Java HotSpot Virtual Machine

Hi,

I'm trying to write a JNI hook in Windows to receive messages when the user shuts down the JVM, say with a Ctrl+C, or by shutting down Windows. Here's my native code:

///////////////////////////////////////////////
jobject shutdownHook;  //both these are set in the
JavaVM* jvm; //JNI entry method

//the method receiving kill signals
BOOL WINAPI HandlerRoutine(DWORD dwCtrlType) {
  JNIEnv* env;
  jvm->AttachCurrentThread((void **) &env, NULL);
  if (shutdownHook != NULL) { 
	  jmethodID mid; 
	  jclass cl = env->FindClass("java/lang/Runnable");
	  mid = env->GetMethodID(cl, "run", "()V");
	  env->CallVoidMethod(shutdownHook, mid);
	  ::MessageBox(NULL, "Got there", "Got There", MB_OK);//for debug porpoises
  }
  return FALSE;
}

JNIEXPORT void JNICALL Java_main_Shutdown_registerShutdownHook
  (JNIEnv * env, jclass, jobject hook) {
	env->GetJavaVM(&jvm);
	shutdownHook = hook;
	SetConsoleCtrlHandler(HandlerRoutine, TRUE);//Win32 API
}
///////////////////////////////////////////////

And the Java defintion, plus an example Java program using it:

///////////////////////////////////////////////
class Shutdown {
  static {
    System.loadLibrary("ShutdownHook");
  }
  public static native void registerShutdownHook(Runnable sh);
}

class Test {
  public static void main(String[] args) throws Exception {
    Shutdown.registerShutdownHook(new Runnable() {
      public void run() {
        System.out.println("PANG!");
      }
    });
    Thread.sleep(60000);
  }
}
///////////////////////////////////////////////

Everything seems to work fine--my native handler method gets the signal, finds the appropriate class, successfully calls the method, and displays the message box. But as far as I can tell, the method on the Java side isn't called...it doesn't print anything out, and other tests have also shown that the method isn't being called.

I'm a relative newbie to JNI...anyone see what I'm doing wrong?

Thanks,

Walter Gildersleeve
Freiburg, Germany

P.S. I'm testing this on WinXP sp2, with JDK 1.4.2_05-b04, native code built with MS VisualStudios 6.