Place Sync/Send in trait.

ethcore/src/block.rs

@@ -171,7 +171,7 @@ pub struct SealedBlock {
 
 impl<'x> OpenBlock<'x> {
 	/// Create a new OpenBlock ready for transaction pushing.
-	pub fn new(engine: &'x Engine, db: Box<JournalDB + Send>, parent: &Header, last_hashes: LastHashes, author: Address, extra_data: Bytes) -> Self {
+	pub fn new(engine: &'x Engine, db: Box<Box<JournalDB>>, parent: &Header, last_hashes: LastHashes, author: Address, extra_data: Bytes) -> Self {
 		let mut r = OpenBlock {
 			block: ExecutedBlock::new(State::from_existing(db, parent.state_root().clone(), engine.account_start_nonce())),
 			engine: engine,
@@ -317,7 +317,7 @@ impl ClosedBlock {
 	}
 
 	/// Drop this object and return the underlieing database.
-	pub fn drain(self) -> Box<JournalDB + Send> { self.block.state.drop().1 }
+	pub fn drain(self) -> Box<Box<JournalDB>> { self.block.state.drop().1 }
 }
 
 impl SealedBlock {
@@ -331,7 +331,7 @@ impl SealedBlock {
 	}
 
 	/// Drop this object and return the underlieing database.
-	pub fn drain(self) -> Box<JournalDB + Send> { self.block.state.drop().1 }
+	pub fn drain(self) -> Box<Box<JournalDB>> { self.block.state.drop().1 }
 }
 
 impl IsBlock for SealedBlock {
@@ -339,7 +339,7 @@ impl IsBlock for SealedBlock {
 }
 
 /// Enact the block given by block header, transactions and uncles
-pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &Engine, db: Box<JournalDB + Send>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Header], engine: &Engine, db: Box<Box<JournalDB>>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	{
 		if ::log::max_log_level() >= ::log::LogLevel::Trace {
 			let s = State::from_existing(db.spawn(), parent.state_root().clone(), engine.account_start_nonce());
@@ -357,20 +357,20 @@ pub fn enact(header: &Header, transactions: &[SignedTransaction], uncles: &[Head
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_bytes(block_bytes: &[u8], engine: &Engine, db: Box<JournalDB + Send>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact_bytes(block_bytes: &[u8], engine: &Engine, db: Box<Box<JournalDB>>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let block = BlockView::new(block_bytes);
 	let header = block.header();
 	enact(&header, &block.transactions(), &block.uncles(), engine, db, parent, last_hashes)
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header
-pub fn enact_verified(block: &PreverifiedBlock, engine: &Engine, db: Box<JournalDB + Send>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
+pub fn enact_verified(block: &PreverifiedBlock, engine: &Engine, db: Box<Box<JournalDB>>, parent: &Header, last_hashes: LastHashes) -> Result<ClosedBlock, Error> {
 	let view = BlockView::new(&block.bytes);
 	enact(&block.header, &block.transactions, &view.uncles(), engine, db, parent, last_hashes)
 }
 
 /// Enact the block given by `block_bytes` using `engine` on the database `db` with given `parent` block header. Seal the block aferwards
-pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: Box<JournalDB + Send>, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
+pub fn enact_and_seal(block_bytes: &[u8], engine: &Engine, db: Box<Box<JournalDB>>, parent: &Header, last_hashes: LastHashes) -> Result<SealedBlock, Error> {
 	let header = BlockView::new(block_bytes).header_view();
 	Ok(try!(try!(enact_bytes(block_bytes, engine, db, parent, last_hashes)).seal(engine, header.seal())))
 }

ethcore/src/client/client.rs

@@ -101,7 +101,7 @@ impl ClientReport {
 pub struct Client<V = CanonVerifier> where V: Verifier {
 	chain: Arc<BlockChain>,
 	engine: Arc<Box<Engine>>,
-	state_db: Mutex<Box<JournalDB + Send>>,
+	state_db: Mutex<Box<Box<JournalDB>>>,
 	block_queue: BlockQueue,
 	report: RwLock<ClientReport>,
 	import_lock: Mutex<()>,

ethcore/src/state.rs

@@ -31,7 +31,7 @@ pub type ApplyResult = Result<Receipt, Error>;
 
 /// Representation of the entire state of all accounts in the system.
 pub struct State {
-	db: Box<JournalDB + Send>,
+	db: Box<Box<JournalDB>>,
 	root: H256,
 	cache: RefCell<HashMap<Address, Option<Account>>>,
 	snapshots: RefCell<Vec<HashMap<Address, Option<Option<Account>>>>>,
@@ -41,7 +41,7 @@ pub struct State {
 impl State {
 	/// Creates new state with empty state root
 	#[cfg(test)]
-	pub fn new(mut db: Box<JournalDB + Send>, account_start_nonce: U256) -> State {
+	pub fn new(mut db: Box<Box<JournalDB>>, account_start_nonce: U256) -> State {
 		let mut root = H256::new();
 		{
 			// init trie and reset root too null
@@ -58,7 +58,7 @@ impl State {
 	}
 
 	/// Creates new state with existing state root
-	pub fn from_existing(db: Box<JournalDB + Send>, root: H256, account_start_nonce: U256) -> State {
+	pub fn from_existing(db: Box<Box<JournalDB>>, root: H256, account_start_nonce: U256) -> State {
 		{
 			// trie should panic! if root does not exist
 			let _ = SecTrieDB::new(db.as_hashdb(), &root);
@@ -126,7 +126,7 @@ impl State {
 	}
 
 	/// Destroy the current object and return root and database.
-	pub fn drop(self) -> (H256, Box<JournalDB + Send>) {
+	pub fn drop(self) -> (H256, Box<Box<JournalDB>>) {
 		(self.root, self.db)
 	}
 

ethcore/src/tests/helpers.rs

@@ -250,7 +250,7 @@ pub fn generate_dummy_empty_blockchain() -> GuardedTempResult<BlockChain> {
 	}
 }
 
-pub fn get_temp_journal_db() -> GuardedTempResult<Box<JournalDB + Send>> {
+pub fn get_temp_journal_db() -> GuardedTempResult<Box<Box<JournalDB>>> {
 	let temp = RandomTempPath::new();
 	let journal_db = Box::new(OptionOneDB::new(temp.as_str()));
 	GuardedTempResult {
@@ -268,7 +268,7 @@ pub fn get_temp_state() -> GuardedTempResult<State> {
 	}
 }
 
-pub fn get_temp_journal_db_in(path: &Path) -> Box<JournalDB + Send> {
+pub fn get_temp_journal_db_in(path: &Path) -> Box<Box<JournalDB>> {
 	Box::new(OptionOneDB::new(path.to_str().unwrap()))
 }
 

util/src/journaldb.rs

@@ -26,9 +26,9 @@ use std::env;
 
 /// A HashDB which can manage a short-term journal potentially containing many forks of mutually
 /// exclusive actions.
-pub trait JournalDB : HashDB {
+pub trait JournalDB : HashDB + Sync + Send {
 	/// Return a copy of ourself, in a box.
-	fn spawn(&self) -> Box<JournalDB + Send>;
+	fn spawn(&self) -> Box<Box<JournalDB>>;
 
 	/// Returns heap memory size used
 	fn mem_used(&self) -> usize;
@@ -418,7 +418,7 @@ impl HashDB for OptionOneDB {
 }
 
 impl JournalDB for OptionOneDB {
-	fn spawn(&self) -> Box<JournalDB + Send> {
+	fn spawn(&self) -> Box<Box<JournalDB>> {
 		Box::new(OptionOneDB {
 			overlay: MemoryDB::new(),
 			backing: self.backing.clone(),