sketch of java/lang/ref/*

classpath/java/lang/ref/Reference.java

@@ -0,0 +1,34 @@
+package java.lang.ref;
+
+public abstract class Reference<T> {
+  private T target;
+  private ReferenceQueue<? super T> queue;
+  Reference<? extends T> next;
+
+  protected Reference(T target, ReferenceQueue<? super T> queue) {
+    this.target = target;
+    this.queue = queue;
+  }
+
+  public T get() {
+    return target;
+  }
+
+  public void clear() {
+    target = 0;
+  }
+
+  public boolean isEnqueued() {
+    return next != null;
+  }
+
+  public boolean enqueue() {
+    if (queue != null) {
+      queue.add(this);
+      queue = null;
+      return true;
+    } else {
+      return false;
+    }
+  }
+}