A couple questions on Advanced Task Killer

M

marlieee !

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1) Which app is responsible for Gmail PUSH notifications? Is it the "Mail" app or "Gmail" one? I try emailing myself using my PC and with the Gmail app running and Mail app killed, I get a notification in a couple seconds. With both apps killed however, it took about a minute? Or are both apps responsible somehow?

2) What exactly are the differences between "Safe", "Aggressive" & "Crazy" levels of auto kill? I read the FAQ but didn't really understand the English structure
 
My advice... don't use it There are some pretty strong opinions out there on Task Killers. I have found that running my device without worrying about task managers yields the same performance. Unless you specifically need to kill an application for some reason, task killers are pointless.
 
That is not the case.

Android multitasking has been implemented in a very specific way and does not work, for instance, in the same way that multitasking does in native Linux. Just because a task manager shows that an app is "running", this does not necessarily mean that the app is actively using system resources. Apps are dynamically assigned priorities by Android, depending on what they are doing. And it is able to automatically close apps - based on their priority - if the phone requires RAM or if that app remains inactive too long. Twistbyte's very good memory usage app will shows you these priorities.

Apps are also treated differently depending on their precise requirements and how they have been implemented.

See here for a good discussion:

http://android-developers.blogspot.com/2010/04/multitasking-android-way.html

and here if you need very low-level detail:

http://developer.android.com/guide/topics/fundamentals.html

J.
 
Bottom line, it's not a background process at all. The notification is triggered by a broadcast receiver that is triggered to run by Android when the gmail received intent is broadcast. It's because of this system that Task Killers are, in general, a total waste of time and will do nothing more than slow your system down when Android is forced to restart and re-cache everything that was killed off.
 
1. In fact, you don't need to kill it to disable this function. You could disable it from the setting panel.

2. Oh, I'm using a process manager, but it has no these options. But I guess, safe means close the program gently, in the way of normal exit, agressive means, try to close it gently, if it doesn't work, then kill the process without inform the process to save any data or status, and crazy means, not trying the gently way, and directly to the rude way
 
The difference in Safe and Aggressive may be just down to priority. Android assigns priorities to each process. 100 being essential (i.e. a core process or something that the user is actively using in the foreground), down to 500 which is just background stuff that nobody will care too much if it's killed.

Android automatically kills process off when it needs more resources, starting with the processes with the lowest (highest number) priority.

I would imagine the task killer is doing something similar, so safe only kills processes that have a priority of 500, and aggressive might kill off 500, 400, and 300... maybe. It's how I would do it anyway.
 
If task killers do nothing, then why is it that without my task killer running, I only had 50 megs of RAM left, and when my task killer is running it frees up about an additional 150 megs of ram? Also, my phone is running significantly faster now.

Also, I believe that the Android system closes the lowest priority app after six apps are opened, IF it needs to free up some memory. And it looks like it only manages apps that are made by Android or Google. I checked on my phone, and only Android and Google apps were being managed like that. All of the other apps that I have been downloading on the Android store that are third party will keep running on my phone unless I force stop them or let task killer close them.
 
Nobody said they don't do anything. They will free up memory as they close down programs. Android needs around 50MB free to run optimally. If you have more than that free you're just wasting RAM by not using it. There's no point in having RAM if you never use it. Hardly any apps at all will suddenly want to use more than 50MB. In fact the only app I know of that would ever do that is the Browser if it has to download a HUGE webpage.

Additionally, running tasks may use up resources, depending on the task. There are many apps that run all the time in the background, although these, for the most part, are just badly written apps. One of my apps, for example, needs to run frequently, but doesn't sit there running in the background 24/7. It only runs when something happens that it needs to respond to.

I have around 60 apps on my phone downloaded from the Market. Of which I have only 8 tasks showing running in Advanced Task Manager. So 8 out of 60 is a pretty low number in my opinion.

Of course your phone may show more because you have more RAM than me (on my G1). It is far more efficient to have an app already loaded into memory, but idle, than have to reload it all, initialise it all, re-load all of its files and resources, settings, etc. So, if you have more than 50MB free, then yes, you'll have more processes showing than me, because Android knows about the advantages to keeping them loaded (fast loading, less power use as a result) if you have enough spare RAM, as opposed to having all that spare RAM going to waste and never being used, and slower loading/more power use.
 
So what about the app fast reboot, this must work similar to a task killer. I use it quite regularly on my hero, it definately speeds my mobile up in every sense from viewing photos to playing games. Sometimes if I have been playing some games, looking at photos, web browsing, then when I play my music the hero struggles with the beginning of every song for a second or so, if I do a fast reboot sorts it out straight away. Ziggy.
 
Right, but you're talking about a Hero, which like my G1 has much lower RAM.

Let's assume that you're in a situation like me, and the phone is constantly low on RAM (under 40MB, give or take 10MB). Whether you use task killer apps, or a rebooter apps (which pretty much kills off everything), or just Android on it's own, they will all do the same job of freeing up RAM to load your next app. The speed increase you're seeing from fast reboot is because you're just doing the task of freeing up memory for Android in advance. Without "fast rebooting" Android may have to kill off a load of stuff to free up memory before starting your next app. This takes time, but then so does fast rebooting. Is doing a fast reboot then loading your app really faster than just loading your app immediately? If you do a fast reboot you've essentially killed off a load of stuff just like a task killer would.

BUT, what would happen if there's enough RAM to keep that app loaded? There may be on your Hero, it just depends on your phone and what other stuff you have running. If you just go straight back into the app, it should appear instantly if you have enough RAM. But, if you kill off the app (either by fast rebooting or with a task killer) and reload it you'll notice it takes longer to load. For small apps the difference is hardly noticeable. But on bigger apps it's the difference between 10 seconds and half a second. So in this scenario you're just slowing down the loading of your app by using fast reboot or a task killer.

What happens if you have a newer phone with loads of RAM? Well in that case the phone is capable of keeping a load of apps in memory, allowing you to access them all very quickly. If you kill them all off then you're just forcing them all to reload slowly when they're next needed.

And really that's where Task Killers do have a purpose. There are some apps that do run frequently, use a ton of memory and CPU and battery, and serve no purpose at that time. For example, I have ShopSavvy installed, which likes to run two processes, using about 25% of my free RAM between them, turn on the GPS, and sit there running for several minutes. I assume it's to keep its known location up to date, but I don't want it to do that unless I'm out shopping and actually want to scan stuff. In this kind of scenario, a Task Killer is good. But that's because this process is just a useless waste of resources at that point in time.

Task Killers require you to have a reasonable amount of knowledge about each task you run, and Android. Kill off the wrong thing and things will start messing up, or the process you kill off will just be restarted automatically shortly after killing it (so you're just wasting CPU time and battery killing it off).

Fast Reboot kills off all of the core processes. That's really dangerous in my opinion. Allow me to quote some of the comments from Fast Reboot:

by Tommy the 6/13/2010
Crashes the Evo 4G then you end up pressing more dialogs then if you would of simply power off. Uninstalling

by Nik the 6/4/2010
Great idea, bad design. Messes up my home screen, phone refuses to make calls until reset by power button. HTC hero cdma (sprint)

by Ahron the 6/1/2010
DO NOT INSTALL! WILL BREAK ALARMS, SYNC, GOOGLE VOCE, ETC

by AndCycle the 5/23/2010
Nice try, killed all service too.

by James the 5/13/2010
Messes some things up.....stop being lazy and just reboot your phone, you shouldnt need this app

by C.R. the 5/13/2010
Good, but buggy. Resets my live wallpaper. Also closes volume locker. Need and exception list. Otherwise great! Droid.

by Scott the 5/3/2010
Htc hero - after fast reboot txts (handcent) wont recieve txts.. have to turn phone on/off.. defeating purpose of reboot

by boomshankerx the 4/25/2010
more stars if it would properly restart USB service on milestone. Otherwise seems to work great.

by David the 4/24/2010
Garbage. Doesn't restart apps that should restart with a reboot. Not only is it not a "reboot," but you have to do a real one after you run it

by M the 4/24/2010
Kills my network every time MotoDroid. Uninstalled.

by G?ran the 4/23/2010
Does not work on HTC Hero. Home screen is not restarted.

From these comments, you can see a clear picture that Fast Reboot kills of stuff that it shouldn't, and doesn't restart them. Android, however, DOES keep a record of what it kills off, and will restart services when more memory is freed up (i.e. when you exit your app). Sure, that means it may have to kill that service off again next time you run something, but then your task killer would have to do that anyway, so you don't lose anything. But in the meantime at least your phone is working properly and being reliable.
 
Hey, thanks for the detailed explanation Extorian, very time consuming for you but appreciated by us all. Well I thought my Hero wasn't affected with the quick reboot until today, I couldn't get on the internet with Orange, I kept getting the message, "incorrect APN settings" I googled it and found others getting the same message, I had to go into MMS Settings and type in 192.168.224.10, it had no numbers in so I typed these in and was instantly back online, a coincidence or fast reboot problem? I'm not sure. Thanks again, Ziggy
 
I'd imagine that's co-incidence, but... people state in the comments I listed above that it makes the phone unable to make calls and other such things, so maybe.
 
I will keep the Quick Reboot on for now seeing as this is the only problem I've come across since installing the app a good 3 months ago, but I will bear in mind what's happened to other users and uninstall it if its creating problems. Just another quick thought why some people do experience problems and others don't, could certain apps running be interfering with it in the same was two virus checkers on a pc will struggle to run or am I talking rubbish. Cheers, Ziggy.
 
It's more about the fact that it kills off everything and that non-system apps have no mechanism by which to restart.

For example, take Handcent. It's a very common SMS Messaging app replacement. If its service gets killed off then you will no longer be notified of incoming SMS messages. You won't know you have received a message until you run the app manually.

With system apps it's different. Android will restart them as needed, in theory.

So if you don't have many apps that replace or improve Android's features, you probably won't notice things going wrong as much. If you do have lots of apps, they may no longer function correctly after being killed off so you will notice it more. Meanwhile, users blame the other apps for not working, when really it's the task killer app causing the problem. You see countless apps on the Market these days that read "Exclude from Task Killers!!!" and stuff like that.
 
Thanks Extorian, Im a lot clearer now and can understand why my mobile doesn`t seem affected, I dont use handcent or any other sms, I tried but wasnt overly impressed, so I just went back to the standard Android messages thats already installed on the Hero, hey Im 54, I dont need bubbles, lol. Only apps I have are stuff like games, word games, notepad and music apps etc, so it seems Im not experiencing any problems like some are.
Thanks for keeping us right mate, its very much appreciated.
Cheers, Ziggy.
 
So if task killer are so harmful/useless, why does my phone feel the need to open apps that I have never used?

There have been a number of times when I haven't used my phone for a number of hours and when I go to make a call the battery is half dead from a full charge and almost every app I have is opened after having "killed" everything before this.

If there is such a setting I haven't found it, but can I simply shut off certain apps that I don't use...such as the corporate calendar, I have a regular calendar on my phone I don't need a second one.
 
Firstly, apps can share code and allow other apps to take advantage of code that already does stuff perfectly well. A good example of this is the TTS Extended app. A number of apps use Text To Speech, especially in earlier versions of Android that didn't have this natively. Instead of each developer having to write all their own code to deal with making your phone speak stuff, they just send the text to TTS Extended and it'll do it for them. Why re-invent the wheel?

So, this explains why some apps are running that you haven't asked to run.

Some apps also run themselves. They can start after the phone has finished booting up, or at any scheduled time they choose. They can automatically be scheduled to run ever X seconds/minutes/hours too.

Apps run themselves for a number of reasons. It just depends on the app. Some apps run to sync stuff (download emails, check for updates, check for new messages, etc). Some apps run to do slow stuff that can be done in advance so the user doesn't have to wait when they run the app themselves. For example, ShopSavvy runs every hour or so to get an update of the phones location from the GPS, so that when you run the app you don't have to wait a minute while it gets the position so that it can tell you about local prices of stuff.

Killing these apps mostly just drain your battery more. They will run anyway. If you kill them though there is battery used when you kill it, way more battery used when it restarts (as it has to re-load everything), and more battery used when it has to restart doing whatever it was trying to do when you killed it. If you just let it run then next time it needs to do something it's already loaded (so no battery used to load it), it'll do its thing and work first time (not having to restart it because you killed it).

Remember, that just because an app is showing as running in the background, doesn't mean it's using ANY CPU, or battery. It can just be loaded and waiting for something, which uses no battery or CPU.

Unfortunately, if there's no setting to turn stuff off in the app itself, then there's no way to stop it running in the background if it wants to. But using the example of your corporate calendar... The system access the corporate calendar code every now and again to sync it, or schedule alarms/notifications to be displayed. If you don't have a corp calendar than I can see why this would appear to be a waste of time and resources, but I can tell you now that if it's already running the check will take maybe a few hundred CPU instructions while it figures out you don't have one or use one. Which on a 1GHz processor will take only a few 1/10,000,000ths of a second. That won't hurt your battery in the slightest. If you have killed it off though, it will have to go through the whole process of reloading it re-initialising everything, possibly reattempting to connect to your corporate server... you're talking several seconds of CPU and IO work there. That WILL hurt your battery if it's doing it 50 times a day.
 
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