Runnable inside Runnable

Question

Basically , i have 5 Runnables for each user.

Inside each Runnable, There must be waiting for a variable to change until it continues. I'll be using either a Semaphore or a CountDownLatch.

So inside each Runnable there is a runnable for waiting.

Here's an example. r1 is a runnable supposed to be user so never ending.

final  Handler handler = new Handler();
Runnable r1 = new Runnable() {
    @Override public void run() {

           // here must be another runnable for waiting
              Runnable r2 = new Runnable() {
                   @Override public void run() {

                        if (condition) {
                            latch.countDown();
                            // ending the runnable
                               handler.removeCallbacks(r2);
                        } else {
                          // keep waiting
                             handler.postDelayed(r2, 1000);
                        }
                   }
              }

           latch.await();
        // restarting the runnable
        handler.postDelayed(r1, 1000);
    }
}

The problem when using latch.await() is that is running in main thread so blocking the UI.

Any idea how to starts those runnable in different threads?

Answer 1

What i wanted to do is a non stop running Thread that somewhere needs to wait a variable to change so it continues other instructions. Somewhere in the UI when a button is clicked ,a semaphore gets incremented. And in the thread it waits until it is available. Here's the solution i made

 Semaphore sem = new Semaphore(0,true);
 //somewhere in UI  sem.release();

 Thread thread = new Thread()
        {
            @Override
            public void run() {
                try {
                    while(true) {
                        sleep(1000);

                        semaphore.acquire();

                        // when updating the UI is needed
                        runOnUiThread(new Runnable() {
                          @Override
                            public void run() {
                                // work
                            }
                        });


                    }
                } catch (InterruptedException e) {

                }
            }
       }