5 ms·

Firefox OS: Tracking reflows and event loop lags

82 points by bpierre 13y ago

stusmall 13y ago
I haven't followed Firefox OS so this was a surprise to me. I noticed their use of adb and logcat. From a platform perspective, how much is in common between Firefox OS and android?
- mbrubeck 13y ago
  Firefox OS uses sources based on Android repos for the HAL, the bionic libc, some of the development tools (like "repo" and "adb"), and some other low-level libraries. Firefox OS doesn't use the Dalvik Java VM or anything built on top of it. https://developer.mozilla.org/en-US/Firefox_OS/Platform/Gonk https://developer.mozilla.org/en-US/Firefox_OS/Platform/Gonk
  - stusmall 13y ago
    Oh, wow. They are quite a bit different then. Thanks for the info!
techwizrd 13y ago
I found the video of how browser's compute the layout of page and reflow elements accordingly really cool. Is there a setting I can flip to view this in action on websites I am working on? I think it would be useful in debugging page rendering performance.
- jlongster 13y ago
  I think you're looking for "paintflashing". Open the Developer Toolbar (shift+f2) and type "paintflashing on".
bob_loblaw 13y ago
He says this is for FFOS 1.4+. When will this make its way to the public? Mozilla Hacks has some directions on how to get 1.2 on your ZTE Open [1], but I've seen nothing about 1.3 let alone 1.4. [1] https://hacks.mozilla.org/2014/01/upgrading-your-zte-open-to-firefox-1-1-or-1-2-fastboot-enabled/ https://hacks.mozilla.org/2014/01/upgrading-your-zte-open-to...
- reidrac 13y ago
  I got 1.2 in my ZTE Open and, although there's an improvement, I wouldn't bother. Go for 1.3 release candidate (at least! 1.4 got feature complete some days ago, but it might be a little bit on the edge).
- mbrubeck 13y ago
  Geeksphone provides nightly (1.4pre) builds for their B2G devices. Mozilla announced plans to sell a reference phone that will also have nightly builds available, though it's not on sale yet.
- zz1 13y ago
  "Now that we have our v1.0 behind us and we’re moving forward with even more partners, we’re going to do our best to bring Firefox OS back into our heartbeat and will make quarterly feature releases available to partners along with six-weekly security updates for the previous two feature releases. As far as I know, that’s the most aggressive mobile OS release strategy out there (and may still require some tweaking)." https://blog.mozilla.org/futurereleases/2013/07/19/mozillas-heartbeat-quarterly-firefox-os-releases/ https://blog.mozilla.org/futurereleases/2013/07/19/mozillas-... You have nonetheless to consider that is the manufacturer who holds responsability for the avalaible images. Firefox OS 1.1 was delivered by Mozilla on October 9th 2013. https://blog.mozilla.org/futurereleases/2013/10/09/firefox-os-update-1-1-adds-new-features-performance-improvements-and-additional-language-support/ https://blog.mozilla.org/futurereleases/2013/10/09/firefox-o...
frik 13y ago
Firefox OS will also support scrolling in a different thread (async pan and zoom), which will make scrolling possible even if the event loop is blocked. That's a great news!
piyush_soni 13y ago
That makes me wonder, how much code do Firefox OS and Firefox Browser have in common? Was just thinking if some of the advances of the mobile OS world could benefit the browser as well :).
- fzzzy 13y ago
  They share the same renderer codebase, Gecko. You are correct that advances for the OS benefit the browser, and vice versa.
  - kbrosnan 13y ago
    The async pan zoom controller (APZ/APZC) is only used on Firefox OS and the former Firefox for Metro. The graphics team wrote something similar for Firefox for Android (JPZC). At some point the plan is to use the APZ in other products. https://wiki.mozilla.org/Platform/GFX/APZ https://wiki.mozilla.org/Platform/GFX/APZ
    - fzzzy 13y ago
      Yes, some specifics about the architecture, such as APZ and multiprocess architecture, are currently Firefox OS only, but this is because of backwards compatibility limitations with Firefox Desktop. Hopefully some day the desktop browser can benefit from these as well.
pekk 13y ago
We could have used (and contributed momentum to!) already existing, open source Linux-based components wrapped up in an existing mobile OS which has already been deployed and shown working on several nice devices and is extremely capable, allowing you to do essentially whatever you can do on a computer (Maemo/Meego/Tizen/Sailfish family). In basically whatever language you want. Because, it IS a computer using a real computer OS which, for those who want it, allows all the control that a Linux computer allows to the user, not just a crummy sandbox. And also there would not be such fundamental performance issues to iron out for several years before the platform became remotely suitable for human consumption. And we wouldn't be pointlessly fighting a two-front battle, not only against iOS and Android etc., but also against every other concurrent attempt to bring a real, uncrippled open source, stack to mobile phones. But... nah... we have plenty of time... let's build an entire NEW, NIH-based operating system! And make sure that every function absolutely must be performed inside a web browser, and depends on Javascript, but with lots of ad hoc new APIs that are not otherwise applicable. Then we can work furiously to make it perform. And everyone who wants to touch our platform is required to deal with the incredible annoying pain of current Javascript web app development every time they want to write anything at all, forever. Welcome to the future, now you must rewrite every capability in Javascript (one of the worst languages everyone has to use) even when there are already high-quality implementations in other languages. We don't want those here. Because we don't just think Javascript is handy due to browsers already supporting it, as a matter of historical accident. We could have used literally anything. We actually sat down and decided there wasn't one single better language than Javascript to write a mobile OS in, and to require everyone to use to access our platform. Not even languages which have been used forever to make OSes, and mobile OSes. Not even a system which would allow choice of languages. Only Javascript. Only our new app API that we just came up with. But give us a few years to implement acceptable FPS as a "feature" on our phone operating system targeted at weak hardware.
- ZeroGravitas 13y ago
  I thought the Maemo/Meego/Tizen/Sailfish family had all shifted towards HTML5 for apps?

82 points by bpierre 13y ago

I haven't followed Firefox OS so this was a surprise to me. I noticed their use of adb and logcat. From a platform perspective, how much is in common between Firefox OS and android?

mbrubeck 13y ago
Firefox OS uses sources based on Android repos for the HAL, the bionic libc, some of the development tools (like "repo" and "adb"), and some other low-level libraries. Firefox OS doesn't use the Dalvik Java VM or anything built on top of it. https://developer.mozilla.org/en-US/Firefox_OS/Platform/Gonk https://developer.mozilla.org/en-US/Firefox_OS/Platform/Gonk
- stusmall 13y ago
  Oh, wow. They are quite a bit different then. Thanks for the info!

techwizrd 13y ago

I found the video of how browser's compute the layout of page and reflow elements accordingly really cool. Is there a setting I can flip to view this in action on websites I am working on? I think it would be useful in debugging page rendering performance.

jlongster 13y ago
I think you're looking for "paintflashing". Open the Developer Toolbar (shift+f2) and type "paintflashing on".

bob_loblaw 13y ago

He says this is for FFOS 1.4+. When will this make its way to the public? Mozilla Hacks has some directions on how to get 1.2 on your ZTE Open [1], but I've seen nothing about 1.3 let alone 1.4. [1] https://hacks.mozilla.org/2014/01/upgrading-your-zte-open-to-firefox-1-1-or-1-2-fastboot-enabled/ https://hacks.mozilla.org/2014/01/upgrading-your-zte-open-to...

reidrac 13y ago
I got 1.2 in my ZTE Open and, although there's an improvement, I wouldn't bother. Go for 1.3 release candidate (at least! 1.4 got feature complete some days ago, but it might be a little bit on the edge).
mbrubeck 13y ago
Geeksphone provides nightly (1.4pre) builds for their B2G devices. Mozilla announced plans to sell a reference phone that will also have nightly builds available, though it's not on sale yet.
zz1 13y ago
"Now that we have our v1.0 behind us and we’re moving forward with even more partners, we’re going to do our best to bring Firefox OS back into our heartbeat and will make quarterly feature releases available to partners along with six-weekly security updates for the previous two feature releases. As far as I know, that’s the most aggressive mobile OS release strategy out there (and may still require some tweaking)." https://blog.mozilla.org/futurereleases/2013/07/19/mozillas-heartbeat-quarterly-firefox-os-releases/ https://blog.mozilla.org/futurereleases/2013/07/19/mozillas-... You have nonetheless to consider that is the manufacturer who holds responsability for the avalaible images. Firefox OS 1.1 was delivered by Mozilla on October 9th 2013. https://blog.mozilla.org/futurereleases/2013/10/09/firefox-os-update-1-1-adds-new-features-performance-improvements-and-additional-language-support/ https://blog.mozilla.org/futurereleases/2013/10/09/firefox-o...

frik 13y ago

Firefox OS will also support scrolling in a different thread (async pan and zoom), which will make scrolling possible even if the event loop is blocked. That's a great news!

piyush_soni 13y ago

That makes me wonder, how much code do Firefox OS and Firefox Browser have in common? Was just thinking if some of the advances of the mobile OS world could benefit the browser as well :).

fzzzy 13y ago
They share the same renderer codebase, Gecko. You are correct that advances for the OS benefit the browser, and vice versa.
- kbrosnan 13y ago
  The async pan zoom controller (APZ/APZC) is only used on Firefox OS and the former Firefox for Metro. The graphics team wrote something similar for Firefox for Android (JPZC). At some point the plan is to use the APZ in other products. https://wiki.mozilla.org/Platform/GFX/APZ https://wiki.mozilla.org/Platform/GFX/APZ
  - fzzzy 13y ago
    Yes, some specifics about the architecture, such as APZ and multiprocess architecture, are currently Firefox OS only, but this is because of backwards compatibility limitations with Firefox Desktop. Hopefully some day the desktop browser can benefit from these as well.

pekk 13y ago

We could have used (and contributed momentum to!) already existing, open source Linux-based components wrapped up in an existing mobile OS which has already been deployed and shown working on several nice devices and is extremely capable, allowing you to do essentially whatever you can do on a computer (Maemo/Meego/Tizen/Sailfish family). In basically whatever language you want. Because, it IS a computer using a real computer OS which, for those who want it, allows all the control that a Linux computer allows to the user, not just a crummy sandbox. And also there would not be such fundamental performance issues to iron out for several years before the platform became remotely suitable for human consumption. And we wouldn't be pointlessly fighting a two-front battle, not only against iOS and Android etc., but also against every other concurrent attempt to bring a real, uncrippled open source, stack to mobile phones. But... nah... we have plenty of time... let's build an entire NEW, NIH-based operating system! And make sure that every function absolutely must be performed inside a web browser, and depends on Javascript, but with lots of ad hoc new APIs that are not otherwise applicable. Then we can work furiously to make it perform. And everyone who wants to touch our platform is required to deal with the incredible annoying pain of current Javascript web app development every time they want to write anything at all, forever. Welcome to the future, now you must rewrite every capability in Javascript (one of the worst languages everyone has to use) even when there are already high-quality implementations in other languages. We don't want those here. Because we don't just think Javascript is handy due to browsers already supporting it, as a matter of historical accident. We could have used literally anything. We actually sat down and decided there wasn't one single better language than Javascript to write a mobile OS in, and to require everyone to use to access our platform. Not even languages which have been used forever to make OSes, and mobile OSes. Not even a system which would allow choice of languages. Only Javascript. Only our new app API that we just came up with. But give us a few years to implement acceptable FPS as a "feature" on our phone operating system targeted at weak hardware.

ZeroGravitas 13y ago
I thought the Maemo/Meego/Tizen/Sailfish family had all shifted towards HTML5 for apps?