
+  {
+    forceImpl();
+  }
+
+  public void finalize () { unmapImpl(); }
 }