63d80fc509
* Remove the need to have a `Store` for an `InstancePre` This commit relaxes a requirement of the `InstancePre` API, notably its construction via `Linker::instantiate_pre`. Previously this function required a `Store<T>` to be present to be able to perform type-checking on the contents of the linker, and now this requirement has been removed. Items stored within a linker are either a `HostFunc`, which has type information inside of it, or an `Extern`, which doesn't have type information inside of it. Due to the usage of `Extern` this is why a `Store` was required during the `InstancePre` construction process, it's used to extract the type of an `Extern`. This commit implements a solution where the type information of an `Extern` is stored alongside the `Extern` itself, meaning that the `InstancePre` construction process no longer requires a `Store<T>`. One caveat of this implementation is that some items, such as tables and memories, technically have a "dynamic type" where during type checking their current size is consulted to match against the minimum size required of an import. This no longer works when using `Linker::instantiate_pre` as the current size used is the one when it was inserted into the linker rather than the one available at instantiation time. It's hoped, however, that this is a relatively esoteric use case that doesn't impact many real-world users. Additionally note that this is an API-breaking change. Not only is the `Store` argument removed from `Linker::instantiate_pre`, but some other methods such as `Linker::define` grew a `Store` argument as the type needs to be extracted when an item is inserted into a linker. Closes #5675 * Fix the C API * Fix benchmark compilation * Add C API docs * Update crates/wasmtime/src/linker.rs Co-authored-by: Andrew Brown <andrew.brown@intel.com> --------- Co-authored-by: Andrew Brown <andrew.brown@intel.com>
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 (locally) 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
-
Fast. Wasmtime is built on the optimizing Cranelift code generator to quickly generate high-quality machine code either at runtime or ahead-of-time. Wasmtime is optimized for efficient instantiation, low-overhead calls between the embedder and wasm, and scalability of concurrent instances.
-
Secure. Wasmtime's development is strongly focused on correctness and security. Building on top of Rust's runtime safety guarantees, each Wasmtime feature goes through careful review and consideration via an RFC process. Once features are designed and implemented, they undergo 24/7 fuzzing donated by Google's OSS Fuzz. As features stabilize they become part of a release, and when things go wrong we have a well-defined security policy in place to quickly mitigate and patch any issues. We follow best practices for defense-in-depth and integrate protections and mitigations for issues like Spectre. Finally, we're working to push the state-of-the-art by collaborating with academic researchers to formally verify critical parts of Wasmtime and Cranelift.
-
Configurable. Wasmtime uses sensible defaults, but can also be configured to provide more fine-grained control over things like CPU and memory consumption. Whether you want to run Wasmtime in a tiny environment or on massive servers with many concurrent instances, we've got you covered.
-
WASI. Wasmtime supports a rich set of APIs for interacting with the host environment through the WASI standard.
-
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.
Languages supported by the Bytecode Alliance:
- Rust - the
wasmtimecrate - C - the
wasm.h,wasi.h, andwasmtime.hheaders, CMake orwasmtimeConan package - C++ - the
wasmtime-cpprepository or usewasmtime-cppConan package - Python - the
wasmtimePyPI package - .NET - the
WasmtimeNuGet package - Go - the
wasmtime-gorepository - Ruby - the
wasmtimegem
Languages supported by the community:
- Elixir - the
wasmexhex package
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.