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f1225dfd930e263287fb61a12fe577b206092574
wasmtime/tests/all/host_funcs.rs
Alex Crichton bcf3544924 Optimize Func::call and its C API (#3319) 
* Optimize `Func::call` and its C API

This commit is an alternative to #3298 which achieves effectively the
same goal of optimizing the `Func::call` API as well as its C API
sibling of `wasmtime_func_call`. The strategy taken here is different
than #3298 though where a new API isn't created, rather a small tweak to
an existing API is done. Specifically this commit handles the major
sources of slowness with `Func::call` with:

* Looking up the type of a function, to typecheck the arguments with and
  use to guide how the results should be loaded, no longer hits the
  rwlock in the `Engine` but instead each `Func` contains its own
  `FuncType`. This can be an unnecessary allocation for funcs not used
  with `Func::call`, so this is a downside of this implementation
  relative to #3298. A mitigating factor, though, is that instance
  exports are loaded lazily into the `Store` and in theory not too many
  funcs are active in the store as `Func` objects.

* Temporary storage is amortized with a long-lived `Vec` in the `Store`
  rather than allocating a new vector on each call. This is basically
  the same strategy as #3294 only applied to different types in
  different places. Specifically `wasmtime::Store` now retains a
  `Vec<u128>` for `Func::call`, and the C API retains a `Vec<Val>` for
  calling `Func::call`.

* Finally, an API breaking change is made to `Func::call` and its type
  signature (as well as `Func::call_async`). Instead of returning
  `Box<[Val]>` as it did before this function now takes a
  `results: &mut [Val]` parameter. This allows the caller to manage the
  allocation and we can amortize-remove it in `wasmtime_func_call` by
  using space after the parameters in the `Vec<Val>` we're passing in.
  This change is naturally a breaking change and we'll want to consider
  it carefully, but mitigating factors are that most embeddings are
  likely using `TypedFunc::call` instead and this signature taking a
  mutable slice better aligns with `Func::new` which receives a mutable
  slice for the results.

Overall this change, in the benchmark of "call a nop function from the C
API" is not quite as good as #3298. It's still a bit slower, on the
order of 15ns, because there's lots of capacity checks around vectors
and the type checks are slightly less optimized than before. Overall
though this is still significantly better than today because allocations
and the rwlock to acquire the type information are both avoided. I
personally feel that this change is the best to do because it has less
of an API impact than #3298.

* Rebase issues
2021-09-21 14:07:05 -05:00

749 lines
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use anyhow::Result;
use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
use wasmtime::*;
use wasmtime_wasi::sync::WasiCtxBuilder;
#[test]
#[should_panic = "cannot use `func_new_async` without enabling async support"]
fn async_required() {
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
drop(linker.func_new_async(
"",
"",
FuncType::new(None, None),
move |_caller, _params, _results| Box::new(async { Ok(()) }),
));
}
#[test]
fn wrap_func() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.allow_shadowing(true);
linker.func_wrap("", "", || {})?;
linker.func_wrap("m", "f", |_: i32| {})?;
linker.func_wrap("m", "f2", |_: i32, _: i64| {})?;
linker.func_wrap("m2", "f", |_: f32, _: f64| {})?;
linker.func_wrap("m2", "f2", || -> i32 { 0 })?;
linker.func_wrap("", "", || -> i64 { 0 })?;
linker.func_wrap("m", "f", || -> f32 { 0.0 })?;
linker.func_wrap("m2", "f", || -> f64 { 0.0 })?;
linker.func_wrap("m3", "", || -> Option<ExternRef> { None })?;
linker.func_wrap("m3", "f", || -> Option<Func> { None })?;
linker.func_wrap("", "f1", || -> Result<(), Trap> { loop {} })?;
linker.func_wrap("", "f2", || -> Result<i32, Trap> { loop {} })?;
linker.func_wrap("", "f3", || -> Result<i64, Trap> { loop {} })?;
linker.func_wrap("", "f4", || -> Result<f32, Trap> { loop {} })?;
linker.func_wrap("", "f5", || -> Result<f64, Trap> { loop {} })?;
linker.func_wrap("", "f6", || -> Result<Option<ExternRef>, Trap> { loop {} })?;
linker.func_wrap("", "f7", || -> Result<Option<Func>, Trap> { loop {} })?;
Ok(())
}
#[test]
fn drop_func() -> Result<()> {
static HITS: AtomicUsize = AtomicUsize::new(0);
struct A;
impl Drop for A {
fn drop(&mut self) {
HITS.fetch_add(1, SeqCst);
}
}
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.allow_shadowing(true);
let a = A;
linker.func_wrap("", "", move || {
drop(&a);
})?;
assert_eq!(HITS.load(SeqCst), 0);
// Define the function again to ensure redefined functions are dropped
let a = A;
linker.func_wrap("", "", move || {
drop(&a);
})?;
assert_eq!(HITS.load(SeqCst), 1);
drop(linker);
assert_eq!(HITS.load(SeqCst), 2);
Ok(())
}
#[test]
fn drop_delayed() -> Result<()> {
static HITS: AtomicUsize = AtomicUsize::new(0);
struct A;
impl Drop for A {
fn drop(&mut self) {
HITS.fetch_add(1, SeqCst);
}
}
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
let a = A;
linker.func_wrap("", "", move || drop(&a))?;
assert_eq!(HITS.load(SeqCst), 0);
let module = Module::new(&engine, &wat::parse_str(r#"(import "" "" (func))"#)?)?;
let mut store = Store::new(&engine, ());
let func = linker.get(&mut store, "", Some("")).unwrap();
Instance::new(&mut store, &module, &[func])?;
drop(store);
assert_eq!(HITS.load(SeqCst), 0);
let mut store = Store::new(&engine, ());
let func = linker.get(&mut store, "", Some("")).unwrap();
Instance::new(&mut store, &module, &[func])?;
drop(store);
assert_eq!(HITS.load(SeqCst), 0);
drop(linker);
assert_eq!(HITS.load(SeqCst), 1);
Ok(())
}
#[test]
fn signatures_match() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.func_wrap("", "f1", || {})?;
linker.func_wrap("", "f2", || -> i32 { loop {} })?;
linker.func_wrap("", "f3", || -> i64 { loop {} })?;
linker.func_wrap("", "f4", || -> f32 { loop {} })?;
linker.func_wrap("", "f5", || -> f64 { loop {} })?;
linker.func_wrap(
"",
"f6",
|_: f32, _: f64, _: i32, _: i64, _: i32, _: Option<ExternRef>, _: Option<Func>| -> f64 {
loop {}
},
)?;
let mut store = Store::new(&engine, ());
let f = linker
.get(&mut store, "", Some("f1"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(f.ty(&store).params().collect::<Vec<_>>(), &[]);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[]);
let f = linker
.get(&mut store, "", Some("f2"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(f.ty(&store).params().collect::<Vec<_>>(), &[]);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[ValType::I32]);
let f = linker
.get(&mut store, "", Some("f3"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(f.ty(&store).params().collect::<Vec<_>>(), &[]);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[ValType::I64]);
let f = linker
.get(&mut store, "", Some("f4"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(f.ty(&store).params().collect::<Vec<_>>(), &[]);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[ValType::F32]);
let f = linker
.get(&mut store, "", Some("f5"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(f.ty(&store).params().collect::<Vec<_>>(), &[]);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[ValType::F64]);
let f = linker
.get(&mut store, "", Some("f6"))
.unwrap()
.into_func()
.unwrap();
assert_eq!(
f.ty(&store).params().collect::<Vec<_>>(),
&[
ValType::F32,
ValType::F64,
ValType::I32,
ValType::I64,
ValType::I32,
ValType::ExternRef,
ValType::FuncRef,
]
);
assert_eq!(f.ty(&store).results().collect::<Vec<_>>(), &[ValType::F64]);
Ok(())
}
#[test]
fn import_works() -> Result<()> {
static HITS: AtomicUsize = AtomicUsize::new(0);
let wasm = wat::parse_str(
r#"
(import "" "f1" (func))
(import "" "f2" (func (param i32) (result i32)))
(import "" "f3" (func (param i32) (param i64)))
(import "" "f4" (func (param i32 i64 i32 f32 f64 externref funcref)))
(func (export "run") (param externref funcref)
call 0
i32.const 0
call 1
i32.const 1
i32.add
i64.const 3
call 2
i32.const 100
i64.const 200
i32.const 300
f32.const 400
f64.const 500
local.get 0
local.get 1
call 3
)
"#,
)?;
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.func_wrap("", "f1", || {
assert_eq!(HITS.fetch_add(1, SeqCst), 0);
})?;
linker.func_wrap("", "f2", |x: i32| -> i32 {
assert_eq!(x, 0);
assert_eq!(HITS.fetch_add(1, SeqCst), 1);
1
})?;
linker.func_wrap("", "f3", |x: i32, y: i64| {
assert_eq!(x, 2);
assert_eq!(y, 3);
assert_eq!(HITS.fetch_add(1, SeqCst), 2);
})?;
linker.func_wrap(
"",
"f4",
|mut caller: Caller<'_, _>,
a: i32,
b: i64,
c: i32,
d: f32,
e: f64,
f: Option<ExternRef>,
g: Option<Func>| {
assert_eq!(a, 100);
assert_eq!(b, 200);
assert_eq!(c, 300);
assert_eq!(d, 400.0);
assert_eq!(e, 500.0);
assert_eq!(
f.as_ref().unwrap().data().downcast_ref::<String>().unwrap(),
"hello"
);
let mut results = [Val::I32(0)];
g.as_ref()
.unwrap()
.call(&mut caller, &[], &mut results)
.unwrap();
assert_eq!(results[0].unwrap_i32(), 42);
assert_eq!(HITS.fetch_add(1, SeqCst), 3);
},
)?;
let module = Module::new(&engine, &wasm)?;
let mut store = Store::new(&engine, ());
let instance = linker.instantiate(&mut store, &module)?;
let run = instance.get_func(&mut store, "run").unwrap();
let funcref = Val::FuncRef(Some(Func::wrap(&mut store, || -> i32 { 42 })));
run.call(
&mut store,
&[
Val::ExternRef(Some(ExternRef::new("hello".to_string()))),
funcref,
],
&mut [],
)?;
assert_eq!(HITS.load(SeqCst), 4);
Ok(())
}
#[test]
fn call_import_many_args() -> Result<()> {
let wasm = wat::parse_str(
r#"
(import "" "host" (func (param i32 i32 i32 i32 i32 i32 i32 i32 i32 i32)))
(func (export "run")
i32.const 1
i32.const 2
i32.const 3
i32.const 4
i32.const 5
i32.const 6
i32.const 7
i32.const 8
i32.const 9
i32.const 10
call 0
)
"#,
)?;
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.func_wrap(
"",
"host",
|x1: i32,
x2: i32,
x3: i32,
x4: i32,
x5: i32,
x6: i32,
x7: i32,
x8: i32,
x9: i32,
x10: i32| {
assert_eq!(x1, 1);
assert_eq!(x2, 2);
assert_eq!(x3, 3);
assert_eq!(x4, 4);
assert_eq!(x5, 5);
assert_eq!(x6, 6);
assert_eq!(x7, 7);
assert_eq!(x8, 8);
assert_eq!(x9, 9);
assert_eq!(x10, 10);
},
)?;
let module = Module::new(&engine, &wasm)?;
let mut store = Store::new(&engine, ());
let instance = linker.instantiate(&mut store, &module)?;
let run = instance.get_func(&mut store, "run").unwrap();
run.call(&mut store, &[], &mut [])?;
Ok(())
}
#[test]
fn call_wasm_many_args() -> Result<()> {
let wasm = wat::parse_str(
r#"
(func (export "run") (param i32 i32 i32 i32 i32 i32 i32 i32 i32 i32)
i32.const 1
get_local 0
i32.ne
if
unreachable
end
i32.const 10
get_local 9
i32.ne
if
unreachable
end
)
(func (export "test")
i32.const 1
i32.const 2
i32.const 3
i32.const 4
i32.const 5
i32.const 6
i32.const 7
i32.const 8
i32.const 9
i32.const 10
call 0
)
"#,
)?;
let engine = Engine::default();
let module = Module::new(&engine, &wasm)?;
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let run = instance.get_func(&mut store, "run").unwrap();
run.call(
&mut store,
&[
1.into(),
2.into(),
3.into(),
4.into(),
5.into(),
6.into(),
7.into(),
8.into(),
9.into(),
10.into(),
],
&mut [],
)?;
let typed_run = instance
.get_typed_func::<(i32, i32, i32, i32, i32, i32, i32, i32, i32, i32), (), _>(
&mut store, "run",
)?;
typed_run.call(&mut store, (1, 2, 3, 4, 5, 6, 7, 8, 9, 10))?;
let test = instance.get_func(&mut store, "test").unwrap();
test.call(&mut store, &[], &mut [])?;
Ok(())
}
#[test]
fn trap_smoke() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::<()>::new(&engine);
linker.func_wrap("", "", || -> Result<(), Trap> { Err(Trap::new("test")) })?;
let mut store = Store::new(&engine, ());
let f = linker
.get(&mut store, "", Some(""))
.unwrap()
.into_func()
.unwrap();
let err = f
.call(&mut store, &[], &mut [])
.unwrap_err()
.downcast::<Trap>()?;
assert!(err.to_string().contains("test"));
assert!(err.i32_exit_status().is_none());
Ok(())
}
#[test]
fn trap_import() -> Result<()> {
let wasm = wat::parse_str(
r#"
(import "" "" (func))
(start 0)
"#,
)?;
let engine = Engine::default();
let mut linker = Linker::new(&engine);
linker.func_wrap("", "", || -> Result<(), Trap> { Err(Trap::new("foo")) })?;
let module = Module::new(&engine, &wasm)?;
let mut store = Store::new(&engine, ());
let trap = linker
.instantiate(&mut store, &module)
.err()
.unwrap()
.downcast::<Trap>()?;
assert!(trap.to_string().contains("foo"));
Ok(())
}
#[test]
fn new_from_signature() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::new(&engine);
let ty = FuncType::new(None, None);
linker.func_new("", "f1", ty, |_, _, _| panic!())?;
let ty = FuncType::new(Some(ValType::I32), Some(ValType::F64));
linker.func_new("", "f2", ty, |_, _, _| panic!())?;
let mut store = Store::new(&engine, ());
let f = linker
.get(&mut store, "", Some("f1"))
.unwrap()
.into_func()
.unwrap();
assert!(f.typed::<(), (), _>(&store).is_ok());
assert!(f.typed::<(), i32, _>(&store).is_err());
assert!(f.typed::<i32, (), _>(&store).is_err());
let f = linker
.get(&mut store, "", Some("f2"))
.unwrap()
.into_func()
.unwrap();
assert!(f.typed::<(), (), _>(&store).is_err());
assert!(f.typed::<(), i32, _>(&store).is_err());
assert!(f.typed::<i32, (), _>(&store).is_err());
assert!(f.typed::<i32, f64, _>(&store).is_ok());
Ok(())
}
#[test]
fn call_wrapped_func() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::new(&engine);
let mut results = [Val::I32(0)];
linker.func_wrap("", "f1", |a: i32, b: i64, c: f32, d: f64| {
assert_eq!(a, 1);
assert_eq!(b, 2);
assert_eq!(c, 3.0);
assert_eq!(d, 4.0);
})?;
linker.func_wrap("", "f2", || 1i32)?;
linker.func_wrap("", "f3", || 2i64)?;
linker.func_wrap("", "f4", || 3.0f32)?;
linker.func_wrap("", "f5", || 4.0f64)?;
let mut store = Store::new(&engine, ());
let f = linker
.get(&mut store, "", Some("f1"))
.unwrap()
.into_func()
.unwrap();
f.call(
&mut store,
&[Val::I32(1), Val::I64(2), 3.0f32.into(), 4.0f64.into()],
&mut [],
)?;
f.typed::<(i32, i64, f32, f64), (), _>(&store)?
.call(&mut store, (1, 2, 3.0, 4.0))?;
let f = linker
.get(&mut store, "", Some("f2"))
.unwrap()
.into_func()
.unwrap();
f.call(&mut store, &[], &mut results)?;
assert_eq!(results[0].unwrap_i32(), 1);
assert_eq!(f.typed::<(), i32, _>(&store)?.call(&mut store, ())?, 1);
let f = linker
.get(&mut store, "", Some("f3"))
.unwrap()
.into_func()
.unwrap();
f.call(&mut store, &[], &mut results)?;
assert_eq!(results[0].unwrap_i64(), 2);
assert_eq!(f.typed::<(), i64, _>(&store)?.call(&mut store, ())?, 2);
let f = linker
.get(&mut store, "", Some("f4"))
.unwrap()
.into_func()
.unwrap();
f.call(&mut store, &[], &mut results)?;
assert_eq!(results[0].unwrap_f32(), 3.0);
assert_eq!(f.typed::<(), f32, _>(&store)?.call(&mut store, ())?, 3.0);
let f = linker
.get(&mut store, "", Some("f5"))
.unwrap()
.into_func()
.unwrap();
f.call(&mut store, &[], &mut results)?;
assert_eq!(results[0].unwrap_f64(), 4.0);
assert_eq!(f.typed::<(), f64, _>(&store)?.call(&mut store, ())?, 4.0);
Ok(())
}
#[test]
fn func_return_nothing() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::new(&engine);
let ty = FuncType::new(None, Some(ValType::I32));
linker.func_new("", "", ty, |_, _, _| Ok(()))?;
let mut store = Store::new(&engine, ());
let f = linker
.get(&mut store, "", Some(""))
.unwrap()
.into_func()
.unwrap();
let err = f
.call(&mut store, &[], &mut [Val::I32(0)])
.unwrap_err()
.downcast::<Trap>()?;
assert!(err
.to_string()
.contains("function attempted to return an incompatible value"));
Ok(())
}
#[test]
fn call_via_funcref() -> Result<()> {
static HITS: AtomicUsize = AtomicUsize::new(0);
struct A;
impl Drop for A {
fn drop(&mut self) {
HITS.fetch_add(1, SeqCst);
}
}
let wasm = wat::parse_str(
r#"
(table $t 1 funcref)
(type $add (func (param i32 i32) (result i32)))
(func (export "call") (param funcref) (result i32 funcref)
(table.set $t (i32.const 0) (local.get 0))
(call_indirect (type $add) (i32.const 3) (i32.const 4) (i32.const 0))
(local.get 0)
)
"#,
)?;
let engine = Engine::default();
let mut linker = Linker::new(&engine);
let a = A;
linker.func_wrap("", "", move |x: i32, y: i32| {
drop(&a);
x + y
})?;
let module = Module::new(&engine, &wasm)?;
let mut store = Store::new(&engine, ());
let instance = Instance::new(&mut store, &module, &[])?;
let f = linker
.get(&mut store, "", Some(""))
.unwrap()
.into_func()
.unwrap();
let mut results = [Val::I32(0), Val::I32(0)];
instance
.get_func(&mut store, "call")
.unwrap()
.call(&mut store, &[f.into()], &mut results)?;
assert_eq!(results[0].unwrap_i32(), 7);
{
let f = results[1].unwrap_funcref().unwrap();
let mut results = [Val::I32(0)];
f.call(&mut store, &[1.into(), 2.into()], &mut results)?;
assert_eq!(results[0].unwrap_i32(), 3);
}
assert_eq!(HITS.load(SeqCst), 0);
drop(store);
assert_eq!(HITS.load(SeqCst), 0);
drop(linker);
assert_eq!(HITS.load(SeqCst), 1);
Ok(())
}
#[test]
fn store_with_context() -> Result<()> {
struct Ctx {
called: bool,
}
let engine = Engine::default();
let mut linker = Linker::new(&engine);
linker.func_wrap("", "", |mut caller: Caller<'_, Ctx>| {
caller.data_mut().called = true;
})?;
let mut store = Store::new(&engine, Ctx { called: false });
let f = linker
.get(&mut store, "", Some(""))
.unwrap()
.into_func()
.unwrap();
f.call(&mut store, &[], &mut [])?;
assert!(store.data().called);
Ok(())
}
#[test]
fn wasi_imports() -> Result<()> {
let engine = Engine::default();
let mut linker = Linker::new(&engine);
wasmtime_wasi::add_to_linker(&mut linker, |s| s)?;
let wasm = wat::parse_str(
r#"
(import "wasi_snapshot_preview1" "proc_exit" (func $__wasi_proc_exit (param i32)))
(memory (export "memory") 0)
(func (export "_start")
(call $__wasi_proc_exit (i32.const 123))
)
"#,
)?;
let module = Module::new(&engine, wasm)?;
let mut store = Store::new(&engine, WasiCtxBuilder::new().build());
let instance = linker.instantiate(&mut store, &module)?;
let start = instance.get_typed_func::<(), (), _>(&mut store, "_start")?;
let trap = start.call(&mut store, ()).unwrap_err();
assert_eq!(trap.i32_exit_status(), Some(123));
Ok(())
}
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