Wednesday, August 29, 2018
Hello 38 beta its nice to meet you
Hello 38 beta its nice to meet you
And at long last the 38 beta is very happy to meet you too (release notes, downloads, hashes). Over the next few weeks I hope you and the new TenFourFox 38 will become very fond of each other, and if you dont, then phbbbbt.
There are many internal improvements to 38. The biggest one specific to us, of course, is the new IonPower JavaScript JIT backend. Ive invested literally months in making TenFourFoxs JavaScript the fastest available for any PowerPC-based computer on any platform, not just because every day websites lard up on more and more crap we have to swim through (viva Gopherspace) but also because a substantial part of the browser is written in JavaScript: the chrome, much of the mid-level plumbing and just about all those addons you love to download and stuff on in there. You speed up JavaScript, you speed up all those things. So now weve sped up many browser operations by about 11 times over 31.x -- obviously the speed of JavaScript is not the only determinant of browser speed, but its a big part of it, and I think youll agree that responsiveness is much improved.
JavaScript also benefits in 38 from a compacting, generational garbage collector (generational garbage collection was supposed to make 31 but was turned off at the last minute). This means recently spawned objects will typically be helplessly slaughtered in their tender youth in a spasm of murderous efficiency based on the empiric observation that many objects are created for brief usage and then never used again, reducing the work that the next-stage incremental garbage collector (which we spent a substantial amount of time tuning in 31 as youll recall, including backing out background finalization and tweaking the timeslice for our slower systems) has to do for objects that survive this pediatric genocide. The garbage collector in 38 goes one step further and compacts the heap as well, which is to say, it moves surviving objects together contiguously in memory instead of leaving gaps that cannot be effectively filled. This makes both object cleanup and creation much quicker in JavaScript, which relies heavily on the garbage collector (the rest of the browser uses more simplistic reference counting to determine object lifetime), to say nothing of a substantial savings in memory usage: on my Quad G5 Im seeing about 200MB less overhead with 48 tabs open.
I also spent some time working on font enumeration performance because of an early showstopper where sites that loaded WOFF fonts spun and spun and spun. After several days of tearing my hair out in clumps the problem turned out to be a glitch in reference counting caused by the unusual way we load platform fonts: since Firefox went 10.6+ it uses CoreText exclusively, but we use almost completely different font code based on the old Apple Type Services which is the only workable choice on 10.4 and the most stable choice on 10.5. ATS is not very fast at instantiating lots of fonts, to say the least, so I made the user font cache stickier (please dont read that as "leaky" -- its sticky because things do get cleaned up, but less aggressively to improve cache hit percentage) and also made a global font cache where the fonts attribute tag directory is cached browser-wide to speed up loading font tables from local fonts on your hard disk. Previously this directory was cached per font entry, meaning if the font entry was purged for re-enumeration it had to be loaded all over again, which usually happened when the browser was hunting for a font with a particular character. This process used to take about fifteen to twenty seconds for the 700+ font faces on my G5. With the global font cache it now takes less than two.
Speaking of showstoppers, heres an interesting one which Ill note here for posterity. nsChildView, the underlying system view which connects Cocoa/Carbon to Gecko, implements the NSTextInput protocol which allows it to accept Unicode input without (as much) mucking about with the Carbon Text Services Manager (Firefox also implements NSTextInputClient, which is the new superset protocol, but this doesnt exist in 10.4). To accept Unicode input, under the hood the operating system actually manipulates a special undocumented TSM input context called, surprisingly, NSTSMInputContext (both this and the undocumented NSInputContext became the documented NSTextInputContext in 10.6), and it gets this object from a previously undocumented method on NSView called (surprise again) inputContext. Well, turns out if you override this method you can potentially cause all sorts of problems, and Mozilla had done just that to handle complex text input for plugins. Under the 10.4 SDK, however, their code ended up returning a null input context and Unicode input didnt work, so since we dont support plugins anyhow the solution was just to remove it completely ... which took several days more to figure out. The moral of the story is, if you have an NSView that is not responding to setMarkedText or other text input protocol methods, make sure you havent overridden inputContext or screwed it up somehow.
I also did some trivial tuning to the libffi glue library to improve the speed of its calls and force it to obey our compiler settings (there was a moment of panic when the 7450 build did not start on the test machines because dyld said XUL was a 970 binary -- libffi had seen it was being built on a G5 and "helpfully" compiled it for that target), backed out some portions of browser chrome that were converted to CoreUI (not supported on 10.4), and patched out the new tab tile page entirely; all new tabs are now blank, like they used to be in previous versions of Firefox and as intended by God Himself. There are also the usual cross-platform HTML5 and CSS improvements you get when we leap from ESR to ESR like this, and graphics are now composited off-main-thread to improve display performance on multiprocessor systems.
That concludes most of the back office stuff. What about user facing improvements? Well, besides the new blank tabs "feature," we have built-in PDF viewing as promised (I think youll find this more useful to preview documents and load them into a quicker viewer to actually read them, but its still very convenient) and Reader View as the biggest changes. Reader View, when the browser believes it can attempt it, appears in the address bar as a little book icon. Click on it and the page will render in a simplified view like you would get from a tool such as Readability, cutting out much of the extraneous formatting. This is a real godsend on slower computers, lemme tell ya! Click the icon again to go back. Certain pages dont work with this, but many will. I have also dragged forward my MP3 decoder support, but see below first, and we have prospectively landed Mozilla bug 1151345 to fix an issue with the application menu (modified for the 10.4 SDK).
You will also note the new, in-content preferences (i.e., preferences appears in a browser tab now instead of a window, a la, natch, Chrome), and that the default search engine is now Yahoo!. I have not made this default to anything else since we can still do our part this way to support MoCo (but you can change it from the preferences, of course).
I am not aware of any remaining showstopper bugs, so therefore Im going ahead with the beta. However, there are some known issues ("bugs" or "features" mayhaps?) which are not critical. None of these will hold up final release currently, but for your information, here they are:
- If you turn on the title bar, private browsing windows have the traffic light buttons in the wrong position. They work; they just look weird. This is somewhat different than issue 247 and probably has a separate, though possibly related, underlying cause. Since this is purely cosmetic and does not occur in the browsers default configuration, we can ship with this bug present but Ill still try to fix it since its fugly (plus, I personally usually have the title bar on).
- MP3 support is still not enabled by default because seeking within a track (except to the beginning) does not work yet. This is the last thing to do to get this support off the ground. If you want to play with it in its current state, however, set tenfourfox.mp3.enabled to true (you will need to create this pref). If I dont get this done by 38.0.2, the pref will stay off until I do, but the rest of it is working already and I have a good idea how to get this last piece functional.
- Im not sure whether to call this a bug or a feature, but scaling now uses a quick and dirty algorithm for many images and some non-.ico favicons apparently because we dont have Skia support. Its definitely lower quality, but it has a lot less latency. Images displayed by themselves still use the high-quality built-in scaler which is not really amenable to the other uses that I can tell. Your call on which is better, though Im not sure I know how to go back the old method or if its even possible anymore.
- To reduce memory pressure, 31 had closed tab and window undos substantially reduced. I have not done that yet for 38 -- near as I can determine, the more efficient memory management means it is no longer worth it, so were back to the default 10 and 3. See what you think.
Localizers: strings are frozen, so start your language pack engines one more time in issue 42. Wed like to get the same language set for 38 that we had for 31, and your help makes it possible. Thank you!
As I mentioned before, its probably 70-30 against there being a source parity version after 38ESR because of the looming threat of Electrolysis, which will not work as-is on 10.4 and is not likely to perform well or even correctly on our older systems. (If Firefox 45, the next scheduled ESR, still allows single process operation then theres a better chance. We still need to get a new toolchain up and a few other things, though, so it wont be a trivial undertaking.) But Im pleased with 38 so far and if we must go it means we go out on a high note, and nothing says we cant keep improving the browser ourselves separate from Mozilla after we split apart (feature parity). Remember, thats exactly what Classilla does, except that were much more advanced than Classilla will ever be, and in fact Pale Moon recently announced theyre doing the same thing. So if 38 turns out to be our swan song as a full-blooded Mozilla tier 3 port, that doesnt mean its the end of TenFourFox as a browser. I promise! Meanwhile, lets celebrate another year of updates! PowerPC forever!
Finally, looking around the Power Mac enthusiast world, it appears that SeaMonkeyPPC has breathed its last -- there have been no updates in over a year. We will pour one out for them. On the other hand, Leopard Webkit continues with regular updates from Tobias, and our friendly builder in the land of the Rising Sun has been keeping up with Tenfourbird. We have the utmost confidence that there will be a Tenfourbird 38 in your hands soon as well.
Some new toys to play with are next up in a couple days.
