This changes the default random source to provide deterministic values
similar to how nanotime and walltime do. This also prevents any worries
about if wasm can deplete the host's underlying source of entropy.
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>
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>
Before, we introduced a type `api.ImportRenamer` to resolve conflicts
where the "env" module was shared between AssemblyScript and
user-defined functions. This API was never used in GitHub, and is
complicated.
AssemblyScript also isn't the only ABI to share the "env" module, as
other web APIs like Emscripten do also. The less complicated approach is
to have packages that need to share "env" use
`ModuleBuilder.ExportFunctions` instead, and use namespaces as needed if
there is overlap.
Signed-off-by: Adrian Cole <adrian@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 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 ensures fake clocks increment so that compilers that implement
sleep with them don't spin.
This also fixes a mutability bug in config where we weren't really doing
clone properly because map references are shared.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This adds two clock interfaces: sys.Walltime and sys.Nanotime to
allow implementations to override readings for purposes of security or
determinism.
The default values of both are a fake timestamp, to avoid the sandbox
break we formerly had by returning the real time. This is similar to how
we don't inherit OS Env values.
This drops the text format (%.wat) and renames
InstantiateModuleFromCode to InstantiateModuleFromBinary as it is no
longer ambiguous.
We decided to stop supporting the text format as it isn't typically used
in production, yet costs a lot of work to develop. Given the resources
available and the increased work added with WebAssembly 2.0 and soon
WASI 2, we can't afford to spend the time on it.
The old parser is used only internally and will eventually be moved to
its own repository named watzero, possibly towards archival.
See #59
Signed-off-by: Adrian Cole <adrian@tetrate.io>
I researched what is available for improving godoc. Notably, this does
the following on every non-internal go file (tests excluded).
* consolidates links where there's a better single one
* wraps See where there are multiple relevant links
* reduces use of Note: where possible
* Uses preformatting for bullets similar to gob
* Uses titles where appropriate
I looked into it and while there are many ways to re-render godoc into
markdown, there are limited options on what to do in godoc itself. There
are tricks implicitly used where preformatting (tab indent) is used to
avoid having to add extra lines everywhere. This is done in gob, for
example.
See https://go.dev/src/encoding/gob/doc.go
See https://github.com/fluhus/godoc-tricks/blob/master/doc.go
See #426
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This consolidates the pattern used for context overrides, notably
replacing clock overrides via experimental.WithTimeNowUnixNano
and making all context keys internal.
This also makes sure experimental example tests are handled the same
way, notably backfilling one for WithFS
This notably changes NewRuntimeJIT to NewRuntimeCompiler as well renames
packages from jit to compiler.
This clarifies the implementation is AOT, not JIT, at least when
clarified to where it occurs (Runtime.CompileModule). In doing so, we
reduce any concern that compilation will happen during function
execution. We also free ourselves to create a JIT option without
confusion in the future via CompileConfig or otherwise.
Fixes#560
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This removes tedium in our examples and docs by using `Runtime.Close`
instead of tracking everything. Internal tests still track too much, but
anyway at least this stops suggesting others should do it.
This also changes our examples to use log.PanicXX so that the line
number goes into the console output.
Signed-off-by: Adrian Cole <adrian@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 commit adds support for multiple tables per module.
Notably, if the WithFeatureReferenceTypes is enabled,
call_indirect, table.init and table.copy instructions
can reference non-zero indexed tables.
part of #484
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
This makes wazero.ModuleConfig 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.
This also fixes a mutability bug in the implementation.
Follow-up from #519 and the last in this series
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 prepares for exposing operations like Memory.Grow while keeping the
ability to trace what did that, by adding a `context.Context` initial
parameter. This adds this to all API methods that mutate or return
mutated data.
Before, we made a change to trace functions and general lifecycle
commands, but we missed this part. Ex. We track functions, but can't
track what closed the module, changed memory or a mutable constant.
Changing to do this now is not only more consistent, but helps us
optimize at least the interpreter to help users identify otherwise
opaque code that can cause harm. This is critical before we add more
functions that can cause harm, such as Memory.Grow.
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>
Thanks to #454, now the compiled binary (code segment) can be reused for
multiple module instances originating from the same source (wasm.Module).
This commit introduces the caching mechanism on engine where it caches
compiled functions keyed on `wasm.Module`. As a result, this allows us to
do the fast module instantiation from the same *CompiledCode.
In order to release the cache properly, this also adds `Close` method
on CompiledCode.
Here's some bench result for instantiating multiple modules from the same CompiledCode:
```
name old time/op new time/op delta
Initialization/interpreter-32 2.84ms ± 3% 0.06ms ± 1% -97.73% (p=0.008 n=5+5)
Initialization/jit-32 10.7ms ±18% 0.1ms ± 1% -99.52% (p=0.008 n=5+5)
name old alloc/op new alloc/op delta
Initialization/interpreter-32 1.25MB ± 0% 0.15MB ± 0% -88.41% (p=0.008 n=5+5)
Initialization/jit-32 4.46MB ± 0% 0.15MB ± 0% -96.69% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
Initialization/interpreter-32 35.2k ± 0% 0.3k ± 0% -99.29% (p=0.008 n=5+5)
Initialization/jit-32 94.1k ± 0% 0.2k ± 0% -99.74% (p=0.008 n=5+5)
```
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
Before, complicated wasm could be hard to implement, particularly as it
might have cyclic imports. This change allows users to re-map imports to
untangle any cycles or to break up monolithic modules like "env".
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>
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 allows users to reduce the memory limit per module below 4 Gi. This
is often needed because Wasm routinely leaves off the max, which implies
spec max (4 Gi). This uses Ki Gi etc in error messages because the spec
chooses to, though we can change to make it less awkward.
This also fixes an issue where we instantiated an engine inside config.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
This introduces `SysConfig` to replace `WASIConfig` and formalize documentation around system calls.
The only incompatible change planned after this is to switch from wasi.FS to fs.FS
Implementation Notes:
Defaulting to os.Stdin os.Stdout and os.Stderr doesn't make sense for
the same reasons as why we don't propagate ENV or ARGV: it violates
sand-boxing. Moreover, these are worse as they prevent concurrency and
can also lead to console overload if accidentally not overridden.
This also changes default stdin to read EOF as that is safer than reading
from os.DevNull, which can run the host out of file descriptors.
Finally, this removes "WithPreopens" for "WithFS" and "WithWorkDirFS",
to focus on the intended result. Similar Docker, if the WorkDir isn't set, it
defaults to the same as root.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
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>
This converges host-defined modules with Wasm defined modules by
introducing a custom section for host-defined functions. The net result
are far less types and consistent initialization.
* HostModule is removed for Module
* HostFunction is removed for Function
* ModuleContext is removed for Module
Note: One impact of this is that the low-level API no longer accepts a
go context (context.Context), rather a `wasm.Module` which the function
is called in context of. This meant exposing `wasm.Module.WithContext`
to override the default.
Signed-off-by: Adrian Cole <adrian@tetrate.io>
Allows users to do the following to enable sign-extension-ops:
```
r := wazero.NewRuntimeWithConfig(wazero.NewRuntimeConfig().WithFeatureSignExtensionOps(true))
```
Resolves#66
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
Co-authored-by: Adrian Cole <adrian@tetrate.io>
