0006a2af95
* Dynamically load utimensat if exists on the host This commit introduces a change to file time management for *nix based hosts in that it firstly tries to load `utimensat` symbol, and if it doesn't exist, then falls back to `utimes` instead. This change is borrowing very heavily from [filetime] crate, however, it introduces a couple of helpers and methods specific to WASI use case (or more generally, to a use case which requires modifying times of entities specified by a pair `(DirFD, RelativePath)` rather than the typical file time specification based only absolute path or raw file descriptor as is the case with [filetime] crate. The trick here is, that on kernels which do not have `utimensat` symbol, this implementation emulates this behaviour by a combination of `openat` and `utimes`. This commit also is meant to address #516. [filetime]: https://github.com/alexcrichton/filetime * Fix symlink NOFOLLOW flag setting * Add docs and specify UTIME_NOW/OMIT on Linux Previously, we relied on [libc] crate for `UTIME_NOW` and `UTIME_OMIT` constants on Linux. However, following the convention assumed in [filetime] crate, this is now changed to directly specified by us in our crate. [libc]: https://github.com/rust-lang/libc [filetime]: https://github.com/alexcrichton/filetime * Refactor UTIME_NOW/OMIT for BSD * Address final discussion points
Wasmtime: a WebAssembly Runtime.
Wasmtime is a standalone wasm-only optimizing runtime for WebAssembly and WASI. It runs WebAssembly code outside of the Web, and can be used both as a command-line utility or as a library embedded in a larger application.
To get started, visit wasmtime.dev.
There are Rust, C, and C++ toolchains that can compile programs with WASI. See the WASI intro for more information, and the WASI tutorial for a tutorial on compiling and running programs using WASI and wasmtime, as well as an overview of the filesystem sandboxing system.
Wasmtime passes the WebAssembly spec testsuite. To run it, update the
tests/spec_testsuite submodule with git submodule update --remote, and it
will be run as part of cargo test.
Wasmtime does not yet implement Spectre mitigations, however this is a subject of ongoing research.
Additional goals for Wasmtime include:
- Support a variety of host APIs (not just WASI), with fast calling sequences, and develop proposals for additional API modules to be part of WASI.
- Facilitate development and testing around the Cranelift and Lightbeam JITs, and other WebAssembly execution strategies.
- Develop a native ABI used for compiling WebAssembly suitable for use in both JIT and AOT to native object files.
Including Wasmtime in your project
Wasmtime exposes an API for embedding as a library through the wasmtime subcrate,
which contains both a high-level and safe Rust API, as well as a C-compatible API
compatible with the proposed WebAssembly C API.
For more information, see the Rust API embedding chapter of the Wasmtime documentation.
It's Wasmtime.