sketch of java/lang/ref/*

classpath/java/lang/ref/PhantomReference.java

@@ -0,0 +1,11 @@
+package java.lang.ref;
+
+public class PhantomReference<T> extends Reference<T> {
+  public PhantomReference(T target, ReferenceQueue<? super T> queue) {
+    super(target, queue);    
+  }
+
+  public PhantomReference(T target) {
+    this(target, null);
+  }
+}

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;
+    }
+  }
+}

classpath/java/lang/ref/ReferenceQueue.java

@@ -0,0 +1,28 @@
+package java.lang.ref;
+
+public abstract class ReferenceQueue<T> {
+  private Reference<? extends T> front;
+  private Reference<? extends T> rear;
+
+  public Reference<? extends T> poll() {
+    Reference<? extends T> r = front;
+    if (front != null) {
+      if (front == front.next) {
+        front = rear = null;
+      } else {
+        front = front.next;
+      }
+    }
+    return r;
+  }
+
+  void add(Reference<? extends T> r) {
+    r.next = r;
+    if (front == null) {
+      front = rear = r;
+    } else {
+      rear.next = r;
+      rear = r;
+    }
+  }
+}

classpath/java/lang/ref/WeakReference.java

@@ -0,0 +1,11 @@
+package java.lang.ref;
+
+public class WeakReference<T> extends Reference<T> {
+  public WeakReference(T target, ReferenceQueue<? super T> queue) {
+    super(target, queue);    
+  }
+
+  public WeakReference(T target) {
+    this(target, null);
+  }
+}

src/types.def

@@ -216,14 +216,23 @@
   (extends jobject)
   (uint64_t value))
 
+(type referenceQueue java/lang/ref/ReferenceQueue
+  (extends jobject)
+  (object front)
+  (object rear))
+
 (type jreference java/lang/ref/Reference
   (extends jobject)
   (void* target)
+  (void* queue)
   (void* next))
 
 (type weakReference java/lang/ref/WeakReference
   (extends jreference))
 
+(type phantomReference java/lang/ref/PhantomReference
+  (extends jreference))
+
 (type byteArray [B
   (extends jobject)
   (array int8_t body))