6 ms·

Can someone point me in the right direction to learn about or just simply explain how modern-day browsers allow for scripts to drain CPU resources?

deleted 9y ago
[deleted]
simias 9y ago
Allow me to return the question: how do you prevent scripts from draining CPU resources? How do you distinguish between legitimate resource usage (like a heavy web application that runs a lot of javascript) from a cryptocurrency miner? How do you throttle one without hurting the other?
- xxs 9y ago
  You avoid sites with heavy javascript usage.
- JD557 9y ago
  Most browsers already send you a warning if the main thread appears to be blocked. Maybe they could also add a warning like: > This page is consuming a lot of resources, do you want to keep executing JavaScript on this page? > Stop / Allow only this time / Allow always
  - gruez 9y ago
    site publishers would resort to social engineering ("click yes on the popup to continue reading)
  - chendragon 9y ago
    Safari already does this kind of. "This webpage was reloaded because it was using significant energy"
  - simias 9y ago
    Possible but if you set the limit too low you're going to have it pop it all the time on heavier websites (especially on less powerful hardware/smartphones). Then you condition the user to dismiss these warnings without thinking about it because of the high rate of false positives. On the other hand if you set it too high then those websites will aim for that limit to maximize profit without triggering the warning. You'll still waste a ton of resources and you've only mitigated the issue somewhat. I'm not saying it's impossible, just that "just add a dialog when CPU usage is high" might be a bit naive. There's a subtle balance to these things.
- 6d6b73 9y ago
  Easy (?) when you install a new browser, it should load few standard pages in the background and check what's their CPU% usage. Get average value for all the tests, multiply it by 2 just to have a little bit of wiggle room. Next time website runs, monitor the usage, if it's over the threshold block the script and ask user if they would like to continue running the script. I'm not going to file patent for this, thanks in the code will be enough. Enjoy :)
  - xbkingx 9y ago
    Except that fails if the browser is installed while something else CPU intensive is running, an update is installing, an antimalware process is doing its initial analysis, or the device is in battery saver mode. As an alternative, you could do a survey at install time - check if a battery is present, get power profiles, run your benchmark js stuff, check CPU, RAM, disk type (HDD/SSD) - then download profiles for that/those configuration(s). Then put a 'sensitivity' slider in the advanced options to allow power users to tweak/turn off the limit. No need to send me code. Cash will do fine.
runeks 9y ago
> Can someone point me in the right direction to learn about or just simply explain how modern-day browsers allow for scripts to drain CPU resources? They allow it because the point of scripts is to consume some level of CPU resources, and setting an arbitrary limit on how much is too much is bound to cause a bad user experience when e.g. rendering large visualizations or playing a fast-paced game.
tgsovlerkhgsel 9y ago
Because a browser can't distinguish between a CPU-intensive app, game or simulation that you want to run in your browser, a cryptocurrency miner that a website runs in your browser after it explicitly asked you and you agreed, and a cryptocurrency miner running in the background. Of course, they could start asking for permission before letting a site use more than X CPU, or before letting the site execute JavaScript at all, but most people don't want additional popups like that. Someone said that Firefox warns you when a site uses a lot of CPU but I couldn't trigger that warning (maybe I didn't run it long enough or the feature is in a newer version).

deleted 9y ago

[deleted]

simias 9y ago

Allow me to return the question: how do you prevent scripts from draining CPU resources? How do you distinguish between legitimate resource usage (like a heavy web application that runs a lot of javascript) from a cryptocurrency miner? How do you throttle one without hurting the other?

xxs 9y ago
You avoid sites with heavy javascript usage.
JD557 9y ago
Most browsers already send you a warning if the main thread appears to be blocked. Maybe they could also add a warning like: > This page is consuming a lot of resources, do you want to keep executing JavaScript on this page? > Stop / Allow only this time / Allow always
- gruez 9y ago
  site publishers would resort to social engineering ("click yes on the popup to continue reading)
- chendragon 9y ago
  Safari already does this kind of. "This webpage was reloaded because it was using significant energy"
- simias 9y ago
  Possible but if you set the limit too low you're going to have it pop it all the time on heavier websites (especially on less powerful hardware/smartphones). Then you condition the user to dismiss these warnings without thinking about it because of the high rate of false positives. On the other hand if you set it too high then those websites will aim for that limit to maximize profit without triggering the warning. You'll still waste a ton of resources and you've only mitigated the issue somewhat. I'm not saying it's impossible, just that "just add a dialog when CPU usage is high" might be a bit naive. There's a subtle balance to these things.
6d6b73 9y ago
Easy (?) when you install a new browser, it should load few standard pages in the background and check what's their CPU% usage. Get average value for all the tests, multiply it by 2 just to have a little bit of wiggle room. Next time website runs, monitor the usage, if it's over the threshold block the script and ask user if they would like to continue running the script. I'm not going to file patent for this, thanks in the code will be enough. Enjoy :)
- xbkingx 9y ago
  Except that fails if the browser is installed while something else CPU intensive is running, an update is installing, an antimalware process is doing its initial analysis, or the device is in battery saver mode. As an alternative, you could do a survey at install time - check if a battery is present, get power profiles, run your benchmark js stuff, check CPU, RAM, disk type (HDD/SSD) - then download profiles for that/those configuration(s). Then put a 'sensitivity' slider in the advanced options to allow power users to tweak/turn off the limit. No need to send me code. Cash will do fine.

runeks 9y ago

> Can someone point me in the right direction to learn about or just simply explain how modern-day browsers allow for scripts to drain CPU resources? They allow it because the point of scripts is to consume some level of CPU resources, and setting an arbitrary limit on how much is too much is bound to cause a bad user experience when e.g. rendering large visualizations or playing a fast-paced game.

tgsovlerkhgsel 9y ago

Because a browser can't distinguish between a CPU-intensive app, game or simulation that you want to run in your browser, a cryptocurrency miner that a website runs in your browser after it explicitly asked you and you agreed, and a cryptocurrency miner running in the background. Of course, they could start asking for permission before letting a site use more than X CPU, or before letting the site execute JavaScript at all, but most people don't want additional popups like that. Someone said that Firefox warns you when a site uses a lot of CPU but I couldn't trigger that warning (maybe I didn't run it long enough or the feature is in a newer version).