add better handling of Proxy lifecycle

README.md

@@ -384,8 +384,8 @@ __Example__
 
 Creates a new java Proxy for the given interface. Functions passed in will run on the v8 main thread and not a new thread.
 
-The returned object has two methods ref() and unref() which you can use to maintain references to prevent premature
-garbage collection. You must call these methods to ensure the proxy stays around.
+The returned object has a method unref() which you can use to free the object for
+garbage collection.
 
 __Arguments__
 

compile-java-code.sh

@@ -8,3 +8,6 @@ javac ${JAVAC_OPTS} *.java
 
 cd ../src-java/node
 javac ${JAVAC_OPTS} *.java
+
+cd ../../
+javah -classpath src-java -d ./src node.NodeDynamicProxyClass

src-java/node/NodeDynamicProxyClass.java

@@ -1,8 +1,10 @@
 package node;
 
-public class NodeDynamicProxyClass implements java.lang.reflect.InvocationHandler
-{
+import java.util.HashSet;
+
+public class NodeDynamicProxyClass implements java.lang.reflect.InvocationHandler {
   private native Object callJs(long ptr, java.lang.reflect.Method m, Object[] args) throws Throwable;
+  private native void unref(long ptr) throws Throwable;
   public long ptr;
 
   public NodeDynamicProxyClass(String path, long ptr) {
@@ -25,11 +27,7 @@ public Object invoke(Object proxy, java.lang.reflect.Method m, Object[] args) th
     return result;
   }
 
-  public void ref() {
-
-  }
-
-  public void unref() {
-
+  public void unref() throws Throwable {
+    unref(this.ptr);
   }
 }

src/java.cpp

@@ -356,6 +356,7 @@ void Java::destroyJVM(JavaVM** jvm, JNIEnv** env) {
   if(result->IsNativeError()) {
     return ThrowException(result);
   }
+  dynamicProxyData->jsObject = v8::Persistent<v8::Value>::New(result);
   return scope.Close(result);
 }
 
@@ -989,3 +990,11 @@ JNIEXPORT jobject JNICALL Java_node_NodeDynamicProxyClass_callJs(JNIEnv *env, jo
   }
   return dynamicProxyData->result;
 }
+
+JNIEXPORT void JNICALL Java_node_NodeDynamicProxyClass_unref(JNIEnv *env, jobject src, jlong ptr) {
+  DynamicProxyData* dynamicProxyData = (DynamicProxyData*)ptr;
+  if(!dynamicProxyDataVerify(dynamicProxyData)) {
+    return;
+  }
+  dynamicProxyData->jsObject.Clear();
+}

src/javaObject.cpp

@@ -97,6 +97,8 @@ JavaObject::~JavaObject() {
     jfieldID ptrField = env->GetFieldID(nodeDynamicProxyClass, "ptr", "J");
     DynamicProxyData* proxyData = (DynamicProxyData*)(long)env->GetLongField(m_obj, ptrField);
     if(dynamicProxyDataVerify(proxyData)) {
+      proxyData->markerStart = 0;
+      proxyData->markerEnd = 0;
       delete proxyData;
     }
   }

src/utils.cpp

@@ -694,7 +694,7 @@ int dynamicProxyDataVerify(DynamicProxyData* data) {
     return 1;
   }
 
-  printf("*** ERROR: Lost reference to the dynamic proxy. You must maintain a reference in javascript land using ref() and unref(). ***\n");
+  printf("*** ERROR: Lost reference to the dynamic proxy. You must maintain a reference in javascript land using ref() and unref(). (%p) ***\n", data);
   return 0;
 }
 

src/utils.h

@@ -35,6 +35,7 @@ struct DynamicProxyData {
   Java* java;
   std::string interfaceName;
   v8::Persistent<v8::Object> functions;
+  v8::Persistent<v8::Value> jsObject;
   std::string methodName;
   jobjectArray args;
   jobject result;