while (gameThreadRunning) {
            Canvas canvas = null;
            try {
                canvas = surfaceHolder.lockCanvas();
                synchronized (surfaceHolder) {
                    if (gameIsRunning()) {
                        if(lastTickTime == -1){
                            lastTickTime = System.nanoTime() - 1;
                        }
                        currentTickTime = System.nanoTime();
                        tickDelta = currentTickTime - lastTickTime;

                        if (updateDelay > 0) {
                            long updateDelayRemaining = tickDelta - updateDelay;
                            if (updateDelayRemaining > 0) {
                                // in that case we need to wait a bit longer before continuing
                                // to respect the configured update delay
                                try {
                                    Thread.sleep(TimeUnit.NANOSECONDS.toMillis(updateDelayRemaining));
                                } catch (InterruptedException e) {
                                }
                            }
                        }