WebAssembly: Yes, but for What?
queue.acm.org
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Amazon switched the Prime Video app to WebAssembly and doubled its performance. They support 8,000 device types: https://www.amazon.science/blog/how-prime-video-updates-its-...
A recent talk on it with transcript: https://www.infoq.com/presentations/prime-video-rust/
The causual inference here is almost certainly incorrect. According to Chrome Blog [0], WebSQL turned out to be a non-starter as early as November 2010, which is before Webassembly was released, and before it became known that SQLite could be ported to Webassembly to run in web browser.
As a result, with a small team we can make a much prettier and slicker app; and it's easy for everyone to be "full stack" without the learning curve that comes with two languages. It's also nice to share code between the server and browser, for things like contracts and small bits of logic that are easily isolated.
One of the more frustrating aspects of WASM via C# is the slow load time because the binary is large. Another frustrating aspect is that, for tight integration with the DOM, it still is best to use JavaScript. As a result, we end up spending time writing wrappers for "best of class" JavaScript libraries instead of using C# libraries.
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In our case, with hindsight, I think server-side Blazor (with pure JavaScript or TypeScript for logic that needs to happen in the browser,) would be better for our purposes. (It basically moves a lot of the state that would be in the browser to the server. This is really helpful for small teams.) There's reasons why I don't think we'll switch any time soon.
Do you mean server side rendering or interactive server mode?
> adding layers never short times or make life easier
Pick one.
Anyway when people say they don't like abstraction layers what they mean is always they don't like abstraction layers except their favorite ones.
But the biggest problem of the web isn't actually JS or WASM, but the inflexible DOM and the (for the most part) poorly designed web APIs.
That's the entire point of WASM: To program in the browser using any language you want.
IMO, the big flaw is WASM is that browser APIs aren't "first class." IE, all calls to the browser APIs have to go through JavaScript.
In principle I support WASM, but in actuality I think it falls short for the majority of applications. It's much easier to learn JS than the web platform. Might as well learn it in the primary language.
This is why there are also languages like TypeScript, but they wouldn't work in our case because we want to keep the corpus of languages small.
Just because I know JavaScript doesn’t mean I want to use it. It’s an ugly and cumbersome language.
The tech community simply wants DOM access for web apps, but the committee is focused on trying to effectively rewrite the JVM in Rust because Rust seems trendy these days.
So the web features languish while the committee still can't agree on how to send strings between two functions on Linux. And the committee moves at a slower pace than the federal government.
As for that, I for one would ask that the federal government revert to going a bit more slowly.
so ppl can be stuck in immigration queue for even longer ?
As someone who went through the US immigration system I'm not deluded about its flaws. But the current situation is absolutely worse.
Rust isn't 'trendy' it's established itself as a leading language.
It's also not controlled by a single corporate like Google (go) or Sun (java) or Microsoft (C#,F#) or Apple (Swift) so a better place to be.
And it's my go-to for anything that isn't front end/web framework.
It has lots of packages now. And can be extended further as it can call other languages modules such as Python.
Can Rust do what C# does? Yes, unquestionably. But there is a value to a runtime and GC. It makes writing application code a bit easier, more assumptions can be made, and less care needs to be given to memory.
It's suboptimal, but usually doesn't matter. I'd rather write a backend in C#, and the performance is usually more than good enough.
The most notable thing about PS in the browser is web components, not WASM.
I think the real value is for first-party complex UIs. The other folks are using React & Friends.
Accessing browser native classes is still an open issue - in fact, you have to go through JS to do anything, with all the associated performance issues. I don't get it why it's so bad - for every native JS class you find on MDN, there's an equivalent C++ class in the Chrome codebase, which somehow gets bound to the JS JIT. Couldn't we expose all the API through a marshalling/validation layer? Memory leaks are a non-issue, since you can leak native objects in both JS and in C, with the only difference being that in JS, the object is still reachable through a gc root.
Another huge issue is the crappy multithreading support. First, the multithreading solution of JS workers + SharedArrayBuffer is horrible, second you aren't allowed to do it without draconian and impractical security measures, due to the security theather around side channel attacks. Which makes running heavy apps, like modern video games, practically impossible.
I remember Epic demoing Unreal in the browser in the early 2010s and a lot of people predicted that in the future, most games will be playable via a website. Yeah, that didn't come to pass.
Instead of becoming the default way of writing and distributing web apps, with the convenience of web deployment and the power of real desktop apps, it became a curiosity and a way of gaining tech clout.
I worked both with NaCl and PNaCl, and they both had their own share of problems, like:
- any interaction with the browser side had to happen via message passing (e.g. the people who today complain that WASM has no DOM access would have a complete mental breakdown if each interaction with the DOM had to go through message passing instead of direct WASM-to-JS calls).
- NaCl had to invent its own APIs for 3D rendering, audio, and pretty much anything else which required any sort of performance (since the only alternative was the above mentioned slow message passing)
- The 'main thread' was basically just an event loop, to get continuous rendering you had to spawn a separate thread (much like what you need to do on the Android NDK)
- They had their own frigging build system which wasn't compatible with anything else. Good luck getting NaCl/PNaCl integrated with something more common like cmake (it works, but it was basically the same PITA like trying to integrate the Android NDK with a proper build system today).
- PNaCl (which was essentially LLVM bitcode) had an enormous startup time, even slower than the very first WASM experiments which used AOT.
Also, NaCl was quickly deprecated in favour of PNaCl, but PNaCl suffered from much worse problems than WASM ever had (especially in startup time and runtime performance was at best comparable to WASM).
If you want to build something like libpng (or a myriad of other C libraries,) you need setjmp/longjmp. Not really a huge problem: Emscripten can handle this, it just needs a tiny bit of help via host functions. You can also use Wasm Exception Handling instead, in which case you don't need any hacks on the host side.
So far this sounds pretty good, but actually it isn't, because:
- Wasm Exception Handling is still not part of the standard. They are supported by browsers and runtimes based on browsers, but they are unsupported by lots of other runtimes (Wazero doesn't seem to support them, for example.)
- When you're using Emscripten outside of a browser, you can use the Emscripten method for sjlj support even in a "standalone" build, calling into some simple host functions, which is handy. The problem is... standalone builds with Emscripten don't really work that well. A lot of the syscalls don't really go anywhere: https://github.com/emscripten-core/emscripten/blob/main/syst...
A non-standalone build is possible, but even though Emscripten does use WASI for many things automatically, a lot of host support is required to make this work properly, so outside of a browser environment I reckon this will take a lot of work, and it seems also that it will be hard to properly implement those functions in many of the standalone Wasm runtimes.
You can compile with a Clang/WASI toolchain instead, which will implement much more of the syscalls via WASI, but I don't think this supports the Esmcripten method for handling Wasm Exception Handling, which means you need to have a runtime with Wasm Exception Handling support.
I guess the Clang/WASI toolchain is doing the right thing here, but it's still somewhat frustrating that Wasm Exception Handling is still not a part of the standard or many of the non-browser runtimes.
Thankfully it's not a myriad, but pretty much only a handful libraries which had been derived from libjpeg one way or another (and libjpeg - and by extension libpng - is a huge pile of excrement, and not just because of its weird "poor man's exception handling via setjmp/longjmp").
If you want to load image files with minimal effort, use stb_image.h instead.
But also, I already ran into two different very common libraries that need it. FreeType also needs setjmp/longjmp!
...yet! :p
EDIT: I realized this comment might be too terse. I contribute to Chicory and wazero, I have recently worked on tail calls for wazero and EH would be the next item on my personal todo list. Let's see!
It seems to me like a lot of the JS outside the browser stuff out there is motivated by JS people not wanting to learn something different. Meanwhile for those of us who have been doing dev outside the browser, all this is worse solutions to problems we've already got solutions for.
Staring at a gray box waiting for something to happen.
Perhaps a more direct example is Node's/Bun's ability to package a JS/TS project into a single binary with only the JS engine browsers use rather than the whole thing.
[0] https://en.wikipedia.org/wiki/Inferno_(operating_system)
[1] Behind-the-scenes it actually mounts your filesystem onto the remote machine and sends it commands to run, rather than actually "mounting" a CPU over the network. https://9p.io/magic/man2html/1/cpu
[2] https://en.wikipedia.org/wiki/Limbo_(programming_language)While the primary target for WebAssembly is indeed the web there are surely plenty of applications for a cross-platform stack-based virtual machine.
> It seems to me like a lot of the JS outside the browser stuff out there is motivated by JS people not wanting to learn something different.
Well that certainly can't be the case here because WebAssembly specifically isn't JavaScript. It's a well specified, reliable platform for different languages to target for cross-platform execution. Is that really so bad? To turn it on its head, if you're going to build a cross-platform application framework, why not use WebAssembly, aside from the fact that it has "web" in the name?
Sandboxing 3rd party code inside existing applications for example. Like plugins for Photoshop-like applications or game mods. Portability is also a big plus for this kind of thing too.
We need a world where we can seamlessly synchronously (no IPC, no network) call a function from a 3rd party and be sure it doesn't make any network requests, read the disk (or any other type of I/O) or read non-assigned RAM.
If we could do that the amount of scrutiny you need for your 3rd party code goes down massively. WASM is a step to get there.
The solution to insanely deep open source tech stacks is to use simpler stacks. This is really my whole problem with the way JS is ubiquitously developed: you simply do not need 99% of the tools the JS devs are using these days. I use very simple full-stacks: so simple that I don't need a JS package manager (I do use pip/pypy, but I'm extremely guarded about what code I'll import--usually <10 packages). I do write some code that could be imported in a library sometimes, but I also barely ever do any rewriting to deal with deprecations, and my builds never break due to a package change. My builds are often reproduceable by accident.
In the short run, I'm not less productive than people who use all of npm. In the long run, I'm far more productive.
And even if that weren't the case, developer productivity at the expense of user security was a pretty bad tradeoff anyway. I really wish fewer people were doing that.
Wasm lets you take something that is coincidentally pure and run it in a way that ensures that it'll stay that way even for novel inputs, but you're still treating it like a black box... Just a particularly well behaved one.
Sometimes you need that because you're dealing with somebody else's code and they weren't especially interested in providing the kinds of assurances that you'd like to have. So I agree, it is a step in the right direction.
But if you want to author code that gives users such assurances, building to wasm is a rather small step. There only so much that can be done at the bytecode level. Much more can be done at a language level (Unison comes to mind, which goes so far as to eliminate the function's name as a source of works-differently-on-my-machine, though Haskell is probably a more common choice).
I'm not involved in Orca, but I can think of 2 reasons:
1. WebAssembly has really fine-grained sandboxing for untrusted code.
2. WebAssembly has good support for starting the program as parts of it are still being downloaded / compiled.
>...if you are building an organization to create a web experience, generally speaking, you would rather pull from the deeper pool of JS developers than the more rarified C++/Wasm skill set
This is ultimately answering the reason why above, but it's important to point out the most critical parts of Figma and the reason Figma is worth what it is are the WASM/GPU accelerated parts which make all the interaction snappy and fluid, even the multiplayer stuff is downstream from this.
But also because it's a huge company now and a lot of the developers they hire could never create those critical parts of course the rest of it will bloat out as developers justify their existence.
ZetaOffice talk[3] about the challenges porting Libreoffice to run client-side in the browser. With topics like GUI Event Handling, Debugging or Multi-Threading, File- System & Size to topics such as CI/CD and dependency handling and upstream.
[1] https://github.com/allotropia/zetajs / https://zetaoffice.net/
[2] https://www.opendesk.eu/en
[3] https://media.ccc.de/v/clt23-249-libreoffice-technology-and-...
I'm trying to use that through Rust on ESP32 with "wamr" but so far I've had quite a few compilation and runtime issues
if someone has some experience with that I'm interested :)
Talking some of the technics of integrating with the web, and how component model might someday be a facility to make that reasonable, but how the browser folks are waiting to see how it goes server-side first, & might not be interested at all.
I don't really understand what limitations using reference types brings, how much glue code is left. I should try & compare some different language's toolchains, see what glue code each relies on!
https://queue.acm.org/detail.cfm?id=3746174
Regarding the submission here... Nothing but respect for Andy here. And yes finding fit is always so critical. But I do think we are on the cusp on much more, and I especially think the actual web, the front end, would/will be getting millions of miles more out of WebAssembly when async wasm components arrive.
> To answer these questions, we adopt an aesthetically unsatisfying device: the market. Which Wasm deployments have stuck around? Where are people happily using Wasm? Which deployments failed? These are all real indicators by people with skin in the game.
Right now it there are countless constraints on who can use wasm and how. To look at who has been trying today, who has had success today, it kind of ignores that wasm has become an increasingly niche harder to use server side only system. As the number of specs grows less and less runtimes are competitive. Shooting for the moon, but maybe, if async wasm components (wasi preview 3) ship and are good, it could radically expand the ball game.
We use WASM in some cases:
* Our Typescript SDK uses wasm-bindgen to compile and release the Rust part of the code. We have chosen WASM over Node native extensions because we wanted to support deno, cloudflare workers, bun, and potentially other runtimes. We've stumbled on few issues related to packaging, but except that it was a smooth process.
* Our Golang SDK uses WaZero + manual bindings using protobuf's. It was a bit of a manual process to set it up, especially surrounding concurrency issues wrt accessing the WaZero runtime plus you need some wasm runtime pooling to get decent performance, but at the end it works well and reliably.
My lesson learned from our experience is that Rust is the real player here, because it delivers on the promise that you can develop libraries that can be easily embedded in high level languages. It's really "write once, bind everywhere".
WASM is just a "packaging"/"distribution" detail in our case, and we picked it just for lack of alternatives. For example in our Python SDK, we could have used WASM but we didn't, instead we went with PyO3 which is an amazingly well done Python -> native code bindgen, and it works without hassle for users as opposed to, for example, CGO in Golang. If Golang had a PyO3-like solution without CGO/any hassle for users, I would have taken it as opposed to doing the WASM bindings myself.
Plus, from what I've tried myself, the whole WASM experience is great only when used in combination with TS/wasm-bindgen, in the other scenarios it's a lot of manual tedious memory moving code involved. Maybe when WIT gets more broadly adopted, and there will be bindgens available in most languages/engines, this will be different.
If you wanna check out the projects and see how it works: https://github.com/restatedev/sdk-shared-core/, https://github.com/restatedev/sdk-go/ and https://github.com/restatedev/sdk-typescript/
Some of what you gain is pretty important though. For example, well written native apps integrate better with the platform’s accessibility features and they typically consume less power, storage, and memory.
Well written web apps can be very accessible too and some companies do actually go out of their way to ensure this.
I’m not disagreeing with you, merely providing more context. Companies like Reddit and Facebook definitely push you more to the apps so they can extract more value out of you.
Either way I don’t see how that’s relevant to the point. It’s not like the web is any different in that regard.
That's not always possible. There might not be enough quality competition and I don't see others following my example to beat the shitty company into submission and make them change their ways if I do that.
> Either way I don’t see how that’s relevant to the point. It’s not like the web is any different in that regard.
Web is very different in that regard. You can pry any app open and change basically anything with a single press of F12. Most of the time, people already did that for you and submitted an ad blocking filter for everyone to use. This isn't even close to the crapware of a typical app store.
Web is the last democratic platform we have left.
As an example: an absolutely vital tool for me is the Vimium keyboard control extension for navigation, which unfortunately can't be used in dedicated apps.
(Other than Google apps, that is.)
One talk seems to claim they have a tool that auto converts docker containers to wasm for huge efficiency gains
Another proposed faster OSes based on wasm’s safety promises
Ps: not claiming either of these will work just interest to consider
Where can one look at that breakdown?
That led me to wasmCloud[1]. As the article says, Wasm on the server isn't a winner yet, but it has a chance.
Also, scaling across clouds, edge, on-prem with minimal effort.
Another benefit I enjoy now is changing links between components at runtime. I can for example deploy v2.0.0 of a component and send traffic to it by simply updating a link - and reverse it should things break.
All that comes at a much lighter cost in terms of actual $, but also size (kilobytes/megabytes vs megabytes/gigabytes with Docker containers)
This is more about monetization and less about technology, and nobody has figured out how to monetize web games beyond hyper-casual 2D games. And you don't need WASM to move a handful 2D sprites around.
Personally I'm quite happy what WASM allows me to do, e.g. the browser has become "just another runtime target" for my C/C++ hobby projects:
- https://floooh.github.io/sokol-html5/
- https://floooh.github.io/tiny8bit/
- https://floooh.github.io/doom-sokol/
...also the actual problem to run game-y stuff in browsers is not WASM, but the terrible state of web APIs, WebGL and WebGPU are both quite okay-ish, but beyond that it's an absolute mess (but OTH, people also cope with game development for Android, which is even worse).
Nailed it. We have JS in the browser, and (particularly with TS) it's a great language for building applications on the web. What's great about WASM is the interop layer we have now between other systems. Our company has a mountain of legacy C++, encoding many years of hard-won business logic, and the ability to tap into that on the frontend (locally, in-client) has been amazing. No more hacky transpilation or maintaining separate codebases; just write your FFI and compile the binary to WASM.
This is .. debateable. A large part of the push for WASM is people who believe that other languages should be allowed to exist in the browser.
1. WASM on the Web: Just don't do it. It's not there yet. WASM actually has overhead compared to regular JavaScript, so it only makes sense for specific operations like video transformations. Otherwise, you're better off with a React stack. React isn't inherently slow—it just makes it easy to write slow code. Plus, most WASM frameworks (like Yew) are still immature with limited ecosystem support.
2. "Lightweight virtualization" sounds great in theory, but reality is different. The promise is "compile once, deploy everywhere," but if you can deploy everywhere, you probably can't deploy anywhere effectively. That's because once you remove networking, time and multi-threading, you are left with pretty much nothing. There is also a no consensus standard. There is WASI but it's a kind of a work-in-progress. Implementation will depend on your host.
I went with Cloudflare Workers, which meant learning their specific environment. The problem with these newer platforms is they don't have the documentation or community support you get with something like Linux. While Cloudflare runs workers on V8 at the edge (which helps), they have restrictions that you only discover as you go. For example, there's no "time" concept available inside a Cloudflare Worker's execution context.
3. Target support is genuinely terrible. Don't assume libraries will compile to wasm32-unknown-unknown—assume the opposite. Most libraries don't separate computational tasks from networking, and Rust's async ecosystem (Tokio) does not play well with WASM, breaking your code. I've had to fork two libraries and submit patches to several others. As a solo developer, this maintenance burden becomes expensive. Making libraries WASM-compatible could be a full-time job.
4. On Scalability: Just because you have a worker, doesn't translate to having "infinite" scalability. Here's the thing - as soon as your application does anything meaningful, you need state. Now your "infinitely scalable" architecture is only as scalable as your state (ie: RDS database) can handle. There isn't really a good server-less database offering and Databases are not the only thing that will bottleneck you here (ie: I have a keycloak server for signups).
> The aim is to build systems with the fine-grained interoperation of shared libraries, specified in a way to allow isolation but without requiring the overhead of an operating system process or a container.
Add time and networking to this mix, and you've basically described an operating system.
> For plug-in and extension use cases, Wasm can be a good option if the host needs isolation from the guest
This is actually WASM's sweet spot. These extensions run in the host environment (like Shopify), and WASM provides JavaScript-like capabilities with language choice and better isolation.
> The cloud Wasm space is a bit of a Wild West
It absolutely is—still in its infancy with little interest from major players to adopt this model.
In conclusion, I'm still torn on the whole thing. Some mornings I wake up to a broken build and wonder what the hell I was thinking. But then there are moments when everything clicks. My worker—27k lines that squeeze down to 3MB—feeling like a jet engine.
The constraints make you want to tear your hair out; but they make you think twice about everything. You can't just throw another dependency at a problem. You need to consider and weigh in any additional code. The worker model makes the request flow clearer and gives you a better understanding of your application life-cycle.
shamless plug (ps: it's nowhere near ready): https://codeinput.com
That's really not what I'm seeing, my WASM home computer emulators (written in plain C) run at about the same performance as their native counterparts (give or take 15%). Just don't switch between the JS and WASM side too often, and use WebGL or WebGPU for rendering (with proper batching).
...of course if you want to have a DOM-based UI framework in WASM, don't do that, but who would come up with such a stupid idea in the first place ;)
Games often need to do at least some DOM work though, like rendering a login dialog or integrating a 3rd party in-app-payment solution (or the obvious one: displaying ads). For this I would also do most work on the JS side.
With Emscripten, such mixed JS/WASM apps are really not that hard, you can even embed JS code snippets right into the C/C++ code.
Um, yes it does? Sure, you have to set some single-source or whatever flag in some header, but it works just fine - I've tested it myself.