5c51940100
* Refactor use of Refs and RefMuts in wasi-common This commit refactors the use of `Ref`s and `RefMut`s in `wasi-common`. Now, `Entry` is stored behind an `Rc` inside the `EntryTable`. The `Entry` itself on the other hand now stores rights behind a `RefCell` and the descriptor as `Rc<RefCell<..>>` combo to enable easy reference tracking and interior mutability which is required down the line in a couple of syscalls. In essence, this implies that we no longer have need for mutable accessor to `Entry` from `WasiCtx`, and so all related methods go away (`get_entry_mut`, etc.). While here, I've also simplified handling and aggregating of rights on the `Entry` object. Instead of storing base and inheriting rights as separate fields, they are now aggregated into one struct `EntryRights` which features convenient constructors for each possible combination; i.e., when only base rights are set, or both base and inheriting are set, or both are left as empty. Since we do need to be able to mutate those rights down the line in `fdstat_set_rights` syscall, this object is kept behind a `RefCell` (note no `Rc` since we don't need to pass it around anywhere). The descriptor field in `Entry` is now kept behind `Rc<RefCell<..>>` combo since we not only need to mutate it down the line, but we also need to be able to pass it around (as part of the machinery making `poll_oneoff` work). I've also removed `as_file` and `try_clone` methods on `Descriptor` struct since they were adding more noise than necessary, and making them work with `Rc` was unnecessarily complicated. Finally, I've converted the `get_dir_from_os_handle` function into a method attached to the `OsHandle` itself, called `dir_stream`. IMHO, it makes more sense to have it there directly as a method than as a separate function. * Use Cell for types that are Copy
wasi-common
A Bytecode Alliance project
A library providing a common implementation of WASI hostcalls for re-use in any WASI-enabled runtime.
The wasi-common crate will ultimately serve as a library providing a common implementation of
WASI hostcalls for re-use in any WASI (and potentially non-WASI) runtimes
such as Wasmtime and Lucet.
The library is an adaption of lucet-wasi crate from the Lucet project, and it is currently based on 40ae1df git revision.
Please note that the library requires Rust compiler version at least 1.37.0.
Supported syscalls
*nix
In our *nix implementation, we currently support the entire WASI API with the exception of socket hostcalls:
sock_recvsock_sendsock_shutdown
We expect these to be implemented when network access is standardised.
We also currently do not support the proc_raise hostcall, as it is expected to
be dropped entirely from WASI.
Windows
In our Windows implementation, we currently support the minimal subset of WASI API which allows for running the very basic "Hello world!" style WASM apps. More coming shortly, so stay tuned!
Development hints
When testing the crate, you may want to enable and run full wasm32 integration testsuite. This
requires wasm32-wasi target installed which can be done as follows using rustup
rustup target add wasm32-wasi
Now, you should be able to run the integration testsuite by running cargo test on the
test-programs package with test-programs/test_programs feature enabled:
cargo test --features test-programs/test_programs --package test-programs
Third-Party Code
Significant parts of our hostcall implementations are derived from the C implementations in
cloudabi-utils. See LICENSE.cloudabi-utils for license information.