Upgradeable validation functions (#918)

* upgrade primitives to allow changing validation function

* set up storage schema for old parachains code

* fix compilation errors

* fix test compilation

* add some tests for past code meta

* most of the runtime logic for code upgrades

* implement old-code pruning

* add a couple tests

* clean up remaining TODOs

* add a whole bunch of tests for runtime functionality

* remove unused function

* fix runtime compilation

* extract some primitives to parachain crate

* add validation-code upgrades to validation params and result

* extend validation params with code upgrade fields

* provide maximums to validation params

* port test-parachains

* add a code-upgrader test-parachain and tests

* fix collator tests

* move test-parachains to own folder to work around compilation errors

* fix test compilation

* update the Cargo.lock

* fix parachains tests

* remove dbg! invocation

* use new pool in code-upgrader

* bump lockfile

* link TODO to issue

polkadot/parachain/test-parachains/tests/wasm_executor/mod.rs

@@ -0,0 +1,95 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Basic parachain that adds a number as part of its state.
+
+use parachain;
+use crate::{adder, DummyExt};
+use crate::parachain::{
+	primitives::{BlockData, ValidationParams},
+	wasm_executor::EXECUTION_TIMEOUT_SEC,
+};
+
+// Code that exposes `validate_block` and loops infinitely
+const INFINITE_LOOP_CODE: &[u8] = halt::WASM_BINARY;
+
+#[test]
+fn terminates_on_timeout() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let result = parachain::wasm_executor::validate_candidate(
+		INFINITE_LOOP_CODE,
+		ValidationParams {
+			block_data: BlockData(Vec::new()),
+			parent_head: Default::default(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+	);
+	match result {
+		Err(parachain::wasm_executor::Error::Timeout) => {},
+		r => panic!("{:?}", r),
+	}
+
+	// check that another parachain can validate normaly
+	adder::execute_good_on_parent();
+}
+
+#[test]
+fn parallel_execution() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let start = std::time::Instant::now();
+
+	let pool2 = pool.clone();
+	let thread = std::thread::spawn(move ||
+		parachain::wasm_executor::validate_candidate(
+		INFINITE_LOOP_CODE,
+		ValidationParams {
+			block_data: BlockData(Vec::new()),
+			parent_head: Default::default(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool2),
+	).ok());
+	let _ = parachain::wasm_executor::validate_candidate(
+		INFINITE_LOOP_CODE,
+		ValidationParams {
+			block_data: BlockData(Vec::new()),
+			parent_head: Default::default(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+	);
+	thread.join().unwrap();
+	// total time should be < 2 x EXECUTION_TIMEOUT_SEC
+	assert!(
+		std::time::Instant::now().duration_since(start)
+		< std::time::Duration::from_secs(EXECUTION_TIMEOUT_SEC * 2)
+	);
+}