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/Cargo.lock

@@ -10,34 +10,6 @@ dependencies = [
  "regex",
 ]
 
-[[package]]
-name = "adder"
-version = "0.7.29-pre1"
-dependencies = [
- "dlmalloc",
- "parity-scale-codec",
- "polkadot-parachain",
- "sp-io",
- "substrate-wasm-builder-runner 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "tiny-keccak 1.5.0",
-]
-
-[[package]]
-name = "adder-collator"
-version = "0.1.0"
-dependencies = [
- "adder",
- "futures 0.3.4",
- "parity-scale-codec",
- "parking_lot 0.10.0",
- "polkadot-collator",
- "polkadot-parachain",
- "polkadot-primitives",
- "sc-client",
- "sc-client-api",
- "sp-core",
-]
-
 [[package]]
 name = "adler32"
 version = "1.0.4"
@@ -1778,13 +1750,6 @@ dependencies = [
  "tokio-util",
 ]
 
-[[package]]
-name = "halt"
-version = "0.7.29-pre1"
-dependencies = [
- "substrate-wasm-builder-runner 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "hash-db"
 version = "0.15.2"
@@ -4294,9 +4259,7 @@ dependencies = [
 name = "polkadot-parachain"
 version = "0.7.29-pre1"
 dependencies = [
- "adder",
  "derive_more 0.99.3",
- "halt",
  "log 0.4.8",
  "parity-scale-codec",
  "parking_lot 0.10.0",
@@ -4309,7 +4272,6 @@ dependencies = [
  "sp-runtime-interface",
  "sp-std",
  "sp-wasm-interface",
- "tiny-keccak 1.5.0",
 ]
 
 [[package]]
@@ -4317,7 +4279,6 @@ name = "polkadot-primitives"
 version = "0.7.29-pre1"
 dependencies = [
  "bitvec",
- "pallet-babe",
  "parity-scale-codec",
  "polkadot-parachain",
  "pretty_assertions",
@@ -7524,6 +7485,65 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "test-parachain-adder"
+version = "0.7.29-pre1"
+dependencies = [
+ "dlmalloc",
+ "parity-scale-codec",
+ "polkadot-parachain",
+ "sp-io",
+ "substrate-wasm-builder-runner 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tiny-keccak 1.5.0",
+]
+
+[[package]]
+name = "test-parachain-adder-collator"
+version = "0.1.0"
+dependencies = [
+ "futures 0.3.4",
+ "parity-scale-codec",
+ "parking_lot 0.10.0",
+ "polkadot-collator",
+ "polkadot-parachain",
+ "polkadot-primitives",
+ "sc-client",
+ "sc-client-api",
+ "sp-core",
+ "test-parachain-adder",
+]
+
+[[package]]
+name = "test-parachain-code-upgrader"
+version = "0.7.22"
+dependencies = [
+ "dlmalloc",
+ "parity-scale-codec",
+ "polkadot-parachain",
+ "sp-io",
+ "substrate-wasm-builder-runner 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tiny-keccak 1.5.0",
+]
+
+[[package]]
+name = "test-parachain-halt"
+version = "0.7.29-pre1"
+dependencies = [
+ "substrate-wasm-builder-runner 1.0.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "test-parachains"
+version = "0.7.22"
+dependencies = [
+ "parity-scale-codec",
+ "polkadot-parachain",
+ "test-parachain-adder",
+ "test-parachain-code-upgrader",
+ "test-parachain-halt",
+ "tiny-keccak 1.5.0",
+]
+
 [[package]]
 name = "textwrap"
 version = "0.11.0"

polkadot/Cargo.toml

@@ -41,13 +41,15 @@ members = [
 	"service",
 	"validation",
 
-	"test-parachains/adder",
+	"parachain/test-parachains",
-	"test-parachains/adder/collator",
+	"parachain/test-parachains/adder",
+	"parachain/test-parachains/adder/collator",
+	"parachain/test-parachains/code-upgrader",
 ]
 exclude = [
 	"runtime/polkadot/wasm",
 	"runtime/kusama/wasm",
-	"test-parachains/adder/wasm",
+	"parachain/test-parachains/adder/wasm",
 ]
 
 [badges]

polkadot/collator/src/lib.rs

@@ -59,7 +59,7 @@ use polkadot_primitives::{
 	BlockId, Hash, Block,
 	parachain::{
 		self, BlockData, DutyRoster, HeadData, Id as ParaId,
-		PoVBlock, ValidatorId, CollatorPair, LocalValidationData
+		PoVBlock, ValidatorId, CollatorPair, LocalValidationData, GlobalValidationSchedule,
 	}
 };
 use polkadot_cli::{
@@ -154,7 +154,8 @@ pub trait ParachainContext: Clone {
 	fn produce_candidate(
 		&mut self,
 		relay_parent: Hash,
-		status: LocalValidationData,
+		global_validation: GlobalValidationSchedule,
+		local_validation: LocalValidationData,
 	) -> Self::ProduceCandidate;
 }
 
@@ -162,6 +163,7 @@ pub trait ParachainContext: Clone {
 pub async fn collate<P>(
 	relay_parent: Hash,
 	local_id: ParaId,
+	global_validation: GlobalValidationSchedule,
 	local_validation_data: LocalValidationData,
 	mut para_context: P,
 	key: Arc<CollatorPair>,
@@ -173,6 +175,7 @@ pub async fn collate<P>(
 {
 	let (block_data, head_data) = para_context.produce_candidate(
 		relay_parent,
+		global_validation,
 		local_validation_data,
 	).map_err(Error::Collator).await?;
 
@@ -281,6 +284,7 @@ fn build_collator_service<S, P, Extrinsic>(
 
 			let work = future::lazy(move |_| {
 				let api = client.runtime_api();
+				let global_validation = try_fr!(api.global_validation_schedule(&id));
 				let local_validation = match try_fr!(api.local_validation_data(&id, para_id)) {
 					Some(local_validation) => local_validation,
 					None => return future::Either::Left(future::ok(())),
@@ -297,6 +301,7 @@ fn build_collator_service<S, P, Extrinsic>(
 				let collation_work = collate(
 					relay_parent,
 					para_id,
+					global_validation,
 					local_validation,
 					parachain_context,
 					key,
@@ -427,6 +432,7 @@ mod tests {
 		fn produce_candidate(
 			&mut self,
 			_relay_parent: Hash,
+			_global: GlobalValidationSchedule,
 			_local_validation: LocalValidationData,
 		) -> Self::ProduceCandidate {
 			// send messages right back.

polkadot/parachain/Cargo.toml

@@ -6,13 +6,18 @@ description = "Types and utilities for creating and working with parachains"
 edition = "2018"
 
 [dependencies]
-codec = { package = "parity-scale-codec", version = "1.3.0", default-features = false, features = [ "derive" ] }
+# note: special care is taken to avoid inclusion of `sp-io` externals when compiling
-derive_more = { version = "0.99.2", optional = true }
+# this crate for WASM. This is critical to avoid forcing all parachain WASM into implementing
-serde = { version = "1.0.102", default-features = false, features = [ "derive" ], optional = true }
+# various unnecessary Substrate-specific endpoints.
+codec = { package = "parity-scale-codec", version = "1.1.0", default-features = false, features = [ "derive" ] }
 sp-std = { package = "sp-std", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
-sp-runtime-interface = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-wasm-interface = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+
+# all optional crates.
+derive_more = { version = "0.99.2", optional = true }
+serde = { version = "1.0.102", default-features = false, features = [ "derive" ], optional = true }
+sp-runtime-interface = { git = "https://github.com/paritytech/substrate", branch = "master", optional = true, default-features = false }
 sp-externalities = { git = "https://github.com/paritytech/substrate", branch = "master", optional = true }
 sc-executor = { git = "https://github.com/paritytech/substrate", branch = "master", optional = true }
 sp-io = { git = "https://github.com/paritytech/substrate", branch = "master", optional = true }
@@ -22,14 +27,9 @@ log = { version = "0.4.8", optional = true }
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
 shared_memory = { version = "0.10.0", optional = true }
 
-[dev-dependencies]
-tiny-keccak = "1.5.0"
-adder = { path = "../test-parachains/adder" }
-halt = { path = "../test-parachains/halt" }
-
 [features]
 default = ["std"]
-wasm-api = []
+wasm-api = ["sp-runtime-interface"]
 std = [
 	"codec/std",
 	"derive_more",
@@ -39,6 +39,7 @@ std = [
 	"sp-core/std",
 	"parking_lot",
 	"log",
+	"sp-runtime-interface",
 	"sp-runtime-interface/std",
 	"sp-externalities",
 	"sc-executor",

polkadot/parachain/src/lib.rs

@@ -45,182 +45,9 @@
 
 #[cfg(feature = "std")]
 pub mod wasm_executor;
+pub mod primitives;
 
 mod wasm_api;
 
-use sp_std::vec::Vec;
-
-use codec::{Encode, Decode, CompactAs};
-use sp_core::{RuntimeDebug, TypeId};
-
 #[cfg(all(not(feature = "std"), feature = "wasm-api"))]
 pub use wasm_api::*;
-
-/// Validation parameters for evaluating the parachain validity function.
-// TODO: balance downloads (https://github.com/paritytech/polkadot/issues/220)
-#[derive(PartialEq, Eq, Decode)]
-#[cfg_attr(feature = "std", derive(Debug, Encode))]
-pub struct ValidationParams {
-	/// The collation body.
-	pub block_data: Vec<u8>,
-	/// Previous head-data.
-	pub parent_head: Vec<u8>,
-}
-
-/// The result of parachain validation.
-// TODO: egress and balance uploads (https://github.com/paritytech/polkadot/issues/220)
-#[derive(PartialEq, Eq, Encode)]
-#[cfg_attr(feature = "std", derive(Debug, Decode))]
-pub struct ValidationResult {
-	/// New head data that should be included in the relay chain state.
-	pub head_data: Vec<u8>,
-}
-
-/// Unique identifier of a parachain.
-#[derive(
-	Clone, CompactAs, Copy, Decode, Default, Encode, Eq,
-	Hash, Ord, PartialEq, PartialOrd, RuntimeDebug,
-)]
-#[cfg_attr(feature = "std", derive(serde::Serialize, serde::Deserialize, derive_more::Display))]
-pub struct Id(u32);
-
-impl TypeId for Id {
-	const TYPE_ID: [u8; 4] = *b"para";
-}
-
-/// Type for determining the active set of parachains.
-pub trait ActiveThreads {
-	/// Return the current ordered set of `Id`s of active parathreads.
-	fn active_threads() -> Vec<Id>;
-}
-
-impl From<Id> for u32 {
-	fn from(x: Id) -> Self { x.0 }
-}
-
-impl From<u32> for Id {
-	fn from(x: u32) -> Self { Id(x) }
-}
-
-const USER_INDEX_START: u32 = 1000;
-
-/// The ID of the first user (non-system) parachain.
-pub const LOWEST_USER_ID: Id = Id(USER_INDEX_START);
-
-impl Id {
-	/// Create an `Id`.
-	pub const fn new(id: u32) -> Self {
-		Self(id)
-	}
-
-	/// Returns `true` if this parachain runs with system-level privileges.
-	pub fn is_system(&self) -> bool { self.0 < USER_INDEX_START }
-}
-
-impl sp_std::ops::Add<u32> for Id {
-	type Output = Self;
-
-	fn add(self, other: u32) -> Self {
-		Self(self.0 + other)
-	}
-}
-
-// TODO: Remove all of this, move sp-runtime::AccountIdConversion to own crate and and use that.
-// #360
-struct TrailingZeroInput<'a>(&'a [u8]);
-impl<'a> codec::Input for TrailingZeroInput<'a> {
-	fn remaining_len(&mut self) -> Result<Option<usize>, codec::Error> {
-		Ok(None)
-	}
-
-	fn read(&mut self, into: &mut [u8]) -> Result<(), codec::Error> {
-		let len = into.len().min(self.0.len());
-		into[..len].copy_from_slice(&self.0[..len]);
-		for i in &mut into[len..] {
-			*i = 0;
-		}
-		self.0 = &self.0[len..];
-		Ok(())
-	}
-}
-
-/// This type can be converted into and possibly from an AccountId (which itself is generic).
-pub trait AccountIdConversion<AccountId>: Sized {
-	/// Convert into an account ID. This is infallible.
-	fn into_account(&self) -> AccountId;
-
- 	/// Try to convert an account ID into this type. Might not succeed.
-	fn try_from_account(a: &AccountId) -> Option<Self>;
-}
-
-/// Format is b"para" ++ encode(parachain ID) ++ 00.... where 00... is indefinite trailing
-/// zeroes to fill AccountId.
-impl<T: Encode + Decode + Default> AccountIdConversion<T> for Id {
-	fn into_account(&self) -> T {
-		(b"para", self).using_encoded(|b|
-			T::decode(&mut TrailingZeroInput(b))
-		).unwrap_or_default()
-	}
-
- 	fn try_from_account(x: &T) -> Option<Self> {
-		x.using_encoded(|d| {
-			if &d[0..4] != b"para" { return None }
-			let mut cursor = &d[4..];
-			let result = Decode::decode(&mut cursor).ok()?;
-			if cursor.iter().all(|x| *x == 0) {
-				Some(result)
-			} else {
-				None
-			}
-		})
-	}
-}
-
-/// Which origin a parachain's message to the relay chain should be dispatched from.
-#[derive(Clone, PartialEq, Eq, Encode, Decode)]
-#[cfg_attr(feature = "std", derive(Debug))]
-#[repr(u8)]
-pub enum ParachainDispatchOrigin {
-	/// As a simple `Origin::Signed`, using `ParaId::account_id` as its value. This is good when
-	/// interacting with standard modules such as `balances`.
-	Signed,
-	/// As the special `Origin::Parachain(ParaId)`. This is good when interacting with parachain-
-	/// aware modules which need to succinctly verify that the origin is a parachain.
-	Parachain,
-	/// As the simple, superuser `Origin::Root`. This can only be done on specially permissioned
-	/// parachains.
-	Root,
-}
-
-impl sp_std::convert::TryFrom<u8> for ParachainDispatchOrigin {
-	type Error = ();
-	fn try_from(x: u8) -> core::result::Result<ParachainDispatchOrigin, ()> {
-		const SIGNED: u8 = ParachainDispatchOrigin::Signed as u8;
-		const PARACHAIN: u8 = ParachainDispatchOrigin::Parachain as u8;
-		Ok(match x {
-			SIGNED => ParachainDispatchOrigin::Signed,
-			PARACHAIN => ParachainDispatchOrigin::Parachain,
-			_ => return Err(()),
-		})
-	}
-}
-
-/// A message from a parachain to its Relay Chain.
-#[derive(Clone, PartialEq, Eq, Encode, Decode, sp_runtime_interface::pass_by::PassByCodec)]
-#[cfg_attr(feature = "std", derive(Debug))]
-pub struct UpwardMessage {
-	/// The origin for the message to be sent from.
-	pub origin: ParachainDispatchOrigin,
-	/// The message data.
-	pub data: Vec<u8>,
-}
-
-/// An incoming message.
-#[derive(PartialEq, Eq, Decode)]
-#[cfg_attr(feature = "std", derive(Debug, Encode))]
-pub struct IncomingMessage {
-	/// The source parachain.
-	pub source: Id,
-	/// The data of the message.
-	pub data: Vec<u8>,
-}

polkadot/parachain/src/primitives.rs

@@ -0,0 +1,221 @@
+// Copyright 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/>.
+
+//! Primitive types which are strictly necessary from a parachain-execution point
+//! of view.
+
+use sp_std::vec::Vec;
+
+use codec::{Encode, Decode, CompactAs};
+use sp_core::{RuntimeDebug, TypeId};
+
+#[cfg(feature = "std")]
+use serde::{Serialize, Deserialize};
+
+#[cfg(feature = "std")]
+use sp_core::bytes;
+
+/// The block number of the relay chain.
+/// 32-bits will allow for 136 years of blocks assuming 1 block per second.
+pub type RelayChainBlockNumber = u32;
+
+/// Parachain head data included in the chain.
+#[derive(PartialEq, Eq, Clone, PartialOrd, Ord, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug, Default))]
+pub struct HeadData(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
+
+/// Parachain validation code.
+#[derive(Default, PartialEq, Eq, Clone, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
+pub struct ValidationCode(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
+
+/// Parachain block data.
+///
+/// Contains everything required to validate para-block, may contain block and witness data.
+#[derive(PartialEq, Eq, Clone, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
+pub struct BlockData(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
+
+/// Unique identifier of a parachain.
+#[derive(
+	Clone, CompactAs, Copy, Decode, Default, Encode, Eq,
+	Hash, Ord, PartialEq, PartialOrd, RuntimeDebug,
+)]
+#[cfg_attr(feature = "std", derive(serde::Serialize, serde::Deserialize, derive_more::Display))]
+pub struct Id(u32);
+
+impl TypeId for Id {
+	const TYPE_ID: [u8; 4] = *b"para";
+}
+
+impl From<Id> for u32 {
+	fn from(x: Id) -> Self { x.0 }
+}
+
+impl From<u32> for Id {
+	fn from(x: u32) -> Self { Id(x) }
+}
+
+const USER_INDEX_START: u32 = 1000;
+
+/// The ID of the first user (non-system) parachain.
+pub const LOWEST_USER_ID: Id = Id(USER_INDEX_START);
+
+impl Id {
+	/// Create an `Id`.
+	pub const fn new(id: u32) -> Self {
+		Self(id)
+	}
+
+	/// Returns `true` if this parachain runs with system-level privileges.
+	pub fn is_system(&self) -> bool { self.0 < USER_INDEX_START }
+}
+
+impl sp_std::ops::Add<u32> for Id {
+	type Output = Self;
+
+	fn add(self, other: u32) -> Self {
+		Self(self.0 + other)
+	}
+}
+
+/// This type can be converted into and possibly from an AccountId (which itself is generic).
+pub trait AccountIdConversion<AccountId>: Sized {
+	/// Convert into an account ID. This is infallible.
+	fn into_account(&self) -> AccountId;
+
+ 	/// Try to convert an account ID into this type. Might not succeed.
+	fn try_from_account(a: &AccountId) -> Option<Self>;
+}
+
+// TODO: Remove all of this, move sp-runtime::AccountIdConversion to own crate and and use that.
+// #360
+struct TrailingZeroInput<'a>(&'a [u8]);
+impl<'a> codec::Input for TrailingZeroInput<'a> {
+	fn remaining_len(&mut self) -> Result<Option<usize>, codec::Error> {
+		Ok(None)
+	}
+
+	fn read(&mut self, into: &mut [u8]) -> Result<(), codec::Error> {
+		let len = into.len().min(self.0.len());
+		into[..len].copy_from_slice(&self.0[..len]);
+		for i in &mut into[len..] {
+			*i = 0;
+		}
+		self.0 = &self.0[len..];
+		Ok(())
+	}
+}
+
+/// Format is b"para" ++ encode(parachain ID) ++ 00.... where 00... is indefinite trailing
+/// zeroes to fill AccountId.
+impl<T: Encode + Decode + Default> AccountIdConversion<T> for Id {
+	fn into_account(&self) -> T {
+		(b"para", self).using_encoded(|b|
+			T::decode(&mut TrailingZeroInput(b))
+		).unwrap_or_default()
+	}
+
+ 	fn try_from_account(x: &T) -> Option<Self> {
+		x.using_encoded(|d| {
+			if &d[0..4] != b"para" { return None }
+			let mut cursor = &d[4..];
+			let result = Decode::decode(&mut cursor).ok()?;
+			if cursor.iter().all(|x| *x == 0) {
+				Some(result)
+			} else {
+				None
+			}
+		})
+	}
+}
+
+/// Which origin a parachain's message to the relay chain should be dispatched from.
+#[derive(Clone, PartialEq, Eq, Encode, Decode)]
+#[cfg_attr(feature = "std", derive(Debug))]
+#[repr(u8)]
+pub enum ParachainDispatchOrigin {
+	/// As a simple `Origin::Signed`, using `ParaId::account_id` as its value. This is good when
+	/// interacting with standard modules such as `balances`.
+	Signed,
+	/// As the special `Origin::Parachain(ParaId)`. This is good when interacting with parachain-
+	/// aware modules which need to succinctly verify that the origin is a parachain.
+	Parachain,
+	/// As the simple, superuser `Origin::Root`. This can only be done on specially permissioned
+	/// parachains.
+	Root,
+}
+
+impl sp_std::convert::TryFrom<u8> for ParachainDispatchOrigin {
+	type Error = ();
+	fn try_from(x: u8) -> core::result::Result<ParachainDispatchOrigin, ()> {
+		const SIGNED: u8 = ParachainDispatchOrigin::Signed as u8;
+		const PARACHAIN: u8 = ParachainDispatchOrigin::Parachain as u8;
+		Ok(match x {
+			SIGNED => ParachainDispatchOrigin::Signed,
+			PARACHAIN => ParachainDispatchOrigin::Parachain,
+			_ => return Err(()),
+		})
+	}
+}
+
+/// A message from a parachain to its Relay Chain.
+#[derive(Clone, PartialEq, Eq, Encode, Decode)]
+#[cfg_attr(
+	any(feature = "std", feature = "wasm-api"),
+	derive(sp_runtime_interface::pass_by::PassByCodec,
+))]
+#[cfg_attr(feature = "std", derive(Debug))]
+pub struct UpwardMessage {
+	/// The origin for the message to be sent from.
+	pub origin: ParachainDispatchOrigin,
+	/// The message data.
+	pub data: Vec<u8>,
+}
+
+/// Validation parameters for evaluating the parachain validity function.
+// TODO: balance downloads (https://github.com/paritytech/polkadot/issues/220)
+#[derive(PartialEq, Eq, Decode)]
+#[cfg_attr(feature = "std", derive(Debug, Encode))]
+pub struct ValidationParams {
+	/// The collation body.
+	pub block_data: BlockData,
+	/// Previous head-data.
+	pub parent_head: HeadData,
+	/// The maximum code size permitted, in bytes.
+	pub max_code_size: u32,
+	/// The maximum head-data size permitted, in bytes.
+	pub max_head_data_size: u32,
+	/// The current relay-chain block number.
+	pub relay_chain_height: RelayChainBlockNumber,
+	/// Whether a code upgrade is allowed or not, and at which height the upgrade
+	/// would be applied after, if so. The parachain logic should apply any upgrade
+	/// issued in this block after the first block
+	/// with `relay_chain_height` at least this value, if `Some`. if `None`, issue
+	/// no upgrade.
+	pub code_upgrade_allowed: Option<RelayChainBlockNumber>,
+}
+
+/// The result of parachain validation.
+// TODO: egress and balance uploads (https://github.com/paritytech/polkadot/issues/220)
+#[derive(PartialEq, Eq, Encode)]
+#[cfg_attr(feature = "std", derive(Debug, Decode))]
+pub struct ValidationResult {
+	/// New head data that should be included in the relay chain state.
+	pub head_data: HeadData,
+	/// An update to the validation code that should be scheduled in the relay chain.
+	pub new_validation_code: Option<ValidationCode>,
+}

polkadot/parachain/src/wasm_api.rs

@@ -16,7 +16,9 @@
 
 //! Utilities for writing parachain WASM.
 
-use crate::UpwardMessage;
+#[cfg(any(feature = "std", all(not(feature = "std"), feature = "wasm-api")))]
+use crate::primitives::UpwardMessage;
+#[cfg(any(feature = "std", all(not(feature = "std"), feature = "wasm-api")))]
 use sp_runtime_interface::runtime_interface;
 #[cfg(feature = "std")]
 use sp_externalities::ExternalitiesExt;
@@ -42,7 +44,9 @@ pub trait Parachain {
 /// Offset and length must have been provided by the validation
 /// function's entry point.
 #[cfg(not(feature = "std"))]
-pub unsafe fn load_params(params: *const u8, len: usize) -> crate::ValidationParams {
+pub unsafe fn load_params(params: *const u8, len: usize)
+	-> crate::primitives::ValidationParams
+{
 	let mut slice = sp_std::slice::from_raw_parts(params, len);
 
 	codec::Decode::decode(&mut slice).expect("Invalid input data")
@@ -53,6 +57,6 @@ pub unsafe fn load_params(params: *const u8, len: usize) -> crate::ValidationPar
 /// As described in the crate docs, this is a pointer to the appended length
 /// of the vector.
 #[cfg(not(feature = "std"))]
-pub fn write_result(result: &crate::ValidationResult) -> u64 {
+pub fn write_result(result: &crate::primitives::ValidationResult) -> u64 {
 	sp_core::to_substrate_wasm_fn_return_value(&result)
 }

polkadot/parachain/src/wasm_executor/mod.rs

@@ -21,7 +21,7 @@
 //! a WASM VM for re-execution of a parachain candidate.
 
 use std::any::{TypeId, Any};
-use crate::{ValidationParams, ValidationResult, UpwardMessage};
+use crate::primitives::{ValidationParams, ValidationResult, UpwardMessage};
 use codec::{Decode, Encode};
 use sp_core::storage::{ChildStorageKey, ChildInfo};
 use sp_core::traits::CallInWasm;

polkadot/parachain/src/wasm_executor/validation_host.rs

@@ -18,7 +18,7 @@
 
 use std::{process, env, sync::Arc, sync::atomic, mem};
 use codec::{Decode, Encode, EncodeAppend};
-use crate::{ValidationParams, ValidationResult, UpwardMessage};
+use crate::primitives::{ValidationParams, ValidationResult, UpwardMessage};
 use super::{validate_candidate_internal, Error, Externalities};
 use super::{MAX_CODE_MEM, MAX_RUNTIME_MEM};
 use shared_memory::{SharedMem, SharedMemConf, EventState, WriteLockable, EventWait, EventSet};

polkadot/parachain/test-parachains/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "test-parachains"
+version = "0.7.22"
+authors = ["Parity Technologies <admin@parity.io>"]
+description = "Integration tests using the test-parachains"
+edition = "2018"
+
+[dependencies]
+tiny-keccak = "1.5.0"
+codec = { package = "parity-scale-codec", version = "1.1.0", default-features = false, features = ["derive"] }
+
+parachain = { package = "polkadot-parachain", path = ".." }
+adder = { package = "test-parachain-adder", path = "adder" }
+halt = { package = "test-parachain-halt", path = "halt" }
+code-upgrader = { package = "test-parachain-code-upgrader", path = "code-upgrader" }
+
+[features]
+default = [ "std" ]
+std = [
+	"adder/std",
+	"halt/std",
+	"code-upgrader/std",
+]

polkadot/parachain/test-parachains/adder/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "adder"
+name = "test-parachain-adder"
 version = "0.7.29-pre1"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Test parachain which adds to a number as its state transition"
@@ -7,7 +7,7 @@ edition = "2018"
 build = "build.rs"
 
 [dependencies]
-parachain = { package = "polkadot-parachain", path = "../../parachain/", default-features = false, features = [ "wasm-api" ] }
+parachain = { package = "polkadot-parachain", path = "../../", default-features = false, features = [ "wasm-api" ] }
 codec = { package = "parity-scale-codec", version = "1.3.0", default-features = false, features = ["derive"] }
 tiny-keccak = "1.5.0"
 dlmalloc = { version = "0.1.3", features = [ "global" ] }
@@ -20,4 +20,4 @@ wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.
 
 [features]
 default = [ "std" ]
-std = []
+std = ["parachain/std"]

polkadot/parachain/test-parachains/adder/collator/Cargo.toml

@@ -1,14 +1,14 @@
 [package]
-name = "adder-collator"
+name = "test-parachain-adder-collator"
 version = "0.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 edition = "2018"
 
 [dependencies]
-adder = { path = ".." }
+adder = { package = "test-parachain-adder", path = ".." }
-parachain = { package = "polkadot-parachain", path = "../../../parachain" }
+parachain = { package = "polkadot-parachain", path = "../../.." }
-collator = { package = "polkadot-collator", path = "../../../collator" }
+collator = { package = "polkadot-collator", path = "../../../../collator" }
-primitives = { package = "polkadot-primitives", path = "../../../primitives" }
+primitives = { package = "polkadot-primitives", path = "../../../../primitives" }
 sp-core = { git = "https://github.com/paritytech/substrate", branch = "master" }
 client = { package = "sc-client", git = "https://github.com/paritytech/substrate", branch = "master" }
 client-api = { package = "sc-client-api", git = "https://github.com/paritytech/substrate", branch = "master" }

polkadot/parachain/test-parachains/adder/collator/src/main.rs

@@ -24,7 +24,7 @@ use sp_core::Pair;
 use codec::{Encode, Decode};
 use primitives::{
 	Hash,
-	parachain::{HeadData, BlockData, Id as ParaId, LocalValidationData},
+	parachain::{HeadData, BlockData, Id as ParaId, LocalValidationData, GlobalValidationSchedule},
 };
 use collator::{
 	InvalidHead, ParachainContext, Network, BuildParachainContext, load_spec, Configuration,
@@ -60,6 +60,7 @@ impl ParachainContext for AdderContext {
 	fn produce_candidate(
 		&mut self,
 		_relay_parent: Hash,
+		_global_validation: GlobalValidationSchedule,
 		local_validation: LocalValidationData,
 	) -> Self::ProduceCandidate
 	{
@@ -83,7 +84,7 @@ impl ParachainContext for AdderContext {
 			add: adder_head.number % 100,
 		};
 
-		let next_head = ::adder::execute(adder_head.hash(), adder_head, &next_body)
+		let next_head = adder::execute(adder_head.hash(), adder_head, &next_body)
 			.expect("good execution params; qed");
 
 		let encoded_head = HeadData(next_head.encode());

polkadot/parachain/test-parachains/adder/src/lib.rs

@@ -63,27 +63,10 @@ pub fn hash_state(state: u64) -> [u8; 32] {
 	tiny_keccak::keccak256(state.encode().as_slice())
 }
 
-#[derive(Default, Encode, Decode)]
-pub struct AddMessage {
-	/// The amount to add based on this message.
-	pub amount: u64,
-}
-
 /// Start state mismatched with parent header's state hash.
 #[derive(Debug)]
 pub struct StateMismatch;
 
-/// Process all incoming messages, yielding the amount of addition from messages.
-///
-/// Ignores unknown message kinds.
-pub fn process_messages<I, T>(iterable: I) -> u64
-	where I: IntoIterator<Item=T>, T: AsRef<[u8]>
-{
-	iterable.into_iter()
-		.filter_map(|data| AddMessage::decode(&mut data.as_ref()).ok())
-		.fold(0u64, |a, c| a.overflowing_add(c.amount).0)
-}
-
 /// Execute a block body on top of given parent head, producing new parent head
 /// if valid.
 pub fn execute(

polkadot/parachain/test-parachains/adder/src/wasm_validation.rs

@@ -18,7 +18,7 @@
 
 use crate::{HeadData, BlockData};
 use core::{intrinsics, panic};
-use parachain::ValidationResult;
+use parachain::primitives::{ValidationResult, HeadData as GenericHeadData};
 use codec::{Encode, Decode};
 
 #[panic_handler]
@@ -40,17 +40,20 @@ pub fn oom(_: core::alloc::Layout) -> ! {
 #[no_mangle]
 pub extern fn validate_block(params: *const u8, len: usize) -> u64 {
 	let params = unsafe { parachain::load_params(params, len) };
-	let parent_head = HeadData::decode(&mut &params.parent_head[..])
+	let parent_head = HeadData::decode(&mut &params.parent_head.0[..])
 		.expect("invalid parent head format.");
 
-	let block_data = BlockData::decode(&mut &params.block_data[..])
+	let block_data = BlockData::decode(&mut &params.block_data.0[..])
 		.expect("invalid block data format.");
 
-	let parent_hash = tiny_keccak::keccak256(&params.parent_head[..]);
+	let parent_hash = tiny_keccak::keccak256(&params.parent_head.0[..]);
 
 	match crate::execute(parent_hash, parent_head, &block_data) {
 		Ok(new_head) => parachain::write_result(
-			&ValidationResult { head_data: new_head.encode() }
+			&ValidationResult {
+				head_data: GenericHeadData(new_head.encode()),
+				new_validation_code: None,
+			}
 		),
 		Err(_) => panic!("execution failure"),
 	}

polkadot/parachain/test-parachains/code-upgrader/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "test-parachain-code-upgrader"
+version = "0.7.22"
+authors = ["Parity Technologies <admin@parity.io>"]
+description = "Test parachain which can upgrade code"
+edition = "2018"
+build = "build.rs"
+
+[dependencies]
+parachain = { package = "polkadot-parachain", path = "../../", default-features = false, features = [ "wasm-api" ] }
+codec = { package = "parity-scale-codec", version = "1.1.0", default-features = false, features = ["derive"] }
+tiny-keccak = "1.5.0"
+dlmalloc = { version = "0.1.3", features = [ "global" ] }
+
+# We need to make sure the global allocator is disabled until we have support of full substrate externalities
+runtime-io = { package = "sp-io", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false, features = [ "disable_allocator" ] }
+
+[build-dependencies]
+wasm-builder-runner = { package = "substrate-wasm-builder-runner", version = "1.0.5" }
+
+[features]
+default = [ "std" ]
+std = ["parachain/std"]

polkadot/parachain/test-parachains/code-upgrader/src/lib.rs

@@ -0,0 +1,156 @@
+// Copyright 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/>.
+
+//! Test parachain WASM which implements code ugprades.
+
+#![no_std]
+
+#![cfg_attr(not(feature = "std"), feature(core_intrinsics, lang_items, core_panic_info, alloc_error_handler))]
+
+use codec::{Encode, Decode};
+use parachain::primitives::{RelayChainBlockNumber, ValidationCode};
+
+#[cfg(not(feature = "std"))]
+mod wasm_validation;
+
+#[cfg(not(feature = "std"))]
+#[global_allocator]
+static ALLOC: dlmalloc::GlobalDlmalloc = dlmalloc::GlobalDlmalloc;
+
+// Make the WASM binary available.
+#[cfg(feature = "std")]
+include!(concat!(env!("OUT_DIR"), "/wasm_binary.rs"));
+
+#[derive(Encode, Decode, Clone, Default)]
+pub struct State {
+	/// The current code that is "active" in this chain.
+	pub code: ValidationCode,
+	/// Code upgrade that is pending.
+	pub pending_code: Option<(ValidationCode, RelayChainBlockNumber)>,
+}
+
+/// Head data for this parachain.
+#[derive(Default, Clone, Hash, Eq, PartialEq, Encode, Decode)]
+pub struct HeadData {
+	/// Block number
+	pub number: u64,
+	/// parent block keccak256
+	pub parent_hash: [u8; 32],
+	/// hash of post-execution state.
+	pub post_state: [u8; 32],
+}
+
+impl HeadData {
+	pub fn hash(&self) -> [u8; 32] {
+		tiny_keccak::keccak256(&self.encode())
+	}
+}
+
+/// Block data for this parachain.
+#[derive(Default, Clone, Encode, Decode)]
+pub struct BlockData {
+	/// State to begin from.
+	pub state: State,
+	/// Code to upgrade to.
+	pub new_validation_code: Option<ValidationCode>,
+}
+
+pub fn hash_state(state: &State) -> [u8; 32] {
+	tiny_keccak::keccak256(state.encode().as_slice())
+}
+
+#[derive(Debug)]
+pub enum Error {
+	/// Start state mismatched with parent header's state hash.
+	StateMismatch,
+	/// New validation code too large.
+	NewCodeTooLarge,
+	/// Code upgrades not allowed at this time.
+	CodeUpgradeDisallowed,
+}
+
+pub struct ValidationResult {
+	/// The new head data.
+	pub head_data: HeadData,
+	/// The new validation code.
+	pub new_validation_code: Option<ValidationCode>,
+}
+
+pub struct RelayChainParams {
+	/// Whether a code upgrade is allowed and at what relay-chain block number
+	/// to process it after.
+	pub code_upgrade_allowed: Option<RelayChainBlockNumber>,
+	/// The maximum code size allowed for an upgrade.
+	pub max_code_size: u32,
+	/// The relay-chain block number.
+	pub relay_chain_block_number: RelayChainBlockNumber,
+}
+
+/// Execute a block body on top of given parent head, producing new parent head
+/// if valid.
+pub fn execute(
+	parent_hash: [u8; 32],
+	parent_head: HeadData,
+	block_data: BlockData,
+	relay_params: &RelayChainParams,
+) -> Result<ValidationResult, Error> {
+	debug_assert_eq!(parent_hash, parent_head.hash());
+
+	if hash_state(&block_data.state) != parent_head.post_state {
+		return Err(Error::StateMismatch);
+	}
+
+	let mut new_state = block_data.state;
+
+	if let Some((pending_code, after)) = new_state.pending_code.take() {
+		if after <= relay_params.relay_chain_block_number {
+			// code applied.
+			new_state.code = pending_code;
+		} else {
+			// reinstate.
+			new_state.pending_code = Some((pending_code, after));
+		}
+	}
+
+	let new_validation_code = if let Some(ref new_validation_code) = block_data.new_validation_code {
+		if new_validation_code.0.len() as u32 > relay_params.max_code_size {
+			return Err(Error::NewCodeTooLarge);
+		}
+
+		// replace the code if allowed and we don't have an upgrade pending.
+		match (new_state.pending_code.is_some(), relay_params.code_upgrade_allowed) {
+			(_, None) => return Err(Error::CodeUpgradeDisallowed),
+			(false, Some(after)) => {
+				new_state.pending_code = Some((new_validation_code.clone(), after));
+				Some(new_validation_code.clone())
+			}
+			(true, Some(_)) => None,
+		}
+	} else {
+		None
+	};
+
+	let head_data = HeadData {
+		number: parent_head.number + 1,
+		parent_hash,
+		post_state: hash_state(&new_state),
+	};
+
+	Ok(ValidationResult {
+		head_data,
+		new_validation_code: new_validation_code,
+	})
+}

polkadot/parachain/test-parachains/code-upgrader/src/wasm_validation.rs

@@ -0,0 +1,71 @@
+// 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/>.
+
+//! WASM validation for adder parachain.
+
+use crate::{HeadData, BlockData, RelayChainParams};
+use core::{intrinsics, panic};
+use parachain::primitives::{ValidationResult, HeadData as GenericHeadData};
+use codec::{Encode, Decode};
+
+#[panic_handler]
+#[no_mangle]
+pub fn panic(_info: &panic::PanicInfo) -> ! {
+	unsafe {
+		intrinsics::abort()
+	}
+}
+
+#[alloc_error_handler]
+#[no_mangle]
+pub fn oom(_: core::alloc::Layout) -> ! {
+	unsafe {
+		intrinsics::abort();
+	}
+}
+
+#[no_mangle]
+pub extern fn validate_block(params: *const u8, len: usize) -> u64 {
+	let params = unsafe { parachain::load_params(params, len) };
+	let parent_head = HeadData::decode(&mut &params.parent_head.0[..])
+		.expect("invalid parent head format.");
+
+	let block_data = BlockData::decode(&mut &params.block_data.0[..])
+		.expect("invalid block data format.");
+
+	let parent_hash = tiny_keccak::keccak256(&params.parent_head.0[..]);
+
+	let res = crate::execute(
+		parent_hash,
+		parent_head,
+		block_data,
+		&RelayChainParams {
+			code_upgrade_allowed: params.code_upgrade_allowed,
+			max_code_size: params.max_code_size,
+			relay_chain_block_number: params.relay_chain_height,
+		},
+	);
+
+	match res {
+		Ok(output) => parachain::write_result(
+			&ValidationResult {
+				head_data: GenericHeadData(output.head_data.encode()),
+				new_validation_code: output.new_validation_code,
+			}
+		),
+		Err(_) => panic!("execution failure"),
+	}
+}

polkadot/parachain/test-parachains/halt/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "halt"
+name = "test-parachain-halt"
 version = "0.7.29-pre1"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Test parachain which executes forever"

polkadot/parachain/test-parachains/halt/build.rs

@@ -0,0 +1,25 @@
+// Copyright 2019-2020 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Substrate 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.
+
+// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
+
+use wasm_builder_runner::WasmBuilder;
+
+fn main() {
+	WasmBuilder::new()
+		.with_current_project()
+		.with_wasm_builder_from_git("https://github.com/paritytech/substrate.git", "8c672e107789ed10973d937ba8cac245404377e2")
+		.export_heap_base()
+		.build()
+}

polkadot/parachain/test-parachains/src/lib.rs

@@ -0,0 +1,17 @@
+// Copyright 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/>.
+
+//! Stub - the fundamental logic of this crate is the integration tests.

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

@@ -16,9 +16,16 @@
 
 //! Basic parachain that adds a number as part of its state.
 
-use polkadot_parachain as parachain;
+use crate::{
-
+	DummyExt,
-use crate::{DummyExt, parachain::ValidationParams};
+	parachain,
+	parachain::primitives::{
+		RelayChainBlockNumber,
+		BlockData as GenericBlockData,
+		HeadData as GenericHeadData,
+		ValidationParams,
+	},
+};
 use codec::{Decode, Encode};
 
 /// Head data for this parachain.
@@ -41,12 +48,6 @@ struct BlockData {
 	add: u64,
 }
 
-#[derive(Encode, Decode)]
-struct AddMessage {
-	/// amount to add.
-	amount: u64,
-}
-
 const TEST_CODE: &[u8] = adder::WASM_BINARY;
 
 fn hash_state(state: u64) -> [u8; 32] {
@@ -75,14 +76,18 @@ pub fn execute_good_on_parent() {
 	let ret = parachain::wasm_executor::validate_candidate(
 		TEST_CODE,
 		ValidationParams {
-			parent_head: parent_head.encode(),
+			parent_head: GenericHeadData(parent_head.encode()),
-			block_data: block_data.encode(),
+			block_data: GenericBlockData(block_data.encode()),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
 		},
 		DummyExt,
 		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
 	).unwrap();
 
-	let new_head = HeadData::decode(&mut &ret.head_data[..]).unwrap();
+	let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
 
 	assert_eq!(new_head.number, 1);
 	assert_eq!(new_head.parent_hash, hash_head(&parent_head));
@@ -111,14 +116,18 @@ fn execute_good_chain_on_parent() {
 		let ret = parachain::wasm_executor::validate_candidate(
 			TEST_CODE,
 			ValidationParams {
-				parent_head: parent_head.encode(),
+				parent_head: GenericHeadData(parent_head.encode()),
-				block_data: block_data.encode(),
+				block_data: GenericBlockData(block_data.encode()),
+				max_code_size: 1024,
+				max_head_data_size: 1024,
+				relay_chain_height: number as RelayChainBlockNumber + 1,
+				code_upgrade_allowed: None,
 			},
 			DummyExt,
 			parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
 		).unwrap();
 
-		let new_head = HeadData::decode(&mut &ret.head_data[..]).unwrap();
+		let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
 
 		assert_eq!(new_head.number, number + 1);
 		assert_eq!(new_head.parent_hash, hash_head(&parent_head));
@@ -148,8 +157,12 @@ fn execute_bad_on_parent() {
 	let _ret = parachain::wasm_executor::validate_candidate(
 		TEST_CODE,
 		ValidationParams {
-			parent_head: parent_head.encode(),
+			parent_head: GenericHeadData(parent_head.encode()),
-			block_data: block_data.encode(),
+			block_data: GenericBlockData(block_data.encode()),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
 		},
 		DummyExt,
 		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),

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

@@ -0,0 +1,224 @@
+// Copyright 2017-2020 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::{
+	DummyExt,
+	parachain::primitives::{
+		BlockData as GenericBlockData,
+		HeadData as GenericHeadData,
+		ValidationParams, ValidationCode,
+	},
+};
+use codec::{Decode, Encode};
+use code_upgrader::{hash_state, HeadData, BlockData, State};
+
+const TEST_CODE: &[u8] = code_upgrader::WASM_BINARY;
+
+#[test]
+pub fn execute_good_no_upgrade() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let parent_head = HeadData {
+		number: 0,
+		parent_hash: [0; 32],
+		post_state: hash_state(&State::default()),
+	};
+
+	let block_data = BlockData {
+		state: State::default(),
+		new_validation_code: None,
+	};
+
+	let ret = parachain::wasm_executor::validate_candidate(
+		TEST_CODE,
+		ValidationParams {
+			parent_head: GenericHeadData(parent_head.encode()),
+			block_data: GenericBlockData(block_data.encode()),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+	).unwrap();
+
+	let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
+
+	assert!(ret.new_validation_code.is_none());
+	assert_eq!(new_head.number, 1);
+	assert_eq!(new_head.parent_hash, parent_head.hash());
+	assert_eq!(new_head.post_state, hash_state(&State::default()));
+}
+
+#[test]
+pub fn execute_good_with_upgrade() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let parent_head = HeadData {
+		number: 0,
+		parent_hash: [0; 32],
+		post_state: hash_state(&State::default()),
+	};
+
+	let block_data = BlockData {
+		state: State::default(),
+		new_validation_code: Some(ValidationCode(vec![1, 2, 3])),
+	};
+
+	let ret = parachain::wasm_executor::validate_candidate(
+		TEST_CODE,
+		ValidationParams {
+			parent_head: GenericHeadData(parent_head.encode()),
+			block_data: GenericBlockData(block_data.encode()),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: Some(20),
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+	).unwrap();
+
+	let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
+
+	assert_eq!(ret.new_validation_code.unwrap(), ValidationCode(vec![1, 2, 3]));
+	assert_eq!(new_head.number, 1);
+	assert_eq!(new_head.parent_hash, parent_head.hash());
+	assert_eq!(
+		new_head.post_state,
+		hash_state(&State {
+			code: ValidationCode::default(),
+			pending_code: Some((ValidationCode(vec![1, 2, 3]), 20)),
+		}),
+	);
+}
+
+#[test]
+#[should_panic]
+pub fn code_upgrade_not_allowed() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let parent_head = HeadData {
+		number: 0,
+		parent_hash: [0; 32],
+		post_state: hash_state(&State::default()),
+	};
+
+	let block_data = BlockData {
+		state: State::default(),
+		new_validation_code: Some(ValidationCode(vec![1, 2, 3])),
+	};
+
+	parachain::wasm_executor::validate_candidate(
+		TEST_CODE,
+		ValidationParams {
+			parent_head: GenericHeadData(parent_head.encode()),
+			block_data: GenericBlockData(block_data.encode()),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
+		},
+		DummyExt,
+		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+	).unwrap();
+}
+
+#[test]
+pub fn applies_code_upgrade_after_delay() {
+	let pool = parachain::wasm_executor::ValidationPool::new();
+
+	let (new_head, state) = {
+		let parent_head = HeadData {
+			number: 0,
+			parent_hash: [0; 32],
+			post_state: hash_state(&State::default()),
+		};
+
+		let block_data = BlockData {
+			state: State::default(),
+			new_validation_code: Some(ValidationCode(vec![1, 2, 3])),
+		};
+
+		let ret = parachain::wasm_executor::validate_candidate(
+			TEST_CODE,
+			ValidationParams {
+				parent_head: GenericHeadData(parent_head.encode()),
+				block_data: GenericBlockData(block_data.encode()),
+				max_code_size: 1024,
+				max_head_data_size: 1024,
+				relay_chain_height: 1,
+				code_upgrade_allowed: Some(2),
+			},
+			DummyExt,
+			parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+		).unwrap();
+
+		let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
+
+		let parent_hash = parent_head.hash();
+		let state = State {
+			code: ValidationCode::default(),
+			pending_code: Some((ValidationCode(vec![1, 2, 3]), 2)),
+		};
+		assert_eq!(ret.new_validation_code.unwrap(), ValidationCode(vec![1, 2, 3]));
+		assert_eq!(new_head.number, 1);
+		assert_eq!(new_head.parent_hash, parent_hash);
+		assert_eq!(new_head.post_state, hash_state(&state));
+
+		(new_head, state)
+	};
+
+	{
+		let parent_head = new_head;
+		let block_data = BlockData {
+			state,
+			new_validation_code: None,
+		};
+
+		let ret = parachain::wasm_executor::validate_candidate(
+			TEST_CODE,
+			ValidationParams {
+				parent_head: GenericHeadData(parent_head.encode()),
+				block_data: GenericBlockData(block_data.encode()),
+				max_code_size: 1024,
+				max_head_data_size: 1024,
+				relay_chain_height: 2,
+				code_upgrade_allowed: None,
+			},
+			DummyExt,
+			parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
+		).unwrap();
+
+		let new_head = HeadData::decode(&mut &ret.head_data.0[..]).unwrap();
+
+		assert!(ret.new_validation_code.is_none());
+		assert_eq!(new_head.number, 2);
+		assert_eq!(new_head.parent_hash, parent_head.hash());
+		assert_eq!(
+			new_head.post_state,
+			hash_state(&State {
+				code: ValidationCode(vec![1, 2, 3]),
+				pending_code: None,
+			}),
+		);
+	}
+}

polkadot/parachain/test-parachains/tests/lib.rs

@@ -15,11 +15,11 @@
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
 mod adder;
+mod code_upgrader;
 mod wasm_executor;
 
-use polkadot_parachain as parachain;
+use parachain::{
-use crate::parachain::{
+	self, primitives::UpwardMessage, wasm_executor::{Externalities, run_worker},
-	UpwardMessage, wasm_executor::{Externalities, run_worker},
 };
 
 struct DummyExt;

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

@@ -16,9 +16,12 @@
 
 //! Basic parachain that adds a number as part of its state.
 
-use polkadot_parachain as parachain;
+use parachain;
 use crate::{adder, DummyExt};
-use crate::parachain::{ValidationParams, wasm_executor::EXECUTION_TIMEOUT_SEC};
+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;
@@ -30,8 +33,12 @@ fn terminates_on_timeout() {
 	let result = parachain::wasm_executor::validate_candidate(
 		INFINITE_LOOP_CODE,
 		ValidationParams {
+			block_data: BlockData(Vec::new()),
 			parent_head: Default::default(),
-			block_data: Vec::new(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
 		},
 		DummyExt,
 		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),
@@ -56,8 +63,12 @@ fn parallel_execution() {
 		parachain::wasm_executor::validate_candidate(
 		INFINITE_LOOP_CODE,
 		ValidationParams {
+			block_data: BlockData(Vec::new()),
 			parent_head: Default::default(),
-			block_data: Vec::new(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
 		},
 		DummyExt,
 		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool2),
@@ -65,8 +76,12 @@ fn parallel_execution() {
 	let _ = parachain::wasm_executor::validate_candidate(
 		INFINITE_LOOP_CODE,
 		ValidationParams {
+			block_data: BlockData(Vec::new()),
 			parent_head: Default::default(),
-			block_data: Vec::new(),
+			max_code_size: 1024,
+			max_head_data_size: 1024,
+			relay_chain_height: 1,
+			code_upgrade_allowed: None,
 		},
 		DummyExt,
 		parachain::wasm_executor::ExecutionMode::RemoteTest(&pool),

polkadot/primitives/Cargo.toml

@@ -18,7 +18,6 @@ runtime_primitives = { package = "sp-runtime", git = "https://github.com/parityt
 polkadot-parachain = { path = "../parachain", default-features = false }
 trie = { package = "sp-trie", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 bitvec = { version = "0.17.4", default-features = false, features = ["alloc"] }
-babe = { package = "pallet-babe", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
 [dev-dependencies]
 sp-serializer = { git = "https://github.com/paritytech/substrate", branch = "master" }
@@ -39,5 +38,4 @@ std = [
 	"serde",
 	"polkadot-parachain/std",
 	"bitvec/std",
-	"babe/std"
 ]

polkadot/primitives/src/lib.rs

@@ -28,8 +28,7 @@ pub mod parachain;
 pub use parity_scale_codec::Compact;
 
 /// An index to a block.
-/// 32-bits will allow for 136 years of blocks assuming 1 block per second.
+pub type BlockNumber = polkadot_parachain::primitives::RelayChainBlockNumber;
-pub type BlockNumber = u32;
 
 /// An instant or duration in time.
 pub type Moment = u64;

polkadot/primitives/src/parachain.rs

@@ -14,13 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
 
-//! Polkadot parachain types.
+//! Primitives which are necessary for parachain execution from a relay-chain
+//! perspective.
 
 use sp_std::prelude::*;
 use sp_std::cmp::Ordering;
 use parity_scale_codec::{Encode, Decode};
 use bitvec::vec::BitVec;
-use super::{Hash, Balance};
+use super::{Hash, Balance, BlockNumber};
 
 #[cfg(feature = "std")]
 use serde::{Serialize, Deserialize};
@@ -32,8 +33,9 @@ use runtime_primitives::traits::Block as BlockT;
 use inherents::InherentIdentifier;
 use application_crypto::KeyTypeId;
 
-pub use polkadot_parachain::{
+pub use polkadot_parachain::primitives::{
-	Id, ParachainDispatchOrigin, LOWEST_USER_ID, UpwardMessage,
+	Id, ParachainDispatchOrigin, LOWEST_USER_ID, UpwardMessage, HeadData, BlockData,
+	ValidationCode,
 };
 
 /// The key type ID for a collator key.
@@ -174,6 +176,8 @@ pub struct GlobalValidationSchedule {
 	pub max_code_size: u32,
 	/// The maximum head-data size permitted, in bytes.
 	pub max_head_data_size: u32,
+	/// The relay-chain block number this is in the context of.
+	pub block_number: BlockNumber,
 }
 
 /// Extra data that is needed along with the other fields in a `CandidateReceipt`
@@ -185,6 +189,18 @@ pub struct LocalValidationData {
 	pub parent_head: HeadData,
 	/// The balance of the parachain at the moment of validation.
 	pub balance: Balance,
+	/// Whether the parachain is allowed to upgrade its validation code.
+	///
+	/// This is `Some` if so, and contains the number of the minimum relay-chain
+	/// height at which the upgrade will be applied, if an upgrade is signaled
+	/// now.
+	///
+	/// A parachain should enact its side of the upgrade at the end of the first
+	/// parablock executing in the context of a relay-chain block with at least this
+	/// height. This may be equal to the current perceived relay-chain block height, in
+	/// which case the code upgrade should be applied at the end of the signaling
+	/// block.
+	pub code_upgrade_allowed: Option<BlockNumber>,
 }
 
 /// Commitments made in a `CandidateReceipt`. Many of these are outputs of validation.
@@ -197,6 +213,8 @@ pub struct CandidateCommitments {
 	pub upward_messages: Vec<UpwardMessage>,
 	/// The root of a block's erasure encoding Merkle tree.
 	pub erasure_root: Hash,
+	/// New validation code.
+	pub new_validation_code: Option<Vec<u8>>,
 }
 
 /// Get a collator signature payload on a relay-parent, block-data combo.
@@ -532,13 +550,6 @@ pub struct AvailableData {
 	// In the future, outgoing messages as well.
 }
 
-/// Parachain block data.
-///
-/// Contains everything required to validate para-block, may contain block and witness data.
-#[derive(PartialEq, Eq, Clone, Encode, Decode)]
-#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
-pub struct BlockData(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
-
 /// A chunk of erasure-encoded block data.
 #[derive(PartialEq, Eq, Clone, Encode, Decode, Default)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
@@ -551,29 +562,11 @@ pub struct ErasureChunk {
 	pub proof: Vec<Vec<u8>>,
 }
 
-impl BlockData {
-	/// Compute hash of block data.
-	#[cfg(feature = "std")]
-	pub fn hash(&self) -> Hash {
-		use runtime_primitives::traits::{BlakeTwo256, Hash};
-		BlakeTwo256::hash(&self.0[..])
-	}
-}
 /// Parachain header raw bytes wrapper type.
 #[derive(PartialEq, Eq)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
 pub struct Header(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
 
-/// Parachain head data included in the chain.
-#[derive(PartialEq, Eq, Clone, PartialOrd, Ord, Encode, Decode)]
-#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug, Default))]
-pub struct HeadData(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
-
-/// Parachain validation code.
-#[derive(PartialEq, Eq)]
-#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
-pub struct ValidationCode(#[cfg_attr(feature = "std", serde(with="bytes"))] pub Vec<u8>);
-
 /// Activity bit field.
 #[derive(PartialEq, Eq, Clone, Default, Encode, Decode)]
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
@@ -648,13 +641,13 @@ impl AttestedCandidate {
 pub struct FeeSchedule {
 	/// The base fee charged for all messages.
 	pub base: Balance,
-	/// The per-byte fee charged on top of that.
+	/// The per-byte fee for messages charged on top of that.
 	pub per_byte: Balance,
 }
 
 impl FeeSchedule {
 	/// Compute the fee for a message of given size.
-	pub fn compute_fee(&self, n_bytes: usize) -> Balance {
+	pub fn compute_message_fee(&self, n_bytes: usize) -> Balance {
 		use sp_std::mem;
 		debug_assert!(mem::size_of::<Balance>() >= mem::size_of::<usize>());
 

polkadot/runtime/common/src/crowdfund.rs

@@ -582,7 +582,7 @@ mod tests {
 	};
 	use frame_support::traits::Contains;
 	use sp_core::H256;
-	use primitives::parachain::{Info as ParaInfo, Id as ParaId};
+	use primitives::parachain::{Info as ParaInfo, Id as ParaId, Scheduling};
 	// The testing primitives are very useful for avoiding having to work with signatures
 	// or public keys. `u64` is used as the `AccountId` and no `Signature`s are requried.
 	use sp_runtime::{
@@ -698,6 +698,10 @@ mod tests {
 			code_size <= MAX_CODE_SIZE
 		}
 
+		fn para_info(_id: ParaId) -> Option<ParaInfo> {
+			Some(ParaInfo { scheduling: Scheduling::Always })
+		}
+
 		fn register_para(
 			id: ParaId,
 			_info: ParaInfo,

polkadot/runtime/common/src/registrar.rs

@@ -52,6 +52,9 @@ pub trait Registrar<AccountId> {
 	/// Checks whether the given validation code falls within the limit.
 	fn code_size_allowed(code_size: u32) -> bool;
 
+	/// Fetches metadata for a para by ID, if any.
+	fn para_info(id: ParaId) -> Option<ParaInfo>;
+
 	/// Register a parachain with given `code` and `initial_head_data`. `id` must not yet be registered or it will
 	/// result in a error.
 	///
@@ -83,6 +86,10 @@ impl<T: Trait> Registrar<T::AccountId> for Module<T> {
 		code_size <= <T as parachains::Trait>::MaxCodeSize::get()
 	}
 
+	fn para_info(id: ParaId) -> Option<ParaInfo> {
+		Self::paras(&id)
+	}
+
 	fn register_para(
 		id: ParaId,
 		info: ParaInfo,
@@ -653,15 +660,15 @@ mod tests {
 		traits::{
 			BlakeTwo256, IdentityLookup, Dispatchable,
 			AccountIdConversion,
-		}, testing::{UintAuthorityId, Header, TestXt}, KeyTypeId, Perbill, curve::PiecewiseLinear,
+		}, testing::{UintAuthorityId, TestXt}, KeyTypeId, Perbill, curve::PiecewiseLinear,
 	};
 	use primitives::{
 		parachain::{
 			ValidatorId, Info as ParaInfo, Scheduling, LOWEST_USER_ID, AttestedCandidate,
 			CandidateReceipt, HeadData, ValidityAttestation, Statement, Chain,
-			CollatorPair, CandidateCommitments, GlobalValidationSchedule, LocalValidationData,
+			CollatorPair, CandidateCommitments,
 		},
-		Balance, BlockNumber,
+		Balance, BlockNumber, Header,
 	};
 	use frame_support::{
 		traits::{KeyOwnerProofSystem, OnInitialize, OnFinalize},
@@ -710,7 +717,7 @@ mod tests {
 		type Origin = Origin;
 		type Call = Call;
 		type Index = u64;
-		type BlockNumber = u64;
+		type BlockNumber = BlockNumber;
 		type Hash = H256;
 		type Hashing = BlakeTwo256;
 		type AccountId = u64;
@@ -741,8 +748,8 @@ mod tests {
 	}
 
 	parameter_types!{
-		pub const LeasePeriod: u64 = 10;
+		pub const LeasePeriod: BlockNumber = 10;
-		pub const EndingPeriod: u64 = 3;
+		pub const EndingPeriod: BlockNumber = 3;
 	}
 
 	impl slots::Trait for Test {
@@ -791,6 +798,10 @@ mod tests {
 	parameter_types! {
 		pub const MaxHeadDataSize: u32 = 100;
 		pub const MaxCodeSize: u32 = 100;
+
+		pub const ValidationUpgradeFrequency: BlockNumber = 10;
+		pub const ValidationUpgradeDelay: BlockNumber = 2;
+		pub const SlashPeriod: BlockNumber = 50;
 		pub const ElectionLookahead: BlockNumber = 0;
 	}
 
@@ -830,11 +841,15 @@ mod tests {
 		type Origin = Origin;
 		type Call = Call;
 		type ParachainCurrency = balances::Module<Test>;
+		type BlockNumberConversion = sp_runtime::traits::Identity;
 		type ActiveParachains = Registrar;
 		type Registrar = Registrar;
 		type Randomness = RandomnessCollectiveFlip;
 		type MaxCodeSize = MaxCodeSize;
 		type MaxHeadDataSize = MaxHeadDataSize;
+		type ValidationUpgradeFrequency = ValidationUpgradeFrequency;
+		type ValidationUpgradeDelay = ValidationUpgradeDelay;
+		type SlashPeriod = SlashPeriod;
 		type Proof = session::historical::Proof;
 		type KeyOwnerProofSystem = session::historical::Module<Test>;
 		type IdentificationTuple = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(KeyTypeId, Vec<u8>)>>::IdentificationTuple;
@@ -929,7 +944,7 @@ mod tests {
 		Slots::on_initialize(System::block_number());
 	}
 
-	fn run_to_block(n: u64) {
+	fn run_to_block(n: BlockNumber) {
 		println!("Running until block {}", n);
 		while System::block_number() < n {
 			if System::block_number() > 1 {
@@ -972,18 +987,13 @@ mod tests {
 			collator: collator.public(),
 			signature: pov_block_hash.using_encoded(|d| collator.sign(d)),
 			pov_block_hash,
-			global_validation: GlobalValidationSchedule {
+			global_validation: Parachains::global_validation_schedule(),
-				max_code_size: <Test as parachains::Trait>::MaxCodeSize::get(),
+			local_validation: Parachains::current_local_validation_data(&id).unwrap(),
-				max_head_data_size: <Test as parachains::Trait>::MaxHeadDataSize::get(),
-			},
-			local_validation: LocalValidationData {
-				balance: Balances::free_balance(&id.into_account()),
-				parent_head: HeadData(Parachains::parachain_head(&id).unwrap()),
-			},
 			commitments: CandidateCommitments {
 				fees: 0,
 				upward_messages: vec![],
 				erasure_root: [1; 32].into(),
+				new_validation_code: None,
 			},
 		};
 		let (candidate, _) = candidate.abridge();

polkadot/runtime/common/src/slots.rs

@@ -878,7 +878,7 @@ mod tests {
 
 	use sp_core::H256;
 	use sp_runtime::{
-		Perbill, testing::Header,
+		Perbill,
 		traits::{BlakeTwo256, Hash, IdentityLookup},
 	};
 	use frame_support::{
@@ -886,7 +886,8 @@ mod tests {
 		traits::{OnInitialize, OnFinalize}
 	};
 	use balances;
-	use primitives::parachain::{Id as ParaId, Info as ParaInfo};
+	use primitives::{BlockNumber, Header};
+	use primitives::parachain::{Id as ParaId, Info as ParaInfo, Scheduling};
 
 	impl_outer_origin! {
 		pub enum Origin for Test {}
@@ -907,7 +908,7 @@ mod tests {
 		type Origin = Origin;
 		type Call = ();
 		type Index = u64;
-		type BlockNumber = u64;
+		type BlockNumber = BlockNumber;
 		type Hash = H256;
 		type Hashing = BlakeTwo256;
 		type AccountId = u64;
@@ -963,6 +964,10 @@ mod tests {
 			code_size <= MAX_CODE_SIZE
 		}
 
+		fn para_info(_id: ParaId) -> Option<ParaInfo> {
+			Some(ParaInfo { scheduling: Scheduling::Always })
+		}
+
 		fn register_para(
 			id: ParaId,
 			_info: ParaInfo,
@@ -997,8 +1002,8 @@ mod tests {
 	}
 
 	parameter_types!{
-		pub const LeasePeriod: u64 = 10;
+		pub const LeasePeriod: BlockNumber = 10;
-		pub const EndingPeriod: u64 = 3;
+		pub const EndingPeriod: BlockNumber = 3;
 	}
 
 	impl Trait for Test {
@@ -1025,7 +1030,7 @@ mod tests {
 		t.into()
 	}
 
-	fn run_to_block(n: u64) {
+	fn run_to_block(n: BlockNumber) {
 		while System::block_number() < n {
 			Slots::on_finalize(System::block_number());
 			Balances::on_finalize(System::block_number());
@@ -1453,8 +1458,8 @@ mod tests {
 
 			assert_ok!(Slots::new_auction(Origin::ROOT, 5, 1));
 
-			for i in 1..6 {
+			for i in 1..6u64 {
-				run_to_block(i);
+				run_to_block(i as _);
 				assert_ok!(Slots::bid(Origin::signed(i), 0, 1, 1, 4, i));
 				for j in 1..6 {
 					assert_eq!(Balances::reserved_balance(j), if j == i { j } else { 0 });
@@ -1481,8 +1486,8 @@ mod tests {
 
 			assert_ok!(Slots::new_auction(Origin::ROOT, 5, 1));
 
-			for i in 1..6 {
+			for i in 1..6u64 {
-				run_to_block(i + 3);
+				run_to_block((i + 3) as _);
 				assert_ok!(Slots::bid(Origin::signed(i), 0, 1, 1, 4, i));
 				for j in 1..6 {
 					assert_eq!(Balances::reserved_balance(j), if j == i { j } else { 0 });

polkadot/runtime/kusama/src/lib.rs

@@ -499,17 +499,26 @@ impl attestations::Trait for Runtime {
 parameter_types! {
 	pub const MaxCodeSize: u32 = 10 * 1024 * 1024; // 10 MB
 	pub const MaxHeadDataSize: u32 = 20 * 1024; // 20 KB
+	pub const ValidationUpgradeFrequency: BlockNumber = 2 * DAYS;
+	pub const ValidationUpgradeDelay: BlockNumber = 8 * HOURS;
+	pub const SlashPeriod: BlockNumber = 7 * DAYS;
 }
 
 impl parachains::Trait for Runtime {
 	type Origin = Origin;
 	type Call = Call;
 	type ParachainCurrency = Balances;
+	type BlockNumberConversion = sp_runtime::traits::Identity;
 	type Randomness = RandomnessCollectiveFlip;
 	type ActiveParachains = Registrar;
 	type Registrar = Registrar;
 	type MaxCodeSize = MaxCodeSize;
 	type MaxHeadDataSize = MaxHeadDataSize;
+
+	type ValidationUpgradeFrequency = ValidationUpgradeFrequency;
+	type ValidationUpgradeDelay = ValidationUpgradeDelay;
+	type SlashPeriod = SlashPeriod;
+
 	type Proof = session::historical::Proof;
 	type KeyOwnerProofSystem = session::historical::Module<Self>;
 	type IdentificationTuple = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(KeyTypeId, Vec<u8>)>>::IdentificationTuple;
@@ -821,7 +830,7 @@ sp_api::impl_runtime_apis! {
 			Parachains::global_validation_schedule()
 		}
 		fn local_validation_data(id: parachain::Id) -> Option<parachain::LocalValidationData> {
-			Parachains::local_validation_data(&id)
+			Parachains::current_local_validation_data(&id)
 		}
 		fn parachain_code(id: parachain::Id) -> Option<Vec<u8>> {
 			Parachains::parachain_code(&id)

polkadot/runtime/polkadot/src/lib.rs

@@ -507,17 +507,27 @@ impl attestations::Trait for Runtime {
 parameter_types! {
 	pub const MaxCodeSize: u32 = 10 * 1024 * 1024; // 10 MB
 	pub const MaxHeadDataSize: u32 = 20 * 1024; // 20 KB
+
+	pub const ValidationUpgradeFrequency: BlockNumber = 7 * DAYS;
+	pub const ValidationUpgradeDelay: BlockNumber = 1 * DAYS;
+	pub const SlashPeriod: BlockNumber = 28 * DAYS;
 }
 
 impl parachains::Trait for Runtime {
 	type Origin = Origin;
 	type Call = Call;
 	type ParachainCurrency = Balances;
+	type BlockNumberConversion = sp_runtime::traits::Identity;
 	type Randomness = RandomnessCollectiveFlip;
 	type ActiveParachains = Registrar;
 	type Registrar = Registrar;
 	type MaxCodeSize = MaxCodeSize;
 	type MaxHeadDataSize = MaxHeadDataSize;
+
+	type ValidationUpgradeFrequency = ValidationUpgradeFrequency;
+	type ValidationUpgradeDelay = ValidationUpgradeDelay;
+	type SlashPeriod = SlashPeriod;
+
 	type Proof = session::historical::Proof;
 	type KeyOwnerProofSystem = session::historical::Module<Self>;
 	type IdentificationTuple = <Self::KeyOwnerProofSystem as KeyOwnerProofSystem<(KeyTypeId, Vec<u8>)>>::IdentificationTuple;
@@ -741,7 +751,7 @@ sp_api::impl_runtime_apis! {
 			Parachains::global_validation_schedule()
 		}
 		fn local_validation_data(id: parachain::Id) -> Option<parachain::LocalValidationData> {
-			Parachains::local_validation_data(&id)
+			Parachains::current_local_validation_data(&id)
 		}
 		fn parachain_code(id: parachain::Id) -> Option<Vec<u8>> {
 			Parachains::parachain_code(&id)

polkadot/runtime/test-runtime/src/lib.rs

@@ -310,17 +310,27 @@ impl attestations::Trait for Runtime {
 parameter_types! {
 	pub const MaxCodeSize: u32 = 10 * 1024 * 1024; // 10 MB
 	pub const MaxHeadDataSize: u32 = 20 * 1024; // 20 KB
+
+	pub const ValidationUpgradeFrequency: BlockNumber = 2;
+	pub const ValidationUpgradeDelay: BlockNumber = 1;
+	pub const SlashPeriod: BlockNumber = 1 * MINUTES;
 }
 
 impl parachains::Trait for Runtime {
 	type Origin = Origin;
 	type Call = Call;
 	type ParachainCurrency = Balances;
+	type BlockNumberConversion = sp_runtime::traits::Identity;
 	type Randomness = RandomnessCollectiveFlip;
 	type ActiveParachains = Registrar;
 	type Registrar = Registrar;
 	type MaxCodeSize = MaxCodeSize;
 	type MaxHeadDataSize = MaxHeadDataSize;
+
+	type ValidationUpgradeFrequency = ValidationUpgradeFrequency;
+	type ValidationUpgradeDelay = ValidationUpgradeDelay;
+	type SlashPeriod = SlashPeriod;
+
 	type Proof = session::historical::Proof;
 	type KeyOwnerProofSystem = session::historical::Module<Self>;
 	type IdentificationTuple = <
@@ -528,7 +538,7 @@ sp_api::impl_runtime_apis! {
 			Parachains::global_validation_schedule()
 		}
 		fn local_validation_data(id: parachain::Id) -> Option<parachain::LocalValidationData> {
-			Parachains::local_validation_data(&id)
+			Parachains::current_local_validation_data(&id)
 		}
 		fn parachain_code(id: parachain::Id) -> Option<Vec<u8>> {
 			Parachains::parachain_code(&id)

polkadot/validation/src/pipeline.rs

@@ -23,13 +23,13 @@ use codec::Encode;
 use polkadot_erasure_coding as erasure;
 use polkadot_primitives::parachain::{
 	CollationInfo, PoVBlock, LocalValidationData, GlobalValidationSchedule, OmittedValidationData,
-	AvailableData, FeeSchedule, CandidateCommitments, ErasureChunk, HeadData, ParachainHost,
+	AvailableData, FeeSchedule, CandidateCommitments, ErasureChunk, ParachainHost,
-	Id as ParaId, AbridgedCandidateReceipt,
+	Id as ParaId, AbridgedCandidateReceipt
 };
 use polkadot_primitives::{Block, BlockId, Balance, Hash};
 use parachain::{
 	wasm_executor::{self, ExecutionMode},
-	UpwardMessage, ValidationParams,
+	primitives::{UpwardMessage, ValidationParams},
 };
 use runtime_primitives::traits::{BlakeTwo256, Hash as HashT};
 use sp_api::ProvideRuntimeApi;
@@ -95,7 +95,7 @@ impl ExternalitiesInner {
 	}
 
 	fn apply_message_fee(&mut self, message_len: usize) -> Result<(), String> {
-		let fee = self.fee_schedule.compute_fee(message_len);
+		let fee = self.fee_schedule.compute_message_fee(message_len);
 		let new_fees_charged = self.fees_charged.saturating_add(fee);
 		if new_fees_charged > self.free_balance {
 			Err("could not cover fee.".into())
@@ -160,8 +160,7 @@ impl FullOutput {
 pub struct ValidatedCandidate<'a> {
 	pov_block: &'a PoVBlock,
 	global_validation: &'a GlobalValidationSchedule,
-	parent_head: &'a HeadData,
+	local_validation: &'a LocalValidationData,
-	balance: Balance,
 	upward_messages: Vec<UpwardMessage>,
 	fees: Balance,
 }
@@ -173,18 +172,14 @@ impl<'a> ValidatedCandidate<'a> {
 		let ValidatedCandidate {
 			pov_block,
 			global_validation,
-			parent_head,
+			local_validation,
-			balance,
 			upward_messages,
 			fees,
 		} = self;
 
 		let omitted_validation = OmittedValidationData {
 			global_validation: global_validation.clone(),
-			local_validation: LocalValidationData {
+			local_validation: local_validation.clone(),
-				parent_head: parent_head.clone(),
-				balance,
-			},
 		};
 
 		let available_data = AvailableData {
@@ -216,6 +211,7 @@ impl<'a> ValidatedCandidate<'a> {
 			upward_messages,
 			fees,
 			erasure_root,
+			new_validation_code: None,
 		};
 
 		Ok(FullOutput {
@@ -244,8 +240,12 @@ pub fn validate<'a>(
 	}
 
 	let params = ValidationParams {
-		parent_head: local_validation.parent_head.0.clone(),
+		parent_head: local_validation.parent_head.clone(),
-		block_data: pov_block.block_data.0.clone(),
+		block_data: pov_block.block_data.clone(),
+		max_code_size: global_validation.max_code_size,
+		max_head_data_size: global_validation.max_head_data_size,
+		relay_chain_height: global_validation.block_number,
+		code_upgrade_allowed: local_validation.code_upgrade_allowed,
 	};
 
 	// TODO: remove when ext does not do this.
@@ -266,7 +266,7 @@ pub fn validate<'a>(
 		execution_mode,
 	) {
 		Ok(result) => {
-			if result.head_data == collation.head_data.0 {
+			if result.head_data == collation.head_data {
 				let (upward_messages, fees) = Arc::try_unwrap(ext.0)
 					.map_err(|_| "<non-unique>")
 					.expect("Wasm executor drops passed externalities on completion; \
@@ -277,8 +277,7 @@ pub fn validate<'a>(
 				Ok(ValidatedCandidate {
 					pov_block,
 					global_validation,
-					parent_head: &local_validation.parent_head,
+					local_validation,
-					balance: local_validation.balance,
 					upward_messages,
 					fees,
 				})
@@ -352,13 +351,13 @@ pub fn full_output_validation_with_api<P>(
 mod tests {
 	use super::*;
 	use parachain::wasm_executor::Externalities as ExternalitiesTrait;
-	use parachain::ParachainDispatchOrigin;
+	use parachain::primitives::ParachainDispatchOrigin;
 
 	#[test]
 	fn ext_checks_fees_and_updates_correctly() {
 		let mut ext = ExternalitiesInner {
 			upward: vec![
-				UpwardMessage{ data: vec![42], origin: ParachainDispatchOrigin::Parachain },
+				UpwardMessage { data: vec![42], origin: ParachainDispatchOrigin::Parachain },
 			],
 			fees_charged: 0,
 			free_balance: 1_000_000,