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Tweak C API for fuel

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* Ensure `store` is in the function names
* Don't abort the process on `add_fuel` when fuel isn't configured
* Allow learning about failure in both `add_fuel` and `fuel_consumed`
This commit is contained in:
Alex Crichton
2021-02-09 07:16:59 -08:00
parent 5b55ba8053
commit de27fbe20f
5 changed files with 37 additions and 17 deletions
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14
crates/c-api/include/wasmtime.h
View File

@@ -655,17 +655,23 @@ WASM_API_EXTERN own wasmtime_interrupt_handle_t *wasmtime_interrupt_handle_new(w
*
* Note that at this time when fuel is entirely consumed it will cause
* wasm to trap. More usages of fuel are planned for the future.
*
* If fuel is not enabled within this store then an error is returned. If fuel
* is successfully added then NULL is returned.
*/
WASM_API_EXTERN void wasmtime_add_fuel(wasm_store_t *store, uint64_t fuel);
WASM_API_EXTERN own wasmtime_error_t *wasmtime_store_add_fuel(wasm_store_t *store, uint64_t fuel);
/**
* \brief Returns the amount of fuel consumed by this store's execution so far.
*
* If fuel consumption is not enabled via #wasmtime_config_consume_fuel_set
* then this function will return 0. Also note that fuel, if enabled, must be
* originally configured via #wasmtime_add_fuel.
* then this function will return false. Otherwise true is returned and the
* fuel parameter is filled in with fuel consuemd so far.
*
* Also note that fuel, if enabled, must be originally configured via
* #wasmtime_store_add_fuel.
*/
WASM_API_EXTERN uint64_t wasmtime_fuel_consumed(wasm_store_t *store);
WASM_API_EXTERN bool wasmtime_store_fuel_consumed(wasm_store_t *store, uint64_t *fuel);
/**
* \brief Requests that WebAssembly code running in the store attached to this

19
crates/c-api/src/store.rs
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@@ -1,4 +1,4 @@
use crate::wasm_engine_t;
use crate::{wasm_engine_t, wasmtime_error_t};
use wasmtime::{InterruptHandle, Store};
#[repr(C)]
@@ -44,11 +44,20 @@ pub extern "C" fn wasmtime_interrupt_handle_interrupt(handle: &wasmtime_interrup
}
#[no_mangle]
pub extern "C" fn wasmtime_add_fuel(store: &wasm_store_t, fuel: u64) {
store.store.add_fuel(fuel);
pub extern "C" fn wasmtime_store_add_fuel(
store: &wasm_store_t,
fuel: u64,
) -> Option<Box<wasmtime_error_t>> {
crate::handle_result(store.store.add_fuel(fuel), |()| {})
}
#[no_mangle]
pub extern "C" fn wasmtime_fuel_consumed(store: &wasm_store_t) -> u64 {
store.store.fuel_consumed().unwrap_or(0)
pub extern "C" fn wasmtime_store_fuel_consumed(store: &wasm_store_t, fuel: &mut u64) -> bool {
match store.store.fuel_consumed() {
Some(amt) => {
*fuel = amt;
true
}
None => false,
}
}