Reclaiming memory from Metro style apps

re: Reclaiming memory from Metro style apps

JamesJohnston — Tue, 24 Apr 2012 15:33:42 GMT

As others have noted, you need more flexibility with running Metro apps in the background. We have some ideas for products we might like to bring to the Metro/Windows 8/Windows Phone platform in the future, but some of the restrictions on Metro apps, such as the suspension of background apps, could preclude this - that would be a real shame.

Windows provides built-in background tasks, you say? As in, we just need to find the right background task, and then our Metro app can be suspended? OK, fine, where is the background task for doing the complicated 3D algorithms our software would require? The answer is what I thought....

The reality is our software might need to do some very CPU intensive computations for a few minutes on a background thread. During this time, we need to *not* be suspended if the user switches away from our app to, say, check their e-mail while they wait. The user *knows* we are going to be doing computations, they will know this will cost them battery life - but results don't come for free, and there is no getting around the fact that CPU cycles must be spent on calculations. The least we can do, and what we would like to be able to do, is let the user (1) switch to another app while allowing computations to continue, (2) set the priority of the thread to low, so that we can keep other apps fast and fluid while we work. We may also need to interface with a hardware device in the background. Once again, background suspension will absolutely break this.

Here's the reality, a lot of useful business apps are going to need to do custom business logic in the background. We're doing a lot more than just playing MP3 files, for heaven's sake!! There is *no way* you will ever be able to cover every background task an app might need to do.

Perhaps when installing the app, you can display a warning that the app multitasks and may compromise battery life. This would be great for filtering out the random poorly-written 99 cent apps from an app store that don't really have any business running in the background. (Does a simple loan calculator app need to run in the background? Of course not; if I was installing such an app that requested this kind of thing, I would probably find another app.) But our users are serious users about our software and are going to be using it for a specific application; suspending it in the background would really break it. In fact, they would probably buy a Windows 8 device just for the express purpose of running our software.

If an app's thread is well-written and uses blocking APIs with infinite timeouts (e.g. WaitForSingleObject with infinite timeout), there is no reason in my mind that the entire private working set can't be paged out to disk - the app is not actually requiring memory or CPU. Poorly-written threads would periodically wake (e.g. using Sleep) and poll/check something, or heaven forbid, spin in a loop and burn CPU cycles. Either of these activities are bad for battery life and memory pressure. Maybe you could add a performance metric that calls out the number of times an app wakes any of its threads in a minute, for example? This could quickly weed out the bad apps that are waking when they don't need to.

Use the Windows Desktop, that's what it's for, you say? The writing is obviously on the wall for the desktop. You're not supporting user-written desktop apps on Windows on ARM, and the Windows 8-based Apollo I doubt will even have the desktop. That means you are basically forcing a Metro-only future on us (even if you haven't publicly announced it yet - this is apparently what you see 10 years from now once desktop apps fade from view). Both of these devices (ARM tablets/laptops, and phones) could potentially be useful devices that our users will want to use. The advances in mobile hardware of the last few years have been incredible - they are faster than the desktop computers of yesteryear. Let us use the power available in such a small form factor!

re: Reclaiming memory from Metro style apps

DEVPROCB — Tue, 24 Apr 2012 15:32:28 GMT

@ Bryan K

The biggest problem with this entire article, is the assumption that Microsoft is as small as Apple. Apple is a consumer company. They make products for consumers. Also remember Apple is a Hardware company. You must run there hardware to run there software. Microsoft is a Software Company. Building a platform which is "hybrid" as you have stated is essential. As you have also stated you had a "hackintosh";you had to basically either write drivers which are very in-efficient and caused more headaches then ever or run a system in verbose mode which functioned semi okay, and you still found your self trying to buy hardware similar to apple to get it to even run. The windows 8 operating system is actually going in the right direction. Not cutting the business relationships with Microsoft which is a very solid business model. It appears you have a lot to learn about the huge differences between Apple and Microsoft. You make reference to, "Who needs Win 32 Apps". Businesses do! Just because a consumer buys the next greatest thing, does not mean businesses can afford to just use an "app" that has no true meaning to there business. Apple has the ability to just discontinue support on apps of there older operating system, because lets face it, apple only came back in the lime light because of the iphone. No one owned mac, besides a niche market of people that were apple eccentric. Looks like you are talented and are heading in the right direction but maybe a little history to look back in the past will help you understand the direction Microsoft has to take with windows 8. The ability to support both business models is key to keep there market share, and maintain huge support of business, and consumer alike. Apple has a different business model, because they came later in the game essentially, and what I mean by that, as before steve jobs came back in,the company was almost bankrupt. So the ability to reinvent and tackle new tasks was much easier, because if it failed there would be no apple, thankfully for them it worked and behold the Iphone!. Good luck in your career

re: Reclaiming memory from Metro style apps

Ecoli — Mon, 23 Apr 2012 16:05:27 GMT

Windows 8 Consumer Preview works OK, but when I create a new folder on a good flash USB disk, Windows Explorer takes too long to create it (about 4 or 5 min.). Hope Microsoft will fix this soon.

re: Reclaiming memory from Metro style apps

pmbAustin — Mon, 23 Apr 2012 15:22:01 GMT

This is a general question/observation:

With WinRT and Metro on Win8, Microsoft is pushing into the consumer tablet space in a big way. Consumers are used to major OS updates and new features at least annually (thanks to iPhone, WP7, Android, and iPad). Is Microsoft going to compete here, updating Metro features and abilities every year?

If so, will these updates be made to Win8/Pro/Enterprise too? And how will that dove-tail with businesses and enterprises prefering stability, and NOT having to update every year? Will this lead to a fragmented Metro market?

If not, how will Microsoft keep excitement about Metro/WinRT up over time, and compete with the constantly updating Android and iOS tablets out there?

re: Reclaiming memory from Metro style apps

philk — Mon, 23 Apr 2012 13:32:19 GMT

What script are you using to start the metro apps? Can you make it available please?

re: Reclaiming memory from Metro style apps

Alex Kven — Sun, 22 Apr 2012 17:46:55 GMT

@David

I'm sure you will be happy to know that Microsoft has been working on a new OS that has metro disabled by default, and will satisfy almost all of the metro-haters and people who write destructive criticism on our blog.

It's called Windows 7.

re: Reclaiming memory from Metro style apps

Micle — Sun, 22 Apr 2012 10:25:53 GMT

Great Article :)

We can also submit our .net related links on http://www.dotnettechy.com to improve traffic.

The dotnettechy.com is a community of .Net developers joined together to learn, to teach, to find solutions, to find interview questions and answers, to find .net website / blog collection and to have fun programming.

re: Reclaiming memory from Metro style apps

Bob — Sun, 22 Apr 2012 09:21:05 GMT

@David

The next version of this blog will allow the ability to 100% turn off Metro-hating trolls.

re: Reclaiming memory from Metro style apps

David — Sun, 22 Apr 2012 06:40:25 GMT

Will the release version of Windows 8 allow the ability to 100% turn off Metro? (Please say yes)

re: Reclaiming memory from Metro style apps

Pol — Sat, 21 Apr 2012 18:11:37 GMT

Windows 8 is so 5 minutes ago. Move on to Windows 9!