Change the injection count of fuel in a store from u32 to u64 (#3048)

* Change the injection count of fuel in a store from u32 to u64

This commit updates the type of the amount of times to inject fuel in
the `out_of_fuel_async_yield` to `u64` instead of `u32`. This should
allow effectively infinite fuel to get injected, even if a small amount
of fuel is injected per iteration.

Closes #2927
Closes #3046

* Fix tokio example

Author: alexcrichton

crates/wasmtime/src/func.rs

@@ -1606,7 +1606,7 @@ impl<T> Caller<'_, T> {
     ///
     /// For more information see
     /// [`Store::out_of_fuel_async_yield`](crate::Store::out_of_fuel_async_yield)
-    pub fn out_of_fuel_async_yield(&mut self, injection_count: u32, fuel_to_inject: u64) {
+    pub fn out_of_fuel_async_yield(&mut self, injection_count: u64, fuel_to_inject: u64) {
         self.store
             .out_of_fuel_async_yield(injection_count, fuel_to_inject)
     }

crates/wasmtime/src/store.rs

@@ -178,7 +178,7 @@ struct StoreInstance {
 enum OutOfGas {
     Trap,
     InjectFuel {
-        injection_count: u32,
+        injection_count: u64,
         fuel_to_inject: u64,
     },
 }
@@ -558,7 +558,7 @@ impl<T> Store<T> {
     ///
     /// This method will panic if it is not called on a store associated with an [async
     /// config](crate::Config::async_support).
-    pub fn out_of_fuel_async_yield(&mut self, injection_count: u32, fuel_to_inject: u64) {
+    pub fn out_of_fuel_async_yield(&mut self, injection_count: u64, fuel_to_inject: u64) {
         self.inner
             .out_of_fuel_async_yield(injection_count, fuel_to_inject)
     }
@@ -655,7 +655,7 @@ impl<'a, T> StoreContextMut<'a, T> {
     /// runs out.
     ///
     /// For more information see [`Store::out_of_fuel_async_yield`]
-    pub fn out_of_fuel_async_yield(&mut self, injection_count: u32, fuel_to_inject: u64) {
+    pub fn out_of_fuel_async_yield(&mut self, injection_count: u64, fuel_to_inject: u64) {
         self.0
             .out_of_fuel_async_yield(injection_count, fuel_to_inject)
     }
@@ -838,7 +838,7 @@ impl StoreInnermost {
         self.out_of_gas_behavior = OutOfGas::Trap;
     }
 
-    fn out_of_fuel_async_yield(&mut self, injection_count: u32, fuel_to_inject: u64) {
+    fn out_of_fuel_async_yield(&mut self, injection_count: u64, fuel_to_inject: u64) {
         assert!(
             self.async_support(),
             "cannot use `out_of_fuel_async_yield` without enabling async support in the config"

examples/tokio/main.rs

@@ -95,8 +95,8 @@ async fn run_wasm(inputs: Inputs) -> Result<(), Error> {
     let mut store = Store::new(&inputs.env.engine, wasi);
 
     // WebAssembly execution will be paused for an async yield every time it
-    // consumes 10000 fuel. Fuel will be refilled u32::MAX times.
-    store.out_of_fuel_async_yield(u32::MAX, 10000);
+    // consumes 10000 fuel. Fuel will be refilled u64::MAX times.
+    store.out_of_fuel_async_yield(u64::MAX, 10000);
 
     // Instantiate into our own unique store using the shared linker, afterwards
     // acquiring the `_start` function for the module and executing it.

tests/all/async_functions.rs

@@ -392,7 +392,7 @@ fn iloop_with_fuel() {
 fn fuel_eventually_finishes() {
     let engine = Engine::new(Config::new().async_support(true).consume_fuel(true)).unwrap();
     let mut store = Store::new(&engine, ());
-    store.out_of_fuel_async_yield(u32::max_value(), 10);
+    store.out_of_fuel_async_yield(u64::max_value(), 10);
     let module = Module::new(
         &engine,
         "