* Change the name of wit-bindgen's host implementation traits.
Instead of naming the host implementation trait something like
`wasi_filesystem::WasiFilesystem`, name it `wasi_filesystem::Host`, and
avoid using the identifier `Host` in other places.
This fixes a collision when generating bindings for the current
wasi-clock API, which contains an interface `wall-clock` which contains
a type `wall-clock`, which created a naming collision on the name
`WallClock`.
* Update tests to use the new trait name.
* Fix one more.
* Add the new test interface to the simple-wasi world.
Early on in WASI, we weren't sure whether we should allow preopens to be
closed, so conservatively, we disallowed them. Among other things, this
protected assumptions in wasi-libc that it can hold onto preopen file
descriptors and rely on them always being open.
However now, I think it makes sense to relax this restriction. wasi-libc
itself doesn't expose the preopen file descriptors, so users shouldn't
ever be closing them naively, unless they have wild closes. And
toolchains other than wasi-libc may want to close preopens as a way to
drop priveleges once the main file handles are opened.
* Add a Result type alias
* Refer to the type in top-level docs
* Use this inside the documentation for the bindgen! macro
* Fix tests
* Address small PR feedback
* Simply re-export anyhow types
* Remove globals from parking spot tests
Use `std:🧵:scope` to keep everything local to just the tests.
* Fix a panic due to a race in `unpark` and `park`
This commit fixes a panic in the `ParkingSpot` implementation where an
`unpark` signal may not get acknowledged when a waiter times out,
causing the waiter to remove itself from the internal map but panic
thinking that it missed an unpark signal.
The fix in this commit is to consume unpark signals when a timeout
happens. This can lead to another possible race I've detailed in the
comments which I believe is allowed by the specification of park/unpark
in wasm.
* Update crates/runtime/src/parking_spot.rs
Co-authored-by: Andrew Brown <andrew.brown@intel.com>
---------
Co-authored-by: Andrew Brown <andrew.brown@intel.com>
* Update world-selection in `bindgen!` macro
Inspired by bytecodealliance/wit-bindgen#494 specifying a world or
document to bindgen is now optional as it's inferred if there's only one
`default world` in a package's documents.
* Add cargo-vet entry
This commit fixes a panic related to type imports where an import of a
type didn't correctly declare the new type index on the Wasmtime side of
things. Additionally this plumbs more support throughout Wasmtime to
support type imports, namely that they do not need to be supplied
through a `Linker`. This additionally implements a feature where empty
instances, even transitively, do not need to be supplied by a Wasmtime
embedder. This means that instances which only have types, for example,
do not need to be supplied into a `Linker` since no runtime information
for them is required anyway.
Closes#5775
This works around a `rustc` bug where compiling with LTO
will sometimes strip out some of the trampoline entrypoint
symbols resulting in a linking failure.
* Update wasm-tools crates
Pulls in a new component binary format which should hopefully be the
last update for awhile.
* Update cargo vet configuration
* Add support for WASI sockets to C API
Add support for WASI sockets in the C API by adding a new API to handle
preopening sockets for clients. This uses HashMap instead of Vec for
preopened sockets to identify if caller has called in more than once
with the same FD number. If so, then we return false so caller is given
hint that they are attempting to overwrite an already existing socket
FD.
* Apply suggestions from code review
Co-authored-by: Peter Huene <peter@huene.dev>
* s/stdlistener/listener/
---------
Co-authored-by: Peter Huene <peter@huene.dev>
* wasi-threads: fix import name
As @TerrorJack pointed out in #5484, that PR implements an older
name--`thread_spawn`. This change uses the now-official name from the
specification--`thread-spawn`.
* fix: update name in test
At some point what is now `funcref` was called `anyfunc` and the spec changed,
but we didn't update our internal names. This does that.
Co-authored-by: Jamey Sharp <jsharp@fastly.com>
This commit includes a set of changes that add initial support for `wasi-threads` to Wasmtime:
* feat: remove mutability from the WasiCtx Table
This patch adds interior mutability to the WasiCtx Table and the Table elements.
Major pain points:
* `File` only needs `RwLock<cap_std::fs::File>` to implement
`File::set_fdflags()` on Windows, because of [1]
* Because `File` needs a `RwLock` and `RwLock*Guard` cannot
be hold across an `.await`, The `async` from
`async fn num_ready_bytes(&self)` had to be removed
* Because `File` needs a `RwLock` and `RwLock*Guard` cannot
be dereferenced in `pollable`, the signature of
`fn pollable(&self) -> Option<rustix::fd::BorrowedFd>`
changed to `fn pollable(&self) -> Option<Arc<dyn AsFd + '_>>`
[1] da238e324e/src/fs/fd_flags.rs (L210-L217)
* wasi-threads: add an initial implementation
This change is a first step toward implementing `wasi-threads` in
Wasmtime. We may find that it has some missing pieces, but the core
functionality is there: when `wasi::thread_spawn` is called by a running
WebAssembly module, a function named `wasi_thread_start` is found in the
module's exports and called in a new instance. The shared memory of the
original instance is reused in the new instance.
This new WASI proposal is in its early stages and details are still
being hashed out in the [spec] and [wasi-libc] repositories. Due to its
experimental state, the `wasi-threads` functionality is hidden behind
both a compile-time and runtime flag: one must build with `--features
wasi-threads` but also run the Wasmtime CLI with `--wasm-features
threads` and `--wasi-modules experimental-wasi-threads`. One can
experiment with `wasi-threads` by running:
```console
$ cargo run --features wasi-threads -- \
--wasm-features threads --wasi-modules experimental-wasi-threads \
<a threads-enabled module>
```
Threads-enabled Wasm modules are not yet easy to build. Hopefully this
is resolved soon, but in the meantime see the use of
`THREAD_MODEL=posix` in the [wasi-libc] repository for some clues on
what is necessary. Wiggle complicates things by requiring the Wasm
memory to be exported with a certain name and `wasi-threads` also
expects that memory to be imported; this build-time obstacle can be
overcome with the `--import-memory --export-memory` flags only available
in the latest Clang tree. Due to all of this, the included tests are
written directly in WAT--run these with:
```console
$ cargo test --features wasi-threads -p wasmtime-cli -- cli_tests
```
[spec]: https://github.com/WebAssembly/wasi-threads
[wasi-libc]: https://github.com/WebAssembly/wasi-libc
This change does not protect the WASI implementations themselves from
concurrent access. This is already complete in previous commits or left
for future commits in certain cases (e.g., wasi-nn).
* wasi-threads: factor out process exit logic
As is being discussed [elsewhere], either calling `proc_exit` or
trapping in any thread should halt execution of all threads. The
Wasmtime CLI already has logic for adapting a WebAssembly error code to
a code expected in each OS. This change factors out this logic to a new
function, `maybe_exit_on_error`, for use within the `wasi-threads`
implementation.
This will work reasonably well for CLI users of Wasmtime +
`wasi-threads`, but embedders will want something better in the future:
when a `wasi-threads` threads fails, they may not want their application
to exit. Handling this is tricky, because it will require cancelling the
threads spawned by the `wasi-threads` implementation, something that is
not trivial to do in Rust. With this change, we defer that work until
later in order to provide a working implementation of `wasi-threads` for
experimentation.
[elsewhere]: https://github.com/WebAssembly/wasi-threads/pull/17
* review: work around `fd_fdstat_set_flags`
In order to make progress with wasi-threads, this change temporarily
works around limitations induced by `wasi-common`'s
`fd_fdstat_set_flags` to allow `&mut self` use in the implementation.
Eventual resolution is tracked in
https://github.com/bytecodealliance/wasmtime/issues/5643. This change
makes several related helper functions (e.g., `set_fdflags`) take `&mut
self` as well.
* test: use `wait`/`notify` to improve `threads.wat` test
Previously, the test simply executed in a loop for some hardcoded number
of iterations. This changes uses `wait` and `notify` and atomic
operations to keep track of when the spawned threads are done and join
on the main thread appropriately.
* various fixes and tweaks due to the PR review
---------
Signed-off-by: Harald Hoyer <harald@profian.com>
Co-authored-by: Harald Hoyer <harald@profian.com>
Co-authored-by: Alex Crichton <alex@alexcrichton.com>
* Prefix component-bindgen-generated-functions with `call_`
This fixes clashes between Rust-native methods and the methods
themselves. For example right now `new` is a Rust-generated function for
constructing the wrapper but this can conflict with a world-exported
function called `new`.
Closes#5585
* Fix types being both shared and owned
This refactors some inherited cruft from the original `wit-bindgen`
repository to be more Wasmtime-specific and fixes a codegen case where
a type was used in both a shared and an owned context.
Closes#5688
* 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>
This commit removes the pooling of `Instance` allocations from the
pooling instance allocator. This means that the allocation of `Instance`
(and `VMContext`) memory, now always happens through the system `malloc`
and `free` instead of optionally being part of the pooling instance
allocator. Along the way this refactors the `InstanceAllocator` trait so
the pooling and on-demand allocators can share more structure with this
new property of the implementation.
The main rationale for this commit is to reduce the RSS of long-lived
programs which allocate instances with the pooling instance allocator
and aren't using the "next available" allocation strategy. In this
situation the memory for an instance is never decommitted until the end
of the program, meaning that eventually all instance slots will become
occupied and resident. This has the effect of Wasmtime slowly eating
more and more memory over time as each slot gets an instance allocated.
By switching to the system allocator this should reduce the current RSS
workload from O(used slots) to O(active slots), which is more in line
with expectations.
* Reimplement the pooling instance allocation strategy
This commit is a reimplementation of the strategy by which the pooling
instance allocator selects a slot for a module. Previously there was a
choice amongst three different algorithms: "reuse affinity", "next
available", and "random". The default was "reuse affinity" but some new
data has come to light which shows that this may not always be a good
default.
Notably the pooling allocator will retain some memory per-slot in the
pooling instance allocator, for example instance data or memory data
if-so-configured. This means that a currently unused, but previously
used, slot can contribute to the RSS usage of a program using Wasmtime.
Consequently the RSS impact here is O(max slots) which can be
counter-intuitive for embedders. This particularly affects "reuse
affinity" because the algorithm for picking a slot when there are no
affine slots is "pick a random slot", which means eventually all slots
will get used.
In discussions about possible ways to tackle this, an alternative to
"pick a strategy" arose and is now implemented in this commit.
Concretely the new allocation algorithm for a slot is now:
* First pick the most recently used affine slot, if one exists.
* Otherwise if the number of affine slots to other modules is above some
threshold N then pick the least-recently used affine slot.
* Otherwise pick a slot that's affine to nothing.
The "N" in this algorithm is configurable and setting it to 0 is the
same as the old "next available" strategy while setting it to infinity
is the same as the "reuse affinity" algorithm. Setting it to something
in the middle provides a knob to allow a modest "cache" of affine slots
while not allowing the total set of slots used to grow too much beyond
the maximal concurrent set of modules. The "random" strategy is now no
longer possible and was removed to help simplify the allocator.
* Resolve rustdoc warnings in `wasmtime-runtime` crate
* Remove `max_cold` as it duplicates the `slot_state.len()`
* More descriptive names
* Add a comment and debug assertion
* Add some list assertions
* Add several `WASMTIME_VERSION_*` macros to `wasmtime.h`.
* Update `scripts/publish.rs`
* To set these macros as per the new version in `./Cargo.toml` during
`./publish bump`.
* To verify the macros match the version in `./Cargo.toml` during
`./publish verify`.
Fix#5635
* Fix libcall relocations for precompiled modules
This commit fixes some asserts and support for relocation libcalls in
precompiled modules loaded from disk. In doing so this reworks how mmaps
are managed for files from disk. All non-file-backed `Mmap` entries are
read/write but file-backed versions were readonly. This commit changes
this such that all `Mmap` objects, even if they're file-backed, start as
read/write. The file-based versions all use copy-on-write to preserve
the private-ness of the mapping.
This is not functionally intended to change anything. Instead this
should have some more memory writable after a module is loaded but the
text section, for example, is still left as read/execute when loading is
finished. Additionally this makes modules compiled in memory more
consistent with modules loaded from disk.
* Update a comment
* Force images to become readonly during publish
This marks compiled images as entirely readonly during the
`CodeMemory::publish` step which happens just before the text section
becomes executable. This ensures that all images, no matter where they
come from, are guaranteed frozen before they start executing.
Nothing major pulled in here, but wanted to update to the latest
versions which enable tail calls by default. When used in Wasmtime,
however, the feature is disabled without the possibility of being
enabled since it's not implemented.
This commit fixes a bug in the `bindgen!` macro for components where
previously the `param` and `result` properties weren't properly
calculated depending on the structure of the type and which types were
visited in which order. This is simplified to use a `LiveTypes`
structure from the `wit-parser` crate and relies on that to do necessary
recursion.
After #5587, this is on by default. We are retaining the traditional
(no-egraphs) path for now, selected by setting this option to `false`,
but we eventually plan to delete it assuming that we don't find serious
regressions or issues. This PR adds a deprecation notice to the option.
* Fix compile error on FreeBSD x64
* Fix compile on FreeBSD arm64
* Update Cargo.lock for ittapi
* vet: certify diff for ittapi libraries
Co-authored-by: Andrew Brown <andrew.brown@intel.com>
The check needs to verify that the maximum number of memories is
precisely one to ensure that multi-memory is disabled yet modules can
still have up to one memory as configured in the pooling allocator.
This PR follows up on #5382 and #5391, which rebuilt the egraph-based optimization framework to be more performant, by enabling it by default.
Based on performance results in #5382 (my measurements on SpiderMonkey and bjorn3's independent confirmation with cg_clif), it seems that this is reasonable to enable. Now that we have been fuzzing compiler configurations with egraph opts (#5388) for 6 weeks, having fixed a few fuzzbugs that came up (#5409, #5420, #5438) and subsequently received no further reports from OSS-Fuzz, I believe it is stable enough to rely on.
This PR enables `use_egraphs`, and also normalizes its meaning: previously it forced optimization (it basically meant "turn on the egraph optimization machinery"), now it runs egraph opts if the opt level indicates (it means "use egraphs to optimize if we are going to optimize"). The conditionals in the top-level pass driver are a little subtle, but will get simpler once we can remove the non-egraph path (which we plan to do eventually!).
Fixes#5181.
A fuzz bug came in last night from #5567 where spectest fuzzing will
first generate a config, possibly with SSE features for SIMD disabled,
only to have SIMD later enabled by `set_spectest_compliant`. This commit
fixes the issue by changing to `is_spectest_compliant` as a query and
throwing out the fuzz case if it isn't. This means that the spectest
fuzzer will throw out more inputs but means we can continue to generate
interesting configs and such for other inputs.
This commit fixes more cases from #5565 where `export` items introducing
indices wasn't handled by accident. Additionally this fixes support for
aliasing types from instances which largely wasn't working before. Most
of the fixes here are about correctly maintaining Wasmtime's view of the
type index spaces.
* Update WIT tooling used by Wasmtime
This commit updates the WIT tooling, namely the wasm-tools family of
crates, with recent updates. Notably:
* bytecodealliance/wasm-tools#867
* bytecodealliance/wasm-tools#871
This updates index spaces in components and additionally bumps the
minimum required version of the component binary format to be consumed
by Wasmtime (because of the index space changes). Additionally WIT
tooling now fully supports `use`.
Note that WIT tooling doesn't, at this time, fully support packages and
depending on remotely defined WIT packages. Currently WIT still needs to
be vendored in the project. It's hoped that future work with `cargo
component` and possible integration here could make the story about
depending on remotely-defined WIT more ergonomic and streamlined.
* Fix `bindgen!` codegen tests
* Add a test for `use` paths an implement support
* Update to crates.io versions of wasm-tools
* Uncomment codegen tests
* Resolve libcall relocations for older CPUs
Long ago Wasmtime used to have logic for resolving relocations
post-compilation for libcalls which I ended up removing during
refactorings last year. As #5563 points out, however, it's possible to
get Wasmtime to panic by disabling SSE features which forces Cranelift
to use libcalls for some floating-point operations instead. Note that
this also requires disabling SIMD because SIMD support has a baseline of
SSE 4.2.
This commit pulls back the old implementations of various libcalls and
reimplements logic necessary to have them work on CPUs without SSE 4.2
Closes#5563
* Fix log message in `wast` support
* Fix offset listed in relocations
Be sure to factor in the offset of the function itself
* Review comments
This commit fixes an issue where when backtraces were disabled but a
host function returned an error it would trigger a debug assertion
within Wasmtime. The fix here is to update the condition of the debug
assertion and add a test doing this behavior to ensure it works in the
future.
I've also further taken the liberty in this commit to remove the
deprecation notice for `Config::wasm_backtrace`. We don't really have a
strong reason for removing this functionality at this time and users
have multiple times now reported issues with performance that seem
worthwhile to keep the option. The latest issue, #5577, has a use case
where it appears the quadratic behavior is back in a way that Wasmtime
won't be able to detect. Namely with lots of wasm interleaved with host
on the stack if the original error isn't threaded through the entire
time then each host error will trigger a new backtrace since it doesn't
see a prior backtrace in the error being returned.
While this could otherwise be fixed with only capturing one contiguous
backtrace perhaps this seems reasonable enough to leave the
`wasm_backtrace` config option for now.
Closes#5577
* wiggle: Inline some trivial functions
This commit marks a number of functions in wiggle as `#[inline]` as
they're otherwise trivial, mostly returning constants. This comes out of
some work I looked at recently with Andrew where some of these functions
showed up in profiles when they shouldn't.
* wiggle: Optimize the `GuestMemory` for shared memory
This commit implements a minor optimization to the `GuestMemory`
implementation for Wasmtime to skip most methods if a shared memory is
in play. Shared memories never get borrowed and this can be used to
internally skip some borrow-checker methods.
* wiggle: Optimize `GuestPtr::to_vec`
This commit replaces the safe implementation of `GuestPtr::to_vec` with
an unsafe implementation. The purpose of this is to speed up the
function when used with shared memory which otherwise performs a bunch
of atomic reads for types like `u8` which does validation-per-element
and isn't vectorizable. On a benchmark I was helping Andrew with this
sped up the host code enough to the point that guest code dwarfed the
execution time.
* Fix build
