2.4.1 beta backports (#10471)

* version: bump beta

* Implement parity_versionInfo & parity_setChain on LC; fix parity_setChain (#10312)

* Light client: implement parity_versionInfo RPC

* Light client: implement set_exit_handler & parity_setChain RPC

* parity_setChain RPC: return an error if failed (instead of `true`)

* Implement eth_subscribe('syncing') RPC for full node & light node

* Fix indentation

* Revert commit: Implement eth_subscribe('syncing')

* Revert change to Cr callback function

* CI publish to aws (#10446)

* move publish aws from gitlab.yml to gitlab scripts

* gitlab.yml cleaning
move publish AWS to gitlab scripts
remove dependencies from android build

* CI aws git checkout (#10451)

* Updating the CI system with the publication of releases and binary files on github

Signed-off-by: Denis S. Soldatov aka General-Beck <general.beck@gmail.com>

* move publish aws from gitlab.yml to gitlab scripts

Signed-off-by: Denis S. Soldatov aka General-Beck <general.beck@gmail.com>

* gitlab.yml cleaning
move publish AWS to gitlab scripts
remove dependencies from android build

Signed-off-by: Denis S. Soldatov aka General-Beck <general.beck@gmail.com>

* Revert "Updating the CI system with the publication of releases and binary files on github"

This reverts commit da87e06f2e4751dbca08a898b52926aef5ad0aba.

* remove no-git for aws

* microfix

* no need in no_git then

* Revert "CI aws git checkout (#10451)" (#10456)

* Revert "CI aws git checkout (#10451)"

This reverts commit 3e1d73126c.

* Update .gitlab-ci.yml

revert aws script with small fixes

* Delete publish-aws.sh

* Tests parallelized (#10452)

* tests splitted, phase 1

* typo

* fix wrong launch commands

* typos

* rearrangements

* use `nproc` function for threads

* use nproc for threads

* let theads be auto, build-andriod no more in regular run

* split val chain and cargo check

* renamed some files

* wrong phase

* check rust files before test jobs

* lint error

* rust files modivied var

* test except changes

* add rust_changes except

* lint error

* fixes

* .gitlab-ci.yml can't be excluded

* pipeline shouldn't start

* pipeline must go

* pipeline must go 2

* pipeline must go 3

* pipeline must go 4

* pipeline must go 5

* pipeline must go 6

* pipeline must go 7

* pipeline must not go 1

* pipeline must go 8

* avoid skippng tests yet, reintroducing them after the caching

* test theory

* parallelized cargo check with combusting helicopters

* less uploads

* alias for cargo checks

* nice template

* Ensure static validator set changes are recognized (#10467)

ethcore/light/src/client/mod.rs

@@ -116,6 +116,9 @@ pub trait LightChainClient: Send + Sync {
 	/// Query whether a block is known.
 	fn is_known(&self, hash: &H256) -> bool;
 
+	/// Set the chain via a spec name.
+	fn set_spec_name(&self, new_spec_name: String) -> Result<(), ()>;
+
 	/// Clear the queue.
 	fn clear_queue(&self);
 
@@ -164,6 +167,8 @@ pub struct Client<T> {
 	listeners: RwLock<Vec<Weak<LightChainNotify>>>,
 	fetcher: T,
 	verify_full: bool,
+	/// A closure to call when we want to restart the client
+	exit_handler: Mutex<Option<Box<Fn(String) + 'static + Send>>>,
 }
 
 impl<T: ChainDataFetcher> Client<T> {
@@ -190,6 +195,7 @@ impl<T: ChainDataFetcher> Client<T> {
 			listeners: RwLock::new(vec![]),
 			fetcher,
 			verify_full: config.verify_full,
+			exit_handler: Mutex::new(None),
 		})
 	}
 
@@ -360,6 +366,14 @@ impl<T: ChainDataFetcher> Client<T> {
 		self.chain.heap_size_of_children()
 	}
 
+	/// Set a closure to call when the client wants to be restarted.
+	///
+	/// The parameter passed to the callback is the name of the new chain spec to use after
+	/// the restart.
+	pub fn set_exit_handler<F>(&self, f: F) where F: Fn(String) + 'static + Send {
+		*self.exit_handler.lock() = Some(Box::new(f));
+	}
+
 	/// Get a handle to the verification engine.
 	pub fn engine(&self) -> &Arc<EthEngine> {
 		&self.engine
@@ -563,6 +577,17 @@ impl<T: ChainDataFetcher> LightChainClient for Client<T> {
 		Client::engine(self)
 	}
 
+	fn set_spec_name(&self, new_spec_name: String) -> Result<(), ()> {
+		trace!(target: "mode", "Client::set_spec_name({:?})", new_spec_name);
+		if let Some(ref h) = *self.exit_handler.lock() {
+			(*h)(new_spec_name);
+			Ok(())
+		} else {
+			warn!("Not hypervised; cannot change chain.");
+			Err(())
+		}
+	}
+
 	fn is_known(&self, hash: &H256) -> bool {
 		self.status(hash) == BlockStatus::InChain
 	}