public void shutdown() {
        synchronized (this) {
            active = false;
            if (pending != null) {
                pending.abort();
            }
        }
    }
Invokes asynchronous JRT requests in a blocking method, that can be aborted by calling shutdown().
This can be used when one would like to use invokeSync(), but when abortion is required.
<p>
This class is thread safe.

@author <a href="mailto:havardpe@yahoo-inc.com">Haavard Pettersen</a>
jrt/src/com/yahoo/jrt/InvokeProxy.java