Refactoring the signing queue

This commit is contained in:
Tomasz Drwięga 2016-06-02 12:12:31 +02:00
parent 555555e6f7
commit e9bcce05a1
2 changed files with 133 additions and 105 deletions

View File

@ -16,19 +16,23 @@
use std::thread;
use std::time::{Instant, Duration};
use std::sync::{mpsc, Mutex, RwLock};
use std::sync::{mpsc, Mutex, RwLock, Arc};
use std::collections::HashMap;
use v1::types::{TransactionRequest, TransactionConfirmation};
use util::{U256, H256};
/// Messages that queue informs about
/// Possible events happening in the queue that can be listened to.
#[derive(Debug, PartialEq)]
pub enum QueueMessage {
pub enum QueueEvent {
/// Receiver should stop work upon receiving `Finish` message.
Finish,
/// Informs about new transaction request.
/// Informs about new request.
NewRequest(U256),
/// Request rejected.
RequestRejected(U256),
/// Request resolved.
RequestConfirmed(U256),
}
/// Defines possible errors returned from queue receiving method.
@ -41,19 +45,20 @@ pub enum QueueError {
}
/// Message Receiver type
pub type QueueMessageReceiver = mpsc::Receiver<QueueMessage>;
pub type QueueEventReceiver = mpsc::Receiver<QueueEvent>;
/// A queue of transactions awaiting to be confirmed and signed.
pub trait SigningQueue: Send + Sync {
/// Add new request to the queue.
fn add_request(&self, transaction: TransactionRequest) -> U256;
/// Returns a `ConfirmationPromise` that can be used to await for resolution of given request.
fn add_request(&self, transaction: TransactionRequest) -> ConfirmationPromise;
/// Remove request from the queue.
/// Notify possible waiters that transaction was rejected.
/// Removes a request from the queue.
/// Notifies possible token holders that transaction was rejected.
fn request_rejected(&self, id: U256) -> Option<TransactionConfirmation>;
/// Remove request from the queue.
/// Notify possible waiters that transaction was confirmed and got given hash.
/// Removes a request from the queue.
/// Notifies possible token holders that transaction was confirmed and given hash was assigned.
fn request_confirmed(&self, id: U256, hash: H256) -> Option<TransactionConfirmation>;
/// Returns a request if it is contained in the queue.
@ -61,32 +66,89 @@ pub trait SigningQueue: Send + Sync {
/// Return copy of all the requests in the queue.
fn requests(&self) -> Vec<TransactionConfirmation>;
}
/// Blocks for some time waiting for confirmation.
/// Returns `None` when timeout reached or transaction was rejected.
/// Returns transaction hash when transaction was confirmed.
fn wait_with_timeout(&self, id: U256) -> Option<H256>;
#[derive(Debug, PartialEq)]
enum ConfirmationResult {
/// The transaction has not yet been confirmed nor rejected.
Waiting,
/// The transaction has been rejected.
Rejected,
/// The transaction has been confirmed.
Confirmed(H256),
}
/// Time you need to confirm the transaction in UI.
/// This is the amount of time token holder will wait before
/// returning `None`.
/// Unless we have a multi-threaded RPC this will lock
/// any other incoming call!
const QUEUE_TIMEOUT_DURATION_SEC : u64 = 20;
#[derive(Debug, Clone)]
enum QueueStatus {
Waiting,
Rejected,
Confirmed(H256),
/// A handle to submitted request.
/// Allows to block and wait for a resolution of that request.
pub struct ConfirmationToken {
result: Arc<Mutex<ConfirmationResult>>,
handle: thread::Thread,
request: TransactionConfirmation,
}
pub struct ConfirmationPromise {
id: U256,
result: Arc<Mutex<ConfirmationResult>>,
}
impl ConfirmationToken {
/// Submit solution to all listeners
fn resolve(&self, result: Option<H256>) {
let mut res = self.result.lock().unwrap();
*res = result.map_or(ConfirmationResult::Rejected, |h| ConfirmationResult::Confirmed(h));
// Notify listener
self.handle.unpark();
}
fn as_promise(&self) -> ConfirmationPromise {
ConfirmationPromise {
id: self.request.id,
result: self.result.clone(),
}
}
}
impl ConfirmationPromise {
/// Blocks current thread and awaits for
/// resolution of the transaction (rejected / confirmed)
/// Returns `None` if transaction was rejected or timeout reached.
/// Returns `Some(hash)` if transaction was confirmed.
pub fn wait_with_timeout(&self) -> Option<H256> {
let timeout = Duration::from_secs(QUEUE_TIMEOUT_DURATION_SEC);
let deadline = Instant::now() + timeout;
info!(target: "own_tx", "Signer: Awaiting transaction confirmation... ({:?}).", self.id);
while Instant::now() < deadline {
// Park thread
thread::park_timeout(timeout);
// Take confirmation result
let res = self.result.lock().unwrap();
// Check the result
match *res {
ConfirmationResult::Rejected => return None,
ConfirmationResult::Confirmed(h) => return Some(h),
ConfirmationResult::Waiting => continue,
}
}
// We reached the timeout. Just return `None` and make sure to remove waiting.
trace!(target: "own_tx", "Signer: Confirmation timeout reached... ({:?}).", self.id);
None
}
}
/// Queue for all unconfirmed transactions.
pub struct ConfirmationsQueue {
id: Mutex<U256>,
waiters: RwLock<HashMap<U256, QueueStatus>>,
queue: RwLock<HashMap<U256, TransactionConfirmation>>,
sender: Mutex<mpsc::Sender<QueueMessage>>,
receiver: Mutex<Option<mpsc::Receiver<QueueMessage>>>,
queue: RwLock<HashMap<U256, ConfirmationToken>>,
sender: Mutex<mpsc::Sender<QueueEvent>>,
receiver: Mutex<Option<mpsc::Receiver<QueueEvent>>>,
}
impl Default for ConfirmationsQueue {
@ -95,7 +157,6 @@ impl Default for ConfirmationsQueue {
ConfirmationsQueue {
id: Mutex::new(U256::from(0)),
waiters: RwLock::new(HashMap::new()),
queue: RwLock::new(HashMap::new()),
sender: Mutex::new(send),
receiver: Mutex::new(Some(recv)),
@ -104,11 +165,11 @@ impl Default for ConfirmationsQueue {
}
impl ConfirmationsQueue {
/// Blocks the thread and starts listening for notifications.
/// For each event `listener` callback function will be invoked.
/// This method can be used only once.
/// Blocks the thread and starts listening for notifications regarding all actions in the queue.
/// For each event, `listener` callback will be invoked.
/// This method can be used only once (only single consumer of events can exist).
pub fn start_listening<F>(&self, listener: F) -> Result<(), QueueError>
where F: Fn(QueueMessage) -> () {
where F: Fn(QueueEvent) -> () {
let recv = self.receiver.lock().unwrap().take();
if let None = recv {
return Err(QueueError::AlreadyUsed);
@ -117,7 +178,7 @@ impl ConfirmationsQueue {
loop {
let message = try!(recv.recv().map_err(|e| QueueError::ReceiverError(e)));
if let QueueMessage::Finish = message {
if let QueueEvent::Finish = message {
return Ok(());
}
@ -125,23 +186,35 @@ impl ConfirmationsQueue {
}
}
/// Notifies receiver that the communcation is over.
/// Notifies consumer that the communcation is over.
/// No more events will be sent after this function is invoked.
pub fn finish(&self) {
self.notify(QueueMessage::Finish);
self.notify(QueueEvent::Finish);
}
fn notify(&self, message: QueueMessage) {
/// Notifies receiver about the event happening in this queue.
fn notify(&self, message: QueueEvent) {
// We don't really care about the result
let _ = self.sender.lock().unwrap().send(message);
}
fn remove(&self, id: U256) -> Option<TransactionConfirmation> {
self.queue.write().unwrap().remove(&id)
}
/// Removes transaction from this queue and notifies `ConfirmationPromise` holders about the result.
/// Notifies also a receiver about that event.
fn remove(&self, id: U256, result: Option<H256>) -> Option<TransactionConfirmation> {
let token = self.queue.write().unwrap().remove(&id);
fn update_status(&self, id: U256, status: QueueStatus) {
let mut waiters = self.waiters.write().unwrap();
waiters.insert(id, status);
if let Some(token) = token {
// notify receiver about the event
self.notify(result.map_or_else(
|| QueueEvent::RequestRejected(id),
|_| QueueEvent::RequestConfirmed(id)
));
// notify token holders about resolution
token.resolve(result);
// return a result
return Some(token.request.clone());
}
None
}
}
@ -152,7 +225,7 @@ impl Drop for ConfirmationsQueue {
}
impl SigningQueue for ConfirmationsQueue {
fn add_request(&self, transaction: TransactionRequest) -> U256 {
fn add_request(&self, transaction: TransactionRequest) -> ConfirmationPromise {
// Increment id
let id = {
let mut last_id = self.id.lock().unwrap();
@ -160,87 +233,42 @@ impl SigningQueue for ConfirmationsQueue {
*last_id
};
// Add request to queue
{
let res = {
let mut queue = self.queue.write().unwrap();
queue.insert(id, TransactionConfirmation {
queue.insert(id, ConfirmationToken {
result: Arc::new(Mutex::new(ConfirmationResult::Waiting)),
handle: thread::current(),
request: TransactionConfirmation {
id: id,
transaction: transaction,
},
});
debug!(target: "own_tx", "Signer: New transaction ({:?}) in confirmation queue.", id);
}
queue.get(&id).map(|token| token.as_promise()).expect("Token was just inserted.")
};
// Notify listeners
self.notify(QueueMessage::NewRequest(id));
id
self.notify(QueueEvent::NewRequest(id));
res
}
fn peek(&self, id: &U256) -> Option<TransactionConfirmation> {
self.queue.read().unwrap().get(id).cloned()
self.queue.read().unwrap().get(id).map(|token| token.request.clone())
}
fn request_rejected(&self, id: U256) -> Option<TransactionConfirmation> {
debug!(target: "own_tx", "Signer: Transaction rejected ({:?}).", id);
let o = self.remove(id);
self.update_status(id, QueueStatus::Rejected);
o
self.remove(id, None)
}
fn request_confirmed(&self, id: U256, hash: H256) -> Option<TransactionConfirmation> {
debug!(target: "own_tx", "Signer: Transaction confirmed ({:?}).", id);
let o = self.remove(id);
self.update_status(id, QueueStatus::Confirmed(hash));
o
self.remove(id, Some(hash))
}
fn requests(&self) -> Vec<TransactionConfirmation> {
let queue = self.queue.read().unwrap();
queue.values().cloned().collect()
}
fn wait_with_timeout(&self, id: U256) -> Option<H256> {
{
let mut waiters = self.waiters.write().unwrap();
let r = waiters.insert(id, QueueStatus::Waiting);
match r {
// This is ok, we can have many waiters
Some(QueueStatus::Waiting) | None => {},
// There already was a response for someone.
// The one waiting for it will cleanup, so...
Some(v) => {
// ... insert old status back
waiters.insert(id, v.clone());
if let QueueStatus::Confirmed(h) = v {
return Some(h);
}
return None;
},
}
}
info!(target: "own_tx", "Signer: Awaiting transaction confirmation... ({:?}).", id);
// Now wait for a response
let deadline = Instant::now() + Duration::from_secs(QUEUE_TIMEOUT_DURATION_SEC);
while Instant::now() < deadline {
let status = {
let waiters = self.waiters.read().unwrap();
waiters.get(&id).expect("Only the waiting thread can remove any message.").clone()
};
match status {
QueueStatus::Waiting => thread::sleep(Duration::from_millis(50)),
QueueStatus::Confirmed(h) => {
self.waiters.write().unwrap().remove(&id);
return Some(h);
},
QueueStatus::Rejected => {
self.waiters.write().unwrap().remove(&id);
return None;
},
}
}
// We reached the timeout. Just return `None` and make sure to remove waiting.
trace!(target: "own_tx", "Signer: Confirmation timeout reached... ({:?}).", id);
self.waiters.write().unwrap().remove(&id);
None
queue.values().map(|token| token.request.clone()).collect()
}
}
@ -277,7 +305,7 @@ mod test {
let q = queue.clone();
let handle = thread::spawn(move || {
let v = q.add_request(request);
q.wait_with_timeout(v).expect("Should return hash")
v.wait_with_timeout().expect("Should return hash")
});
let id = U256::from(1);
@ -307,13 +335,13 @@ mod test {
*v = Some(notification);
}).expect("Should be closed nicely.")
});
let v = queue.add_request(request);
queue.add_request(request);
queue.finish();
// then
handle.join().expect("Thread should finish nicely");
let r = received.lock().unwrap().take();
assert_eq!(r, Some(QueueMessage::NewRequest(v)));
assert_eq!(r, Some(QueueEvent::NewRequest(U256::from(1))));
}
#[test]

View File

@ -54,7 +54,7 @@ impl EthSigning for EthSigningQueueClient {
.and_then(|(request, )| {
let queue = take_weak!(self.queue);
let id = queue.add_request(request);
let result = queue.wait_with_timeout(id);
let result = id.wait_with_timeout();
to_value(&result.unwrap_or_else(H256::new))
})
}