da5c82b786
In #3231 the wasm data sections were moved from the `wasmtime_environ::Module` structure into the `CompilationArtifacts`. Each `wasmtime_runtime::Instance` holds raw pointers into the data section owned by the compilation artifacts under the assumption that the runtime keeps the artifacts alive while the module is in use. Data is needed beyond original initialization for `memory.init` instructions as well as lazy-initialization with the `uffd` feature. The intention of #3231 was that all `CompiledModule` structures, which own `CompilationArtifacts` were owned by a store's `ModuleRegistry`, so this was already taken care of. It turns out, however, that empty modules which contain no functions are not held within a `ModuleRegistry` since there was no need prior to retain them. This commit remedies this mistake by retaining the `CompiledModule` structure, even if there aren't any functions compiled in. This should unblock #3235 and fixes the spurious error found there. The test here, at least on Linux, will deterministically reproduce the error before this commit since `uffd` was initializing wasm memory with free'd host memory.
wasmtime
A standalone runtime for WebAssembly
A Bytecode Alliance project
Guide | Contributing | Website | Chat
Installation
The Wasmtime CLI can be installed on Linux and macOS with a small install script:
$ curl https://wasmtime.dev/install.sh -sSf | bash
Windows or otherwise interested users can download installers and binaries directly from the GitHub Releases page.
Example
If you've got the Rust compiler installed then you can take some Rust source code:
fn main() {
println!("Hello, world!");
}
and compile/run it with:
$ rustup target add wasm32-wasi
$ rustc hello.rs --target wasm32-wasi
$ wasmtime hello.wasm
Hello, world!
Features
-
Lightweight. Wasmtime is a standalone runtime for WebAssembly that scales with your needs. It fits on tiny chips as well as makes use of huge servers. Wasmtime can be embedded into almost any application too.
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code at runtime.
-
Configurable. Whether you need to precompile your wasm ahead of time, generate code blazingly fast with Lightbeam, or interpret it at runtime, Wasmtime has you covered for all your wasm-executing needs.
-
WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
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Standards Compliant. Wasmtime passes the official WebAssembly test suite, implements the official C API of wasm, and implements future proposals to WebAssembly as well. Wasmtime developers are intimately engaged with the WebAssembly standards process all along the way too.
Language Support
You can use Wasmtime from a variety of different languages through embeddings of the implementation:
- Rust - the
wasmtimecrate - C - the
wasm.h,wasi.h, andwasmtime.hheaders - [C++] - the
wasmtime-cpprepository - Python - the
wasmtimePyPI package - .NET - the
WasmtimeNuGet package - Go - the
wasmtime-gorepository
Documentation
📚 Read the Wasmtime guide here! 📚
The wasmtime guide is the best starting point to learn about what Wasmtime can do for you or help answer your questions about Wasmtime. If you're curious in contributing to Wasmtime, it can also help you do that!
It's Wasmtime.