How to "wait" a Thread in Android

Java Problem Overview

private void startGameTimeElapseThread(){
	new Thread(new Runnable() {
		Date d = new Date();
		public void run() {
			while (gameOn){
				Log.d(TAG,""+d.getTime()+" "+gameStatus.getLastTimeUpdated());
				
				postInvalidate(795, 150, 1024, 300);
				try {
					synchronized (this) {
						wait(1000);	
					}
				} catch (InterruptedException e) {
					// TODO Auto-generated catch block
					Log.d(TAG, "Waiting didnt work!!");
					e.printStackTrace();
				}
			}
	    }
	}).start();
}

Here I wanted to make call the "Log.d" and "postInvalidate" every one second. But when i check it from LogCat it seems loop runs faster than i want it to be. Why doesnt this loop just wait for 1000ms ?

Following are the output in LogCat. So you can see its not sleeping for a 1 second at all. I used Thread.sleep as well ( after you suggesting )

05-27 11:40:10.060: DEBUG/NOPSA-P(4546): 1306496408950 1306496387535
05-27 11:40:10.070: DEBUG/NOPSA-P(4546): 1306496410037 1306496387535
05-27 11:40:10.232: DEBUG/NOPSA-P(4546): 1306496410201 1306496387535
05-27 11:40:10.250: DEBUG/NOPSA-P(4546): 1306496408214 1306496387535
05-27 11:40:10.310: DEBUG/NOPSA-P(4546): 1306496405988 1306496387535
05-27 11:40:10.361: DEBUG/NOPSA-P(4546): 1306496409327 1306496387535
05-27 11:40:10.431: DEBUG/NOPSA-P(4546): 1306496410398 1306496387535
05-27 11:40:10.521: DEBUG/NOPSA-P(4546): 1306496409478 1306496387535
05-27 11:40:10.593: DEBUG/NOPSA-P(4546): 1306496410566 1306496387535
05-27 11:40:11.230: DEBUG/NOPSA-P(4546): 1306496409678 1306496387535
05-27 11:40:11.230: DEBUG/NOPSA-P(4546): 1306496410201 1306496387535
05-27 11:40:11.241: DEBUG/NOPSA-P(4546): 1306496409878 1306496387535
05-27 11:40:11.241: DEBUG/NOPSA-P(4546): 1306496410037 1306496387535
05-27 11:40:11.241: DEBUG/NOPSA-P(4546): 1306496408950 1306496387535
05-27 11:40:11.260: DEBUG/NOPSA-P(4546): 1306496408214 1306496387535
05-27 11:40:11.314: DEBUG/NOPSA-P(4546): 1306496405988 1306496387535
05-27 11:40:11.314: DEBUG/NOPSA-P(4546): 1306496411254 1306496387535
05-27 11:40:11.361: DEBUG/NOPSA-P(4546): 1306496409327 1306496387535
05-27 11:40:11.431: DEBUG/NOPSA-P(4546): 1306496410398 1306496387535
05-27 11:40:11.520: DEBUG/NOPSA-P(4546): 1306496409478 1306496387535
05-27 11:40:11.551: DEBUG/NOPSA-P(4546): 1306496411508 1306496387535
05-27 11:40:11.712: DEBUG/NOPSA-P(4546): 1306496410566 1306496387535
05-27 11:40:11.881: DEBUG/NOPSA-P(4546): 1306496411865 1306496387535
05-27 11:40:12.051: DEBUG/NOPSA-P(4546): 1306496412025 1306496387535
05-27 11:40:12.211: DEBUG/NOPSA-P(4546): 1306496412198 1306496387535
05-27 11:40:12.231: DEBUG/NOPSA-P(4546): 1306496409678 1306496387535
05-27 11:40:12.242: DEBUG/NOPSA-P(4546): 1306496410201 1306496387535
05-27 11:40:12.251: DEBUG/NOPSA-P(4546): 1306496408950 1306496387535
05-27 11:40:12.251: DEBUG/NOPSA-P(4546): 1306496409878 1306496387535
05-27 11:40:12.251: DEBUG/NOPSA-P(4546): 1306496410037 1306496387535
05-27 11:40:12.261: DEBUG/NOPSA-P(4546): 1306496408214 1306496387535
05-27 11:40:12.311: DEBUG/NOPSA-P(4546): 1306496405988 1306496387535
05-27 11:40:12.341: DEBUG/NOPSA-P(4546): 1306496411254 1306496387535
05-27 11:40:12.371: DEBUG/NOPSA-P(4546): 1306496409327 1306496387535
05-27 11:40:12.442: DEBUG/NOPSA-P(4546): 1306496410398 1306496387535
05-27 11:40:12.471: DEBUG/NOPSA-P(4546): 1306496412431 1306496387535
05-27 11:40:12.521: DEBUG/NOPSA-P(4546): 1306496409478 1306496387535
05-27 11:40:12.553: DEBUG/NOPSA-P(4546): 1306496411508 1306496387535
05-27 11:40:12.671: DEBUG/NOPSA-P(4546): 1306496412639 1306496387535
05-27 11:40:12.711: DEBUG/NOPSA-P(4546): 1306496410566 1306496387535
05-27 11:40:12.841: DEBUG/NOPSA-P(4546): 1306496412813 1306496387535
05-27 11:40:12.891: DEBUG/NOPSA-P(4546): 1306496411865 1306496387535
05-27 11:40:13.001: DEBUG/NOPSA-P(4546): 1306496412983 1306496387535
05-27 11:40:13.051: DEBUG/NOPSA-P(4546): 1306496412025 1306496387535
05-27 11:40:13.193: DEBUG/NOPSA-P(4546): 1306496413166 1306496387535
05-27 11:40:13.231: DEBUG/NOPSA-P(4546): 1306496409678 1306496387535
05-27 11:40:13.251: DEBUG/NOPSA-P(4546): 1306496410201 1306496387535
05-27 11:40:13.251: DEBUG/NOPSA-P(4546): 1306496409878 1306496387535
05-27 11:40:13.251: DEBUG/NOPSA-P(4546): 1306496410037 1306496387535
05-27 11:40:13.251: DEBUG/NOPSA-P(4546): 1306496408950 1306496387535
05-27 11:40:13.261: DEBUG/NOPSA-P(4546): 1306496408214 1306496387535
05-27 11:40:13.271: DEBUG/NOPSA-P(4546): 1306496412198 1306496387535
05-27 11:40:13.321: DEBUG/NOPSA-P(4546): 1306496405988 1306496387535
05-27 11:40:13.341: DEBUG/NOPSA-P(4546): 1306496411254 1306496387535
05-27 11:40:13.371: DEBUG/NOPSA-P(4546): 1306496409327 1306496387535
05-27 11:40:13.431: DEBUG/NOPSA-P(4546): 1306496413405 1306496387535
05-27 11:40:13.441: DEBUG/NOPSA-P(4546): 1306496410398 1306496387535
05-27 11:40:13.481: DEBUG/NOPSA-P(4546): 1306496412431 1306496387535
05-27 11:40:13.532: DEBUG/NOPSA-P(4546): 1306496409478 1306496387535

This is the latest Code. gameOn is a boolean, for now it's true.

private void startGameTimeElapseThread(){
	if (gameOn){
		new Thread(new Runnable() {
			Date d = new Date();
			public void run() {
					
					Log.d(TAG,""+d.getTime()+"ms  "+d.getTime()/1000+"sec");
					postInvalidate(795, 150, 1024, 300);
					android.os.SystemClock.sleep(1000); 
					startGameTimeElapseThread();
					
		    }
		}).start();
	}
}

The output is

05-27 12:00:51.211: DEBUG/NOPSA-P(5098): 1306497650761ms  1306497650sec
05-27 12:00:51.211: DEBUG/NOPSA-P(5098): 1306497650786ms  1306497650sec
05-27 12:00:51.221: DEBUG/NOPSA-P(5098): 1306497650764ms  1306497650sec
05-27 12:00:51.221: DEBUG/NOPSA-P(5098): 1306497650763ms  1306497650sec
05-27 12:00:51.221: DEBUG/NOPSA-P(5098): 1306497650769ms  1306497650sec
05-27 12:00:51.231: DEBUG/NOPSA-P(5098): 1306497650749ms  1306497650sec
05-27 12:00:51.231: DEBUG/NOPSA-P(5098): 1306497650736ms  1306497650sec
05-27 12:00:51.231: DEBUG/NOPSA-P(5098): 1306497650742ms  1306497650sec
05-27 12:00:51.241: DEBUG/NOPSA-P(5098): 1306497650746ms  1306497650sec
05-27 12:00:51.241: DEBUG/NOPSA-P(5098): 1306497650848ms  1306497650sec
05-27 12:00:51.251: DEBUG/NOPSA-P(5098): 1306497650729ms  1306497650sec
05-27 12:00:51.271: DEBUG/NOPSA-P(5098): 1306497650739ms  1306497650sec
05-27 12:00:51.271: DEBUG/NOPSA-P(5098): 1306497650739ms  1306497650sec
05-27 12:00:51.271: DEBUG/NOPSA-P(5098): 1306497650868ms  1306497650sec
05-27 12:00:51.271: DEBUG/NOPSA-P(5098): 1306497650798ms  1306497650sec
05-27 12:00:51.281: DEBUG/NOPSA-P(5098): 1306497650870ms  1306497650sec
05-27 12:00:51.291: DEBUG/NOPSA-P(5098): 1306497651020ms  1306497651sec
05-27 12:00:51.551: DEBUG/NOPSA-P(5098): 1306497651498ms  1306497651sec
05-27 12:00:51.551: DEBUG/NOPSA-P(5098): 1306497651502ms  1306497651sec
05-27 12:00:51.642: DEBUG/NOPSA-P(5098): 1306497651523ms  1306497651sec
05-27 12:00:51.651: DEBUG/NOPSA-P(5098): 1306497651537ms  1306497651sec
05-27 12:00:51.691: DEBUG/NOPSA-P(5098): 1306497651529ms  1306497651sec
05-27 12:00:51.701: DEBUG/NOPSA-P(5098): 1306497651534ms  1306497651sec
05-27 12:00:51.784: DEBUG/NOPSA-P(5098): 1306497651527ms  1306497651sec
05-27 12:00:51.801: DEBUG/NOPSA-P(5098): 1306497651570ms  1306497651sec
05-27 12:00:51.801: DEBUG/NOPSA-P(5098): 1306497651564ms  1306497651sec
05-27 12:00:51.891: DEBUG/NOPSA-P(5098): 1306497651682ms  1306497651sec
05-27 12:00:51.891: DEBUG/NOPSA-P(5098): 1306497651690ms  1306497651sec
05-27 12:00:51.891: DEBUG/NOPSA-P(5098): 1306497651685ms  1306497651sec
05-27 12:00:51.901: DEBUG/NOPSA-P(5098): 1306497651693ms  1306497651sec
05-27 12:00:51.914: DEBUG/NOPSA-P(5098): 1306497651647ms  1306497651sec
05-27 12:00:51.914: DEBUG/NOPSA-P(5098): 1306497651667ms  1306497651sec
05-27 12:00:51.921: DEBUG/NOPSA-P(5098): 1306497651666ms  1306497651sec
05-27 12:00:51.921: DEBUG/NOPSA-P(5098): 1306497651658ms  1306497651sec
05-27 12:00:51.921: DEBUG/NOPSA-P(5098): 1306497651663ms  1306497651sec
05-27 12:00:51.932: DEBUG/NOPSA-P(5098): 1306497651688ms  1306497651sec
05-27 12:00:51.941: DEBUG/NOPSA-P(5098): 1306497651711ms  1306497651sec
05-27 12:00:51.961: DEBUG/NOPSA-P(5098): 1306497651792ms  1306497651sec
05-27 12:00:51.971: DEBUG/NOPSA-P(5098): 1306497651629ms  1306497651sec
05-27 12:00:51.981: DEBUG/NOPSA-P(5098): 1306497651714ms  1306497651sec
05-27 12:00:52.083: DEBUG/NOPSA-P(5098): 1306497652048ms  1306497652sec

Java Solutions

Solution 1 - Java

You need the sleep method of the Thread class.

> public static void sleep (long time) > > Causes the thread which sent this message to sleep for the given interval of time (given in milliseconds). The precision is not guaranteed - the Thread may sleep more or less than requested. > > Parameters > > time The time to sleep in milliseconds.

Solution 2 - Java

Don't use wait(), use either android.os.SystemClock.sleep(1000); or Thread.sleep(1000);.

The main difference between them is that Thread.sleep() can be interrupted early -- you'll be told, but it's still not the full second. The android.os call will not wake early.

Solution 3 - Java

I just add this line exactly as it appears below (if you need a second delay):

try {
    Thread.sleep(1000);
} catch(InterruptedException e) {
    // Process exception
}

I find the catch IS necessary (Your app can crash due to Android OS as much as your own code).

Solution 4 - Java

You can try this one it is short :)

SystemClock.sleep(7000);

It will sleep for 7 sec look at documentation

Solution 5 - Java

Write Thread.sleep(1000); it will make the thread sleep for 1000ms

Content Type	Original Author	Original Content on Stackoverflow
Question	dinesh707	View Question on Stackoverflow
Solution 1 - Java	Prince John Wesley	View Answer on Stackoverflow
Solution 2 - Java	mah	View Answer on Stackoverflow
Solution 3 - Java	John Ashmore	View Answer on Stackoverflow
Solution 4 - Java	Gelldur	View Answer on Stackoverflow
Solution 5 - Java	Harinder	View Answer on Stackoverflow