tests and docs

client/executor/runtime-test/src/lib.rs

@@ -312,29 +312,40 @@ sp_core::wasm_export_functions! {
 
 	fn test_fork() {
 		let data = vec![1u8, 2u8];
-		let data_new = sp_io::tasks::spawn(incrementer, data).join();
+		let data_new = sp_io::tasks::spawn(tasks::incrementer, data).join();
 
 		assert_eq!(data_new, vec![2u8, 3u8]);
 	}
 
 	fn test_nested_fork() {
 		let data = vec![7u8, 13u8];
-		let data_new = sp_io::tasks::spawn(parallel_incrementer, data).join();
+		let data_new = sp_io::tasks::spawn(tasks::parallel_incrementer, data).join();
 
 		assert_eq!(data_new, vec![10u8, 16u8]);
 	}
- }
 
- #[cfg(not(feature = "std"))]
- fn incrementer(data: Vec<u8>) -> Vec<u8> {
-	data.into_iter().map(|v| v + 1).collect()
+	fn test_panic_in_fork_panics_on_join() {
+		let data_new = sp_io::tasks::spawn(tasks::panicker, vec![]).join();
+	}
  }
 
  #[cfg(not(feature = "std"))]
- fn parallel_incrementer(data: Vec<u8>) -> Vec<u8> {
-	let first = data.into_iter().map(|v| v + 2).collect::<Vec<_>>();
-	let second = sp_io::tasks::spawn(incrementer, first).join();
-	second
+ mod tasks {
+	use sp_std::prelude::*;
+
+	pub fn incrementer(data: Vec<u8>) -> Vec<u8> {
+	   data.into_iter().map(|v| v + 1).collect()
+	}
+
+	pub fn panicker(_: Vec<u8>) -> Vec<u8> {
+		panic!()
+	}
+
+	pub fn parallel_incrementer(data: Vec<u8>) -> Vec<u8> {
+	   let first = data.into_iter().map(|v| v + 2).collect::<Vec<_>>();
+	   let second = sp_io::tasks::spawn(incrementer, first).join();
+	   second
+	}
  }
 
 #[cfg(not(feature = "std"))]

client/executor/src/integration_tests/mod.rs

@@ -788,3 +788,21 @@ fn nested_forking_should_work(wasm_method: WasmExecutionMethod) {
 	).unwrap();
 }
 
+#[test_case(WasmExecutionMethod::Interpreted)]
+#[cfg_attr(feature = "wasmtime", test_case(WasmExecutionMethod::Compiled))]
+fn panic_in_fork_panics_on_join(wasm_method: WasmExecutionMethod) {
+
+	let mut ext = TestExternalities::default();
+	let mut ext = ext.ext();
+
+	if let Err(e) = call_in_wasm(
+		"test_panic_in_fork_panics_on_join",
+		&[],
+		wasm_method,
+		&mut ext,
+	) {
+		assert!(format!("{}", e).contains("Runtime panicked: No signal from forked execution"));
+	} else {
+		panic!("wasm call should be error")
+	}
+}

client/executor/src/native_executor.rs

@@ -323,7 +323,7 @@ impl sp_io::RuntimeSpawn for RuntimeInstanceSpawn {
 
 					// FIXME: Should be refactored to shared "instance factory".
 					// Instantiating wasm here every time is suboptimal at the moment, shared
-					// pool of istances should be used.
+					// pool of instances should be used.
 					let instance = module.new_instance().expect("Failed to create new instance for fork");
 
 					instance.call(

primitives/io/src/tasks.rs

@@ -18,7 +18,6 @@
 //! Runtime tasks.
 //!
 //! Contains runtime-usable functions for spawning parallel purely computational tasks.
-//!
 
 #[cfg(feature = "std")]
 mod inner {
@@ -79,19 +78,19 @@ mod inner {
 #[cfg(not(feature = "std"))]
 mod inner {
 
+	use core::mem;
 	use sp_std::{vec::Vec, prelude::Box};
 
-
-	/// Dynamic dispatch of wasm blob.
+	/// Dispatch wrapper for wasm blob.
 	///
-	/// Arguments are expected to be scale encoded in vector at address `payload_ptr` with length of
-	/// `payload_len`.
+	/// Serves as trampoline to call any rust function with (Vec<u8>) -> Vec<u8> compiled
+	/// into the runtime.
 	///
-	/// Arguments: function pointer (u32), input (Vec<u8>).
+	/// Function item should be provided with `func_ref`. Argument for the call
+	/// will be generated from bytes at `payload_ptr` with `payload_len`.
 	///
-	/// Function at pointer is expected to have signature of `(Vec<u8>) -> Vec<u8>`. Since this dynamic dispatch
-	/// function and the invoked function are compiled with the same compiler, there should be no problem with
-	/// ABI incompatibility.
+	/// NOTE: Since this dynamic dispatch function and the invoked function are compiled with
+	/// the same compiler, there should be no problem with ABI incompatibility.
 	extern "C" fn dispatch_wrapper(func_ref: u32, payload_ptr: u32, payload_len: u32) -> u64 {
 		let payload_len = payload_len as usize;
 		let output = unsafe {
@@ -107,13 +106,11 @@ mod inner {
 	pub fn spawn(entry_point: fn(Vec<u8>) -> Vec<u8>, payload: Vec<u8>) -> DataJoinHandle {
 		let func_ptr: usize = unsafe { core::mem::transmute(entry_point) };
 
-		let handle = unsafe {
-			crate::runtime_tasks::spawn(
-				dispatch_wrapper as usize as _,
-				func_ptr as u32,
-				payload,
-			)
-		};
+		let handle = crate::runtime_tasks::spawn(
+			dispatch_wrapper as usize as _,
+			func_ptr as u32,
+			payload,
+		);
 		DataJoinHandle { handle }
 	}