Merge branch 'master' into lightserv

2016-12-09 21:37:55 +01:00 · 2016-12-09 21:37:55 +01:00 · 503b126c93
commit 503b126c93
parent 415fccfffb 2226324495
88 changed files with 1606 additions and 736 deletions
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@ -422,13 +422,14 @@ test-rust-stable:
  image: ethcore/rust:stable
  before_script:
    - git submodule update --init --recursive
-    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep \.js | wc -l)
-    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0  ]; then echo "skip js test"; else ./js/scripts/install-deps.sh;fi
+    - export RUST_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep -v ^js/ | wc -l)
+    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep ^js/ | wc -l)
+    - echo "rust/js modified: $RUST_FILES_MODIFIED / $JS_FILES_MODIFIED"
+    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "Skipping JS deps install since no JS files modified."; else ./js/scripts/install-deps.sh;fi
  script:
    - export RUST_BACKTRACE=1
-    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "skip js test"&./test.sh $CARGOFLAGS; else echo "skip rust test"&./js/scripts/lint.sh&./js/scripts/test.sh&./js/scripts/build.sh; fi
+    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "Skipping JS lint since no JS files modified."; else ./js/scripts/lint.sh && ./js/scripts/test.sh && ./js/scripts/build.sh; fi
+    - if [ "$RUST_FILES_MODIFIED" = 0 ]; then echo "Skipping Rust tests since no Rust files modified."; else ./test.sh $CARGOFLAGS; fi
  tags:
    - rust
    - rust-stable
@ -437,13 +438,13 @@ js-test:
  image: ethcore/rust:stable
  before_script:
    - git submodule update --init --recursive
-    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep \.js | wc -l)
+    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep ^js/ | wc -l)
    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "skip js test"; else ./js/scripts/install-deps.sh;fi
+    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "Skipping JS deps install since no JS files modified."; else ./js/scripts/install-deps.sh;fi
  script:
    - export RUST_BACKTRACE=1
    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "skip js test"; else echo "skip rust test"&./js/scripts/lint.sh&./js/scripts/test.sh&./js/scripts/build.sh; fi
+    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "Skipping JS lint since no JS files modified."; else ./js/scripts/lint.sh && ./js/scripts/test.sh && ./js/scripts/build.sh; fi
  tags:
    - rust
    - rust-stable
@ -484,11 +485,11 @@ js-release:
    - stable
  image: ethcore/rust:stable
  before_script:
-    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep \.js | wc -l)
+    - export JS_FILES_MODIFIED=$(git --no-pager diff --name-only $CI_BUILD_REF^ $CI_BUILD_REF | grep ^js/ | wc -l)
    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0  ]; then echo "skip js build"; else ./js/scripts/install-deps.sh;fi
+    - if [ "$JS_FILES_MODIFIED" = 0  ]; then echo "Skipping JS deps install since no JS files modified."; else ./js/scripts/install-deps.sh;fi
  script:
    - echo $JS_FILES_MODIFIED
-    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "skip js build"; else ./js/scripts/build.sh&&./js/scripts/release.sh; fi
+    - if [ "$JS_FILES_MODIFIED" = 0 ]; then echo "Skipping JS rebuild since no JS files modified."; else ./js/scripts/build.sh && ./js/scripts/release.sh; fi
  tags:
    - javascript
--- a/Cargo.lock
+++ b/Cargo.lock
@ -676,6 +676,7 @@ dependencies = [
 "clippy 0.0.103 (registry+https://github.com/rust-lang/crates.io-index)",
 "env_logger 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
 "ethcore 1.5.0",
+ "ethcore-devtools 1.5.0",
 "ethcore-io 1.5.0",
 "ethcore-ipc 1.5.0",
 "ethcore-ipc-codegen 1.5.0",
@ -683,6 +684,7 @@ dependencies = [
 "ethcore-light 1.5.0",
 "ethcore-network 1.5.0",
 "ethcore-util 1.5.0",
+ "ethkey 0.2.0",
 "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
 "parking_lot 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
@ -1288,7 +1290,7 @@ dependencies = [
 [[package]]
 name = "parity-ui-precompiled"
 version = "1.4.0"
-source = "git+https://github.com/ethcore/js-precompiled.git#f5365b857b006ed60c02eb9360d60d7ddef65104"
+source = "git+https://github.com/ethcore/js-precompiled.git#3d3b2f9e8e8b0fd62c172240bfd001a317cf2979"
 dependencies = [
 "parity-dapps-glue 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
--- a/ethcore/res/authority_round.json
+++ b/ethcore/res/authority_round.json
@ -4,7 +4,8 @@
 		"AuthorityRound": {
 			"params": {
 				"gasLimitBoundDivisor": "0x0400",
-				"stepDuration": "1",
+				"stepDuration": 1,
+				"startStep": 2,
 				"authorities" : [
 					"0x7d577a597b2742b498cb5cf0c26cdcd726d39e6e",
 					"0x82a978b3f5962a5b0957d9ee9eef472ee55b42f1"
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@ -255,6 +255,11 @@ impl Client {
 		self.notify.write().push(Arc::downgrade(&target));
 	}

+	/// Returns engine reference.
+	pub fn engine(&self) -> &Engine {
+		&*self.engine
+	}
+
 	fn notify<F>(&self, f: F) where F: Fn(&ChainNotify) {
 		for np in self.notify.read().iter() {
 			if let Some(n) = np.upgrade() {
@ -563,6 +568,11 @@ impl Client {
 		results.len()
 	}

+	/// Get shared miner reference.
+	pub fn miner(&self) -> Arc<Miner> {
+		self.miner.clone()
+	}
+
 	/// Used by PoA to try sealing on period change.
 	pub fn update_sealing(&self) {
 		self.miner.update_sealing(self)
@ -1060,6 +1070,10 @@ impl BlockChainClient for Client {
 		self.transaction_address(id).and_then(|address| self.chain.read().transaction(&address))
 	}

+	fn transaction_block(&self, id: TransactionID) -> Option<H256> {
+		self.transaction_address(id).map(|addr| addr.block_hash)
+	}
+
 	fn uncle(&self, id: UncleID) -> Option<Bytes> {
 		let index = id.position;
 		self.block_body(id.block).and_then(|body| BodyView::new(&body).uncle_rlp_at(index))
--- a/ethcore/src/client/test_client.rs
+++ b/ethcore/src/client/test_client.rs
@ -255,7 +255,7 @@ impl TestBlockChainClient {
 	}

 	/// Make a bad block by setting invalid extra data.
-	pub fn corrupt_block(&mut self, n: BlockNumber) {
+	pub fn corrupt_block(&self, n: BlockNumber) {
 		let hash = self.block_hash(BlockID::Number(n)).unwrap();
 		let mut header: BlockHeader = decode(&self.block_header(BlockID::Number(n)).unwrap());
 		header.set_extra_data(b"This extra data is way too long to be considered valid".to_vec());
@ -267,7 +267,7 @@ impl TestBlockChainClient {
 	}

 	/// Make a bad block by setting invalid parent hash.
-	pub fn corrupt_block_parent(&mut self, n: BlockNumber) {
+	pub fn corrupt_block_parent(&self, n: BlockNumber) {
 		let hash = self.block_hash(BlockID::Number(n)).unwrap();
 		let mut header: BlockHeader = decode(&self.block_header(BlockID::Number(n)).unwrap());
 		header.set_parent_hash(H256::from(42));
@ -432,6 +432,10 @@ impl BlockChainClient for TestBlockChainClient {
 		None	// Simple default.
 	}

+	fn transaction_block(&self, _id: TransactionID) -> Option<H256> {
+		None	// Simple default.
+	}
+
 	fn uncle(&self, _id: UncleID) -> Option<Bytes> {
 		None	// Simple default.
 	}
--- a/ethcore/src/client/traits.rs
+++ b/ethcore/src/client/traits.rs
@ -129,6 +129,9 @@ pub trait BlockChainClient : Sync + Send {
 	/// Get transaction with given hash.
 	fn transaction(&self, id: TransactionID) -> Option<LocalizedTransaction>;

+	/// Get the hash of block that contains the transaction, if any.
+	fn transaction_block(&self, id: TransactionID) -> Option<H256>;
+
 	/// Get uncle with given id.
 	fn uncle(&self, id: UncleID) -> Option<Bytes>;

--- a/ethcore/src/engines/authority_round.rs
+++ b/ethcore/src/engines/authority_round.rs
@ -49,6 +49,8 @@ pub struct AuthorityRoundParams {
 	pub authorities: Vec<Address>,
 	/// Number of authorities.
 	pub authority_n: usize,
+	/// Starting step,
+	pub start_step: Option<u64>,
 }

 impl From<ethjson::spec::AuthorityRoundParams> for AuthorityRoundParams {
@ -58,6 +60,7 @@ impl From<ethjson::spec::AuthorityRoundParams> for AuthorityRoundParams {
 			step_duration: Duration::from_secs(p.step_duration.into()),
 			authority_n: p.authorities.len(),
 			authorities: p.authorities.into_iter().map(Into::into).collect::<Vec<_>>(),
+			start_step: p.start_step.map(Into::into),
 		}
 	}
 }
@ -97,7 +100,7 @@ impl AsMillis for Duration {
 impl AuthorityRound {
 	/// Create a new instance of AuthorityRound engine.
 	pub fn new(params: CommonParams, our_params: AuthorityRoundParams, builtins: BTreeMap<Address, Builtin>) -> Result<Arc<Self>, Error> {
-		let initial_step = (unix_now().as_secs() / our_params.step_duration.as_secs()) as usize;
+		let initial_step = our_params.start_step.unwrap_or_else(|| (unix_now().as_secs() / our_params.step_duration.as_secs())) as usize;
 		let engine = Arc::new(
 			AuthorityRound {
 				params: params,
@ -160,14 +163,7 @@ impl IoHandler<()> for TransitionHandler {
 	fn timeout(&self, io: &IoContext<()>, timer: TimerToken) {
 		if timer == ENGINE_TIMEOUT_TOKEN {
 			if let Some(engine) = self.engine.upgrade() {
-				engine.step.fetch_add(1, AtomicOrdering::SeqCst);
-				engine.proposed.store(false, AtomicOrdering::SeqCst);
-				if let Some(ref channel) = *engine.message_channel.lock() {
-					match channel.send(ClientIoMessage::UpdateSealing) {
-						Ok(_) => trace!(target: "poa", "timeout: UpdateSealing message sent for step {}.", engine.step.load(AtomicOrdering::Relaxed)),
-						Err(err) => trace!(target: "poa", "timeout: Could not send a sealing message {} for step {}.", err, engine.step.load(AtomicOrdering::Relaxed)),
-					}
-				}
+				engine.step();
 				io.register_timer_once(ENGINE_TIMEOUT_TOKEN, engine.remaining_step_duration().as_millis())
 					.unwrap_or_else(|e| warn!(target: "poa", "Failed to restart consensus step timer: {}.", e))
 			}
@ -184,6 +180,17 @@ impl Engine for AuthorityRound {
 	fn params(&self) -> &CommonParams { &self.params }
 	fn builtins(&self) -> &BTreeMap<Address, Builtin> { &self.builtins }

+	fn step(&self) {
+		self.step.fetch_add(1, AtomicOrdering::SeqCst);
+		self.proposed.store(false, AtomicOrdering::SeqCst);
+		if let Some(ref channel) = *self.message_channel.lock() {
+			match channel.send(ClientIoMessage::UpdateSealing) {
+				Ok(_) => trace!(target: "poa", "timeout: UpdateSealing message sent for step {}.", self.step.load(AtomicOrdering::Relaxed)),
+				Err(err) => trace!(target: "poa", "timeout: Could not send a sealing message {} for step {}.", err, self.step.load(AtomicOrdering::Relaxed)),
+			}
+		}
+	}
+
 	/// Additional engine-specific information for the user/developer concerning `header`.
 	fn extra_info(&self, header: &Header) -> BTreeMap<String, String> {
 		map![
@ -235,6 +242,8 @@ impl Engine for AuthorityRound {
 			} else {
 				warn!(target: "poa", "generate_seal: FAIL: Accounts not provided.");
 			}
+		} else {
+			trace!(target: "poa", "generate_seal: Not a proposer for step {}.", step);
 		}
 		None
 	}
--- a/ethcore/src/engines/mod.rs
+++ b/ethcore/src/engines/mod.rs
@ -160,4 +160,6 @@ pub trait Engine : Sync + Send {

 	/// Add an account provider useful for Engines that sign stuff.
 	fn register_account_provider(&self, _account_provider: Arc<AccountProvider>) {}
+	/// Trigger next step of the consensus engine.
+	fn step(&self) {}
 }
--- a/ethcore/src/miner/miner.rs
+++ b/ethcore/src/miner/miner.rs
@ -23,7 +23,7 @@ use account_provider::{AccountProvider, Error as AccountError};
 use views::{BlockView, HeaderView};
 use header::Header;
 use state::{State, CleanupMode};
-use client::{MiningBlockChainClient, Executive, Executed, EnvInfo, TransactOptions, BlockID, CallAnalytics};
+use client::{MiningBlockChainClient, Executive, Executed, EnvInfo, TransactOptions, BlockID, CallAnalytics, TransactionID};
 use client::TransactionImportResult;
 use executive::contract_address;
 use block::{ClosedBlock, SealedBlock, IsBlock, Block};
@ -357,6 +357,8 @@ impl Miner {
 		let block_number = open_block.block().fields().header.number();

 		// TODO Push new uncles too.
+		let mut tx_count: usize = 0;
+		let tx_total = transactions.len();
 		for tx in transactions {
 			let hash = tx.hash();
 			let start = Instant::now();
@ -378,7 +380,7 @@ impl Miner {
 				},
 				_ => {},
 			}
-
+			trace!(target: "miner", "Adding tx {:?} took {:?}", hash, took);
 			match result {
 				Err(Error::Execution(ExecutionError::BlockGasLimitReached { gas_limit, gas_used, gas })) => {
 					debug!(target: "miner", "Skipping adding transaction to block because of gas limit: {:?} (limit: {:?}, used: {:?}, gas: {:?})", hash, gas_limit, gas_used, gas);
@ -407,9 +409,12 @@ impl Miner {
 						   "Error adding transaction to block: number={}. transaction_hash={:?}, Error: {:?}",
 						   block_number, hash, e);
 				},
-				_ => {}	// imported ok
+				_ => {
+					tx_count += 1;
+				}	// imported ok
 			}
 		}
+		trace!(target: "miner", "Pushed {}/{} transactions", tx_count, tx_total);

 		let block = open_block.close();

@ -580,6 +585,10 @@ impl Miner {
 		let best_block_header: Header = ::rlp::decode(&chain.best_block_header());
 		transactions.into_iter()
 			.map(|tx| {
+				if chain.transaction_block(TransactionID::Hash(tx.hash())).is_some() {
+					debug!(target: "miner", "Rejected tx {:?}: already in the blockchain", tx.hash());
+					return Err(Error::Transaction(TransactionError::AlreadyImported));
+				}
 				match self.engine.verify_transaction_basic(&tx, &best_block_header) {
 					Err(e) => {
 						debug!(target: "miner", "Rejected tx {:?} with invalid signature: {:?}", tx.hash(), e);
--- a/ethcore/src/spec/spec.rs
+++ b/ethcore/src/spec/spec.rs
@ -273,7 +273,7 @@ impl Spec {
 	pub fn new_instant() -> Spec { load_bundled!("instant_seal") }

 	/// Create a new Spec with AuthorityRound consensus which does internal sealing (not requiring work).
-	/// Accounts with secrets "1".sha3() and "2".sha3() are the authorities.
+	/// Accounts with secrets "0".sha3() and "1".sha3() are the authorities.
 	pub fn new_test_round() -> Self { load_bundled!("authority_round") }
 }

--- a/js/package.json
+++ b/js/package.json
@ -1,6 +1,6 @@
 {
  "name": "parity.js",
-  "version": "0.2.100",
+  "version": "0.2.105",
  "main": "release/index.js",
  "jsnext:main": "src/index.js",
  "author": "Parity Team <admin@parity.io>",
--- a/js/src/3rdparty/etherscan/links.js
+++ b/js/src/3rdparty/etherscan/links.js
@ -14,10 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

+export const url = (isTestnet = false) => {
+  return `https://${isTestnet ? 'testnet.' : ''}etherscan.io`;
+};
+
 export const txLink = (hash, isTestnet = false) => {
-  return `https://${isTestnet ? 'testnet.' : ''}etherscan.io/tx/${hash}`;
+  return `${url(isTestnet)}/tx/${hash}`;
 };

 export const addressLink = (address, isTestnet = false) => {
-  return `https://${isTestnet ? 'testnet.' : ''}etherscan.io/address/${address}`;
+  return `${url(isTestnet)}/address/${address}`;
 };
--- a/js/src/api/contract/contract.js
+++ b/js/src/api/contract/contract.js
@ -240,8 +240,8 @@ export default class Contract {
  }

  _bindEvent = (event) => {
-    event.subscribe = (options = {}, callback) => {
-      return this._subscribe(event, options, callback);
+    event.subscribe = (options = {}, callback, autoRemove) => {
+      return this._subscribe(event, options, callback, autoRemove);
    };

    event.unsubscribe = (subscriptionId) => {
@ -306,16 +306,31 @@ export default class Contract {
    return this._api.eth.newFilter(options);
  }

-  subscribe (eventName = null, options = {}, callback) {
+  subscribe (eventName = null, options = {}, callback, autoRemove) {
    try {
      const event = this._findEvent(eventName);
-      return this._subscribe(event, options, callback);
+      return this._subscribe(event, options, callback, autoRemove);
    } catch (e) {
      return Promise.reject(e);
    }
  }

-  _subscribe (event = null, _options, callback) {
+  _sendData (subscriptionId, error, logs) {
+    const { autoRemove, callback } = this._subscriptions[subscriptionId];
+    let result = true;
+
+    try {
+      result = callback(error, logs);
+    } catch (error) {
+      console.warn('_sendData', subscriptionId, error);
+    }
+
+    if (autoRemove && result && typeof result === 'boolean') {
+      this.unsubscribe(subscriptionId);
+    }
+  }
+
+  _subscribe (event = null, _options, callback, autoRemove = false) {
    const subscriptionId = nextSubscriptionId++;
    const { skipInitFetch } = _options;
    delete _options['skipInitFetch'];
@ -325,6 +340,7 @@ export default class Contract {
      .then((filterId) => {
        this._subscriptions[subscriptionId] = {
          options: _options,
+          autoRemove,
          callback,
          filterId
        };
@ -337,8 +353,7 @@ export default class Contract {
        return this._api.eth
          .getFilterLogs(filterId)
          .then((logs) => {
-            callback(null, this.parseEventLogs(logs));
-
+            this._sendData(subscriptionId, null, this.parseEventLogs(logs));
            this._subscribeToChanges();
            return subscriptionId;
          });
@ -437,13 +452,13 @@ export default class Contract {
        })
      )
      .then((logsArray) => {
-        logsArray.forEach((logs, idx) => {
+        logsArray.forEach((logs, subscriptionId) => {
          if (!logs || !logs.length) {
            return;
          }

          try {
-            subscriptions[idx].callback(null, this.parseEventLogs(logs));
+            this.sendData(subscriptionId, null, this.parseEventLogs(logs));
          } catch (error) {
            console.error('_sendSubscriptionChanges', error);
          }
--- a/js/src/api/subscriptions/manager.js
+++ b/js/src/api/subscriptions/manager.js
@ -59,7 +59,7 @@ export default class Manager {
    return subscription;
  }

-  subscribe (subscriptionName, callback) {
+  subscribe (subscriptionName, callback, autoRemove = false) {
    return new Promise((resolve, reject) => {
      const subscription = this._validateType(subscriptionName);

@ -75,6 +75,7 @@ export default class Manager {
      this.subscriptions[subscriptionId] = {
        name: subscriptionName,
        id: subscriptionId,
+        autoRemove,
        callback
      };

@ -101,13 +102,18 @@ export default class Manager {
  }

  _sendData (subscriptionId, error, data) {
-    const { callback } = this.subscriptions[subscriptionId];
+    const { autoRemove, callback } = this.subscriptions[subscriptionId];
+    let result = true;

    try {
-      callback(error, data);
+      result = callback(error, data);
    } catch (error) {
      console.error(`Unable to update callback for subscriptionId ${subscriptionId}`, error);
    }
+
+    if (autoRemove && result && typeof result === 'boolean') {
+      this.unsubscribe(subscriptionId);
+    }
  }

  _updateSubscriptions = (subscriptionName, error, data) => {
--- a/js/src/contracts/code/index.js
+++ b/js/src/contracts/code/index.js
@ -14,7 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

-import wallet from './wallet';
+import { wallet } from './wallet';

 export {
  wallet
--- a/js/src/contracts/code/wallet.js
+++ b/js/src/contracts/code/wallet.js
--- a/js/src/contracts/snippets/enhanced-wallet.sol
+++ b/js/src/contracts/snippets/enhanced-wallet.sol
@ -0,0 +1,460 @@
+//sol Wallet
+// Multi-sig, daily-limited account proxy/wallet.
+// @authors:
+// Gav Wood <g@ethdev.com>
+// inheritable "property" contract that enables methods to be protected by requiring the acquiescence of either a
+// single, or, crucially, each of a number of, designated owners.
+// usage:
+// use modifiers onlyowner (just own owned) or onlymanyowners(hash), whereby the same hash must be provided by
+// some number (specified in constructor) of the set of owners (specified in the constructor, modifiable) before the
+// interior is executed.
+pragma solidity ^0.4.6;
+
+contract multisig {
+    // EVENTS
+
+    // this contract can accept a confirmation, in which case
+    // we record owner and operation (hash) alongside it.
+    event Confirmation(address owner, bytes32 operation);
+    event Revoke(address owner, bytes32 operation);
+
+    // some others are in the case of an owner changing.
+    event OwnerChanged(address oldOwner, address newOwner);
+    event OwnerAdded(address newOwner);
+    event OwnerRemoved(address oldOwner);
+
+    // the last one is emitted if the required signatures change
+    event RequirementChanged(uint newRequirement);
+
+    // Funds has arrived into the wallet (record how much).
+    event Deposit(address _from, uint value);
+    // Single transaction going out of the wallet (record who signed for it, how much, and to whom it's going).
+    event SingleTransact(address owner, uint value, address to, bytes data);
+    // Multi-sig transaction going out of the wallet (record who signed for it last, the operation hash, how much, and to whom it's going).
+    event MultiTransact(address owner, bytes32 operation, uint value, address to, bytes data);
+    // Confirmation still needed for a transaction.
+    event ConfirmationNeeded(bytes32 operation, address initiator, uint value, address to, bytes data);
+}
+
+contract multisigAbi is multisig {
+    function isOwner(address _addr) returns (bool);
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool);
+
+    function confirm(bytes32 _h) returns(bool);
+
+    // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
+    function setDailyLimit(uint _newLimit);
+
+    function addOwner(address _owner);
+
+    function removeOwner(address _owner);
+
+    function changeRequirement(uint _newRequired);
+
+    // Revokes a prior confirmation of the given operation
+    function revoke(bytes32 _operation);
+
+    function changeOwner(address _from, address _to);
+
+    function execute(address _to, uint _value, bytes _data) returns(bool);
+}
+
+contract WalletLibrary is multisig {
+    // TYPES
+
+    // struct for the status of a pending operation.
+    struct PendingState {
+        uint yetNeeded;
+        uint ownersDone;
+        uint index;
+    }
+
+    // Transaction structure to remember details of transaction lest it need be saved for a later call.
+    struct Transaction {
+        address to;
+        uint value;
+        bytes data;
+    }
+
+    /******************************
+     ***** MULTI OWNED SECTION ****
+     ******************************/
+
+    // MODIFIERS
+
+    // simple single-sig function modifier.
+    modifier onlyowner {
+        if (isOwner(msg.sender))
+            _;
+    }
+    // multi-sig function modifier: the operation must have an intrinsic hash in order
+    // that later attempts can be realised as the same underlying operation and
+    // thus count as confirmations.
+    modifier onlymanyowners(bytes32 _operation) {
+        if (confirmAndCheck(_operation))
+            _;
+    }
+
+    // METHODS
+
+    // constructor is given number of sigs required to do protected "onlymanyowners" transactions
+    // as well as the selection of addresses capable of confirming them.
+    function initMultiowned(address[] _owners, uint _required) {
+        m_numOwners = _owners.length + 1;
+        m_owners[1] = uint(msg.sender);
+        m_ownerIndex[uint(msg.sender)] = 1;
+        m_required = _required;
+
+        for (uint i = 0; i < _owners.length; ++i)
+        {
+            m_owners[2 + i] = uint(_owners[i]);
+            m_ownerIndex[uint(_owners[i])] = 2 + i;
+        }
+    }
+
+    // Revokes a prior confirmation of the given operation
+    function revoke(bytes32 _operation) {
+        uint ownerIndex = m_ownerIndex[uint(msg.sender)];
+        // make sure they're an owner
+        if (ownerIndex == 0) return;
+        uint ownerIndexBit = 2**ownerIndex;
+        var pending = m_pending[_operation];
+        if (pending.ownersDone & ownerIndexBit > 0) {
+            pending.yetNeeded++;
+            pending.ownersDone -= ownerIndexBit;
+            Revoke(msg.sender, _operation);
+        }
+    }
+
+    // Replaces an owner `_from` with another `_to`.
+    function changeOwner(address _from, address _to) onlymanyowners(sha3(msg.data)) {
+        if (isOwner(_to)) return;
+        uint ownerIndex = m_ownerIndex[uint(_from)];
+        if (ownerIndex == 0) return;
+
+        clearPending();
+        m_owners[ownerIndex] = uint(_to);
+        m_ownerIndex[uint(_from)] = 0;
+        m_ownerIndex[uint(_to)] = ownerIndex;
+        OwnerChanged(_from, _to);
+    }
+
+    function addOwner(address _owner) onlymanyowners(sha3(msg.data)) {
+        if (isOwner(_owner)) return;
+
+        clearPending();
+        if (m_numOwners >= c_maxOwners)
+            reorganizeOwners();
+        if (m_numOwners >= c_maxOwners)
+            return;
+        m_numOwners++;
+        m_owners[m_numOwners] = uint(_owner);
+        m_ownerIndex[uint(_owner)] = m_numOwners;
+        OwnerAdded(_owner);
+    }
+
+    function removeOwner(address _owner) onlymanyowners(sha3(msg.data)) {
+        uint ownerIndex = m_ownerIndex[uint(_owner)];
+        if (ownerIndex == 0) return;
+        if (m_required > m_numOwners - 1) return;
+
+        m_owners[ownerIndex] = 0;
+        m_ownerIndex[uint(_owner)] = 0;
+        clearPending();
+        reorganizeOwners(); //make sure m_numOwner is equal to the number of owners and always points to the optimal free slot
+        OwnerRemoved(_owner);
+    }
+
+    function changeRequirement(uint _newRequired) onlymanyowners(sha3(msg.data)) {
+        if (_newRequired > m_numOwners) return;
+        m_required = _newRequired;
+        clearPending();
+        RequirementChanged(_newRequired);
+    }
+
+    function isOwner(address _addr) returns (bool) {
+        return m_ownerIndex[uint(_addr)] > 0;
+    }
+
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool) {
+        var pending = m_pending[_operation];
+        uint ownerIndex = m_ownerIndex[uint(_owner)];
+
+        // make sure they're an owner
+        if (ownerIndex == 0) return false;
+
+        // determine the bit to set for this owner.
+        uint ownerIndexBit = 2**ownerIndex;
+        return !(pending.ownersDone & ownerIndexBit == 0);
+    }
+
+    // INTERNAL METHODS
+
+    function confirmAndCheck(bytes32 _operation) internal returns (bool) {
+        // determine what index the present sender is:
+        uint ownerIndex = m_ownerIndex[uint(msg.sender)];
+        // make sure they're an owner
+        if (ownerIndex == 0) return;
+
+        var pending = m_pending[_operation];
+        // if we're not yet working on this operation, switch over and reset the confirmation status.
+        if (pending.yetNeeded == 0) {
+            // reset count of confirmations needed.
+            pending.yetNeeded = m_required;
+            // reset which owners have confirmed (none) - set our bitmap to 0.
+            pending.ownersDone = 0;
+            pending.index = m_pendingIndex.length++;
+            m_pendingIndex[pending.index] = _operation;
+        }
+        // determine the bit to set for this owner.
+        uint ownerIndexBit = 2**ownerIndex;
+        // make sure we (the message sender) haven't confirmed this operation previously.
+        if (pending.ownersDone & ownerIndexBit == 0) {
+            Confirmation(msg.sender, _operation);
+            // ok - check if count is enough to go ahead.
+            if (pending.yetNeeded <= 1) {
+                // enough confirmations: reset and run interior.
+                delete m_pendingIndex[m_pending[_operation].index];
+                delete m_pending[_operation];
+                return true;
+            }
+            else
+            {
+                // not enough: record that this owner in particular confirmed.
+                pending.yetNeeded--;
+                pending.ownersDone |= ownerIndexBit;
+            }
+        }
+    }
+
+    function reorganizeOwners() private {
+        uint free = 1;
+        while (free < m_numOwners)
+        {
+            while (free < m_numOwners && m_owners[free] != 0) free++;
+            while (m_numOwners > 1 && m_owners[m_numOwners] == 0) m_numOwners--;
+            if (free < m_numOwners && m_owners[m_numOwners] != 0 && m_owners[free] == 0)
+            {
+                m_owners[free] = m_owners[m_numOwners];
+                m_ownerIndex[m_owners[free]] = free;
+                m_owners[m_numOwners] = 0;
+            }
+        }
+    }
+
+    function clearPending() internal {
+        uint length = m_pendingIndex.length;
+        for (uint i = 0; i < length; ++i)
+            if (m_pendingIndex[i] != 0)
+                delete m_pending[m_pendingIndex[i]];
+        delete m_pendingIndex;
+    }
+
+
+    /******************************
+     ****** DAY LIMIT SECTION *****
+     ******************************/
+
+    // MODIFIERS
+
+    // simple modifier for daily limit.
+    modifier limitedDaily(uint _value) {
+        if (underLimit(_value))
+            _;
+    }
+
+    // METHODS
+
+    // constructor - stores initial daily limit and records the present day's index.
+    function initDaylimit(uint _limit) {
+        m_dailyLimit = _limit;
+        m_lastDay = today();
+    }
+    // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
+    function setDailyLimit(uint _newLimit) onlymanyowners(sha3(msg.data)) {
+        m_dailyLimit = _newLimit;
+    }
+    // resets the amount already spent today. needs many of the owners to confirm.
+    function resetSpentToday() onlymanyowners(sha3(msg.data)) {
+        m_spentToday = 0;
+    }
+
+    // INTERNAL METHODS
+
+    // checks to see if there is at least `_value` left from the daily limit today. if there is, subtracts it and
+    // returns true. otherwise just returns false.
+    function underLimit(uint _value) internal onlyowner returns (bool) {
+        // reset the spend limit if we're on a different day to last time.
+        if (today() > m_lastDay) {
+            m_spentToday = 0;
+            m_lastDay = today();
+        }
+        // check to see if there's enough left - if so, subtract and return true.
+        // overflow protection                    // dailyLimit check
+        if (m_spentToday + _value >= m_spentToday && m_spentToday + _value <= m_dailyLimit) {
+            m_spentToday += _value;
+            return true;
+        }
+        return false;
+    }
+
+    // determines today's index.
+    function today() private constant returns (uint) { return now / 1 days; }
+
+
+    /******************************
+     ********* WALLET SECTION *****
+     ******************************/
+
+    // METHODS
+
+    // constructor - just pass on the owner array to the multiowned and
+    // the limit to daylimit
+    function initWallet(address[] _owners, uint _required, uint _daylimit) {
+        initMultiowned(_owners, _required);
+        initDaylimit(_daylimit) ;
+    }
+
+    // kills the contract sending everything to `_to`.
+    function kill(address _to) onlymanyowners(sha3(msg.data)) {
+        suicide(_to);
+    }
+
+    // Outside-visible transact entry point. Executes transaction immediately if below daily spend limit.
+    // If not, goes into multisig process. We provide a hash on return to allow the sender to provide
+    // shortcuts for the other confirmations (allowing them to avoid replicating the _to, _value
+    // and _data arguments). They still get the option of using them if they want, anyways.
+    function execute(address _to, uint _value, bytes _data) onlyowner returns(bool _callValue) {
+        // first, take the opportunity to check that we're under the daily limit.
+        if (underLimit(_value)) {
+            SingleTransact(msg.sender, _value, _to, _data);
+            // yes - just execute the call.
+            _callValue =_to.call.value(_value)(_data);
+        } else {
+            // determine our operation hash.
+            bytes32 _r = sha3(msg.data, block.number);
+            if (!confirm(_r) && m_txs[_r].to == 0) {
+                m_txs[_r].to = _to;
+                m_txs[_r].value = _value;
+                m_txs[_r].data = _data;
+                ConfirmationNeeded(_r, msg.sender, _value, _to, _data);
+            }
+        }
+    }
+
+    // confirm a transaction through just the hash. we use the previous transactions map, m_txs, in order
+    // to determine the body of the transaction from the hash provided.
+    function confirm(bytes32 _h) onlymanyowners(_h) returns (bool) {
+        if (m_txs[_h].to != 0) {
+            m_txs[_h].to.call.value(m_txs[_h].value)(m_txs[_h].data);
+            MultiTransact(msg.sender, _h, m_txs[_h].value, m_txs[_h].to, m_txs[_h].data);
+            delete m_txs[_h];
+            return true;
+        }
+    }
+
+    // INTERNAL METHODS
+
+    function clearWalletPending() internal {
+        uint length = m_pendingIndex.length;
+        for (uint i = 0; i < length; ++i)
+            delete m_txs[m_pendingIndex[i]];
+        clearPending();
+    }
+
+    // FIELDS
+    address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
+
+    // the number of owners that must confirm the same operation before it is run.
+    uint m_required;
+    // pointer used to find a free slot in m_owners
+    uint m_numOwners;
+
+    uint public m_dailyLimit;
+    uint public m_spentToday;
+    uint public m_lastDay;
+
+    // list of owners
+    uint[256] m_owners;
+    uint constant c_maxOwners = 250;
+
+    // index on the list of owners to allow reverse lookup
+    mapping(uint => uint) m_ownerIndex;
+    // the ongoing operations.
+    mapping(bytes32 => PendingState) m_pending;
+    bytes32[] m_pendingIndex;
+
+    // pending transactions we have at present.
+    mapping (bytes32 => Transaction) m_txs;
+}
+
+
+contract Wallet is multisig {
+
+    // WALLET CONSTRUCTOR
+    //   calls the `initWallet` method of the Library in this context
+    function Wallet(address[] _owners, uint _required, uint _daylimit) {
+        // Signature of the Wallet Library's init function
+        bytes4 sig = bytes4(sha3("initWallet(address[],uint256,uint256)"));
+        address target = _walletLibrary;
+
+        // Compute the size of the call data : arrays has 2
+        // 32bytes for offset and length, plus 32bytes per element ;
+        // plus 2 32bytes for each uint
+        uint argarraysize = (2 + _owners.length);
+        uint argsize = (2 + argarraysize) * 32;
+
+        assembly {
+            // Add the signature first to memory
+            mstore(0x0, sig)
+            // Add the call data, which is at the end of the
+            // code
+            codecopy(0x4,  sub(codesize, argsize), argsize)
+            // Delegate call to the library
+            delegatecall(sub(gas, 10000), target, 0x0, add(argsize, 0x4), 0x0, 0x0)
+        }
+    }
+
+    // METHODS
+
+    // gets called when no other function matches
+    function() payable {
+        // just being sent some cash?
+        if (msg.value > 0)
+            Deposit(msg.sender, msg.value);
+        else if (msg.data.length > 0)
+            _walletLibrary.delegatecall(msg.data);
+    }
+
+    // Gets an owner by 0-indexed position (using numOwners as the count)
+    function getOwner(uint ownerIndex) constant returns (address) {
+        return address(m_owners[ownerIndex + 1]);
+    }
+
+    // As return statement unavailable in fallback, explicit the method here
+
+    function hasConfirmed(bytes32 _operation, address _owner) constant returns (bool) {
+        return _walletLibrary.delegatecall(msg.data);
+    }
+
+    function isOwner(address _addr) returns (bool) {
+        return _walletLibrary.delegatecall(msg.data);
+    }
+
+    // FIELDS
+    address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
+
+    // the number of owners that must confirm the same operation before it is run.
+    uint public m_required;
+    // pointer used to find a free slot in m_owners
+    uint public m_numOwners;
+
+    uint public m_dailyLimit;
+    uint public m_spentToday;
+    uint public m_lastDay;
+
+    // list of owners
+    uint[256] m_owners;
+}
--- a/js/src/jsonrpc/rollup.config.js
+++ b/js/src/jsonrpc/rollup.config.js
@ -1,12 +0,0 @@
-import babel from 'rollup-plugin-babel';
-
-export default {
-  entry: 'src/index.js',
-  dest: 'release/index.js',
-  format: 'cjs',
-  plugins: [babel({
-    babelrc: false,
-    presets: ['es2015-rollup', 'stage-0'],
-    runtimeHelpers: true
-  })]
-};
--- a/js/src/modals/AddAddress/addAddress.js
+++ b/js/src/modals/AddAddress/addAddress.js
@ -19,7 +19,7 @@ import ContentAdd from 'material-ui/svg-icons/content/add';
 import ContentClear from 'material-ui/svg-icons/content/clear';

 import { Button, Modal, Form, Input, InputAddress } from '~/ui';
-import { ERRORS, validateAddress, validateName } from '../../util/validation';
+import { ERRORS, validateAddress, validateName } from '~/util/validation';

 export default class AddAddress extends Component {
  static contextTypes = {
--- a/js/src/modals/AddContract/addContract.js
+++ b/js/src/modals/AddContract/addContract.js
@ -21,7 +21,7 @@ import NavigationArrowForward from 'material-ui/svg-icons/navigation/arrow-forwa
 import NavigationArrowBack from 'material-ui/svg-icons/navigation/arrow-back';

 import { Button, Modal, Form, Input, InputAddress, RadioButtons } from '~/ui';
-import { ERRORS, validateAbi, validateAddress, validateName } from '../../util/validation';
+import { ERRORS, validateAbi, validateAddress, validateName } from '~/util/validation';

 import { eip20, wallet } from '~/contracts/abi';

--- a/js/src/modals/CreateWallet/WalletType/walletType.js
+++ b/js/src/modals/CreateWallet/WalletType/walletType.js
@ -17,6 +17,7 @@
 import React, { Component, PropTypes } from 'react';

 import { RadioButtons } from '~/ui';
+import { walletSourceURL } from '~/contracts/code/wallet';

 // import styles from '../createWallet.css';

@ -46,7 +47,9 @@ export default class WalletType extends Component {
        description: (
          <span>
            <span>Create/Deploy a </span>
-            <a href='https://github.com/ethereum/dapp-bin/blob/master/wallet/wallet.sol' target='_blank'>standard multi-signature </a>
+            <a href={ walletSourceURL } target='_blank'>
+              standard multi-signature
+            </a>
            <span> Wallet</span>
          </span>
        )
--- a/js/src/modals/CreateWallet/createWalletStore.js
+++ b/js/src/modals/CreateWallet/createWalletStore.js
@ -16,13 +16,13 @@

 import { observable, computed, action, transaction } from 'mobx';

-import { validateUint, validateAddress, validateName } from '~/util/validation';
-import { ERROR_CODES } from '~/api/transport/error';
-
 import Contract from '~/api/contract';
+import Contracts from '~/contracts';
+import { ERROR_CODES } from '~/api/transport/error';
 import { wallet as walletAbi } from '~/contracts/abi';
-import { wallet as walletCode } from '~/contracts/code';
+import { wallet as walletCode, walletLibraryRegKey, fullWalletCode } from '~/contracts/code/wallet';

+import { validateUint, validateAddress, validateName } from '~/util/validation';
 import WalletsUtils from '~/util/wallets';

 const STEPS = {
@ -160,14 +160,25 @@ export default class CreateWalletStore {

    const { account, owners, required, daylimit } = this.wallet;

-    const options = {
-      data: walletCode,
-      from: account
-    };
+    Contracts
+      .get()
+      .registry
+      .lookupAddress(walletLibraryRegKey)
+      .then((address) => {
+        const walletLibraryAddress = (address || '').replace(/^0x/, '').toLowerCase();
+        const code = walletLibraryAddress.length && !/^0+$/.test(walletLibraryAddress)
+          ? walletCode.replace(/(_)+WalletLibrary(_)+/g, walletLibraryAddress)
+          : fullWalletCode;

-    this.api
-      .newContract(walletAbi)
-      .deploy(options, [ owners, required, daylimit ], this.onDeploymentState)
+        const options = {
+          data: code,
+          from: account
+        };
+
+        return this.api
+          .newContract(walletAbi)
+          .deploy(options, [ owners, required, daylimit ], this.onDeploymentState);
+      })
      .then((address) => {
        this.deployed = true;
        this.wallet.address = address;
--- a/js/src/modals/DeployContract/DetailsStep/detailsStep.js
+++ b/js/src/modals/DeployContract/DetailsStep/detailsStep.js
@ -18,8 +18,8 @@ import React, { Component, PropTypes } from 'react';
 import { MenuItem } from 'material-ui';

 import { AddressSelect, Form, Input, Select } from '~/ui';
-import { validateAbi } from '../../../util/validation';
-import { parseAbiType } from '../../../util/abi';
+import { validateAbi } from '~/util/validation';
+import { parseAbiType } from '~/util/abi';

 export default class DetailsStep extends Component {
  static contextTypes = {
--- a/js/src/modals/DeployContract/ParametersStep/parametersStep.js
+++ b/js/src/modals/DeployContract/ParametersStep/parametersStep.js
@ -32,7 +32,7 @@
 import React, { Component, PropTypes } from 'react';

 import { Form, TypedInput } from '~/ui';
-import { parseAbiType } from '../../../util/abi';
+import { parseAbiType } from '~/util/abi';

 import styles from '../deployContract.css';

--- a/js/src/modals/DeployContract/deployContract.js
+++ b/js/src/modals/DeployContract/deployContract.js
@ -19,7 +19,7 @@ import ActionDoneAll from 'material-ui/svg-icons/action/done-all';
 import ContentClear from 'material-ui/svg-icons/content/clear';

 import { BusyStep, CompletedStep, CopyToClipboard, Button, IdentityIcon, Modal, TxHash } from '~/ui';
-import { ERRORS, validateAbi, validateCode, validateName } from '../../util/validation';
+import { ERRORS, validateAbi, validateCode, validateName } from '~/util/validation';

 import DetailsStep from './DetailsStep';
 import ParametersStep from './ParametersStep';
--- a/js/src/modals/EditMeta/editMeta.js
+++ b/js/src/modals/EditMeta/editMeta.js
@ -19,7 +19,7 @@ import ContentClear from 'material-ui/svg-icons/content/clear';
 import ContentSave from 'material-ui/svg-icons/content/save';

 import { Button, Form, Input, InputChip, Modal } from '~/ui';
-import { validateName } from '../../util/validation';
+import { validateName } from '~/util/validation';

 export default class EditMeta extends Component {
  static contextTypes = {
--- a/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js
+++ b/js/src/modals/ExecuteContract/DetailsStep/detailsStep.js
@ -15,13 +15,19 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

 import React, { Component, PropTypes } from 'react';
-import { MenuItem } from 'material-ui';
+import { Checkbox, MenuItem } from 'material-ui';

 import { AddressSelect, Form, Input, Select, TypedInput } from '~/ui';
 import { parseAbiType } from '~/util/abi';

 import styles from '../executeContract.css';

+const CHECK_STYLE = {
+  position: 'absolute',
+  top: '38px',
+  left: '1em'
+};
+
 export default class DetailsStep extends Component {
  static propTypes = {
    accounts: PropTypes.object.isRequired,
@ -31,10 +37,12 @@ export default class DetailsStep extends Component {
    onAmountChange: PropTypes.func.isRequired,
    fromAddress: PropTypes.string,
    fromAddressError: PropTypes.string,
+    gasEdit: PropTypes.bool,
    onFromAddressChange: PropTypes.func.isRequired,
    func: PropTypes.object,
    funcError: PropTypes.string,
    onFuncChange: PropTypes.func,
+    onGasEditClick: PropTypes.func,
    values: PropTypes.array.isRequired,
    valuesError: PropTypes.array.isRequired,
    warning: PropTypes.string,
@ -42,7 +50,7 @@ export default class DetailsStep extends Component {
  }

  render () {
-    const { accounts, amount, amountError, fromAddress, fromAddressError, onFromAddressChange, onAmountChange } = this.props;
+    const { accounts, amount, amountError, fromAddress, fromAddressError, gasEdit, onGasEditClick, onFromAddressChange, onAmountChange } = this.props;

    return (
      <Form>
@ -56,12 +64,23 @@ export default class DetailsStep extends Component {
          onChange={ onFromAddressChange } />
        { this.renderFunctionSelect() }
        { this.renderParameters() }
-        <Input
-          label='transaction value (in ETH)'
-          hint='the amount to send to with the transaction'
-          value={ amount }
-          error={ amountError }
-          onSubmit={ onAmountChange } />
+        <div className={ styles.columns }>
+          <div>
+            <Input
+              label='transaction value (in ETH)'
+              hint='the amount to send to with the transaction'
+              value={ amount }
+              error={ amountError }
+              onSubmit={ onAmountChange } />
+          </div>
+          <div>
+            <Checkbox
+              checked={ gasEdit }
+              label='edit gas price or value'
+              onCheck={ onGasEditClick }
+              style={ CHECK_STYLE } />
+          </div>
+        </div>
      </Form>
    );
  }
--- a/js/src/modals/ExecuteContract/executeContract.css
+++ b/js/src/modals/ExecuteContract/executeContract.css
@ -42,3 +42,15 @@
  padding: 0.75em;
  text-align: center;
 }
+
+.columns {
+  display: flex;
+  flex-wrap: wrap;
+  position: relative;
+
+  &>div {
+    flex: 0 1 50%;
+    width: 50%;
+    position: relative;
+  }
+}
--- a/js/src/modals/ExecuteContract/executeContract.js
+++ b/js/src/modals/ExecuteContract/executeContract.js
@ -17,19 +17,36 @@
 import React, { Component, PropTypes } from 'react';
 import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
+import { observer } from 'mobx-react';
 import ActionDoneAll from 'material-ui/svg-icons/action/done-all';
 import ContentClear from 'material-ui/svg-icons/content/clear';
+import NavigationArrowBack from 'material-ui/svg-icons/navigation/arrow-back';
+import NavigationArrowForward from 'material-ui/svg-icons/navigation/arrow-forward';

-import { BusyStep, CompletedStep, Button, IdentityIcon, Modal, TxHash } from '~/ui';
-import { MAX_GAS_ESTIMATION } from '../../util/constants';
-import { validateAddress, validateUint } from '../../util/validation';
+import { BusyStep, Button, CompletedStep, GasPriceEditor, IdentityIcon, Modal, TxHash } from '~/ui';
+import { MAX_GAS_ESTIMATION } from '~/util/constants';
+import { validateAddress, validateUint } from '~/util/validation';
 import { parseAbiType } from '~/util/abi';

 import DetailsStep from './DetailsStep';

-import ERRORS from '../Transfer/errors';
 import { ERROR_CODES } from '~/api/transport/error';

+const STEP_DETAILS = 0;
+const STEP_BUSY_OR_GAS = 1;
+const STEP_BUSY = 2;
+
+const TITLES = {
+  transfer: 'function details',
+  sending: 'sending',
+  complete: 'complete',
+  gas: 'gas selection',
+  rejected: 'rejected'
+};
+const STAGES_BASIC = [TITLES.transfer, TITLES.sending, TITLES.complete];
+const STAGES_GAS = [TITLES.transfer, TITLES.gas, TITLES.sending, TITLES.complete];
+
+@observer
 class ExecuteContract extends Component {
  static contextTypes = {
    api: PropTypes.object.isRequired,
@ -46,21 +63,22 @@ class ExecuteContract extends Component {
    onFromAddressChange: PropTypes.func.isRequired
  }

+  gasStore = new GasPriceEditor.Store(this.context.api, this.props.gasLimit);
+
  state = {
    amount: '0',
    amountError: null,
+    busyState: null,
    fromAddressError: null,
    func: null,
    funcError: null,
-    gas: null,
-    gasLimitError: null,
+    gasEdit: false,
+    rejected: false,
+    step: STEP_DETAILS,
+    sending: false,
    values: [],
    valuesError: [],
-    step: 0,
-    sending: false,
-    busyState: null,
-    txhash: null,
-    rejected: false
+    txhash: null
  }

  componentDidMount () {
@ -79,15 +97,21 @@ class ExecuteContract extends Component {
  }

  render () {
-    const { sending } = this.state;
+    const { sending, step, gasEdit, rejected } = this.state;
+    const steps = gasEdit ? STAGES_GAS : STAGES_BASIC;
+
+    if (rejected) {
+      steps[steps.length - 1] = TITLES.rejected;
+    }

    return (
      <Modal
        actions={ this.renderDialogActions() }
-        title='execute function'
        busy={ sending }
-        waiting={ [1] }
-        visible>
+        current={ step }
+        steps={ steps }
+        visible
+        waiting={ gasEdit ? [STEP_BUSY] : [STEP_BUSY_OR_GAS] }>
        { this.renderStep() }
      </Modal>
    );
@ -95,7 +119,7 @@ class ExecuteContract extends Component {

  renderDialogActions () {
    const { onClose, fromAddress } = this.props;
-    const { sending, step, fromAddressError, valuesError } = this.state;
+    const { gasEdit, sending, step, fromAddressError, valuesError } = this.state;
    const hasError = fromAddressError || valuesError.find((error) => error);

    const cancelBtn = (
@ -105,21 +129,44 @@ class ExecuteContract extends Component {
        icon={ <ContentClear /> }
        onClick={ onClose } />
    );
+    const postBtn = (
+      <Button
+        key='postTransaction'
+        label='post transaction'
+        disabled={ !!(sending || hasError) }
+        icon={ <IdentityIcon address={ fromAddress } button /> }
+        onClick={ this.postTransaction } />
+    );
+    const nextBtn = (
+      <Button
+        key='nextStep'
+        label='next'
+        icon={ <NavigationArrowForward /> }
+        onClick={ this.onNextClick } />
+    );
+    const prevBtn = (
+      <Button
+        key='prevStep'
+        label='prev'
+        icon={ <NavigationArrowBack /> }
+        onClick={ this.onPrevClick } />
+    );

-    if (step === 0) {
+    if (step === STEP_DETAILS) {
      return [
        cancelBtn,
-        <Button
-          key='postTransaction'
-          label='post transaction'
-          disabled={ !!(sending || hasError) }
-          icon={ <IdentityIcon address={ fromAddress } button /> }
-          onClick={ this.postTransaction } />
+        gasEdit ? nextBtn : postBtn
      ];
-    } else if (step === 1) {
+    } else if (step === (gasEdit ? STEP_BUSY : STEP_BUSY_OR_GAS)) {
      return [
        cancelBtn
      ];
+    } else if (gasEdit && (step === STEP_BUSY_OR_GAS)) {
+      return [
+        cancelBtn,
+        prevBtn,
+        postBtn
+      ];
    }

    return [
@ -133,7 +180,8 @@ class ExecuteContract extends Component {

  renderStep () {
    const { onFromAddressChange } = this.props;
-    const { step, busyState, gasLimitError, txhash, rejected } = this.state;
+    const { gasEdit, step, busyState, txhash, rejected } = this.state;
+    const { errorEstimated } = this.gasStore;

    if (rejected) {
      return (
@ -144,23 +192,29 @@ class ExecuteContract extends Component {
      );
    }

-    if (step === 0) {
+    if (step === STEP_DETAILS) {
      return (
        <DetailsStep
          { ...this.props }
          { ...this.state }
-          warning={ gasLimitError }
+          warning={ errorEstimated }
          onAmountChange={ this.onAmountChange }
          onFromAddressChange={ onFromAddressChange }
          onFuncChange={ this.onFuncChange }
+          onGasEditClick={ this.onGasEditClick }
          onValueChange={ this.onValueChange } />
      );
-    } else if (step === 1) {
+    } else if (step === (gasEdit ? STEP_BUSY : STEP_BUSY_OR_GAS)) {
      return (
        <BusyStep
          title='The function execution is in progress'
          state={ busyState } />
      );
+    } else if (gasEdit && (step === STEP_BUSY_OR_GAS)) {
+      return (
+        <GasPriceEditor
+          store={ this.gasStore } />
+      );
    }

    return (
@ -171,6 +225,7 @@ class ExecuteContract extends Component {
  }

  onAmountChange = (amount) => {
+    this.gasStore.setEthValue(amount);
    this.setState({ amount }, this.estimateGas);
  }

@ -221,7 +276,7 @@ class ExecuteContract extends Component {

  estimateGas = (_fromAddress) => {
    const { api } = this.context;
-    const { fromAddress, gasLimit } = this.props;
+    const { fromAddress } = this.props;
    const { amount, func, values } = this.state;
    const options = {
      gas: MAX_GAS_ESTIMATION,
@ -237,18 +292,11 @@ class ExecuteContract extends Component {
      .estimateGas(options, values)
      .then((gasEst) => {
        const gas = gasEst.mul(1.2);
-        let gasLimitError = null;

-        if (gas.gte(MAX_GAS_ESTIMATION)) {
-          gasLimitError = ERRORS.gasException;
-        } else if (gas.gt(gasLimit)) {
-          gasLimitError = ERRORS.gasBlockLimit;
-        }
+        console.log(`estimateGas: received ${gasEst.toFormat(0)}, adjusted to ${gas.toFormat(0)}`);

-        this.setState({
-          gas,
-          gasLimitError
-        });
+        this.gasStore.setEstimated(gasEst.toFixed(0));
+        this.gasStore.setGas(gas.toFixed(0));
      })
      .catch((error) => {
        console.warn('estimateGas', error);
@ -258,22 +306,20 @@ class ExecuteContract extends Component {
  postTransaction = () => {
    const { api, store } = this.context;
    const { fromAddress } = this.props;
-    const { amount, func, values } = this.state;
+    const { amount, func, gasEdit, values } = this.state;
+    const steps = gasEdit ? STAGES_GAS : STAGES_BASIC;
+    const finalstep = steps.length - 1;
    const options = {
-      gas: MAX_GAS_ESTIMATION,
+      gas: this.gasStore.gas,
+      gasPrice: this.gasStore.price,
      from: fromAddress,
      value: api.util.toWei(amount || 0)
    };

-    this.setState({ sending: true, step: 1 });
+    this.setState({ sending: true, step: gasEdit ? STEP_BUSY : STEP_BUSY_OR_GAS });

    func
-      .estimateGas(options, values)
-      .then((gas) => {
-        options.gas = gas.mul(1.2).toFixed(0);
-        console.log(`estimateGas: received ${gas.toFormat(0)}, adjusted to ${gas.mul(1.2).toFormat(0)}`);
-        return func.postTransaction(options, values);
-      })
+      .postTransaction(options, values)
      .then((requestId) => {
        this.setState({ busyState: 'Waiting for authorization in the Parity Signer' });

@ -281,7 +327,7 @@ class ExecuteContract extends Component {
          .pollMethod('parity_checkRequest', requestId)
          .catch((error) => {
            if (error.code === ERROR_CODES.REQUEST_REJECTED) {
-              this.setState({ rejected: true });
+              this.setState({ rejected: true, step: finalstep });
              return false;
            }

@ -289,13 +335,31 @@ class ExecuteContract extends Component {
          });
      })
      .then((txhash) => {
-        this.setState({ sending: false, step: 2, txhash, busyState: 'Your transaction has been posted to the network' });
+        this.setState({ sending: false, step: finalstep, txhash, busyState: 'Your transaction has been posted to the network' });
      })
      .catch((error) => {
        console.error('postTransaction', error);
        store.dispatch({ type: 'newError', error });
      });
  }
+
+  onGasEditClick = () => {
+    this.setState({
+      gasEdit: !this.state.gasEdit
+    });
+  }
+
+  onNextClick = () => {
+    this.setState({
+      step: this.state.step + 1
+    });
+  }
+
+  onPrevClick = () => {
+    this.setState({
+      step: this.state.step - 1
+    });
+  }
 }

 function mapStateToProps (state) {
--- a/js/src/modals/SMSVerification/store.js
+++ b/js/src/modals/SMSVerification/store.js
@ -21,9 +21,8 @@ import { sha3 } from '~/api/util/sha3';
 import Contracts from '~/contracts';

 import { checkIfVerified, checkIfRequested, awaitPuzzle } from '~/contracts/sms-verification';
-import { postToServer } from '../../3rdparty/sms-verification';
-import checkIfTxFailed from '../../util/check-if-tx-failed';
-import waitForConfirmations from '../../util/wait-for-block-confirmations';
+import { postToServer } from '~/3rdparty/sms-verification';
+import { checkIfTxFailed, waitForConfirmations } from '~/util/tx';

 export const LOADING = 'fetching-contract';
 export const QUERY_DATA = 'query-data';
--- a/js/src/modals/SaveContract/saveContract.js
+++ b/js/src/modals/SaveContract/saveContract.js
@ -20,7 +20,7 @@ import SaveIcon from 'material-ui/svg-icons/content/save';
 import ContentClear from 'material-ui/svg-icons/content/clear';

 import { Button, Modal, Editor, Form, Input } from '~/ui';
-import { ERRORS, validateName } from '../../util/validation';
+import { ERRORS, validateName } from '~/util/validation';

 import styles from './saveContract.css';

--- a/js/src/modals/Shapeshift/shapeshift.js
+++ b/js/src/modals/Shapeshift/shapeshift.js
@ -19,7 +19,7 @@ import ActionDoneAll from 'material-ui/svg-icons/action/done-all';
 import ContentClear from 'material-ui/svg-icons/content/clear';

 import { Button, IdentityIcon, Modal } from '~/ui';
-import initShapeshift from '../../3rdparty/shapeshift';
+import initShapeshift from '~/3rdparty/shapeshift';
 import shapeshiftLogo from '../../../assets/images/shapeshift-logo.png';

 import AwaitingDepositStep from './AwaitingDepositStep';
--- a/js/src/modals/Transfer/Extras/extras.js
+++ b/js/src/modals/Transfer/Extras/extras.js
@ -16,96 +16,28 @@

 import React, { Component, PropTypes } from 'react';

-import Form, { Input } from '~/ui/Form';
-import GasPriceSelector from '../GasPriceSelector';
-
-import styles from '../transfer.css';
+import { GasPriceEditor, Form, Input } from '~/ui';

 export default class Extras extends Component {
  static propTypes = {
    isEth: PropTypes.bool,
    data: PropTypes.string,
    dataError: PropTypes.string,
-    gas: PropTypes.string,
-    gasEst: PropTypes.string,
-    gasError: PropTypes.string,
-    gasPrice: PropTypes.oneOfType([
-      PropTypes.string,
-      PropTypes.object
-    ]),
-    gasPriceDefault: PropTypes.string,
-    gasPriceError: PropTypes.string,
-    gasPriceHistogram: PropTypes.object,
    total: PropTypes.string,
    totalError: PropTypes.string,
-    onChange: PropTypes.func.isRequired
+    onChange: PropTypes.func.isRequired,
+    gasStore: PropTypes.object.isRequired
  }

  render () {
-    const { gas, gasPrice, gasError, gasEst, gasPriceDefault, gasPriceError, gasPriceHistogram, total, totalError } = this.props;
-
-    const gasLabel = `gas amount (estimated: ${gasEst})`;
-    const priceLabel = `gas price (current: ${gasPriceDefault})`;
+    const { gasStore, onChange } = this.props;

    return (
      <Form>
-
        { this.renderData() }
-
-        <div className={ styles.columns }>
-          <div style={ { flex: 65 } }>
-            <GasPriceSelector
-              gasPriceHistogram={ gasPriceHistogram }
-              gasPrice={ gasPrice }
-              onChange={ this.onEditGasPrice }
-            />
-          </div>
-
-          <div
-            className={ styles.row }
-            style={ {
-              flex: 35, paddingLeft: '1rem',
-              justifyContent: 'space-around',
-              paddingBottom: 12
-            } }
-          >
-            <div className={ styles.row }>
-              <Input
-                label={ gasLabel }
-                hint='the amount of gas to use for the transaction'
-                error={ gasError }
-                value={ gas }
-                onChange={ this.onEditGas } />
-
-              <Input
-                label={ priceLabel }
-                hint='the price of gas to use for the transaction'
-                error={ gasPriceError }
-                value={ (gasPrice || '').toString() }
-                onChange={ this.onEditGasPrice } />
-            </div>
-
-            <div className={ styles.row }>
-              <Input
-                disabled
-                label='total transaction amount'
-                hint='the total amount of the transaction'
-                error={ totalError }
-                value={ `${total} ETH` } />
-            </div>
-          </div>
-        </div>
-
-        <div>
-          <p className={ styles.gasPriceDesc }>
-            You can choose the gas price based on the
-            distribution of recent included transactions' gas prices.
-            The lower the gas price is, the cheaper the transaction will
-            be. The higher the gas price is, the faster it should
-            get mined by the network.
-          </p>
-        </div>
-
+        <GasPriceEditor
+          store={ gasStore }
+          onChange={ onChange } />
      </Form>
    );
  }
@ -129,14 +61,6 @@ export default class Extras extends Component {
    );
  }

-  onEditGas = (event) => {
-    this.props.onChange('gas', event.target.value);
-  }
-
-  onEditGasPrice = (event, value) => {
-    this.props.onChange('gasPrice', value);
-  }
-
  onEditData = (event) => {
    this.props.onChange('data', event.target.value);
  }
--- a/js/src/modals/Transfer/store.js
+++ b/js/src/modals/Transfer/store.js
@ -23,7 +23,8 @@ import { bytesToHex } from '~/api/util/format';
 import Contract from '~/api/contract';
 import ERRORS from './errors';
 import { ERROR_CODES } from '~/api/transport/error';
-import { DEFAULT_GAS, DEFAULT_GASPRICE, MAX_GAS_ESTIMATION } from '~/util/constants';
+import { DEFAULT_GAS, MAX_GAS_ESTIMATION } from '~/util/constants';
+import GasPriceStore from '~/ui/GasPriceEditor/store';

 const TITLES = {
  transfer: 'transfer details',
@ -48,14 +49,6 @@ export default class TransferStore {
  @observable data = '';
  @observable dataError = null;

-  @observable gas = DEFAULT_GAS;
-  @observable gasError = null;
-
-  @observable gasEst = '0';
-  @observable gasLimitError = null;
-  @observable gasPrice = DEFAULT_GASPRICE;
-  @observable gasPriceError = null;
-
  @observable recipient = '';
  @observable recipientError = ERRORS.requireRecipient;

@ -68,11 +61,8 @@ export default class TransferStore {
  @observable value = '0.0';
  @observable valueError = null;

-  gasPriceHistogram = {};
-
  account = null;
  balance = null;
-  gasLimit = null;
  onClose = null;

  senders = null;
@ -81,6 +71,8 @@ export default class TransferStore {
  isWallet = false;
  wallet = null;

+  gasStore = null;
+
  @computed get steps () {
    const steps = [].concat(this.extras ? STAGES_EXTRA : STAGES_BASIC);

@ -93,7 +85,7 @@ export default class TransferStore {

  @computed get isValid () {
    const detailsValid = !this.recipientError && !this.valueError && !this.totalError && !this.senderError;
-    const extrasValid = !this.gasError && !this.gasPriceError && !this.totalError;
+    const extrasValid = !this.gasStore.errorGas && !this.gasStore.errorPrice && !this.totalError;
    const verifyValid = !this.passwordError;

    switch (this.stage) {
@ -118,11 +110,12 @@ export default class TransferStore {
    const { account, balance, gasLimit, senders, onClose, newError, sendersBalances } = props;
    this.account = account;
    this.balance = balance;
-    this.gasLimit = gasLimit;
    this.onClose = onClose;
    this.isWallet = account && account.wallet;
    this.newError = newError;

+    this.gasStore = new GasPriceStore(api, gasLimit);
+
    if (this.isWallet) {
      this.wallet = props.wallet;
      this.walletContract = new Contract(this.api, walletAbi);
@ -179,26 +172,6 @@ export default class TransferStore {
    }
  }

-  @action getDefaults = () => {
-    Promise
-      .all([
-        this.api.parity.gasPriceHistogram(),
-        this.api.eth.gasPrice()
-      ])
-      .then(([gasPriceHistogram, gasPrice]) => {
-        transaction(() => {
-          this.gasPrice = gasPrice.toString();
-          this.gasPriceDefault = gasPrice.toFormat();
-          this.gasPriceHistogram = gasPriceHistogram;
-
-          this.recalculate();
-        });
-      })
-      .catch((error) => {
-        console.warn('getDefaults', error);
-      });
-  }
-
  @action onSend = () => {
    this.onNext();
    this.sending = true;
@ -281,25 +254,11 @@ export default class TransferStore {
  }

  @action _onUpdateGas = (gas) => {
-    const gasError = this._validatePositiveNumber(gas);
-
-    transaction(() => {
-      this.gas = gas;
-      this.gasError = gasError;
-
-      this.recalculate();
-    });
+    this.recalculate();
  }

  @action _onUpdateGasPrice = (gasPrice) => {
-    const gasPriceError = this._validatePositiveNumber(gasPrice);
-
-    transaction(() => {
-      this.gasPrice = gasPrice;
-      this.gasPriceError = gasPriceError;
-
-      this.recalculate();
-    });
+    this.recalculate();
  }

  @action _onUpdateRecipient = (recipient) => {
@ -362,7 +321,7 @@ export default class TransferStore {

  @action recalculateGas = () => {
    if (!this.isValid) {
-      this.gas = 0;
+      this.gasStore.setGas('0');
      return this.recalculate();
    }

@ -370,28 +329,20 @@ export default class TransferStore {
      .estimateGas()
      .then((gasEst) => {
        let gas = gasEst;
-        let gasLimitError = null;

        if (gas.gt(DEFAULT_GAS)) {
          gas = gas.mul(1.2);
        }

-        if (gas.gte(MAX_GAS_ESTIMATION)) {
-          gasLimitError = ERRORS.gasException;
-        } else if (gas.gt(this.gasLimit)) {
-          gasLimitError = ERRORS.gasBlockLimit;
-        }
-
        transaction(() => {
-          this.gas = gas.toFixed(0);
-          this.gasEst = gasEst.toFormat();
-          this.gasLimitError = gasLimitError;
+          this.gasStore.setEstimated(gasEst.toFixed(0));
+          this.gasStore.setGas(gas.toFixed(0));

          this.recalculate();
        });
      })
      .catch((error) => {
-        console.error('etimateGas', error);
+        console.warn('etimateGas', error);
        this.recalculate();
      });
  }
@ -411,9 +362,9 @@ export default class TransferStore {
      return;
    }

-    const { gas, gasPrice, tag, valueAll, isEth, isWallet } = this;
+    const { tag, valueAll, isEth, isWallet } = this;

-    const gasTotal = new BigNumber(gasPrice || 0).mul(new BigNumber(gas || 0));
+    const gasTotal = new BigNumber(this.gasStore.price || 0).mul(new BigNumber(this.gasStore.gas || 0));

    const availableEth = new BigNumber(balance.tokens[0].value);

@ -453,10 +404,12 @@ export default class TransferStore {
    }

    transaction(() => {
-      this.total = this.api.util.fromWei(totalEth).toString();
+      this.total = this.api.util.fromWei(totalEth).toFixed();
      this.totalError = totalError;
      this.value = value;
      this.valueError = valueError;
+      this.gasStore.setErrorTotal(totalError);
+      this.gasStore.setEthValue(totalEth);
    });
  }

@ -522,8 +475,8 @@ export default class TransferStore {
    };

    if (!gas) {
-      options.gas = this.gas;
-      options.gasPrice = this.gasPrice;
+      options.gas = this.gasStore.gas;
+      options.gasPrice = this.gasStore.price;
    } else {
      options.gas = MAX_GAS_ESTIMATION;
    }
--- a/js/src/modals/Transfer/transfer.css
+++ b/js/src/modals/Transfer/transfer.css
@ -144,15 +144,6 @@
  font-size: 1.2rem;
 }

-.chart {
-  position: absolute;
-  width: 100%;
-}
-
-.gasPriceDesc {
-  font-size: 0.9em;
-}
-
 .warning {
  border-radius: 0.5em;
  background: #f80;
--- a/js/src/modals/Transfer/transfer.js
+++ b/js/src/modals/Transfer/transfer.js
@ -56,10 +56,6 @@ class Transfer extends Component {

  store = new TransferStore(this.context.api, this.props);

-  componentDidMount () {
-    this.store.getDefaults();
-  }
-
  render () {
    const { stage, extras, steps } = this.store;

@ -186,27 +182,20 @@ class Transfer extends Component {
  }

  renderExtrasPage () {
-    if (!this.store.gasPriceHistogram) {
+    if (!this.store.gasStore.histogram) {
      return null;
    }

-    const { isEth, data, dataError, gas, gasEst, gasError, gasPrice } = this.store;
-    const { gasPriceDefault, gasPriceError, gasPriceHistogram, total, totalError } = this.store;
+    const { isEth, data, dataError, total, totalError } = this.store;

    return (
      <Extras
        isEth={ isEth }
        data={ data }
        dataError={ dataError }
-        gas={ gas }
-        gasEst={ gasEst }
-        gasError={ gasError }
-        gasPrice={ gasPrice }
-        gasPriceDefault={ gasPriceDefault }
-        gasPriceError={ gasPriceError }
-        gasPriceHistogram={ gasPriceHistogram }
        total={ total }
        totalError={ totalError }
+        gasStore={ this.store.gasStore }
        onChange={ this.store.onUpdateDetails } />
    );
  }
@ -263,15 +252,15 @@ class Transfer extends Component {
  }

  renderWarning () {
-    const { gasLimitError } = this.store;
+    const { errorEstimated } = this.store.gasStore;

-    if (!gasLimitError) {
+    if (!errorEstimated) {
      return null;
    }

    return (
      <div className={ styles.warning }>
-        { gasLimitError }
+        { errorEstimated }
      </div>
    );
  }
--- a/js/src/redux/providers/walletActions.js
+++ b/js/src/redux/providers/walletActions.js
@ -17,12 +17,10 @@
 import { isEqual, uniq } from 'lodash';

 import Contract from '~/api/contract';
-import { wallet as WALLET_ABI } from '~/contracts/abi';
 import { bytesToHex, toHex } from '~/api/util/format';
-
 import { ERROR_CODES } from '~/api/transport/error';
-import { MAX_GAS_ESTIMATION } from '../../util/constants';
-
+import { wallet as WALLET_ABI } from '~/contracts/abi';
+import { MAX_GAS_ESTIMATION } from '~/util/constants';
 import WalletsUtils from '~/util/wallets';

 import { newError } from '~/ui/Errors/actions';
--- a/js/src/ui/Form/TypedInput/typedInput.js
+++ b/js/src/ui/Form/TypedInput/typedInput.js
@ -22,12 +22,11 @@ import IconButton from 'material-ui/IconButton';
 import AddIcon from 'material-ui/svg-icons/content/add';
 import RemoveIcon from 'material-ui/svg-icons/content/remove';

+import { fromWei, toWei } from '~/api/util/wei';
 import Input from '~/ui/Form/Input';
 import InputAddressSelect from '~/ui/Form/InputAddressSelect';
 import Select from '~/ui/Form/Select';
-
 import { ABI_TYPES } from '~/util/abi';
-import { fromWei, toWei } from '~/api/util/wei';

 import styles from './typedInput.css';

--- a/js/src/ui/GasPriceEditor/GasPriceSelector/gasPriceSelector.css
+++ b/js/src/ui/GasPriceEditor/GasPriceSelector/gasPriceSelector.css
@ -15,3 +15,13 @@
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */

+.chart {
+  position: absolute;
+  width: 100%;
+}
+
+.columns {
+  display: flex;
+  flex-wrap: wrap;
+  position: relative;
+}
--- a/js/src/ui/GasPriceEditor/GasPriceSelector/gasPriceSelector.js
+++ b/js/src/ui/GasPriceEditor/GasPriceSelector/gasPriceSelector.js
@ -29,10 +29,7 @@ import {
 import Slider from 'material-ui/Slider';
 import BigNumber from 'bignumber.js';

-import componentStyles from './gasPriceSelector.css';
-import mainStyles from '../transfer.css';
-
-const styles = Object.assign({}, mainStyles, componentStyles);
+import styles from './gasPriceSelector.css';

 const COLORS = {
  default: 'rgba(255, 99, 132, 0.2)',
@ -194,10 +191,7 @@ class CustomizedShape extends Component {

 class CustomTooltip extends Component {
  static propTypes = {
-    gasPriceHistogram: PropTypes.shape({
-      bucketBounds: PropTypes.array.isRequired,
-      counts: PropTypes.array.isRequired
-    }).isRequired,
+    gasPriceHistogram: PropTypes.object.isRequired,
    type: PropTypes.string,
    payload: PropTypes.array,
    label: PropTypes.number,
@ -231,12 +225,16 @@ class CustomTooltip extends Component {
  }
 }

+const TOOL_STYLE = {
+  color: 'rgba(255,255,255,0.5)',
+  backgroundColor: 'rgba(0, 0, 0, 0.75)',
+  padding: '0 0.5em',
+  fontSize: '0.75em'
+};
+
 export default class GasPriceSelector extends Component {
  static propTypes = {
-    gasPriceHistogram: PropTypes.shape({
-      bucketBounds: PropTypes.array.isRequired,
-      counts: PropTypes.array.isRequired
-    }).isRequired,
+    gasPriceHistogram: PropTypes.object.isRequired,
    onChange: PropTypes.func.isRequired,

    gasPrice: PropTypes.oneOfType([
@ -287,21 +285,23 @@ export default class GasPriceSelector extends Component {
  renderSlider () {
    const { sliderValue } = this.state;

-    return (<div className={ styles.columns }>
-      <Slider
-        min={ 0 }
-        max={ 1 }
-        value={ sliderValue }
-        onChange={ this.onEditGasPriceSlider }
-        style={ {
-          flex: 1,
-          padding: '0 0.3em'
-        } }
-        sliderStyle={ {
-          marginBottom: 12
-        } }
-      />
-    </div>);
+    return (
+      <div className={ styles.columns }>
+        <Slider
+          min={ 0 }
+          max={ 1 }
+          value={ sliderValue }
+          onChange={ this.onEditGasPriceSlider }
+          style={ {
+            flex: 1,
+            padding: '0 0.3em'
+          } }
+          sliderStyle={ {
+            marginBottom: 12
+          } }
+        />
+      </div>
+    );
  }

  renderChart () {
@ -316,85 +316,83 @@ export default class GasPriceSelector extends Component {
    const countIndex = Math.max(0, Math.min(selectedIndex, gasPriceHistogram.counts.length - 1));
    const selectedCount = countModifier(gasPriceHistogram.counts[countIndex]);

-    return (<div className={ styles.columns }>
-      <div style={ { flex: 1, height } }>
-        <div className={ styles.chart }>
-          <ResponsiveContainer
-            height={ height }
-          >
-            <ScatterChart
-              margin={ { top: 0, right: 0, left: 0, bottom: 0 } }
+    return (
+      <div className={ styles.columns }>
+        <div style={ { flex: 1, height } }>
+          <div className={ styles.chart }>
+            <ResponsiveContainer
+              height={ height }
            >
-              <Scatter
-                data={ [
-                  { x: sliderValue, y: 0 },
-                  { x: sliderValue, y: selectedCount },
-                  { x: sliderValue, y: chartData.yDomain[1] }
-                ] }
-                shape={ <CustomizedShape showValue={ selectedCount } /> }
-                line
-                isAnimationActive={ false }
-              />
+              <ScatterChart
+                margin={ { top: 0, right: 0, left: 0, bottom: 0 } }
+              >
+                <Scatter
+                  data={ [
+                    { x: sliderValue, y: 0 },
+                    { x: sliderValue, y: selectedCount },
+                    { x: sliderValue, y: chartData.yDomain[1] }
+                  ] }
+                  shape={ <CustomizedShape showValue={ selectedCount } /> }
+                  line
+                  isAnimationActive={ false }
+                />

-              <XAxis
-                hide
-                height={ 0 }
-                dataKey='x'
-                domain={ [0, 1] }
-              />
-              <YAxis
-                hide
-                width={ 0 }
-                dataKey='y'
-                domain={ chartData.yDomain }
-              />
-            </ScatterChart>
-          </ResponsiveContainer>
-        </div>
+                <XAxis
+                  hide
+                  height={ 0 }
+                  dataKey='x'
+                  domain={ [0, 1] }
+                />
+                <YAxis
+                  hide
+                  width={ 0 }
+                  dataKey='y'
+                  domain={ chartData.yDomain }
+                />
+              </ScatterChart>
+            </ResponsiveContainer>
+          </div>

-        <div className={ styles.chart }>
-          <ResponsiveContainer
-            height={ height }
-          >
-            <BarChart
-              data={ chartData.values }
-              margin={ { top: 0, right: 0, left: 0, bottom: 0 } }
-              barCategoryGap={ 1 }
-              ref='barChart'
+          <div className={ styles.chart }>
+            <ResponsiveContainer
+              height={ height }
            >
-              <Bar
-                dataKey='value'
-                stroke={ COLORS.line }
-                onClick={ this.onClickGasPrice }
-                shape={ <CustomBar selected={ selectedIndex } onClick={ this.onClickGasPrice } /> }
-              />
+              <BarChart
+                data={ chartData.values }
+                margin={ { top: 0, right: 0, left: 0, bottom: 0 } }
+                barCategoryGap={ 1 }
+                ref='barChart'
+              >
+                <Bar
+                  dataKey='value'
+                  stroke={ COLORS.line }
+                  onClick={ this.onClickGasPrice }
+                  shape={ <CustomBar selected={ selectedIndex } onClick={ this.onClickGasPrice } /> }
+                />

-              <Tooltip
-                wrapperStyle={ {
-                  backgroundColor: 'rgba(0, 0, 0, 0.75)',
-                  padding: '0 0.5em',
-                  fontSize: '0.9em'
-                } }
-                cursor={ this.renderCustomCursor() }
-                content={ <CustomTooltip gasPriceHistogram={ gasPriceHistogram } /> }
-              />
+                <Tooltip
+                  wrapperStyle={ TOOL_STYLE }
+                  cursor={ this.renderCustomCursor() }
+                  content={ <CustomTooltip gasPriceHistogram={ gasPriceHistogram } /> }
+                />

-              <XAxis
-                hide
-                dataKey='index'
-                type='category'
-                domain={ chartData.xDomain }
-              />
-              <YAxis
-                hide
-                type='number'
-                domain={ chartData.yDomain }
-              />
-            </BarChart>
-          </ResponsiveContainer>
+                <XAxis
+                  hide
+                  dataKey='index'
+                  type='category'
+                  domain={ chartData.xDomain }
+                />
+                <YAxis
+                  hide
+                  type='number'
+                  domain={ chartData.yDomain }
+                />
+              </BarChart>
+            </ResponsiveContainer>
+          </div>
        </div>
      </div>
-    </div>);
+    );
  }

  renderCustomCursor = () => {
--- a/js/src/ui/GasPriceEditor/GasPriceSelector/index.js
+++ b/js/src/ui/GasPriceEditor/GasPriceSelector/index.js
--- a/js/src/ui/GasPriceEditor/gasPriceEditor.css
+++ b/js/src/ui/GasPriceEditor/gasPriceEditor.css
@ -14,11 +14,36 @@
 /* You should have received a copy of the GNU General Public License
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */
-.signer {
+
+.columns {
+  display: flex;
+  flex-wrap: wrap;
+  position: relative;
 }

-.container {
+.graphColumn {
+  flex: 65;
 }

-.mainContainer {
+.editColumn {
+  flex: 35;
+  padding-left: 1em;
+  justify-ontent: space-around;
+  padding-bottom: 12;
+  display: flex;
+  flex-wrap: wrap;
+  position: relative;
+  flex-direction: column;
+}
+
+.gasPriceDesc {
+  font-size: 0.75em;
+  opacity: 0.5;
+}
+
+.row {
+  display: flex;
+  flex-wrap: wrap;
+  position: relative;
+  flex-direction: column;
 }
--- a/js/src/ui/GasPriceEditor/gasPriceEditor.js
+++ b/js/src/ui/GasPriceEditor/gasPriceEditor.js
@ -0,0 +1,108 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity 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.
+
+// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import BigNumber from 'bignumber.js';
+import React, { Component, PropTypes } from 'react';
+import { observer } from 'mobx-react';
+
+import Input from '../Form/Input';
+import GasPriceSelector from './GasPriceSelector';
+import Store from './store';
+
+import styles from './gasPriceEditor.css';
+
+@observer
+export default class GasPriceEditor extends Component {
+  static contextTypes = {
+    api: PropTypes.object.isRequired
+  };
+
+  static propTypes = {
+    store: PropTypes.object.isRequired,
+    onChange: PropTypes.func
+  }
+
+  static Store = Store;
+
+  render () {
+    const { api } = this.context;
+    const { store } = this.props;
+    const { estimated, priceDefault, price, gas, histogram, errorGas, errorPrice, errorTotal, totalValue } = store;
+
+    const eth = api.util.fromWei(totalValue).toFormat();
+    const gasLabel = `gas (estimated: ${new BigNumber(estimated).toFormat()})`;
+    const priceLabel = `price (current: ${new BigNumber(priceDefault).toFormat()})`;
+
+    return (
+      <div className={ styles.columns }>
+        <div className={ styles.graphColumn }>
+          <GasPriceSelector
+            gasPriceHistogram={ histogram }
+            gasPrice={ price }
+            onChange={ this.onEditGasPrice } />
+          <div className={ styles.gasPriceDesc }>
+            You can choose the gas price based on the
+            distribution of recent included transaction gas prices.
+            The lower the gas price is, the cheaper the transaction will
+            be. The higher the gas price is, the faster it should
+            get mined by the network.
+          </div>
+        </div>
+
+        <div className={ styles.editColumn }>
+          <div className={ styles.row }>
+            <Input
+              label={ gasLabel }
+              hint='the amount of gas to use for the transaction'
+              error={ errorGas }
+              value={ gas }
+              onChange={ this.onEditGas } />
+
+            <Input
+              label={ priceLabel }
+              hint='the price of gas to use for the transaction'
+              error={ errorPrice }
+              value={ price }
+              onChange={ this.onEditGasPrice } />
+          </div>
+
+          <div className={ styles.row }>
+            <Input
+              disabled
+              label='total transaction amount'
+              hint='the total amount of the transaction'
+              error={ errorTotal }
+              value={ `${eth} ETH` } />
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+  onEditGas = (event, gas) => {
+    const { store, onChange } = this.props;
+
+    store.setGas(gas);
+    onChange && onChange('gas', gas);
+  }
+
+  onEditGasPrice = (event, price) => {
+    const { store, onChange } = this.props;
+
+    store.setPrice(price);
+    onChange && onChange('gasPrice', price);
+  }
+}
--- a/js/src/ui/GasPriceEditor/index.js
+++ b/js/src/ui/GasPriceEditor/index.js
@ -14,6 +14,4 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

-export default (chain) => {
-  return chain === 'morden' || chain === 'ropsten' || chain === 'testnet';
-};
+export default from './gasPriceEditor';
--- a/js/src/ui/GasPriceEditor/store.js
+++ b/js/src/ui/GasPriceEditor/store.js
@ -0,0 +1,123 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity 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.
+
+// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+import BigNumber from 'bignumber.js';
+import { action, computed, observable, transaction } from 'mobx';
+
+import { ERRORS, validatePositiveNumber } from '~/util/validation';
+import { DEFAULT_GAS, DEFAULT_GASPRICE, MAX_GAS_ESTIMATION } from '~/util/constants';
+
+export default class GasPriceEditor {
+  @observable errorEstimated = null;
+  @observable errorGas = null;
+  @observable errorPrice = null;
+  @observable errorTotal = null;
+  @observable estimated = DEFAULT_GAS;
+  @observable histogram = null;
+  @observable price = DEFAULT_GASPRICE;
+  @observable priceDefault = DEFAULT_GASPRICE;
+  @observable gas = DEFAULT_GAS;
+  @observable gasLimit = 0;
+  @observable weiValue = '0';
+
+  constructor (api, gasLimit, loadDefaults = true) {
+    this._api = api;
+    this.gasLimit = gasLimit;
+
+    if (loadDefaults) {
+      this.loadDefaults();
+    }
+  }
+
+  @computed get totalValue () {
+    try {
+      return new BigNumber(this.gas).mul(this.price).add(this.weiValue);
+    } catch (error) {
+      return new BigNumber(0);
+    }
+  }
+
+  @action setErrorTotal = (errorTotal) => {
+    this.errorTotal = errorTotal;
+  }
+
+  @action setEstimated = (estimated) => {
+    transaction(() => {
+      const bn = new BigNumber(estimated);
+
+      this.estimated = estimated;
+
+      if (bn.gte(MAX_GAS_ESTIMATION)) {
+        this.errorEstimated = ERRORS.gasException;
+      } else if (bn.gte(this.gasLimit)) {
+        this.errorEstimated = ERRORS.gasBlockLimit;
+      } else {
+        this.errorEstimated = null;
+      }
+    });
+  }
+
+  @action setEthValue = (weiValue) => {
+    this.weiValue = weiValue;
+  }
+
+  @action setHistogram = (gasHistogram) => {
+    this.histogram = gasHistogram;
+  }
+
+  @action setPrice = (price) => {
+    transaction(() => {
+      this.errorPrice = validatePositiveNumber(price).numberError;
+      this.price = price;
+    });
+  }
+
+  @action setGas = (gas) => {
+    transaction(() => {
+      const { numberError } = validatePositiveNumber(gas);
+      const bn = new BigNumber(gas);
+
+      this.gas = gas;
+
+      if (numberError) {
+        this.errorGas = numberError;
+      } else if (bn.gte(this.gasLimit)) {
+        this.errorGas = ERRORS.gasBlockLimit;
+      } else {
+        this.errorGas = null;
+      }
+    });
+  }
+
+  @action loadDefaults () {
+    Promise
+      .all([
+        this._api.parity.gasPriceHistogram(),
+        this._api.eth.gasPrice()
+      ])
+      .then(([gasPriceHistogram, gasPrice]) => {
+        transaction(() => {
+          this.setPrice(gasPrice.toFixed(0));
+          this.setHistogram(gasPriceHistogram);
+
+          this.priceDefault = gasPrice.toFixed();
+        });
+      })
+      .catch((error) => {
+        console.warn('getDefaults', error);
+      });
+  }
+}
--- a/js/src/ui/TxHash/txHash.js
+++ b/js/src/ui/TxHash/txHash.js
@ -20,7 +20,7 @@ import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
 import { LinearProgress } from 'material-ui';

-import { txLink } from '../../3rdparty/etherscan/links';
+import { txLink } from '~/3rdparty/etherscan/links';
 import ShortenedHash from '../ShortenedHash';

 import styles from './txHash.css';
--- a/js/src/ui/TxList/txList.js
+++ b/js/src/ui/TxList/txList.js
@ -20,7 +20,7 @@ import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
 import { observer } from 'mobx-react';

-import { txLink, addressLink } from '../../3rdparty/etherscan/links';
+import { txLink, addressLink } from '~/3rdparty/etherscan/links';

 import IdentityIcon from '../IdentityIcon';
 import IdentityName from '../IdentityName';
--- a/js/src/ui/index.js
+++ b/js/src/ui/index.js
@ -31,6 +31,7 @@ import CopyToClipboard from './CopyToClipboard';
 import Editor from './Editor';
 import Errors from './Errors';
 import Form, { AddressSelect, FormWrap, TypedInput, Input, InputAddress, InputAddressSelect, InputChip, InputInline, Select, RadioButtons } from './Form';
+import GasPriceEditor from './GasPriceEditor';
 import IdentityIcon from './IdentityIcon';
 import IdentityName from './IdentityName';
 import Loading from './Loading';
@ -67,7 +68,7 @@ export {
  Errors,
  Form,
  FormWrap,
-  TypedInput,
+  GasPriceEditor,
  Input,
  InputAddress,
  InputAddressSelect,
@ -91,5 +92,6 @@ export {
  Tooltip,
  Tooltips,
  TxHash,
-  TxList
+  TxList,
+  TypedInput
 };
--- a/js/src/util/check-if-tx-failed.js
+++ b/js/src/util/check-if-tx-failed.js
@ -1,28 +0,0 @@
-// Copyright 2015, 2016 Ethcore (UK) Ltd.
-// This file is part of Parity.
-
-// Parity 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.
-
-// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
-
-const checkIfTxFailed = (api, tx, gasSent) => {
-  return api.pollMethod('eth_getTransactionReceipt', tx)
-  .then((receipt) => {
-    // TODO: Right now, there's no way to tell wether the EVM code crashed.
-    // Because you usually send a bit more gas than estimated (to make sure
-    // it gets mined quickly), we transaction probably failed if all the gas
-    // has been used up.
-    return receipt.gasUsed.eq(gasSent);
-  });
-};
-
-export default checkIfTxFailed;
--- a/js/src/util/wait-for-block-confirmations.js
+++ b/js/src/util/wait-for-block-confirmations.js
@ -18,7 +18,18 @@ const isValidReceipt = (receipt) => {
  return receipt && receipt.blockNumber && receipt.blockNumber.gt(0);
 };

-const waitForConfirmations = (api, tx, confirmations) => {
+export function checkIfTxFailed (api, tx, gasSent) {
+  return api.pollMethod('eth_getTransactionReceipt', tx)
+  .then((receipt) => {
+    // TODO: Right now, there's no way to tell wether the EVM code crashed.
+    // Because you usually send a bit more gas than estimated (to make sure
+    // it gets mined quickly), we transaction probably failed if all the gas
+    // has been used up.
+    return receipt.gasUsed.eq(gasSent);
+  });
+}
+
+export function waitForConfirmations (api, tx, confirmations) {
  return new Promise((resolve, reject) => {
    api.pollMethod('eth_getTransactionReceipt', tx, isValidReceipt)
    .then((receipt) => {
@ -39,6 +50,4 @@ const waitForConfirmations = (api, tx, confirmations) => {
      .catch(reject);
    });
  });
-};
-
-export default waitForConfirmations;
+}
--- a/js/src/util/validation.js
+++ b/js/src/util/validation.js
@ -20,6 +20,7 @@ import util from '~/api/util';

 export const ERRORS = {
  invalidAddress: 'address is an invalid network address',
+  invalidAmount: 'the supplied amount should be a valid positive number',
  duplicateAddress: 'the address is already in your address book',
  invalidChecksum: 'address has failed the checksum formatting',
  invalidName: 'name should not be blank and longer than 2',
@ -27,7 +28,9 @@ export const ERRORS = {
  invalidCode: 'code should be the compiled hex string',
  invalidNumber: 'invalid number format',
  negativeNumber: 'input number should be positive',
-  decimalNumber: 'input number should not contain decimals'
+  decimalNumber: 'input number should not contain decimals',
+  gasException: 'the transaction will throw an exception with the current values',
+  gasBlockLimit: 'the transaction execution will exceed the block gas limit'
 };

 export function validateAbi (abi, api) {
@ -133,6 +136,25 @@ export function validateName (name) {
  };
 }

+export function validatePositiveNumber (number) {
+  let numberError = null;
+
+  try {
+    const v = new BigNumber(number);
+
+    if (v.lt(0)) {
+      numberError = ERRORS.invalidAmount;
+    }
+  } catch (e) {
+    numberError = ERRORS.invalidAmount;
+  }
+
+  return {
+    number,
+    numberError
+  };
+}
+
 export function validateUint (value) {
  let valueError = null;

--- a/js/src/views/Account/Transactions/transactions.css
+++ b/js/src/views/Account/Transactions/transactions.css
@ -15,9 +15,6 @@
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */

-.transactions {
-}
-
 .infonone {
  opacity: 0.25;
 }
--- a/js/src/views/Account/Transactions/transactions.js
+++ b/js/src/views/Account/Transactions/transactions.js
@ -18,7 +18,7 @@ import React, { Component, PropTypes } from 'react';
 import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';

-import etherscan from '../../../3rdparty/etherscan';
+import etherscan from '~/3rdparty/etherscan';
 import { Container, TxList } from '~/ui';

 import styles from './transactions.css';
--- a/js/src/views/Account/account.css
+++ b/js/src/views/Account/account.css
@ -14,8 +14,6 @@
 /* You should have received a copy of the GNU General Public License
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */
-.account {
-}

 .btnicon {
  width: 24px;
--- a/js/src/views/Account/account.js
+++ b/js/src/views/Account/account.js
@ -105,7 +105,7 @@ class Account extends Component {
    }

    return (
-      <div className={ styles.account }>
+      <div>
        { this.renderDeleteDialog(account) }
        { this.renderEditDialog(account) }
        { this.renderFundDialog() }
--- a/js/src/views/Accounts/Summary/summary.js
+++ b/js/src/views/Accounts/Summary/summary.js
@ -14,6 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.

+import BigNumber from 'bignumber.js';
 import React, { Component, PropTypes } from 'react';
 import { Link } from 'react-router';
 import { isEqual } from 'lodash';
@ -113,15 +114,16 @@ export default class Summary extends Component {

  renderOwners () {
    const { owners } = this.props;
+    const ownersValid = (owners || []).filter((owner) => owner.address && new BigNumber(owner.address).gt(0));

-    if (!owners || owners.length === 0) {
+    if (!ownersValid || ownersValid.length === 0) {
      return null;
    }

    return (
      <div className={ styles.owners }>
        {
-          owners.map((owner) => (
+          ownersValid.map((owner) => (
            <div key={ owner.address }>
              <div
                data-tip
--- a/js/src/views/Accounts/accounts.css
+++ b/js/src/views/Accounts/accounts.css
@ -14,8 +14,6 @@
 /* You should have received a copy of the GNU General Public License
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */
-.accounts {
-}

 .accountTooltip {
  top: 13.3em;
--- a/js/src/views/Accounts/accounts.js
+++ b/js/src/views/Accounts/accounts.js
@ -82,7 +82,7 @@ class Accounts extends Component {

  render () {
    return (
-      <div className={ styles.accounts }>
+      <div>
        { this.renderNewDialog() }
        { this.renderNewWalletDialog() }
        { this.renderActionbar() }
@ -293,13 +293,17 @@ function mapStateToProps (state) {

  const walletsOwners = Object
    .keys(walletsInfo)
-    .map((wallet) => ({
-      owners: walletsInfo[wallet].owners.map((owner) => ({
-        address: owner,
-        name: accountsInfo[owner] && accountsInfo[owner].name || owner
-      })),
-      address: wallet
-    }))
+    .map((wallet) => {
+      const owners = walletsInfo[wallet].owners || [];
+
+      return {
+        owners: owners.map((owner) => ({
+          address: owner,
+          name: accountsInfo[owner] && accountsInfo[owner].name || owner
+        })),
+        address: wallet
+      };
+    })
    .reduce((walletsOwners, wallet) => {
      walletsOwners[wallet.address] = wallet.owners;
      return walletsOwners;
--- a/js/src/views/Address/address.css
+++ b/js/src/views/Address/address.css
@ -14,37 +14,37 @@
 /* You should have received a copy of the GNU General Public License
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */
-.address {
-}

-.delete .hero {
-  padding-bottom: 1em;
-}
+.delete {
+  .hero {
+    padding-bottom: 1em;
+  }

-.delete .info {
-  display: inline-block;
-}
+  .info {
+    display: inline-block;
+  }

-.delete .icon {
-  display: inline-block;
-}
+  .icon {
+    display: inline-block;
+  }

-.delete .nameinfo {
-  display: inline-block;
-  text-align: left;
-}
+  .nameinfo {
+    display: inline-block;
+    text-align: left;
+  }

-.delete .header {
-  text-transform: uppercase;
-  font-size: 1.25em;
-  padding-bottom: 0.25em;
-}
+  .header {
+    text-transform: uppercase;
+    font-size: 1.25em;
+    padding-bottom: 0.25em;
+  }

-.delete .address {
-}
+  .address {
+  }

-.delete .description {
-  padding-top: 1em;
-  font-size: 0.75em;
-  color: #aaa;
+  .description {
+    padding-top: 1em;
+    font-size: 0.75em;
+    color: #aaa;
+  }
 }
--- a/js/src/views/Address/address.js
+++ b/js/src/views/Address/address.js
@ -28,8 +28,6 @@ import Transactions from '../Account/Transactions';
 import Delete from './Delete';
 import { setVisibleAccounts } from '~/redux/providers/personalActions';

-import styles from './address.css';
-
 class Address extends Component {
  static contextTypes = {
    api: PropTypes.object.isRequired,
@ -85,7 +83,7 @@ class Address extends Component {
    }

    return (
-      <div className={ styles.address }>
+      <div>
        { this.renderEditDialog(contact) }
        { this.renderActionbar(contact) }
        <Delete
--- a/js/src/views/Addresses/addresses.css
+++ b/js/src/views/Addresses/addresses.css
@ -14,8 +14,6 @@
 /* You should have received a copy of the GNU General Public License
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */
-.addresses {
-}

 .list {
  display: flex;
@ -26,21 +24,21 @@
  flex: 0 1 50%;
  width: 50%;
  position: relative;
-}

-.address:nth-child(odd)>div {
-  padding-right: 0.5em !important;
-}
+  &:nth-child(odd)>div {
+    padding-right: 0.5em !important;
+  }

-.address:nth-child(even)>div {
-  padding-left: 0.5em !important;
+  &:nth-child(even)>div {
+    padding-left: 0.5em !important;
+  }
 }

 .empty {
  width: 100%;
  display: block;
-}

-.empty div {
-  color: #aaa;
+  div {
+    color: #aaa;
+  }
 }
--- a/js/src/views/Addresses/addresses.js
+++ b/js/src/views/Addresses/addresses.js
@ -76,7 +76,7 @@ class Addresses extends Component {
    const { searchValues, sortOrder } = this.state;

    return (
-      <div className={ styles.addresses }>
+      <div>
        { this.renderActionbar() }
        { this.renderAddAddress() }
        <Page>
--- a/js/src/views/Connection/connection.js
+++ b/js/src/views/Connection/connection.js
@ -19,7 +19,6 @@ import { connect } from 'react-redux';
 import { bindActionCreators } from 'redux';
 import ActionCompareArrows from 'material-ui/svg-icons/action/compare-arrows';
 import ActionDashboard from 'material-ui/svg-icons/action/dashboard';
-// import CommunicationVpnKey from 'material-ui/svg-icons/communication/vpn-key';
 import HardwareDesktopMac from 'material-ui/svg-icons/hardware/desktop-mac';
 import NotificationVpnLock from 'material-ui/svg-icons/notification/vpn-lock';

--- a/js/src/views/Contract/Events/Event/event.js
+++ b/js/src/views/Contract/Events/Event/event.js
@ -20,7 +20,7 @@ import React, { Component, PropTypes } from 'react';

 import { IdentityIcon, IdentityName, Input, InputAddress } from '~/ui';
 import ShortenedHash from '~/ui/ShortenedHash';
-import { txLink } from '../../../../3rdparty/etherscan/links';
+import { txLink } from '~/3rdparty/etherscan/links';

 import styles from '../../contract.css';

--- a/js/src/views/Contract/contract.css
+++ b/js/src/views/Contract/contract.css
@ -15,26 +15,26 @@
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */

-.contract {
-}
-
 .events {
  width: 100%;
  border: none;
  border-spacing: 0;
-}

-.events tr {
-  line-height: 32px;
-  vertical-align: top;
+  tr {
+    line-height: 32px;
+    vertical-align: top;
+  }
 }

 .event {
-}
+  td {
+    vertical-align: top;
+    padding: 1em 0.5em;

-.event td {
-  vertical-align: top;
-  padding: 1em 0.5em;
+    div {
+      white-space: nowrap;
+    }
+  }
 }

 .txhash {
@ -47,10 +47,6 @@
  color: #aaa;
 }

-.event td div {
-  white-space: nowrap;
-}
-
 .mined {
 }

--- a/js/src/views/Contract/contract.js
+++ b/js/src/views/Contract/contract.js
@ -124,7 +124,7 @@ class Contract extends Component {
    }

    return (
-      <div className={ styles.contract }>
+      <div>
        { this.renderActionbar(account) }
        { this.renderDeleteDialog(account) }
        { this.renderEditDialog(account) }
--- a/js/src/views/Contracts/contracts.css
+++ b/js/src/views/Contracts/contracts.css
@ -1,18 +0,0 @@
-/* Copyright 2015, 2016 Ethcore (UK) Ltd.
-/* This file is part of Parity.
-/*
-/* Parity 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.
-/*
-/* Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
-*/
-.contracts {
-}
--- a/js/src/views/Contracts/contracts.js
+++ b/js/src/views/Contracts/contracts.js
@ -28,8 +28,6 @@ import { setVisibleAccounts } from '~/redux/providers/personalActions';

 import List from '../Accounts/List';

-import styles from './contracts.css';
-
 class Contracts extends Component {
  static contextTypes = {
    api: PropTypes.object.isRequired
@ -80,7 +78,7 @@ class Contracts extends Component {
    const { searchValues, sortOrder } = this.state;

    return (
-      <div className={ styles.contracts }>
+      <div>
        { this.renderActionbar() }
        { this.renderAddContract() }
        { this.renderAddContract() }
@ -159,7 +157,6 @@ class Contracts extends Component {

    return (
      <Actionbar
-        className={ styles.toolbar }
        title='Contracts'
        buttons={ buttons } />
    );
--- a/js/src/views/Settings/settings.css
+++ b/js/src/views/Settings/settings.css
@ -15,9 +15,6 @@
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */

-.layout {
-}
-
 .menu {
  display: inline-block;
 }
@ -35,31 +32,24 @@
  padding: 16px 2em !important;
  line-height: 24px !important;
  width: auto !important;
-}

-.tabactive {
-}
+  &>div {
+    height: 24px !important;

-.tab>div,
-.tabactive>div {
-  height: 24px !important;
-}
+    &>div {
+      display: inline-block !important;
+    }
+  }

-.tab>div>div,
-.tabactive>div>div {
-  display: inline-block !important;
-}
+  svg {
+    margin-right: 0.5em;
+    margin-bottom: 0 !important;
+  }

-.tab svg,
-.tabactive svg {
-  margin-right: 0.5em;
-  margin-bottom: 0 !important;
-}
-
-.tab .menu,
-.tabactive .menu {
-  vertical-align: top;
-  display: inline-block;
+  .menu {
+    vertical-align: top;
+    display: inline-block;
+  }
 }

 .imageIcon {
@ -68,6 +58,8 @@
  opacity: 0.5;
 }

-.tabactive .imageIcon {
-  opacity: 1;
+.tabactive {
+  .imageIcon {
+    opacity: 1;
+  }
 }
--- a/js/src/views/Settings/settings.js
+++ b/js/src/views/Settings/settings.js
@ -45,7 +45,7 @@ export default class Settings extends Component {
    }

    return (
-      <div className={ styles.layout }>
+      <div>
        <Actionbar title='settings' className={ styles.bar }>
          <Tabs className={ styles.tabs } value={ hash }>
            { this.renderTab(hash, 'views', <ImageRemoveRedEye />) }
--- a/js/src/views/Signer/components/Account/AccountLink/AccountLink.js
+++ b/js/src/views/Signer/components/Account/AccountLink/AccountLink.js
@ -16,7 +16,7 @@

 import React, { Component, PropTypes } from 'react';

-import { addressLink } from '../../../../../3rdparty/etherscan/links';
+import { addressLink } from '~/3rdparty/etherscan/links';
 import styles from './AccountLink.css';

 export default class AccountLink extends Component {
--- a/js/src/views/Signer/components/TxHashLink/TxHashLink.js
+++ b/js/src/views/Signer/components/TxHashLink/TxHashLink.js
@ -16,7 +16,7 @@

 import React, { Component, PropTypes } from 'react';

-import { txLink } from '../../../../3rdparty/etherscan/links';
+import { txLink } from '~/3rdparty/etherscan/links';

 export default class TxHashLink extends Component {

--- a/js/src/views/Signer/containers/Embedded/embedded.css
+++ b/js/src/views/Signer/containers/Embedded/embedded.css
@ -23,9 +23,6 @@
  width: $embedWidth;
 }

-.pending {
-}
-
 .none {
  color: #aaa;
 }
--- a/js/src/views/Signer/containers/Embedded/embedded.js
+++ b/js/src/views/Signer/containers/Embedded/embedded.js
@ -71,7 +71,7 @@ class Embedded extends Component {
    const items = pending.sort(this._sortRequests).map(this.renderPending);

    return (
-      <div className={ styles.pending }>
+      <div>
        { items }
      </div>
    );
--- a/js/src/views/Signer/containers/RequestsPage/RequestsPage.css
+++ b/js/src/views/Signer/containers/RequestsPage/RequestsPage.css
@ -15,12 +15,6 @@
 /* along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 */

-.request {
-}
-
 .noRequestsMsg {
  color: #aaa;
 }
-
-.items {
-}
--- a/js/src/views/Signer/containers/RequestsPage/RequestsPage.js
+++ b/js/src/views/Signer/containers/RequestsPage/RequestsPage.js
@ -98,9 +98,7 @@ class RequestsPage extends Component {

    return (
      <Container title='Pending Requests'>
-        <div className={ styles.items }>
-          { items }
-        </div>
+        { items }
      </Container>
    );
  }
@ -111,7 +109,6 @@ class RequestsPage extends Component {

    return (
      <RequestPending
-        className={ styles.request }
        onConfirm={ actions.startConfirmRequest }
        onReject={ actions.startRejectRequest }
        isSending={ isSending || false }
--- a/js/src/views/Signer/signer.js
+++ b/js/src/views/Signer/signer.js
@ -19,12 +19,10 @@ import React, { Component } from 'react';
 import { Actionbar } from '~/ui';
 import RequestsPage from './containers/RequestsPage';

-import styles from './signer.css';
-
 export default class Signer extends Component {
  render () {
    return (
-      <div className={ styles.signer }>
+      <div>
        <Actionbar
          title='Trusted Signer' />
        <RequestsPage />
--- a/js/src/views/Status/containers/StatusPage/StatusPage.js
+++ b/js/src/views/Status/containers/StatusPage/StatusPage.js
@ -23,8 +23,6 @@ import { clearStatusLogs, toggleStatusLogs, toggleStatusRefresh } from '~/redux/
 import Debug from '../../components/Debug';
 import Status from '../../components/Status';

-import styles from './statusPage.css';
-
 class StatusPage extends Component {
  static propTypes = {
    nodeStatus: PropTypes.object.isRequired,
@ -41,7 +39,7 @@ class StatusPage extends Component {

  render () {
    return (
-      <div className={ styles.body }>
+      <div>
        <Status { ...this.props } />
        <Debug { ...this.props } />
      </div>
--- a/js/src/views/Status/containers/StatusPage/statusPage.css
+++ b/js/src/views/Status/containers/StatusPage/statusPage.css
@ -1,18 +0,0 @@
-/* Copyright 2015, 2016 Ethcore (UK) Ltd.
-/* This file is part of Parity.
-/*
-/* Parity 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.
-/*
-/* Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
-*/
-.body {
-}
--- a/json/src/spec/authority_round.rs
+++ b/json/src/spec/authority_round.rs
@ -30,6 +30,10 @@ pub struct AuthorityRoundParams {
 	pub step_duration: Uint,
 	/// Valid authorities
 	pub authorities: Vec<Address>,
+	/// Starting step. Determined automatically if not specified.
+	/// To be used for testing only.
+	#[serde(rename="startStep")]
+	pub start_step: Option<Uint>,
 }

 /// Authority engine deserialization.
@ -50,7 +54,8 @@ mod tests {
 			"params": {
 				"gasLimitBoundDivisor": "0x0400",
 				"stepDuration": "0x02",
-				"authorities" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"]
+				"authorities" : ["0xc6d9d2cd449a754c494264e1809c50e34d64562b"],
+				"startStep" : 24
 			}
 		}"#;

--- a/sync/Cargo.toml
+++ b/sync/Cargo.toml
@ -27,6 +27,8 @@ heapsize = "0.3"
 ethcore-ipc = { path = "../ipc/rpc" }
 semver = "0.2"
 ethcore-ipc-nano = { path = "../ipc/nano" }
+ethcore-devtools = { path = "../devtools" }
+ethkey = { path = "../ethkey" }
 parking_lot = "0.3"

 [features]
--- a/sync/src/lib.rs
+++ b/sync/src/lib.rs
@ -39,6 +39,9 @@ extern crate rlp;

 extern crate ethcore_light as light;

+#[cfg(test)] extern crate ethcore_devtools as devtools;
+#[cfg(test)] extern crate ethkey;
+
 #[macro_use]
 extern crate log;
 #[macro_use]
--- a/sync/src/tests/chain.rs
+++ b/sync/src/tests/chain.rs
@ -24,8 +24,8 @@ use SyncConfig;
 fn two_peers() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
-	net.peer_mut(1).chain.add_blocks(1000, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(1000, EachBlockWith::Uncle);
 	net.sync();
 	assert!(net.peer(0).chain.block(BlockID::Number(1000)).is_some());
 	assert_eq!(*net.peer(0).chain.blocks.read(), *net.peer(1).chain.blocks.read());
@ -35,7 +35,7 @@ fn two_peers() {
 fn long_chain() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(2);
-	net.peer_mut(1).chain.add_blocks(50000, EachBlockWith::Nothing);
+	net.peer(1).chain.add_blocks(50000, EachBlockWith::Nothing);
 	net.sync();
 	assert!(net.peer(0).chain.block(BlockID::Number(50000)).is_some());
 	assert_eq!(*net.peer(0).chain.blocks.read(), *net.peer(1).chain.blocks.read());
@ -45,8 +45,8 @@ fn long_chain() {
 fn status_after_sync() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
-	net.peer_mut(1).chain.add_blocks(1000, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(1000, EachBlockWith::Uncle);
 	net.sync();
 	let status = net.peer(0).sync.read().status();
 	assert_eq!(status.state, SyncState::Idle);
@ -55,8 +55,8 @@ fn status_after_sync() {
 #[test]
 fn takes_few_steps() {
 	let mut net = TestNet::new(3);
-	net.peer_mut(1).chain.add_blocks(100, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(100, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(100, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(100, EachBlockWith::Uncle);
 	let total_steps = net.sync();
 	assert!(total_steps < 20);
 }
@ -67,8 +67,8 @@ fn empty_blocks() {
 	let mut net = TestNet::new(3);
 	for n in 0..200 {
 		let with = if n % 2 == 0 { EachBlockWith::Nothing } else { EachBlockWith::Uncle };
-		net.peer_mut(1).chain.add_blocks(5, with.clone());
-		net.peer_mut(2).chain.add_blocks(5, with);
+		net.peer(1).chain.add_blocks(5, with.clone());
+		net.peer(2).chain.add_blocks(5, with);
 	}
 	net.sync();
 	assert!(net.peer(0).chain.block(BlockID::Number(1000)).is_some());
@ -79,14 +79,14 @@ fn empty_blocks() {
 fn forked() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
-	net.peer_mut(0).chain.add_blocks(30, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.add_blocks(30, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(30, EachBlockWith::Uncle);
-	net.peer_mut(0).chain.add_blocks(10, EachBlockWith::Nothing); //fork
-	net.peer_mut(1).chain.add_blocks(20, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(20, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle); //fork between 1 and 2
-	net.peer_mut(2).chain.add_blocks(1, EachBlockWith::Nothing);
+	net.peer(0).chain.add_blocks(30, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(30, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(30, EachBlockWith::Uncle);
+	net.peer(0).chain.add_blocks(10, EachBlockWith::Nothing); //fork
+	net.peer(1).chain.add_blocks(20, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(20, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle); //fork between 1 and 2
+	net.peer(2).chain.add_blocks(1, EachBlockWith::Nothing);
 	// peer 1 has the best chain of 601 blocks
 	let peer1_chain = net.peer(1).chain.numbers.read().clone();
 	net.sync();
@ -102,12 +102,12 @@ fn forked_with_misbehaving_peer() {
 	let mut net = TestNet::new(3);
 	// peer 0 is on a totally different chain with higher total difficulty
 	net.peer_mut(0).chain = TestBlockChainClient::new_with_extra_data(b"fork".to_vec());
-	net.peer_mut(0).chain.add_blocks(50, EachBlockWith::Nothing);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Nothing);
-	net.peer_mut(2).chain.add_blocks(10, EachBlockWith::Nothing);
+	net.peer(0).chain.add_blocks(50, EachBlockWith::Nothing);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Nothing);
+	net.peer(2).chain.add_blocks(10, EachBlockWith::Nothing);

-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Nothing);
-	net.peer_mut(2).chain.add_blocks(20, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Nothing);
+	net.peer(2).chain.add_blocks(20, EachBlockWith::Uncle);
 	// peer 1 should sync to peer 2, others should not change
 	let peer0_chain = net.peer(0).chain.numbers.read().clone();
 	let peer2_chain = net.peer(2).chain.numbers.read().clone();
@ -124,13 +124,13 @@ fn net_hard_fork() {
 	ref_client.add_blocks(50, EachBlockWith::Uncle);
 	{
 		let mut net = TestNet::new_with_fork(2, Some((50, ref_client.block_hash(BlockID::Number(50)).unwrap())));
-		net.peer_mut(0).chain.add_blocks(100, EachBlockWith::Uncle);
+		net.peer(0).chain.add_blocks(100, EachBlockWith::Uncle);
 		net.sync();
 		assert_eq!(net.peer(1).chain.chain_info().best_block_number, 100);
 	}
 	{
 		let mut net = TestNet::new_with_fork(2, Some((50, ref_client.block_hash(BlockID::Number(50)).unwrap())));
-		net.peer_mut(0).chain.add_blocks(100, EachBlockWith::Nothing);
+		net.peer(0).chain.add_blocks(100, EachBlockWith::Nothing);
 		net.sync();
 		assert_eq!(net.peer(1).chain.chain_info().best_block_number, 0);
 	}
@ -140,8 +140,8 @@ fn net_hard_fork() {
 fn restart() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(3);
-	net.peer_mut(1).chain.add_blocks(1000, EachBlockWith::Uncle);
-	net.peer_mut(2).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(1000, EachBlockWith::Uncle);
+	net.peer(2).chain.add_blocks(1000, EachBlockWith::Uncle);

 	net.sync();

@ -166,37 +166,37 @@ fn status_empty() {
 #[test]
 fn status_packet() {
 	let mut net = TestNet::new(2);
-	net.peer_mut(0).chain.add_blocks(100, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.add_blocks(1, EachBlockWith::Uncle);
+	net.peer(0).chain.add_blocks(100, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(1, EachBlockWith::Uncle);

 	net.start();

 	net.sync_step_peer(0);

-	assert_eq!(1, net.peer(0).queue.len());
-	assert_eq!(0x00, net.peer(0).queue[0].packet_id);
+	assert_eq!(1, net.peer(0).queue.read().len());
+	assert_eq!(0x00, net.peer(0).queue.read()[0].packet_id);
 }

 #[test]
 fn propagate_hashes() {
 	let mut net = TestNet::new(6);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle);
 	net.sync();

-	net.peer_mut(0).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(0).chain.add_blocks(10, EachBlockWith::Uncle);
 	net.sync();
 	net.trigger_chain_new_blocks(0); //first event just sets the marker
 	net.trigger_chain_new_blocks(0);

 	// 5 peers with NewHahses, 4 with blocks
-	assert_eq!(9, net.peer(0).queue.len());
+	assert_eq!(9, net.peer(0).queue.read().len());
 	let mut hashes = 0;
 	let mut blocks = 0;
-	for i in 0..net.peer(0).queue.len() {
-		if net.peer(0).queue[i].packet_id == 0x1 {
+	for i in 0..net.peer(0).queue.read().len() {
+		if net.peer(0).queue.read()[i].packet_id == 0x1 {
 			hashes += 1;
 		}
-		if net.peer(0).queue[i].packet_id == 0x7 {
+		if net.peer(0).queue.read()[i].packet_id == 0x7 {
 			blocks += 1;
 		}
 	}
@ -207,24 +207,24 @@ fn propagate_hashes() {
 #[test]
 fn propagate_blocks() {
 	let mut net = TestNet::new(20);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle);
 	net.sync();

-	net.peer_mut(0).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(0).chain.add_blocks(10, EachBlockWith::Uncle);
 	net.trigger_chain_new_blocks(0); //first event just sets the marker
 	net.trigger_chain_new_blocks(0);

-	assert!(!net.peer(0).queue.is_empty());
+	assert!(!net.peer(0).queue.read().is_empty());
 	// NEW_BLOCK_PACKET
-	let blocks = net.peer(0).queue.iter().filter(|p| p.packet_id == 0x7).count();
+	let blocks = net.peer(0).queue.read().iter().filter(|p| p.packet_id == 0x7).count();
 	assert!(blocks > 0);
 }

 #[test]
 fn restart_on_malformed_block() {
 	let mut net = TestNet::new(2);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.corrupt_block(6);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(1).chain.corrupt_block(6);
 	net.sync_steps(20);

 	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 5);
@ -233,8 +233,8 @@ fn restart_on_malformed_block() {
 #[test]
 fn restart_on_broken_chain() {
 	let mut net = TestNet::new(2);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.corrupt_block_parent(6);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(1).chain.corrupt_block_parent(6);
 	net.sync_steps(20);

 	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 5);
@ -243,8 +243,8 @@ fn restart_on_broken_chain() {
 #[test]
 fn high_td_attach() {
 	let mut net = TestNet::new(2);
-	net.peer_mut(1).chain.add_blocks(10, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.corrupt_block_parent(6);
+	net.peer(1).chain.add_blocks(10, EachBlockWith::Uncle);
+	net.peer(1).chain.corrupt_block_parent(6);
 	net.sync_steps(20);

 	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 5);
@ -255,8 +255,8 @@ fn high_td_attach() {
 fn disconnect_on_unrelated_chain() {
 	::env_logger::init().ok();
 	let mut net = TestNet::new(2);
-	net.peer_mut(0).chain.add_blocks(200, EachBlockWith::Uncle);
-	net.peer_mut(1).chain.add_blocks(100, EachBlockWith::Nothing);
+	net.peer(0).chain.add_blocks(200, EachBlockWith::Uncle);
+	net.peer(1).chain.add_blocks(100, EachBlockWith::Nothing);
 	net.sync();
 	assert_eq!(net.disconnect_events, vec![(0, 0)]);
 }
--- a/sync/src/tests/consensus.rs
+++ b/sync/src/tests/consensus.rs
@ -0,0 +1,78 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity 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.
+
+// Parity 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 Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+use util::*;
+use ethcore::client::BlockChainClient;
+use ethcore::spec::Spec;
+use ethcore::miner::MinerService;
+use ethcore::transaction::*;
+use ethcore::account_provider::AccountProvider;
+use ethkey::KeyPair;
+use super::helpers::*;
+use SyncConfig;
+
+#[test]
+fn test_authority_round() {
+	::env_logger::init().ok();
+
+	let s1 = KeyPair::from_secret("1".sha3()).unwrap();
+	let s2 = KeyPair::from_secret("0".sha3()).unwrap();
+	let spec_factory = || {
+		let spec = Spec::new_test_round();
+		let account_provider = AccountProvider::transient_provider();
+		account_provider.insert_account(s1.secret().clone(), "").unwrap();
+		account_provider.insert_account(s2.secret().clone(), "").unwrap();
+		spec.engine.register_account_provider(Arc::new(account_provider));
+		spec
+	};
+	let mut net = TestNet::new_with_spec(2, SyncConfig::default(), spec_factory);
+	let mut net = &mut *net;
+	// Push transaction to both clients. Only one of them gets lucky to mine a block.
+	net.peer(0).chain.miner().set_author(s1.address());
+	net.peer(0).chain.engine().set_signer(s1.address(), "".to_owned());
+	net.peer(1).chain.miner().set_author(s2.address());
+	net.peer(1).chain.engine().set_signer(s2.address(), "".to_owned());
+	let tx1 = Transaction {
+		nonce: 0.into(),
+		gas_price: 0.into(),
+		gas: 21000.into(),
+		action: Action::Call(Address::default()),
+		value: 0.into(),
+		data: Vec::new(),
+	}.sign(s1.secret(), None);
+	// exhange statuses
+	net.sync_steps(5);
+	net.peer(0).chain.miner().import_own_transaction(&net.peer(0).chain, tx1).unwrap();
+	net.sync();
+	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 1);
+	assert_eq!(net.peer(1).chain.chain_info().best_block_number, 1);
+
+	let tx2 = Transaction {
+		nonce: 0.into(),
+		gas_price: 0.into(),
+		gas: 21000.into(),
+		action: Action::Call(Address::default()),
+		value: 0.into(),
+		data: Vec::new(),
+	}.sign(s2.secret(), None);
+	net.peer(1).chain.miner().import_own_transaction(&net.peer(1).chain, tx2).unwrap();
+	net.peer(1).chain.engine().step();
+	net.peer(1).chain.miner().update_sealing(&net.peer(1).chain);
+	net.sync();
+	assert_eq!(net.peer(0).chain.chain_info().best_block_number, 2);
+	assert_eq!(net.peer(1).chain.chain_info().best_block_number, 2);
+}
+
--- a/sync/src/tests/helpers.rs
+++ b/sync/src/tests/helpers.rs
@ -17,16 +17,33 @@
 use util::*;
 use network::*;
 use tests::snapshot::*;
-use ethcore::client::{TestBlockChainClient, BlockChainClient};
+use ethcore::client::{TestBlockChainClient, BlockChainClient, Client as EthcoreClient, ClientConfig, ChainNotify};
 use ethcore::header::BlockNumber;
 use ethcore::snapshot::SnapshotService;
+use ethcore::spec::Spec;
+use ethcore::miner::Miner;
+use ethcore::db::NUM_COLUMNS;
 use sync_io::SyncIo;
+use io::IoChannel;
 use api::WARP_SYNC_PROTOCOL_ID;
 use chain::ChainSync;
 use ::SyncConfig;
+use devtools::{self, GuardedTempResult};

-pub struct TestIo<'p> {
-	pub chain: &'p mut TestBlockChainClient,
+pub trait FlushingBlockChainClient: BlockChainClient {
+	fn flush(&self) {}
+}
+
+impl FlushingBlockChainClient for EthcoreClient {
+	fn flush(&self) {
+		self.flush_queue();
+	}
+}
+
+impl FlushingBlockChainClient for TestBlockChainClient {}
+
+pub struct TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
+	pub chain: &'p C,
 	pub snapshot_service: &'p TestSnapshotService,
 	pub queue: &'p mut VecDeque<TestPacket>,
 	pub sender: Option<PeerId>,
@ -34,8 +51,8 @@ pub struct TestIo<'p> {
 	overlay: RwLock<HashMap<BlockNumber, Bytes>>,
 }

-impl<'p> TestIo<'p> {
-	pub fn new(chain: &'p mut TestBlockChainClient, ss: &'p TestSnapshotService, queue: &'p mut VecDeque<TestPacket>, sender: Option<PeerId>) -> TestIo<'p> {
+impl<'p, C> TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
+	pub fn new(chain: &'p C, ss: &'p TestSnapshotService, queue: &'p mut VecDeque<TestPacket>, sender: Option<PeerId>) -> TestIo<'p, C> {
 		TestIo {
 			chain: chain,
 			snapshot_service: ss,
@ -47,7 +64,7 @@ impl<'p> TestIo<'p> {
 	}
 }

-impl<'p> SyncIo for TestIo<'p> {
+impl<'p, C> SyncIo for TestIo<'p, C> where C: FlushingBlockChainClient, C: 'p {
 	fn disable_peer(&mut self, peer_id: PeerId) {
 		self.disconnect_peer(peer_id);
 	}
@ -99,7 +116,7 @@ impl<'p> SyncIo for TestIo<'p> {
 	}

 	fn protocol_version(&self, protocol: &ProtocolId, peer_id: PeerId) -> u8 {
-		if protocol == &WARP_SYNC_PROTOCOL_ID { 1 } else { self.eth_protocol_version(peer_id) }
+		if protocol == &WARP_SYNC_PROTOCOL_ID { 2 } else { self.eth_protocol_version(peer_id) }
 	}

 	fn chain_overlay(&self) -> &RwLock<HashMap<BlockNumber, Bytes>> {
@ -113,31 +130,31 @@ pub struct TestPacket {
 	pub recipient: PeerId,
 }

-pub struct TestPeer {
-	pub chain: TestBlockChainClient,
+pub struct TestPeer<C> where C: FlushingBlockChainClient {
+	pub chain: C,
 	pub snapshot_service: Arc<TestSnapshotService>,
 	pub sync: RwLock<ChainSync>,
-	pub queue: VecDeque<TestPacket>,
+	pub queue: RwLock<VecDeque<TestPacket>>,
 }

-pub struct TestNet {
-	pub peers: Vec<TestPeer>,
+pub struct TestNet<C> where C: FlushingBlockChainClient {
+	pub peers: Vec<Arc<TestPeer<C>>>,
 	pub started: bool,
 	pub disconnect_events: Vec<(PeerId, PeerId)>, //disconnected (initiated by, to)
 }

-impl TestNet {
-	pub fn new(n: usize) -> TestNet {
+impl TestNet<TestBlockChainClient> {
+	pub fn new(n: usize) -> TestNet<TestBlockChainClient> {
 		Self::new_with_config(n, SyncConfig::default())
 	}

-	pub fn new_with_fork(n: usize, fork: Option<(BlockNumber, H256)>) -> TestNet {
+	pub fn new_with_fork(n: usize, fork: Option<(BlockNumber, H256)>) -> TestNet<TestBlockChainClient> {
 		let mut config = SyncConfig::default();
 		config.fork_block = fork;
 		Self::new_with_config(n, config)
 	}

-	pub fn new_with_config(n: usize, config: SyncConfig) -> TestNet {
+	pub fn new_with_config(n: usize, config: SyncConfig) -> TestNet<TestBlockChainClient> {
 		let mut net = TestNet {
 			peers: Vec::new(),
 			started: false,
@ -147,31 +164,77 @@ impl TestNet {
 			let chain = TestBlockChainClient::new();
 			let ss = Arc::new(TestSnapshotService::new());
 			let sync = ChainSync::new(config.clone(), &chain);
-			net.peers.push(TestPeer {
+			net.peers.push(Arc::new(TestPeer {
 				sync: RwLock::new(sync),
 				snapshot_service: ss,
 				chain: chain,
-				queue: VecDeque::new(),
-			});
+				queue: RwLock::new(VecDeque::new()),
+			}));
 		}
 		net
 	}
+}

-	pub fn peer(&self, i: usize) -> &TestPeer {
+impl TestNet<EthcoreClient> {
+	pub fn new_with_spec<F>(n: usize, config: SyncConfig, spec_factory: F) -> GuardedTempResult<TestNet<EthcoreClient>>
+		where F: Fn() -> Spec
+	{
+		let mut net = TestNet {
+			peers: Vec::new(),
+			started: false,
+			disconnect_events: Vec::new(),
+		};
+		let dir = devtools::RandomTempPath::new();
+		for _ in 0..n {
+			let mut client_dir = dir.as_path().clone();
+			client_dir.push(devtools::random_filename());
+
+			let db_config = DatabaseConfig::with_columns(NUM_COLUMNS);
+
+			let spec = spec_factory();
+			let client = Arc::try_unwrap(EthcoreClient::new(
+				ClientConfig::default(),
+				&spec,
+				client_dir.as_path(),
+				Arc::new(Miner::with_spec(&spec)),
+				IoChannel::disconnected(),
+				&db_config
+			).unwrap()).ok().unwrap();
+
+			let ss = Arc::new(TestSnapshotService::new());
+			let sync = ChainSync::new(config.clone(), &client);
+			let peer = Arc::new(TestPeer {
+				sync: RwLock::new(sync),
+				snapshot_service: ss,
+				chain: client,
+				queue: RwLock::new(VecDeque::new()),
+			});
+			peer.chain.add_notify(peer.clone());
+			net.peers.push(peer);
+		}
+		GuardedTempResult::<TestNet<EthcoreClient>> {
+			_temp: dir,
+			result: Some(net)
+		}
+	}
+}
+
+impl<C> TestNet<C> where C: FlushingBlockChainClient {
+	pub fn peer(&self, i: usize) -> &TestPeer<C> {
 		&self.peers[i]
 	}

-	pub fn peer_mut(&mut self, i: usize) -> &mut TestPeer {
-		&mut self.peers[i]
+	pub fn peer_mut(&mut self, i: usize) -> &mut TestPeer<C> {
+		Arc::get_mut(&mut self.peers[i]).unwrap()
 	}

 	pub fn start(&mut self) {
 		for peer in 0..self.peers.len() {
 			for client in 0..self.peers.len() {
 				if peer != client {
-					let mut p = &mut self.peers[peer];
+					let p = &self.peers[peer];
 					p.sync.write().update_targets(&p.chain);
-					p.sync.write().on_peer_connected(&mut TestIo::new(&mut p.chain, &p.snapshot_service, &mut p.queue, Some(client as PeerId)), client as PeerId);
+					p.sync.write().on_peer_connected(&mut TestIo::new(&p.chain, &p.snapshot_service, &mut p.queue.write(), Some(client as PeerId)), client as PeerId);
 				}
 			}
 		}
@ -179,18 +242,20 @@ impl TestNet {

 	pub fn sync_step(&mut self) {
 		for peer in 0..self.peers.len() {
-			if let Some(packet) = self.peers[peer].queue.pop_front() {
+			let packet = self.peers[peer].queue.write().pop_front();
+			if let Some(packet) = packet {
 				let disconnecting = {
-					let mut p = &mut self.peers[packet.recipient];
+					let p = &self.peers[packet.recipient];
+					let mut queue = p.queue.write();
 					trace!("--- {} -> {} ---", peer, packet.recipient);
 					let to_disconnect = {
-						let mut io = TestIo::new(&mut p.chain, &p.snapshot_service, &mut p.queue, Some(peer as PeerId));
+						let mut io = TestIo::new(&p.chain, &p.snapshot_service, &mut queue, Some(peer as PeerId));
 						ChainSync::dispatch_packet(&p.sync, &mut io, peer as PeerId, packet.packet_id, &packet.data);
 						io.to_disconnect
 					};
 					for d in &to_disconnect {
 						// notify this that disconnecting peers are disconnecting
-						let mut io = TestIo::new(&mut p.chain, &p.snapshot_service, &mut p.queue, Some(*d));
+						let mut io = TestIo::new(&p.chain, &p.snapshot_service, &mut queue, Some(*d));
 						p.sync.write().on_peer_aborting(&mut io, *d);
 						self.disconnect_events.push((peer, *d));
 					}
@ -198,8 +263,9 @@ impl TestNet {
 				};
 				for d in &disconnecting {
 					// notify other peers that this peer is disconnecting
-					let mut p = &mut self.peers[*d];
-					let mut io = TestIo::new(&mut p.chain, &p.snapshot_service, &mut p.queue, Some(peer as PeerId));
+					let p = &self.peers[*d];
+					let mut queue = p.queue.write();
+					let mut io = TestIo::new(&p.chain, &p.snapshot_service, &mut queue, Some(peer as PeerId));
 					p.sync.write().on_peer_aborting(&mut io, peer as PeerId);
 				}
 			}
@ -209,13 +275,17 @@ impl TestNet {
 	}

 	pub fn sync_step_peer(&mut self, peer_num: usize) {
-		let mut peer = self.peer_mut(peer_num);
-		peer.sync.write().maintain_sync(&mut TestIo::new(&mut peer.chain, &peer.snapshot_service, &mut peer.queue, None));
+		let peer = self.peer(peer_num);
+		peer.chain.flush();
+		let mut queue = peer.queue.write();
+		peer.sync.write().maintain_peers(&mut TestIo::new(&peer.chain, &peer.snapshot_service, &mut queue, None));
+		peer.sync.write().maintain_sync(&mut TestIo::new(&peer.chain, &peer.snapshot_service, &mut queue, None));
+		peer.sync.write().propagate_new_transactions(&mut TestIo::new(&peer.chain, &peer.snapshot_service, &mut queue, None));
 	}

 	pub fn restart_peer(&mut self, i: usize) {
-		let peer = self.peer_mut(i);
-		peer.sync.write().restart(&mut TestIo::new(&mut peer.chain, &peer.snapshot_service, &mut peer.queue, None));
+		let peer = self.peer(i);
+		peer.sync.write().restart(&mut TestIo::new(&peer.chain, &peer.snapshot_service, &mut peer.queue.write(), None));
 	}

 	pub fn sync(&mut self) -> u32 {
@ -239,11 +309,38 @@ impl TestNet {
 	}

 	pub fn done(&self) -> bool {
-		self.peers.iter().all(|p| p.queue.is_empty())
+		self.peers.iter().all(|p| p.queue.read().is_empty())
 	}

 	pub fn trigger_chain_new_blocks(&mut self, peer_id: usize) {
-		let mut peer = self.peer_mut(peer_id);
-		peer.sync.write().chain_new_blocks(&mut TestIo::new(&mut peer.chain, &peer.snapshot_service, &mut peer.queue, None), &[], &[], &[], &[], &[]);
+		let peer = self.peer(peer_id);
+		let mut queue = peer.queue.write();
+		peer.sync.write().chain_new_blocks(&mut TestIo::new(&peer.chain, &peer.snapshot_service, &mut queue, None), &[], &[], &[], &[], &[]);
 	}
 }
+
+impl ChainNotify for TestPeer<EthcoreClient> {
+	fn new_blocks(&self,
+		imported: Vec<H256>,
+		invalid: Vec<H256>,
+		enacted: Vec<H256>,
+		retracted: Vec<H256>,
+		sealed: Vec<H256>,
+		_duration: u64)
+	{
+		let mut queue = self.queue.write();
+		let mut io = TestIo::new(&self.chain, &self.snapshot_service, &mut queue, None);
+		self.sync.write().chain_new_blocks(
+			&mut io,
+			&imported,
+			&invalid,
+			&enacted,
+			&retracted,
+			&sealed);
+	}
+
+	fn start(&self) {}
+
+	fn stop(&self) {}
+}
+
--- a/sync/src/tests/mod.rs
+++ b/sync/src/tests/mod.rs
@ -17,6 +17,7 @@
 pub mod helpers;
 pub mod snapshot;
 mod chain;
+mod consensus;

 #[cfg(feature = "ipc")]
 mod rpc;
--- a/sync/src/tests/snapshot.rs
+++ b/sync/src/tests/snapshot.rs
@ -129,7 +129,7 @@ fn snapshot_sync() {
 	let snapshot_service = Arc::new(TestSnapshotService::new_with_snapshot(16, H256::new(), 500000));
 	for i in 0..4 {
 		net.peer_mut(i).snapshot_service = snapshot_service.clone();
-		net.peer_mut(i).chain.add_blocks(1, EachBlockWith::Nothing);
+		net.peer(i).chain.add_blocks(1, EachBlockWith::Nothing);
 	}
 	net.sync_steps(50);
 	assert_eq!(net.peer(4).snapshot_service.state_restoration_chunks.lock().len(), net.peer(0).snapshot_service.manifest.as_ref().unwrap().state_hashes.len());
--- a/util/io/src/service.rs
+++ b/util/io/src/service.rs
@ -394,7 +394,7 @@ impl<Message> IoChannel<Message> where Message: Send + Clone + Sync + 'static {
 /// 'Message' is a notification message type
 pub struct IoService<Message> where Message: Send + Sync + Clone + 'static {
 	panic_handler: Arc<PanicHandler>,
-	thread: Option<JoinHandle<()>>,
+	thread: Mutex<Option<JoinHandle<()>>>,
 	host_channel: Mutex<Sender<IoMessage<Message>>>,
 	handlers: Arc<RwLock<Slab<Arc<IoHandler<Message>>, HandlerId>>>,
 }
@ -424,12 +424,26 @@ impl<Message> IoService<Message> where Message: Send + Sync + Clone + 'static {
 		});
 		Ok(IoService {
 			panic_handler: panic_handler,
-			thread: Some(thread),
+			thread: Mutex::new(Some(thread)),
 			host_channel: Mutex::new(channel),
 			handlers: handlers,
 		})
 	}

+	pub fn stop(&self) {
+		trace!(target: "shutdown", "[IoService] Closing...");
+		// Clear handlers so that shared pointers are not stuck on stack
+		// in Channel::send_sync
+		self.handlers.write().clear();
+		self.host_channel.lock().send(IoMessage::Shutdown).unwrap_or_else(|e| warn!("Error on IO service shutdown: {:?}", e));
+		if let Some(thread) = self.thread.lock().take() {
+			thread.join().unwrap_or_else(|e| {
+				debug!(target: "shutdown", "Error joining IO service event loop thread: {:?}", e);
+			});
+		}
+		trace!(target: "shutdown", "[IoService] Closed.");
+	}
+
 	/// Regiter an IO handler with the event loop.
 	pub fn register_handler(&self, handler: Arc<IoHandler<Message>+Send>) -> Result<(), IoError> {
 		try!(self.host_channel.lock().send(IoMessage::AddHandler {
@ -452,17 +466,7 @@ impl<Message> IoService<Message> where Message: Send + Sync + Clone + 'static {

 impl<Message> Drop for IoService<Message> where Message: Send + Sync + Clone {
 	fn drop(&mut self) {
-		trace!(target: "shutdown", "[IoService] Closing...");
-		// Clear handlers so that shared pointers are not stuck on stack
-		// in Channel::send_sync
-		self.handlers.write().clear();
-		self.host_channel.lock().send(IoMessage::Shutdown).unwrap_or_else(|e| warn!("Error on IO service shutdown: {:?}", e));
-		if let Some(thread) = self.thread.take() {
-			thread.join().unwrap_or_else(|e| {
-				debug!(target: "shutdown", "Error joining IO service event loop thread: {:?}", e);
-			});
-		}
-		trace!(target: "shutdown", "[IoService] Closed.");
+		self.stop()
 	}
 }