gc VS wasmtime

It may take some time for WasmGC to be usable by .NET. Based on the discussions the first version of WasmGC does not have a good way to handle a few .NET specific scenarios, and said scenarios are "post-post-mvp". [0]

My concern, of course, is that there is not much incentive for those features to be added if .NET is the only platform that needs them... at that point having a form of 'include' (to where a specific GC version can just be cached and loaded by another WASM assembly) would be more useful, despite the pain it would create.

[0] - https://github.com/WebAssembly/gc/issues/77

Yes, that's definitely true: a single GC will not be optimal for everything, or even possible. Atm interior pointers are not supported at all, for example, but they are on the roadmap for later:

https://github.com/WebAssembly/gc/blob/main/proposals/gc/Pos...

What launched now is enough WasmGC to support a big and useful set of languages (Java, Kotlin, Dart, OCaml, Scheme), but a lot more work will be required here!

GC proposal is from 2018: https://github.com/WebAssembly/proposals/issues/16 and there’s code: https://github.com/WebAssembly/gc/blob/master/proposals/gc/O...

Seems like an awefully long time for progress to be made, given all the possibilities it would unlock.

First is the size. Writing a server-side and client-side program is possible with Rust, and the resulting WASM package will be small enough. At the same time, Microsoft Blazor converts C# code to WASM, but the client delivery has to include the reduced .NET runtime, taking several megabytes for a script. The same is true for GoLang, even with an attempt to reduce the runtime delivery in TinyGo WASM. Developers want to work with their favorite languages, whether it is Java, Kotlin, Dart, C#, F#, Swift, Ruby, Python, C, C++, GoLang, or Rust. These languages produce groups of runtimes. For example, JVM and .NET have many common parts, Ruby and Python are dynamically interpreted at runtime, and all mentioned depend on automatic garbage collection. For smaller WASM packages, browser vendors can include extended runtime implementations, for example, by delivering a general garbage collector as part of WASM. Garbage collection support by WASM is currently in progress: WASM GC, .NET WASM Notes.

My understanding is that the main limitation is technical. WASM doens't do GC or the host system calling conventions and cannot interact directly with object from Javascript because of this. However, this is being worked[0] on and will be solved eventually. Even without this the performance overhead of bridging to JS is low enough that WASM frameworks can beat out React.

0: https://github.com/WebAssembly/gc/blob/main/proposals/gc/Ove...

I’ve just watched a video on YouTube from Google I/O 2023 on Flutter for the web. Kevin Moore explains that Flutter can compile to Wasm, but now that GC support has been added to the standard and WasmGC is supported in Chromium and Firefox, I’m quite intrigued.

I have found the main thread about using WebAssembly GC in C#: https://github.com/WebAssembly/gc/issues/77. If I understand it correctly, it is not possible to use the current prototype version of GC in C#.

The .net team has given their notes on it, the concern is more on the memory layout from what I remember. Though it may be possible still. The runtime would likely still ship some gc code, but only a subset for cases not supported by the wasm gc itself and a few more for interfacing with the gc service, which overall should still result on smaller payloads compared to current sizes.

I assume that's one of the parts of the work done at https://github.com/WebAssembly/gc - not happening any soon yet, but it'll eventually be done.

Just a documentation change, fortunately:

https://github.com/bytecodealliance/wasmtime/commits?author=...

They've submitted little documentation tweaks to other projects, too, for example:

https://learn.microsoft.com/en-us/cpp/overview/whats-new-cpp...

I don't know whether this is a formerly-legitimate open source contributor who went rogue, or a deep-cover persona spreading innocuous-looking documentation changes around to other projects as a smokescreen.

WebAssembly is extremely portable. WebAssembly runs on: all major web browsers, V8 runtimes like Node.js, and independent Wasm runtimes like Wasmtime, Lucet, and Wasmer.

cpu: 4 disk: 60 memory: 12 arch: host hostname: colima autoActivate: true forwardAgent: false # I only tested this with 'docker', not 'containerd': runtime: docker kubernetes: enabled: false version: v1.24.3+k3s1 k3sArgs: [] network: address: true dns: [] dnsHosts: host.docker.internal: host.lima.internal # Added: # - containerd-snapshotter: true (meaning containerd will be used for pulling images) docker: features: buildkit: true containerd-snapshotter: true vmType: vz rosetta: true mountType: virtiofs mountInotify: false cpuType: host # This provisioning script installs build dependencies, WasmEdge and builds the WASM runtime shims for containerd. # NOTE: this takes a LOOONG time! provision: - mode: system script: | [ -f /etc/docker/daemon.json ] && echo "Already provisioned!" && exit 0 echo "Installing system updates:" apt-get update -y apt-get upgrade -y echo "Installing WasmEdge and runwasi build dependencies:" # NOTE: packages curl, git and python3 already installed: apt-get install -y make gcc build-essential pkgconf libtool libsystemd-dev libprotobuf-c-dev libcap-dev libseccomp-dev libyajl-dev libgcrypt20-dev go-md2man autoconf automake criu pkg-config libdbus-glib-1-dev libelf-dev libclang-dev libzstd-dev protobuf-compiler apt-get clean -y - mode: user script: | [ -f /etc/docker/daemon.json ] && echo "Already provisioned!" && exit 0 # # Setting vars for this script: # # Which WASM runtimes to install (wasmedge, wasmtime and wasmer are supported): WASM_RUNTIMES="wasmedge wasmtime wasmer" # # Location of the containerd config file: CONTAINERD_CONFIG="/etc/containerd/config.toml" # # Target location for the WASM runtimes and containerd shims ($TARGET/bin and $TARGET/lib): TARGET="/usr/local" # # Install rustup: # echo "Installing rustup for building runwasi:" curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- --default-toolchain none -y source "$HOME/.cargo/env" # # Install selected WASM runtimes and containerd shims: # [[ -z "${WASM_RUNTIMES// /}" ]] && echo "No WASM runtimes selected - exiting!" && exit 0 git clone https://github.com/containerd/runwasi echo "Installing WASM runtimes and building containerd shims: ${WASM_RUNTIMES}:" sudo mkdir -p /etc/containerd/ containerd config default | sudo tee $CONTAINERD_CONFIG >/dev/null for runtimeName in $WASM_RUNTIMES; do case $runtimeName in wasmedge) echo "Installing WasmEdge:" curl -sSfL https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | sudo bash -s -- -p $TARGET echo echo "`wasmedge -v` installed!" ;; wasmtime) echo "Installing wasmtime:" curl -sSfL https://wasmtime.dev/install.sh | bash sudo cp .wasmtime/bin/* ${TARGET}/bin/ rm -rf .wasmtime echo "`wasmtime -V` installed!" ;; wasmer) echo "Installing wasmer:" curl -sSfL https://get.wasmer.io | sh sudo cp .wasmer/bin/* ${TARGET}/bin/ sudo cp .wasmer/lib/* ${TARGET}/lib/ rm -rf .wasmer echo "`wasmer -V` installed!" ;; *) echo "ERROR: WASM runtime $runtimeName is not supported!" exit 1 ;; esac cd runwasi echo "Building containerd-shim-${runtimeName}:" cargo build -p containerd-shim-${runtimeName} --release echo "Installing containerd-shim-${runtimeName}-v1:" sudo install ./target/release/containerd-shim-${runtimeName}-v1 ${TARGET}/bin sudo ln -sf ${TARGET}/bin/containerd-shim-${runtimeName}-v1 ${TARGET}/bin/containerd-shim-${runtimeName}d-v1 sudo ln -sf ${TARGET}/bin/containerd-shim-${runtimeName}-v1 ${TARGET}/bin/containerd-${runtimeName}d echo "containerd-shim-${runtimeName} installed." cd .. echo "[plugins.\"io.containerd.grpc.v1.cri\".containerd.runtimes.${runtimeName}]" | sudo tee -a $CONTAINERD_CONFIG >/dev/null echo " runtime_type = \"io.containerd.${runtimeName}.v1\"" | sudo tee -a $CONTAINERD_CONFIG >/dev/null done echo "containerd WASM runtimes and shims installed." # # Restart the systemctl services to pick up the installed shims. # NOTE: We need to 'stop' docker because at this point the actual daemon.json config is not yet provisioned: # echo "Restarting/reloading docker/containerd services:" sudo systemctl daemon-reload sudo systemctl restart containerd sudo systemctl stop docker sshConfig: true mounts: [] env: {}

When you say wasm container, you mean something like wasmtime that provides a non-browser wasm runtime?

https://github.com/bytecodealliance/wasmtime

We can't run this directly from the command line unless we install some runtime like wasmtime:

The roadmap I linked above. The WASI folks have done a poor job at communicating, no doubt, but I'm surprised someone like yourself literally building a competitor spec isn't following what they are doing closely.

Just for you I did some googling: see here[0] for the current status of WASI threads overall, or here[1] and here[2] for what they are up to with WASI in general. In this PR[3] you can see they enabled threads (atomic instructions and shared memory, not thread creation) by default in wasmtime. And in this[4] repository you can see they are actively developing the thread creation API and have it as their #1 priority.

If folks want to use WASIX as a quick and dirty hack to compile existing programs, then by all means, have at it! I can see that being a technical win. Just know that your WASIX program isn't going to run natively in wasmtime (arguably the best WASM runtime today), nor will it run in browsers, because they're not going to expose WASIX - they're going to go with the standards instead. so far you're the only person I've met that thinks exposing POSIX fork() to WASM is a good idea, seemingly because it just lets you build existing apps 'without modification'.

Comical you accuse me of being polarizing, while pushing for your world with two competing WASI standards, two competing thread creation APIs, and a split WASM ecosystem overall.

[0] https://github.com/bytecodealliance/jco/issues/247#issuecomm...

[1] https://bytecodealliance.org/articles/wasmtime-and-cranelift...

[2] https://bytecodealliance.org/articles/webassembly-the-update...

[3] https://github.com/bytecodealliance/wasmtime/pull/7285

[4] https://github.com/WebAssembly/shared-everything-threads

Thanks for the question!

Spin could definitely run in more places than what we have pre-built binaries for. Specifically, we could run on all platforms Wasmtime supports today (https://github.com/bytecodealliance/wasmtime/releases/tag/v1...), including RISC and S390X, for example.

And while we have been experimenting a bit with running Spin on RISC, we haven't really had the bandwidth or requirement to build a production build for those yet.

Are you interested in a specific operating system or CPU architecture? Would love to understand your scenario.

> I used to think we'd eventually get to capability based security, but now I see we'll always be stuck with application permission flags, the almost worthless bastard cousin, instead.

My hope is that WASI will introduce capability based security to the mainstream on non-mobile computers [0] - it might just take some time for them to get it right. (And hopefully no half-baked status-quo-reinforcing regressive single—runtime-backed alternatives win in the meantime.)

[0]: https://github.com/bytecodealliance/wasmtime/blob/main/docs/...

WasmTime finished finished the RFC for the implementation details in June: https://github.com/bytecodealliance/wasmtime/issues/5032

[3]: https://github.com/bytecodealliance/wasmtime/pull/2611