Eliminating Data Races in Firefox – A Technical Report
We successfully deployed ThreadSanitizer in the Firefox project to eliminate data races in our remaining C/C++ components. In the process, we found several impactful bugs and can safely say that data races are often underestimated in terms of their impact on program correctness. We recommend that all multithreaded C/C++ projects adopt the ThreadSanitizer tool to enhance code quality.
Porting Firefox to Apple Silicon
Even with all the pieces in place, quite a bit of work to do.
The release of Apple Silicon-based Macs at the end of last year generated a flurry of news coverage and some surprises at the machine’s performance. This post details some background information on the experience of porting Firefox to run natively on these CPUs.
We’ll start with some background on the Mac transition and give an overview of Firefox internals that needed to know about the new architecture, before moving on to the concept of Universal Binaries.
We’ll then explain how DRM/EME works on the new platform, talk about our experience with macOS Big Sur, and discuss various updater problems we had to deal with. We’ll conclude with the release and an overview of various other improvements that are in the pipeline.
The Bytecode Alliance: Building a secure, composable future for WebAssembly
We have a vision of a WebAssembly ecosystem that is secure by default, fixing cracks in today’s software foundations. And based on advances rapidly emerging in the WebAssembly community, we believe we can make this vision real.
WebAssembly can provide the kind of isolation that makes it safe to run untrusted code. We can have an architecture that’s like Unix’s many small processes, or like containers and microservices. But this isolation is much lighter weight, and the communication between them isn’t much slower than a regular function call. This means you can use them to wrap a single WebAssembly module instance, or a small collection of module instances that want to share things like memory among themselves.
The Baseline Interpreter: a faster JS interpreter in Firefox 70
The Baseline Interpreter sits between the C++ interpreter and the Baseline JIT and has elements from both. It executes all bytecode instructions with a fixed interpreter loop (like the C++ interpreter). In addition, it uses Inline Caches to improve performance and collect type information (like the Baseline JIT).
Technical Details on the Recent Firefox Add-on Outage
Recently, Firefox had an incident in which most add-ons stopped working. This was due to an error on our end: we let one of the certificates used to sign add-ons expire which had the effect of disabling the vast majority of add-ons. Now that we’ve fixed the problem for most users and most people’s add-ons are restored, I wanted to walk through the details of what happened, why, and how we repaired it.
Standardizing WASI: A system interface to run WebAssembly outside the web
WebAssembly is an assembly language for a conceptual machine, not a physical one. This is why it can be run across a variety of different machine architectures.
Just as WebAssembly is an assembly language for a conceptual machine, WebAssembly needs a system interface for a conceptual operating system, not any single operating system. This way, it can be run across all different OSs.
This is what WASI is — a system interface for the WebAssembly platform.
Implications of Rewriting a Browser Component in Rust
The style component is the part of a browser that applies CSS rules to a page. This is a top-down process on the DOM tree: given the parent style, the styles of children can be calculated independently—a perfect use-case for parallel computation. By 2017, Mozilla had made two previous attempts to parallelize the style system using C++. Both had failed.
Entering the Quantum Era—How Firefox got fast again and where it’s going to get faster
Over the past seven months, we’ve been rapidly replacing major parts of the engine, introducing Rust and parts of Servo to Firefox. Plus, we’ve had a browser performance strike force scouring the codebase for performance issues, both obvious and non-obvious. We call this Project Quantum, and the first general release of the reborn Firefox Quantum comes out tomorrow.
The whole web at maximum FPS: How WebRender gets rid of jank
With WebRender, we want apps to run at a silky smooth 60 frames per second (FPS) or better no matter how big the display is or how much of the page is changing from frame to frame. And it works. Pages that chug along at 15 FPS in Chrome or today’s Firefox run at 60 FPS with WebRender. So how does WebRender do that? It fundamentally changes the way the rendering engine works to make it more like a 3D game engine.
Inside a super fast CSS engine: Quantum CSS (aka Stylo)
This new engine brings together state-of-the-art innovations from four different browsers to create a new super CSS engine.
Firefox 54: E10S-Multi, WebExtension APIs, CSS clip-path
New stuff in new firefox.
A cartoon intro to WebAssembly
WebAssembly is fast. You’ve probably heard this. But what is it that makes WebAssembly fast? In this series, I want to explain to you why WebAssembly is fast.
Firebug lives on in Firefox DevTools
Firebug is dead. Long live Firebug.