This adds host functions that work on dynamic function tables. These are
only used by emscripten, but require some infrastructure to support it.
I added the least possible to due the task. This also only handles i32
and void returns with up to four parameters as that covers the needs of
PDFium. Future integrations may need more parameters or a mix of floats.
Such use cases should be addressed as they come as otherwise it is a lot
of work for the cartesian product of all combinations.
See 1b0d724fd5/test/passes/post-emscripten.wast
See https://github.com/jerbob92/go-pdfium-wasm
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This switches to gofumpt and applies changes, as I've noticed working
in dapr (who uses this) that it finds some things that are annoying,
such as inconsistent block formatting in test tables.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This restores the ability to leave out the initial context parameter
when defining functions with reflection. This is important because some
projects are porting from a different library to wazero, and all the
alternatives are not contextualized.
For example, this project is porting envoy host functions, and the
original definitions (in mosn) don't have a context parameter. By being
lenient, they can migrate easier.
See 6b813482b6/pkg/proxywasm/wazero/imports_v1.go
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This PR follows @hafeidejiangyou advice to not only enable end users to
avoid reflection when calling host functions, but also use that approach
ourselves internally. The performance results are staggering and will be
noticable in high performance applications.
Before
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 1000000 1050 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 525492 2224 ns/op
```
Now
```
BenchmarkHostCall/Call
BenchmarkHostCall/Call-16 14807203 83.22 ns/op
Benchmark_EnvironGet/environGet
Benchmark_EnvironGet/environGet-16 951690 1054 ns/op
```
To accomplish this, this PR consolidates code around host function
definition and enables a fast path for functions where the user takes
responsibility for defining its WebAssembly mappings. Existing users
will need to change their code a bit, as signatures have changed.
For example, we are now more strict that all host functions require a
context parameter zero. Also, we've replaced
`HostModuleBuilder.ExportFunction` and `ExportFunctions` with a new type
`HostFunctionBuilder` that consolidates the responsibility and the
documentation.
```diff
ctx := context.Background()
-hello := func() {
+hello := func(context.Context) {
fmt.Fprintln(stdout, "hello!")
}
-_, err := r.NewHostModuleBuilder("env").ExportFunction("hello", hello).Instantiate(ctx, r)
+_, err := r.NewHostModuleBuilder("env").
+ NewFunctionBuilder().WithFunc(hello).Export("hello").
+ Instantiate(ctx, r)
```
Power users can now use `HostFunctionBuilder` to define functions that
won't use reflection. There are two choices of interfaces to use
depending on if that function needs access to the calling module or not:
`api.GoFunction` and `api.GoModuleFunction`. Here's an example defining
one.
```go
builder.WithGoFunction(api.GoFunc(func(ctx context.Context, params []uint64) []uint64 {
x, y := uint32(params[0]), uint32(params[1])
sum := x + y
return []uint64{sum}
}, []api.ValueType{api.ValueTypeI32, api.ValueTypeI32}, []api.ValueType{api.ValueTypeI32})
```
As you'll notice and as documented, this approach is more verbose and
not for everyone. If you aren't making a low-level library, you are
likely able to afford the 1us penalty for the convenience of reflection.
However, we are happy to enable this option for foundational libraries
and those with high performance requirements (like ourselves)!
Fixes#825
Signed-off-by: Adrian Cole <adrian@tetrate.io>
It is more often the case that projects are enabling a freestanding
target, and that may or may not have an exporting memory depending on
how that's interpreted. This adds the ability to inspect memories
similar to how you can already inspect compiled code prior to
instantiation. For example, you can enforce an ABI constraint that
"memory" must be exported even if WASI is not in use.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We formerly introduced `MemorySizer` as a way to control capacity independently of size. This was the first and only feature in `CompileConfig`. While possibly used privately, `MemorySizer` has never been used in public GitHub code.
These APIs interfere with how we do caching of compiled modules. Notably, they can change the min or max defined in wasm, which invalidates some constants. This has also had a bad experience, forcing everyone to boilerplate`wazero.NewCompileConfig()` despite that API never being used in open source.
This addresses the use cases in a different way, by moving configuration to `RuntimeConfig` instead. This allows us to remove `MemorySizer` and `CompileConfig`, and the problems with them, yet still retaining functionality in case someone uses it.
* `RuntimeConfig.WithMemoryLimitPages(uint32)`: Prevents memory from growing to 4GB (spec limit) per instance.
* This works regardless of whether the wasm encodes max or not. If there is no max, it becomes effectively this value.
* `RuntimeConfig.WithMemoryCapacityFromMax(bool)`: Prevents reallocations (when growing).
* Wasm that never sets max will grow from min to the limit above.
Note: Those who want to change their wasm (ex insert a max where there was none), have to do that externally, ex via compiler settings or post-build transformations such as [wabin](https://github.com/tetratelabs/wabin)
Signed-off-by: Adrian Cole <adrian@tetrate.io>
We at one point considered making `ModuleBuilder` create complete
WebAssembly binaries. However, we recently spun out
[wabin](https://github.com/tetratelabs/wabin), which allows this.
Meanwhile, the features in `ModuleBuilder` were confusing and misused.
For example, the only two cases memory was exported on GitHub were done
by accident. This is because host functions act on the guest's memory,
not their own.
Hence, this removes memory and globals from host side definitions, and
renames the type to HostModuleBuilder to clarify this is not ever going
to be used to construct normal Wasm binaries.
Most importantly, this simplifies the API and reduces a lot of code. It
is important to make changes like this, particularly deleting any
experimental things that didn't end up useful.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Anuraag Agrawal <anuraaga@gmail.com>
While compilers should be conservative when targeting WebAssembly Core
features, runtimes should be lenient as otherwise people need to
constantly turn on all features. Currently, most examples have to turn
on 2.0 features because compilers such as AssemblyScript and TinyGo use
them by default. This matches the policy with the reality, and should
make first time use easier.
This top-levels an internal type as `api.CoreFeatures` and defaults to
2.0 as opposed to 1.0, our previous default. This is less cluttered than
the excess of `WithXXX` methods we had prior to implementing all
planned WebAssembly Core Specification 1.0 features.
Finally, this backfills rationale as flat config types were a distinct
decision even if feature set selection muddied the topic.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds an experimental package gojs which implements the host side of Wasm compiled by GOARCH=wasm GOOS=js go build -o X.wasm X.go
This includes heavy disclaimers, in part inherited by Go's comments https://github.com/golang/go/blob/go1.19/src/syscall/js/js.go#L10-L11
Due to this many will still use TinyGo instead.
That said, this is frequently asked for and has interesting features including reflection and HTTP client support.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This introduces wasm.CallEngine internal type, and assign it to the api.Function
implementations. api.Function.Call now uses that CallEngine assigned to it
to make function calls.
Internally, when creating CallEngine implementation, the compiler engine allocates
call frames and values stack. Previously, we allocate these stacks for each function calls,
which was a severe overhead as we can recognize in the benchmarks. As a result,
this reduces the memory usage (== reduces the GC jobs) as long as we reuse
the same api.Function multiple times.
As a side effect, now api.Function.Call is not goroutine-safe. So this adds the comment
about it on that method.
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
staticcheck linters broke until recent golangci-lint. Now, normal
behaviour of enforcing no nil context works again. Ex.
```
assemblyscript/assemblyscript_example_test.go:16:25: SA1012: do not pass a nil Context, even if a function permits it; pass context.TODO if you are unsure about which Context to use (staticcheck)
r := wazero.NewRuntime(nil)
```
Since default lint already checks for nil context, this removes our
permission of nil context args. The original reason we permitted nil is
no longer valid: we once allowed context to be stashed in config, and
removed that as it caused bugs. We forgot to undo allowing nil
explicitly.
Note: this doesn't particularly check in our code for nil context,
similar as we don't particularly check in our code for nil anything
else. End users should use linters as none of our parameters should be
nil anyway.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This simplifies FunctionListener definition by making it possible to
implement both interfaces without intermediate state. Passing the
function definition to the before/after callbacks is the key.
This also continues efforts towards Go 1.19 doc formatting.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Before, we allowed stubbed host functions to be defined in wasm instead
of Go. This improves performance and reduces a chance of side-effects vs
Go. In fact, any pure function was supported in wasm, provided it only
called pure functions.
This changes internals so that a wasm-defined host function can use
memory. Notably, host functions use the caller's memory, so this is
simpler to initially support in the interpreter.
This is needed to simplify and reduce performance hit of GOARCH=wasm,
GOOS=js code, which perform a lot of memory reads and do not have
idiomatic signatures.
Note: wasm-defined host functions remain internal until we gain
experience, at least conclusion of the wasm_exec host module.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
* Makes CacheNumInUint64 lazy and stops crashing in assemblyscript
This makes CacheNumInUint64 lazy so that all tests for function types
don't need to handle it. This also changes the assemblyscript special
functions so they don't crash when attempting to log. Finally, this
refactors `wasm.Func` so that it can enclose the parameter names as it
is more sensible than defining them elsewhere.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This refactors host functions with no-op or constant returns to be
implemented with wasm instead of the host function bridge. This allows
better performance.
This also breaks up and makes WASI tests consistent, in a way that shows
parameter name drifts easier.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This removes the constraint of a module being exclusively wasm or host
functions. Later pull requests can optimize special imports to be
implemented in wasm, particularly useful for disabled logging callbacks.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This improves the experimental logging listener to show parameter name
and values like so:
```
--> ._start.command_export()
--> .__wasm_call_ctors()
--> .__wasilibc_initialize_environ()
==> wasi_snapshot_preview1.environ_sizes_get(result.environc=1048572,result.environBufSize=1048568)
<== ESUCCESS
<-- ()
==> wasi_snapshot_preview1.fd_prestat_get(fd=3,result.prestat=1048568)
<== ESUCCESS
--> .dlmalloc(2)
--> .sbrk(0)
<-- (1114112)
<-- (1060080)
--snip--
```
The convention `==>` implies it was a host function call
(def.IsHostFunction). This also improves the lifecycle by creating
listeners during compile. Finally, this backfills param names for
assemblyscript and wasi.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This top-levels `api.FunctionDefinition` which was formerly
experimental, and also adds import metadata to it. Now, it holds all
metadata known at compile time.
Here are the public API visible changes:
* api.ExportedFunction - replaced with api.FunctionDefinition as it is
usable for all types of functions.
* api.Function - `.ParamTypes/ResultTypes()` are replaced with
`.Definition().
* api.FunctionDefinition - extracted from experimental and adds
`.Import()` to get the any imported module and function name.
* experimental.FunctionDefinition - replaced with
api.FunctionDefinition.
* experimental.FunctionListenerFactory - adds first arg of the
instantiated module name, as it can be different than compiled.
* wazero.CompiledModule - Adds `.ImportedFunctions()` and changes result
type of `.ExportedFunctions()` to api.FunctionDefinition.
Internally, logic to create function definition are consolidated between
host and wasm-defined functions, notably wasm.Module now includes
`.BuildFunctionDefinitions()` which reduces duplication in
wasm.ModuleInstance `.BuildFunctions()`,
This obviates #681 by deleting the `ExportedFunction` type which
overlaps with this information.
This fixes#637 as it includes more metadata including imports.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Co-authored-by: Takeshi Yoneda <takeshi@tetrate.io>
This changes the AssemblyScript abort handler and WASI proc_exit
implementation to panic the caller which eventually invoked close.
This ensures no code executes afterwards, For example, LLVM inserts
unreachable instructions after calls to exit.
See https://github.com/emscripten-core/emscripten/issues/12322
See #601
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This consolidates to use EBADF in places go uses it in syscalls to
reduce where we formally returned both bool and err. This also removes
the redundant panic type handling as go will already panic with a
similar message.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This removes WithWorkDirFS and any other attempts to resolve the current directory (".") in host functions. This is a reaction to reality of compilers who track this inside wasm (not via host functions). One nice side effect is substantially simpler internal implementation of file-systems.
This also allows experimental.WithFS to block file access via passing nil.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This implements wasi_snapshot_preview1.poll_oneoff for relative clock events,
and in doing so stubs `Nanosleep` which defaults to noop, but can be configured
to `time.Sleep`.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This completes the implementation of SIMD proposal for both
the interpreter and compiler(amd64).
This also fixes#210 by adding the complete documentation
over all the wazeroir operations.
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
Co-authored-by: Crypt Keeper <64215+codefromthecrypt@users.noreply.github.com>
