Re: Suspending and resuming JNI thread

"" <>
30 Nov 2006 05:01:10 -0800
i, Beaton

Thanku very much for ur reply, even though i not clear .... i am posted
sample code exactly what i am using...

   /* Mynative Class***/

     class Mynative implements Runnable
        Thread t;
          { t=new Thread(this); }

        public synchronized void run()
        static System.loadLibrary("Clib");

  /*MyGui Class***/
    class GUI extends JDialog implements ActioinListener
       Mynative mm=new Mynative();
      /*Button creation and adding*/
     public void actionPerformed(ActionEvent ee)
          mm.t.start(); //C execution started fine...
and printing in infinite loop
          mm.t.suspend(); // no response... still
           mm.t.resume(); // no response.. still printing
            mm.t.stop(); // no response.. still

   public class Threadwindow
  public static void main(String args[]) {
        GUI window = new GUI();


/*Cfun()----in C file--*/

   JNIEXPORT void JNICALL Java_Mynative_Cfun (JNIEnv *env1, jobject
        { printf(" C code :..."); }

 Please explain me .. how i have to change the code inorder to make
working of suspend, resume and stop with ur code...

Thanking u,

Gordon Beaton wrote:

On 30 Nov 2006 01:45:54 -0800, wrote:

What my question is .. how can i suspend and resume JNI the thread

Thread methods suspend(), resume() etc are deprecated:

At any rate, your native thread cannot be forced to suspend or exit,
it needs to *cooperate* with the controlling thread. The easiest way
is to periodically call a Java method that can wait on a semaphore.

One way is to create a new instance of the following class, to pass to
your native method:

  public class Suspender {
    private boolean cancelled = false;
    private boolean suspended = false;

    public synchronized boolean wait_here() {
      try {
        while (suspended) {
      catch (InterruptedException e) {
        cancelled = true;

      return cancelled;

    public synchronized void suspend() {
      suspended = true;

    public synchronized void resume() {
      suspended = false;

    public synchronized void cancel() {
      cancelled = true;

From the native method, periodically call wait_here(). If the
controlling thread calls suspend(), the native thread will block in
the next call to wait_here(). When the controlling thread calls
resume(), the native thread will continue.

If the controlling thread calls cancel(), wait_here() will return
true, signalling the native method to return.


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