Meeting 2012 02 08

Attending

Brian, Patrick, Alon, Donovan, Dave, Niko, Boris, Brendan

Low-level questions

• Donovan: got networking half-working
• Patrick: priority #1: calling from C to Rust; need to get graphics up and running; needs OS event loops which need to call into Rust
• Donovan: how does libuv even work with SDL?
• Patrick: two event loops
• Donovan: ew?
• Brian: it's good -- separate GUI event loop from I/O
• Alon: that's a problem we have now, so this is better
• Donovan: windowing approach?
• Patrick: native on all platforms
• Donovan: sounds scary
• Patrick: not necessarily; I like the modern Chrome approach; major stuff looks native, and other stuff implemented like nested tabs
• Alon: lot of work
• Patrick: basically talking about menus, address bar, tabs
• Dave: want to build UI with HTML/JS
• Patrick: well, it's canvas
• Dave: yeah, but want to implement front-end stuff in JS, not in Rust
• Donovan: Qt, GTK, ...?
• Patrick: native; only Opera uses a lib (Qt), and it's tough
• Alon: could we keep in thin?
• Boris: platform integration is the stuff we really need; events, opening windows; may be able to lift just that out of Gecko; I'd rather not reinvent that
• Patrick: do we care about plugins? if so we have to go native
• Alon: well, maybe SDL, just to get up and running

Goals

• Dave: time out: I'd like to get a game plan in this meeting
• Patrick: should we set a concrete goal?
• Niko: Wikipedia
• Dave: why don't we shoot for Q3 -- we'll get good progress over the summer with help from interns, and that gives us another quarter to push after that
• Patrick: it's a stretch, but stretches are good
• Niko: BZ, what do you think?
• Boris: that will need a lot of stuff; we may find some distractions in Wikipedia that take a lot of time but aren't interesting
• Dave: that's fine; we can remove them to get a demo standing up
• Donovan: intermediate goals: 1) command-line browser, 2) canvas
• Patrick: canvas is a simple milestone
• Alon: not needed for Wikipedia
• Patrick: but good test for graphics
• Niko: what's a command-line browser?
• Donovan: like lynx
• Dave: sounds like a distraction
• Donovan: I disagree, it's not hard
• Niko: well, maybe if it's truly simple
• Donovan: yeah
• Dave: only if it doesn't take any time to polish something that isn't actually part of the goal
• Alon: series of HTML files building up to Wikipedia?
• Niko: BZ, do you have real-world examples that make for nice orthogonal tests?
• Boris: not off-hand; google.com front page used to be but not anymore; plain text file is a stepping stone
• Dave: we can build tests around what we implement, right? like opcodes in a compiler
• Boris: well, pieces of the platform are not as compositional as opcodes, so you have to think about how they interact more
• Niko: the "spike" approach to compilers: think of one interesting spike from top through bottom of platform, build what you need to make it work, stub out the rest
• Boris: y
• Niko: we can take Wikipedia and start eliminating

Short-term

• Niko: where should we start?
• Donovan: Michael B has his thing that uses SDL, which he used to render Broadway
• Patrick: I would start with window + events
• Donovan: 1) networking, 2) SDL, 3) Azure
• Patrick: those can be worked on simultaneously
• Donovan: networking's mostly done
• Patrick: will need to be redone when libuv stabilizes, but for now that's good
• Donovan: yeah, libuv is still pretty unstable
• Patrick: need shadow DOM
• Boris: layout data structures are separate; there's not a 1:1 mapping between shadow DOM and layout
• Niko: these goals don't include the core problems! i.e., parallel layout
• Boris: there's data flow and execution flow
• Niko: ISTM that BZ is one of the few people in a position to validate such a design
• Boris: I have thoughts on pipeline parallelism, but not as much on dataflow parallelism; don't know enough about Rust yet -- would love to talk with people about that
• Niko: don't think too much what Rust can currently do; think about the hardware and what you need, and we'll see what Rust needs to do to support you
• Donovan: my goal for a month or so is to have the net stuff solid, maybe some Azure stuff
• Patrick: I thought we want SDL for now

Medium-term

• Patrick: big picture:

1. DOM.js + shadow DOM
2. frame tree
3. layers
4. rendering engine in the back

• Patrick: good to get a plan of how those'll be implemented; gonna need frame tree in Rust
• Niko: that's detailed enough for now; I'll work on it with BZ
• Donovan: I'm more interested in low level stuff, happy to let you guys drive the high level parallel algorithms
• Boris: I don't know graphics enough; cjones?
• Patrick: I have more experience with that now after working on Fennec
• Donovan: have folks read the Berkeley paper? (http://www.eecs.berkeley.edu/~lmeyerov/projects/pbrowser/)
• Dave: as we go along, think about what platform elements we could throw out for better perf, or back off to slow paths
• Boris: sure
• Patrick: also do that in the open! don't surprise people with silently breaking compat, but turn it into a conversation
• Dave: and make sure to have an alternative that works better; don't just wantonly remove functionality

JS integration

• Donovan: should discuss Rust-SpiderMonkey bindings
• Brian: put it in Cargo, good stress test for Cargo
• Donovan: I have test.rs, which starts an actor for each command line argument; uses DOM.js parser
• Brendan: do we have WeakMap and Proxy overload?
• Donovan: should ask David
• Boris: with private names we could improve the performance
• Donovan: still need proxies
• Dave: isn't document.all the one thing we can't virtualize?
• Boris: yes, it acts like a falsey object
• Brendan: ah yes, "masquerades" as undefined
• Boris: I have some data on proxies: roughly 1 microsecond hit per property access; but if we control the proxy we can eliminate a lot of extra checks we know aren't needed

Long term

• Brendan: I've been talking about Servo with yearly goals; aim for the future
• Brendan: before summer, want to see what Ras and Leo have done; let's all make sure to read their papers
• Boris: send links to papers?
• Brendan: I'll do that
• Patrick: we should do fish tank demos
• Brendan: yes. need both sizzle and steak
• Boris: I'll be in SF in late March for work week; we can do more whiteboarding then