This makes host functions index consistently on insertion order, rather
than lexicographic order. This helps with ABI such as Emscripten, which
need an expected order.
This also constrains the internal code around host functions to only one
export name. More than one was never used. By restricting this, logic is
simpler and smaller.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Formerly, we introduced `wazero.Namespace` to help avoid module name or import conflicts while still sharing the runtime's compilation cache. Now that we've introduced `CompilationCache` `wazero.Namespace` is no longer necessary. By removing it, we reduce the conceptual load on end users as well internal complexity. Since most users don't use namespace, the change isn't very impactful.
Users who are only trying to avoid module name conflict can generate a name like below instead of using multiple runtimes:
```go
moduleName := fmt.Sprintf("%d", atomic.AddUint64(&m.instanceCounter, 1))
module, err := runtime.InstantiateModule(ctx, compiled, config.WithName(moduleName))
```
For `HostModuleBuilder` users, we no longer take `Namespace` as the last parameter of `Instantiate` method:
```diff
// log to the console.
_, err := r.NewHostModuleBuilder("env").
NewFunctionBuilder().WithFunc(logString).Export("log").
- Instantiate(ctx, r)
+ Instantiate(ctx)
if err != nil {
log.Panicln(err)
}
```
The following is an example diff a use of namespace can use to keep compilation cache while also ensuring their modules don't conflict:
```diff
func useMultipleRuntimes(ctx context.Context, cache) {
- r := wazero.NewRuntime(ctx)
+ cache := wazero.NewCompilationCache()
for i := 0; i < N; i++ {
- // Create a new namespace to instantiate modules into.
- ns := r.NewNamespace(ctx) // Note: this is closed when the Runtime is
+ r := wazero.NewRuntimeWithConfig(ctx, wazero.NewRuntimeConfig().WithCompilationCache(cache))
// Instantiate a new "env" module which exports a stateful function.
_, err := r.NewHostModuleBuilder("env").
```
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
This adds ResultNames to HostFunctionBuilder and FunctionDefinition
which helps for multi-results or special-cased ones.
End users can access result names in `FunctionDefinition.ResultNames` or
set for their own host functions via
`HostFunctionBuilder.WithResultNames`. This change adds them for all
built-in functions where result names help.
Most notably, GOOS=js uses `ProxyFunc` to allow logging when a function
returns multiple results. Before, the results were returned without
names: e.g. `11231,1` and now they are named like `n=11231,ok=1`.
We soon plan to allow more visibility in WASI, for example, logging
results that will write to memory offsets. This infrastructure makes it
possible to do that.
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>
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>
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 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 commit implements the v128.const, i32x4.add and i64x2.add in
interpreter mode and this adds support for the vector value types in the
locals and globals.
Notably, the vector type values can be passed and returned by exported functions
as well as host functions via two-uint64 encodings as described in #484 (comment).
Note: implementation of these instructions on JIT will be done in subsequent PR.
part of #484
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
This performs several changes to allow compilation config to be
centralized and scoped properly. The immediate effects are that we can
now process external types during `Runtime.CompileModule` instead of
doing so later during `Runtime.InstantiateModule`. Another nice side
effect is memory size problems can err at a source line instead of
having to be handled in several places.
There are some API effects to this, and to pay for them, some less used
APIs were removed. The "easy APIs" are left alone. For example, the APIs
to compile and instantiate a module from Go or Wasm in one step are left
alone.
Here are the changes, some of which are only for consistency. Rationale
is summarized in each point.
* ModuleBuilder.Build -> ModuleBuilder.Compile
* The result of this is similar to `CompileModule`, and pairs better
with `ModuleBuilder.Instantiate` which is like `InstantiateModule`.
* CompiledCode -> CompiledModule
* We punted on this name, the result is more than just code. This is
better I think and more consistent as it introduces less terms.
* Adds CompileConfig param to Runtime.CompileModule.
* This holds existing features and will have future ones, such as
mapping externtypes to uint64 for wasm that doesn't yet support it.
* Merges Runtime.InstantiateModuleWithConfig with Runtime.InstantiateModule
* This allows us to explain APIs in terms of implicit or explicit
compilation and config, vs implicit, kindof implicit, and explicit.
* Removes Runtime.InstantiateModuleFromCodeWithConfig
* Similar to above, this API only saves the compilation step and also
difficult to reason with from a name POV.
* RuntimeConfig.WithMemory(CapacityPages|LimitPages) -> CompileConfig.WithMemorySizer
* This allows all error handling to be attached to the source line
* This also allows someone to reduce unbounded memory while knowing
what its minimum is.
* ModuleConfig.With(Import|ImportModule) -> CompileConfig.WithImportRenamer
* This allows more types of import manipulation, also without
conflating functions with globals.
* Adds api.ExternType
* Needed for ImportRenamer and will be needed later for ExportRenamer.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This makes wazero.CompiledCode an interface instead of a struct to
prevent it from being used incorrectly. For example, even though the
fields are not exported, someone can mistakenly instantiate this
when it is a struct, and in doing so violate internal assumptions.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
WebAssembly Core Working Draft 1 recently came out. Before that, we had
a toe-hold feature bucked called FinishedFeatures. This replaces
`RuntimeConfig.WithFinishedFeatures` with `RuntimeConfig.WithWasmCore2`.
This also adds `WithWasmCore1` for those who want to lock into 1.0
features as opposed to relying on defaults.
This also fixes some design debt where we hadn't finished migrating
public types that require constructor functions (NewXxx) to interfaces.
By using interfaces, we prevent people from accidentally initializing
key configuration directly (via &Xxx), causing nil field refs. This also
helps prevent confusion about how to use the type (ex pointer or not) as
there's only one way (as an interface).
See https://github.com/tetratelabs/wazero/issues/516
Signed-off-by: Adrian Cole <adrian@tetrate.io>
`Runtime.WithMemoryCapacityPages` is a function that determines memory
capacity in pages (65536 bytes per page). The inputs are the min and
possibly nil max defined by the module, and the default is to return
the min.
Ex. To set capacity to max when exists:
```golang
c.WithMemoryCapacityPages(func(minPages uint32, maxPages *uint32) uint32 {
if maxPages != nil {
return *maxPages
}
return minPages
})
```
Note: This applies at compile time, ModuleBuilder.Build or Runtime.CompileModule.
Fixes#500
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This is an API breaking change that does a few things:
* Stop encouraging practice that can break context propagation:
* Stops caching `context.Context` in `wazero.RuntimeConfig`
* Stops caching `context.Context` in `api.Module`
* Fixes context propagation in function calls:
* Changes `api.Function`'s arg0 from `api.Module` to `context.Context`
* Adds `context.Context` parameter in instantiation (propagates to
.start)
* Allows context propagation for heavy operations like compile:
* Adds `context.Context` as the initial parameter of `CompileModule`
The design we had earlier was a good start, but this is the only way to
ensure coherence when users start correlating or tracing. While adding a
`context.Context` parameter may seem difficult, wazero is a low-level
library and WebAssembly is notoriously difficult to troubleshoot. In
other words, it will be easier to explain to users to pass (even nil) as
the context parameter vs try to figure out things without coherent
context.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This commit allows CompiledCode to be re-used regardless of
the existence of import replacement configs for instantiation.
In order to achieve this, we introduce ModuleID, which is sha256
checksum calculated on source bytes, as a key for module compilation
cache. Previously, we used*wasm.Module as keys for caches which
differ before/after import replacement.
Signed-off-by: Takeshi Yoneda takeshi@tetrate.io
This commit makes it possible for functions to be compiled before instantiation.
Notably, this adds CompileModule method on Engine interface where we pass
wasm.Module (which is the decoded module) to engines, and engines compile
all the module functions and caches them keyed on *wasm.Module.
In order to achieve that, this stops the compiled native code from embedding typeID
which is assigned for all the function types in a store.
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
This implements our own assertion library so that we can remove the
testify dependency. I've changed a lot of call sites so that we only
have to maintain a minimal amount of assertions.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This starts the process of removing all dependencies from wazero, by
isolating all assertions we use into a single file. This allows us to
port those assertions as we have time, and when twitchy is gone, the
project literally has no dependencies except go!
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Global constants can be defined in wasm or in ModuleBuilder. In either
case, they end up being decoded and interpreted during instantiation.
This chooses signed encoding to avoid surprises. A more comprehensive
explanation was added to RATIONALE.md, but the motivation was a global
100 coming out negative.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adjusts towards the exiting code which used int32/64 instead of
uint32/64. The reason is that the spec indicates intepretation as signed
numbers, which affects the maximum value.
See https://www.w3.org/TR/wasm-core-1/#value-types%E2%91%A2
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds functions to configure memory with ModuleBuilder. This uses
two functions, ExportMemory and ExportMemoryWithMax, as working with
uint32 pointers is awkward.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
During #425, @neilalexander gave constructive feedback that the API is
both moving fast, and not good enough yet. This attempts to reduce the
incidental complexity at the cost of a little conflation.
### odd presence of `wasm` and `wasi` packages -> `api` package
We had public API packages in wasm and wasi, which helped us avoid
leaking too many internals as public. That these had names that look
like there should be implementations in them cause unnecessary
confusion. This squashes both into one package "api" which has no
package collission with anything.
We've long struggled with the poorly specified and non-uniformly
implemented WASI specification. Trying to bring visibility to its
constraints knowing they are routinely invalid taints our API for no
good reason. This removes all `WASI` commands for a default to invoke
the function `_start` if it exists. In doing so, there's only one path
to start a module.
Moreover, this puts all wasi code in a top-level package "wasi" as it
isn't re-imported by any internal types.
### Reuse of Module for pre and post instantiation to `Binary` -> `Module`
Module is defined by WebAssembly in many phases, from decoded to
instantiated. However, using the same noun in multiple packages is very
confusing. We at one point tried a name "DecodedModule" or
"InstantiatedModule", but this is a fools errand. By deviating slightly
from the spec we can make it unambiguous what a module is.
This make a result of compilation a `Binary`, retaining `Module` for an
instantiated one. In doing so, there's no longer any name conflicts
whatsoever.
### Confusion about config -> `ModuleConfig`
Also caused by splitting wasm into wasm+wasi is configuration. This
conflates both into the same type `ModuleConfig` as it is simpler than
trying to explain a "will never be finished" api of wasi snapshot-01 in
routine use of WebAssembly. In other words, this further moves WASI out
of the foreground as it has been nothing but burden.
```diff
--- a/README.md
+++ b/README.md
@@ -49,8 +49,8 @@ For example, here's how you can allow WebAssembly modules to read
-wm, err := r.InstantiateModule(wazero.WASISnapshotPreview1())
-defer wm.Close()
+wm, err := wasi.InstantiateSnapshotPreview1(r)
+defer wm.Close()
-sysConfig := wazero.NewSysConfig().WithFS(os.DirFS("/work/home"))
-module, err := wazero.StartWASICommandWithConfig(r, compiled, sysConfig)
+config := wazero.ModuleConfig().WithFS(os.DirFS("/work/home"))
+module, err := r.InstantiateModule(binary, config)
defer module.Close()
...
```
This reverts `Runtime.NewModule` back to `InstantiateModule` as it calls
more attention to the registration aspect of it, and also makes a chain
of `NewXX` more clear. This is particularly helpful as this change
introduces `ModuleBuilder` which is created by `NewModuleBuilder`.
`ModuleBuilder` is a way to define a WebAssembly 1.0 (20191205) in Go.
The first iteration allows setting the module name and exported
functions. The next PR will add globals.
Ex. Below defines and instantiates a module named "env" with one function:
```go
hello := func() {
fmt.Fprintln(stdout, "hello!")
}
_, err := r.NewModuleBuilder("env").ExportFunction("hello", hello).InstantiateModule()
```
If the same module may be instantiated multiple times, it is more efficient to separate steps. Ex.
```go
env, err := r.NewModuleBuilder("env").ExportFunction("get_random_string", getRandomString).Build()
_, err := r.InstantiateModule(env.WithName("env.1"))
_, err := r.InstantiateModule(env.WithName("env.2"))
```
Note: Builder methods do not return errors, to allow chaining. Any validation errors are deferred until Build.
Note: Insertion order is not retained. Anything defined by this builder is sorted lexicographically on Build.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
