public  void callFunction(String funName,
    List params,
    Environment environment,
    InvokeContext ctx) throws Exception 
{
    Scriptable thrScope = null;
    checkForModifiedScripts(environment);
    try {
      thrScope = enterContext(environment, ctx);
      Object callFunction = scope.get("callFunction", thrScope);
      if (callFunction == Scriptable.NOT_FOUND)
          throw new RuntimeException("Cannot find 'callFunction' "
                                     + "(system.js not loaded?)");
      Object fun = scope.get(funName, thrScope);
      if (fun == Scriptable.NOT_FOUND)
        throw new RuntimeException("'" + funName + "' is undefined!");
      if (!(fun instanceof Function))
        throw new RuntimeException("'" + funName + "' is not a function!");
      Context cx = Context.getCurrentContext();
      int size = (params != null ? params.size() : 0);
      Object[] funArgs = new Object[size];
      if (size != 0) {
        for (int i = 0; i <  size; i++) {
          Object obj = ((Interpreter.Argument)params.get(i)).value;
          funArgs[i] = ScriptRuntime.toObject(cx, thrScope, obj);
        }
      }
      NativeArray funArgsArray = new NativeArray(funArgs);
      Object callFunArgs[] = { fun, funArgsArray };
      ((Function) callFunction).call(cx, thrScope, thrScope, callFunArgs);
    }
    finally {
      exitContext(thrScope);
    }
}

 protected Scriptable enterContext(Environment environment,
    InvokeContext ctx) throws Exception 
{
    Context context = Context.enter();
    context.setOptimizationLevel(OPTIMIZATION_LEVEL);
    context.setCompileFunctionsWithDynamicScope(true);
    Scriptable thrScope = context.newObject(scope);
    thrScope.setPrototype(scope);
    // We want 'thrScope' to be a new top-level scope, so set its
    // parent scope to null. This means that any variables created
    // by assignments will be properties of "thrScope".
    thrScope.setParentScope(null);
    // Put in the thread scope the Cocoon object, which gives access
    // to the interpreter object, and some Cocoon objects. See
    // JSCocoon for more details.
    Object args[] = {};
    Scriptable cocoon = context.newObject(scope, "Cocoon", args);
    ((JSCocoon)cocoon).setInterpreter(this);
    ((JSCocoon)cocoon).setContext(manager, environment, ctx);
    ((JSCocoon)cocoon).setContinuationsManager(continuationsMgr);
    ((JSCocoon)cocoon).setScope(thrScope);
    thrScope.put("cocoon", thrScope, cocoon);
    return thrScope;
}

 protected  void exitContext(Scriptable thrScope) 
{
    JSCocoon cocoon = (JSCocoon)thrScope.get("cocoon", thrScope);
    cocoon.invalidateContext();
    Context.getCurrentContext().exit();
}

Remove the Cocoon object from the JavaScript thread scope so it can be garbage collected, together with all the objects it contains.

 public  void handleContinuation(String id,
    Environment environment,
    InvokeContext ctx) throws Exception 
{
    WebContinuation wk = continuationsMgr.lookupWebContinuation(id);
    if (wk == null)
      throw new RuntimeException("No continuation with id " + id);
    Context context = Context.enter();
    context.setOptimizationLevel(OPTIMIZATION_LEVEL);
    context.setCompileFunctionsWithDynamicScope(true);
    // Obtain the JS continuation object from it, and setup the
    // JSCocoon object associated in the dynamic scope of the saved
    // continuation with the environment and context objects.
    JSWebContinuation jswk = (JSWebContinuation)wk.getUserObject();
    JSCocoon cocoon = jswk.getJSCocoon();
    cocoon.setContext(manager, environment, ctx);
    Scriptable kScope = cocoon.getScope();
    // We can now resume the processing from the state saved by the
    // continuation object. Setup the JavaScript Context object.
    Object handleContFunction = scope.get("handleContinuation", kScope);
    if (handleContFunction == Scriptable.NOT_FOUND)
      throw new RuntimeException("Cannot find 'handleContinuation' "
                                 + "(system.js not loaded?)");
    Object args[] = { jswk };
    try {
      ((Function)handleContFunction).call(context, kScope, kScope, args);
    }
    finally {
      context.exit();
    }
}

 public  void initialize() throws Exception 
{
    
    Context context = Context.enter();
    context.setOptimizationLevel(OPTIMIZATION_LEVEL);
    try {
      scope = new JSGlobal(context);
      // Register some handy classes with JavaScript, so we can make
      // use of them from the flow layer.
      // Access to the Cocoon log
      ScriptableObject.defineClass(scope, JSLog.class);
      // Access to Cocoon internal objects
      ScriptableObject.defineClass(scope, JSCocoon.class);
      // Wrapper for WebContinuation
      ScriptableObject.defineClass(scope, JSWebContinuation.class);
      // Define some functions on the top level scope
      String[] names = { "print" };
      try {
        ((ScriptableObject)scope)
          .defineFunctionProperties(names, JSGlobal.class,
                                    ScriptableObject.DONTENUM);
      } catch (PropertyException e) {
        throw new Error(e.getMessage());
      }
      // Define some global variables in JavaScript
      Object args[] = {};
      Scriptable log = context.newObject(scope, "Log", args);
      ((JSLog)log).setLogger(getLogger());
      scope.put("log", scope, log);
    } catch (Exception e) {
      context.exit();
      System.out.println("problem initializing JavaScriptInterpreter: ");
      e.printStackTrace();
      throw e;
    }
}

 public Source readScript(Environment environment,
    String sourceName) throws Exception 
{
    Scriptable thrScope = null;
    Source source = null;
    System.out.println("Reading file " + sourceName);
    try {
      thrScope = enterContext(environment, null);
      source = environment.resolve(sourceName);
      InputStream inputStream = source.getInputStream();
      Reader reader = new BufferedReader(new InputStreamReader(inputStream));
      Context ctx = Context.getCurrentContext();
      ctx.evaluateReader(scope, reader, sourceName, 1, null);
    }
    catch (Exception ex) {
      ex.printStackTrace();
      throw ex;
    }
    finally {
      exitContext(thrScope);
    }
    return source;
}