Merge #201

201: Fix ASB - Prevent the future from being stopped in production r=da-kami a=da-kami



Co-authored-by: Daniel Karzel <daniel@comit.network>

swap/src/bitcoin/wallet.rs

@@ -7,7 +7,7 @@ use crate::{
     execution_params::ExecutionParams,
 };
 use ::bitcoin::{util::psbt::PartiallySignedTransaction, Txid};
-use anyhow::{anyhow, bail, Result};
+use anyhow::{anyhow, bail, Context, Result};
 use async_trait::async_trait;
 use backoff::{backoff::Constant as ConstantBackoff, tokio::retry};
 use bdk::{
@@ -23,12 +23,18 @@ use tokio::{sync::Mutex, time::interval};
 
 const SLED_TREE_NAME: &str = "default_tree";
 
-#[derive(Debug)]
+#[derive(Debug, thiserror::Error)]
 enum Error {
+    #[error("Sending the request failed")]
     Io(reqwest::Error),
+    #[error("Conversion to Integer failed")]
     Parse(std::num::ParseIntError),
+    #[error("The transaction is not minded yet")]
     NotYetMined,
-    JsonDeserialisation(reqwest::Error),
+    #[error("Deserialization failed")]
+    JsonDeserialization(reqwest::Error),
+    #[error("Electrum client error")]
+    ElectrumClient(electrum_client::Error),
 }
 
 pub struct Wallet {
@@ -162,14 +168,24 @@ impl BroadcastSignedTransaction for Wallet {
 impl WatchForRawTransaction for Wallet {
     async fn watch_for_raw_transaction(&self, txid: Txid) -> Result<Transaction> {
         tracing::debug!("watching for tx: {}", txid);
-        retry(ConstantBackoff::new(Duration::from_secs(1)), || async {
+        let tx = retry(ConstantBackoff::new(Duration::from_secs(1)), || async {
-            let client = Client::new(self.rpc_url.as_ref())?;
+            let client = Client::new(self.rpc_url.as_ref())
-            let tx = client.transaction_get(&txid)?;
+                .map_err(|err| backoff::Error::Permanent(Error::ElectrumClient(err)))?;
-            tracing::debug!("found tx: {}", txid);
+
-            Ok(tx)
+            let tx = client.transaction_get(&txid).map_err(|err| match err {
+                electrum_client::Error::Protocol(err) => {
+                    tracing::debug!("Received protocol error {} from Electrum, retrying...", err);
+                    backoff::Error::Transient(Error::NotYetMined)
+                }
+                err => backoff::Error::Permanent(Error::ElectrumClient(err)),
+            })?;
+
+            Result::<_, backoff::Error<Error>>::Ok(tx)
         })
         .await
-        .map_err(|err| anyhow!("transient errors to be retried: {:?}", err))
+        .context("transient errors to be retried")?;
+
+        Ok(tx)
     }
 }
 
@@ -200,7 +216,7 @@ impl GetBlockHeight for Wallet {
             Result::<_, backoff::Error<Error>>::Ok(height)
         })
         .await
-        .map_err(|err| anyhow!("transient errors to be retried: {:?}", err))?;
+        .context("transient errors to be retried")?;
 
         Ok(BlockHeight::new(height))
     }
@@ -225,7 +241,7 @@ impl TransactionBlockHeight for Wallet {
             let tx_status: TransactionStatus = resp
                 .json()
                 .await
-                .map_err(|err| backoff::Error::Permanent(Error::JsonDeserialisation(err)))?;
+                .map_err(|err| backoff::Error::Permanent(Error::JsonDeserialization(err)))?;
 
             let block_height = tx_status
                 .block_height
@@ -234,7 +250,7 @@ impl TransactionBlockHeight for Wallet {
             Result::<_, backoff::Error<Error>>::Ok(block_height)
         })
         .await
-        .map_err(|err| anyhow!("transient errors to be retried: {:?}", err))?;
+        .context("transient errors to be retried")?;
 
         Ok(BlockHeight::new(height))
     }

swap/src/protocol/alice/event_loop.rs

@@ -20,8 +20,8 @@ use libp2p::{
 };
 use rand::rngs::OsRng;
 use std::sync::Arc;
-use tokio::sync::{broadcast, mpsc};
+use tokio::sync::{broadcast, mpsc, mpsc::error::SendError};
-use tracing::{debug, error, trace, warn};
+use tracing::{debug, error, trace};
 use uuid::Uuid;
 
 // TODO: Use dynamic
@@ -246,14 +246,16 @@ impl EventLoop {
         .build()
         .await?;
 
-        let (remote, remote_handle) = alice::run(swap).remote_handle();
+        let (swap, swap_handle) = alice::run(swap).remote_handle();
-        tokio::spawn(remote);
+        tokio::spawn(swap);
 
-        let _ = self
+        // For testing purposes the handle is currently sent via a channel so we can
-            .swap_handle_sender
+        // await it. If a remote handle is dropped, the future of the swap is
-            .send(remote_handle)
+        // also stopped. If we error upon sending the handle through the channel
-            .await
+        // we have to call forget to detach the handle from the swap future.
-            .map_err(|err| warn!("Could not send swap handle over channel: {:?}", err));
+        if let Err(SendError(handle)) = self.swap_handle_sender.send(swap_handle).await {
+            handle.forget();
+        }
 
         Ok(())
     }