Allow wifi data while sleeping and wake device

Question

I searched and was not able to find the answer to this question. I am working on app that will run all the time. I am using wifi and everything works fine until the device sleeps. One device sends out multicast packets and the other one should get them and wake up but it is not. Right now the network thread is started from a service thread started by StartService() from my main class. IN the service I get a wifi lock and a wifi multicast lock so that wifi and multicast "should" stay on when the device sleeps. I also tried adding a partial wake lock to the mix but still nothing works. Any ideas? I am devleoping on two nexus ones running android 2.3.3 right now.

Answer 1

You need to set the PowerManager.ACQUIRE_CAUSES_WAKEUP flag in your WakeLock, however PowerManager.ACQUIRE_CAUSES_WAKEUP flag doesn't work with PowerManager.PARTIAL_WAKE_LOCK, but it should work with PowerManager.SCREEN_DIM_WAKE_LOCK. Below code should wake the display and CPU of your device, when you call acquire() on the WakeLock. The 5 second sleep should give your WiFi enough time to wake.

WakeLock lock = ((PowerManager) getSystemService(POWER_SERVICE)).newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK
                    | PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
lock.acquire();
try {
    Thread.sleep(5000);
} catch (InterruptedException e) {                  
}   
// do work here..
lock.release()