490221 - bad long term operation behaviour with e.g. flash plug ins and other animations

Status: RESOLVED DUPLICATE of bug 40848

(Firefox :: General, defect)

Description

[Alexander Stohr]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.0.9) Gecko/2009040821 Firefox/3.0.9 (.NET CLR 3.5.30729)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.0.9) Gecko/2009040821 Firefox/3.0.9 (.NET CLR 3.5.30729)

as a good deal of modern PC sales tend to have a multi core processor built in
there is something to really think about - or better say i've spotted the problem
it in the wild one of those multi core processors.
in more detail, i am heavily using tabbed browsing and often visiting sites like 
youtube and lots of others that are based upon scripting and advanced visualisation plugins.

when i was browsing for some time and having opended say 8 window instances with some 1 to 15 tabs each, the whole browser system often gets more and
more clumsy over the time (lets say some 5 or 10 days).

the observations i've made were that i had a permanent load (e.g. by looking 
after it with the sysinternals/microsoft tool process explorer in the tray)
and this load went from say 25% to 50% without crossing the 50% level.
that far i proceed the lower limit will close up with the upper limit.
Only when using other applications the total load will be able to jump
up to 100% and only then when those other applications are doing true works.

i am using a flash blocker to get rid of at least some very nasty ads
but of course there is content that i have explicitely enabled on a 
time by time decision or even permanently.

There might be side effects, like flash using up more and more memory,
e.g. when having it run with the YouTube "final" slide shows for some time
(and as far as i know about Safari, it will kill safari based flash video
playback in about 1 h with that!) so that not all of the problems might
originate from FireFox, but it cannot be denied that FF still could do better
managing the resources, even if the plug-in is sub-optimally implemented.

what do i see then that is basically not there when the broser is frelshly running?
i am seeing this:
* fully buffered flash videos will play for some 5 seconds, then stop for
  1-2 seconds either only with sound or even sound and image or only with video.
* when closing a playing video in a tab it can take up to 5 seconds until
  the sound of it is gone.
* when just clicking into a visible but lowerd browser window then the whole
  window content might get white or dimmed and i've to wait for 5-10 seconds
  until the contens get refreshed and operable (scrolling) again.
* when editing some texts (bugzilla, wikipedia) i am getting sudden stops
  of character output in the rage of 3-5 seconds delay. the more critical
  is the behaviour that i can click at some location in such a text with the
  mouse, then even sometimes already seeing the replaced cursor but the new
  text that got entered after that will still (partly) be written to the old
  cursor location.
- in some cases even browser windows will vanish or others will suddenly
  pop up on screen as a "side result" of my normal interaction
  like if there were problems fiddeling out which mouse button or key press
  was meant for which of the currently created windows. this sort of FF
  beeing confused even manifests in the form of window start bar entrys
  beeing removed from the start bar and then re-created on the end of the
  start bar listing, thus making it a mess for me finding my previousely know
  location of certain windows again. this might happen to 1 to 3 or even all 
  windows without any long-term indication - just a minimize-restore flicker maybe.
  (Note: i am not using those start bar option called "group by application".)

i have to assume that all those effects are pretty related to each other
and do basically originate to a insufficient or inadequate implementation
of multi tasking for the management of permanent or semi-permanent acitivity
of code for any of the pages currently present in tabs.

i would suggest to consider this improvements:
- create at least two (or even three) categories of threads:
  * one for the high priority user interaction on the browser window
    and tab that is on top of the desktop.
  * one with lesser priority for any other visible but non interactive tab.
  * one with lowest priority for all invisible, unexposed tabs.
  (you might see some reason to skip the middle level by just putting
  it either into high or low priority, but if kept separate its much cleaner.)
- give all those threads the ability to not stick to a specific CPU core
  but let the OS distribute them across the available CPUs on its own will.
- give the user the possiblity to add certain tabs, URLs and plugins
  to run in a higher or lower priority by default (e.g. listening web radio
  in a background tab at high priority, or "slowing down" animations on
  certain pretty ads loaded pages), and allow the user to give any page a kick.
- allow the user to give an up to 100% priority on (crash & update) restarts 
  for the top of the heap visible tabs in the windows so that he will see
  first where he ended last, and load anything else later in the backtround
  or instantly when the user raises some of the tabs by his own will.
  
The hoped or expected result would be a browser that is much more responsive
to any user interaction even if running it for a longer time frame in a load
situation where there are more animations on the pages than in average.
in fact the amount of scripting and animations is steadily growing
so such a change would be a very good improvement for anybody in the world.

i know that a "one thread per tab" method is possible but not really a good
solution -

at present i am just seeing a clumsy browser every now and then in my scenarios
and i am seeing that this browser is not at all capable of taking advantage
of my dual core processor for resolving this browser perfromance lack state.

Firefox is a basically very good browser but there are currently quite 
evident some lacks in the use of certain "state of the art" technologies.
With this report i try to give you the valueable inputs that there are
already related problems that you should be able to address by making use
of these technologies and thus resulting in significantly improved program.


Reproducible: Always

Steps to Reproduce:
1. launch browser
2. launch mutliple windows
3. launch multiple pages in several tabs, prefer script and flash using pages
4. operate the browser for some time, maybe hours or even a few days (i hope you can reproduce it faster by special measures of load testing)
5. watch the CPU load indicator in the tray of the windows PS tool.
Actual Results:  
observation of a purely single threaded implementation
clumsy browser behavoir, inresponsiveness, random window popping, stuttering vids.

Expected Results:  
smooth, gentle, foreseeable and responsive behaviour

i wouldnt belive this to be FF
unless i've seen it with my own eyes.