Use an explicit handle when spawning RPC calls

This resolves a panic like the following, which is caused when a
non-Tokio thread tries to broadcast a transaction, for example
when a transaction is broadcasted indirectly by the background
processor.

```
thread '<unnamed>' panicked at 'there is no reactor running, must be called from the context of a Tokio 1.x runtime', src/bitcoind_client.rs:253:9
```

diff --git a/src/bitcoind_client.rs b/src/bitcoind_client.rs
index 73ee635dec917c2d861994832ccb582e60215f01..0b37ac34823e9c44dc62135141170c9cc375714b 100644 (file)
--- a/src/bitcoind_client.rs
+++ b/src/bitcoind_client.rs
@@ -24,6 +24,7 @@ pub struct BitcoindClient {
        rpc_user: String,
        rpc_password: String,
        fees: Arc<HashMap<Target, AtomicU32>>,
+       handle: tokio::runtime::Handle,
 }
 
 #[derive(Clone, Eq, Hash, PartialEq)]
@@ -66,6 +67,7 @@ const MIN_FEERATE: u32 = 253;
 impl BitcoindClient {
        pub async fn new(
                host: String, port: u16, rpc_user: String, rpc_password: String,
+               handle: tokio::runtime::Handle,
        ) -> std::io::Result<Self> {
                let http_endpoint = HttpEndpoint::for_host(host.clone()).with_port(port);
                let rpc_credentials =
@@ -89,19 +91,21 @@ impl BitcoindClient {
                        rpc_user,
                        rpc_password,
                        fees: Arc::new(fees),
+                       handle: handle.clone(),
                };
                BitcoindClient::poll_for_fee_estimates(
                        client.fees.clone(),
                        client.bitcoind_rpc_client.clone(),
-               )
-               .await;
+                       handle,
+               );
                Ok(client)
        }
 
-       async fn poll_for_fee_estimates(
+       fn poll_for_fee_estimates(
                fees: Arc<HashMap<Target, AtomicU32>>, rpc_client: Arc<Mutex<RpcClient>>,
+               handle: tokio::runtime::Handle,
        ) {
-               tokio::spawn(async move {
+               handle.spawn(async move {
                        loop {
                                let background_estimate = {
                                        let mut rpc = rpc_client.lock().await;
@@ -250,7 +254,7 @@ impl BroadcasterInterface for BitcoindClient {
        fn broadcast_transaction(&self, tx: &Transaction) {
                let bitcoind_rpc_client = self.bitcoind_rpc_client.clone();
                let tx_serialized = serde_json::json!(encode::serialize_hex(tx));
-               tokio::spawn(async move {
+               self.handle.spawn(async move {
                        let mut rpc = bitcoind_rpc_client.lock().await;
                        // This may error due to RL calling `broadcast_transaction` with the same transaction
                        // multiple times, but the error is safe to ignore.

diff --git a/src/main.rs b/src/main.rs
index 955fc4d308e8360c42761501de25fcb9b8e22f3c..6f359756475134d64a693841ad9d1240094850df 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -299,6 +299,7 @@ async fn start_ldk() {
                args.bitcoind_rpc_port,
                args.bitcoind_rpc_username.clone(),
                args.bitcoind_rpc_password.clone(),
+               tokio::runtime::Handle::current(),
        )
        .await
        {