Remove sp_tasks::spawn API and related code + host functions

Cargo.toml

@@ -98,7 +98,6 @@ members = [
 	"frame/election-provider-support/solution-type/fuzzer",
 	"frame/examples/basic",
 	"frame/examples/offchain-worker",
-	"frame/examples/parallel",
 	"frame/executive",
 	"frame/gilt",
 	"frame/grandpa",
@@ -204,7 +203,6 @@ members = [
 	"primitives/state-machine",
 	"primitives/std",
 	"primitives/storage",
-	"primitives/tasks",
 	"primitives/test-primitives",
 	"primitives/timestamp",
 	"primitives/tracing",

client/executor/Cargo.toml

@@ -31,7 +31,6 @@ sp-externalities = { version = "0.12.0", path = "../../primitives/externalities"
 sp-io = { version = "6.0.0", path = "../../primitives/io" }
 sp-panic-handler = { version = "4.0.0", path = "../../primitives/panic-handler" }
 sp-runtime-interface = { version = "6.0.0", path = "../../primitives/runtime-interface" }
-sp-tasks = { version = "4.0.0-dev", path = "../../primitives/tasks" }
 sp-trie = { version = "6.0.0", path = "../../primitives/trie" }
 sp-version = { version = "5.0.0", path = "../../primitives/version" }
 sp-wasm-interface = { version = "6.0.0", path = "../../primitives/wasm-interface" }

client/executor/runtime-test/Cargo.toml

@@ -19,7 +19,6 @@ sp-io = { version = "6.0.0", default-features = false, features = ["improved_pan
 sp-runtime = { version = "6.0.0", default-features = false, path = "../../../primitives/runtime" }
 sp-sandbox = { version = "0.10.0-dev", default-features = false, path = "../../../primitives/sandbox" }
 sp-std = { version = "4.0.0", default-features = false, path = "../../../primitives/std" }
-sp-tasks = { version = "4.0.0-dev", default-features = false, path = "../../../primitives/tasks" }
 
 [build-dependencies]
 substrate-wasm-builder = { version = "5.0.0-dev", path = "../../../utils/wasm-builder" }
@@ -32,5 +31,4 @@ std = [
 	"sp-runtime/std",
 	"sp-sandbox/std",
 	"sp-std/std",
-	"sp-tasks/std",
 ]

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

@@ -318,24 +318,6 @@ sp_core::wasm_export_functions! {
 		message_slice.copy_from_slice(test_message);
 	}
 
-	fn test_spawn() {
-		let data = vec![1u8, 2u8];
-		let data_new = sp_tasks::spawn(tasks::incrementer, data).join();
-
-		assert_eq!(data_new, vec![2u8, 3u8]);
-	}
-
-	fn test_nested_spawn() {
-		let data = vec![7u8, 13u8];
-		let data_new = sp_tasks::spawn(tasks::parallel_incrementer, data).join();
-
-		assert_eq!(data_new, vec![10u8, 16u8]);
-	}
-
-	fn test_panic_in_spawned() {
-		sp_tasks::spawn(tasks::panicker, vec![]).join();
-	}
-
 	fn test_return_i8() -> i8 {
 		-66
 	}
@@ -358,25 +340,6 @@ sp_core::wasm_export_functions! {
 	}
 }
 
-#[cfg(not(feature = "std"))]
-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_tasks::spawn(incrementer, first).join();
-		second
-	}
-}
-
 /// A macro to define a test entrypoint for each available sandbox executor.
 macro_rules! wasm_export_sandbox_test_functions {
 	(

client/executor/src/integration_tests/mod.rs

@@ -770,33 +770,6 @@ fn wasm_tracing_should_work(wasm_method: WasmExecutionMethod) {
 	assert_eq!(len, 2);
 }
 
-test_wasm_execution!(spawning_runtime_instance_should_work);
-fn spawning_runtime_instance_should_work(wasm_method: WasmExecutionMethod) {
-	let mut ext = TestExternalities::default();
-	let mut ext = ext.ext();
-
-	call_in_wasm("test_spawn", &[], wasm_method, &mut ext).unwrap();
-}
-
-test_wasm_execution!(spawning_runtime_instance_nested_should_work);
-fn spawning_runtime_instance_nested_should_work(wasm_method: WasmExecutionMethod) {
-	let mut ext = TestExternalities::default();
-	let mut ext = ext.ext();
-
-	call_in_wasm("test_nested_spawn", &[], wasm_method, &mut ext).unwrap();
-}
-
-test_wasm_execution!(panic_in_spawned_instance_panics_on_joining_its_result);
-fn panic_in_spawned_instance_panics_on_joining_its_result(wasm_method: WasmExecutionMethod) {
-	let mut ext = TestExternalities::default();
-	let mut ext = ext.ext();
-
-	let error_result =
-		call_in_wasm("test_panic_in_spawned", &[], wasm_method, &mut ext).unwrap_err();
-
-	assert!(error_result.to_string().contains("Spawned task"));
-}
-
 test_wasm_execution!(memory_is_cleared_between_invocations);
 fn memory_is_cleared_between_invocations(wasm_method: WasmExecutionMethod) {
 	// This is based on the code generated by compiling a runtime *without*