drk/interactive: use a print queue instead of two way signal for background task

Cargo.lock

@@ -2467,6 +2467,7 @@ dependencies = [
  "darkfi_deployooor_contract",
  "darkfi_money_contract",
  "easy-parallel",
+ "futures",
  "lazy_static",
  "libc",
  "linenoise-rs",

bin/drk/Cargo.toml

@@ -20,6 +20,7 @@ darkfi-serial = "0.5.0"
 # Misc
 blake3 = "1.8.2"
 bs58 = "0.5.1"
+futures = "0.3.31"
 lazy_static = "1.5.0"
 libc = "0.2"
 linenoise-rs = "0.1.1"

bin/drk/src/interactive.rs

@@ -16,15 +16,22 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-use std::{io::ErrorKind, mem::zeroed, ptr::null_mut, str::FromStr};
+use std::{io::ErrorKind, str::FromStr};
 
-use libc::{fd_set, select, timeval, FD_SET, FD_ZERO};
+use futures::{select, FutureExt};
+use libc::{fcntl, F_GETFL, F_SETFL, O_NONBLOCK};
 use linenoise_rs::{
     linenoise_history_add, linenoise_history_load, linenoise_history_save,
     linenoise_set_completion_callback, linenoise_set_hints_callback, LinenoiseState,
 };
+use smol::channel::{unbounded, Receiver, Sender};
 
-use darkfi::{cli_desc, system::StoppableTask, util::path::expand_path};
+use darkfi::{
+    cli_desc,
+    system::{msleep, ExecutorPtr, StoppableTask, StoppableTaskPtr},
+    util::path::expand_path,
+    Error,
+};
 
 use crate::{
     cli_util::{generate_completions, kaching},
@@ -100,7 +107,7 @@ fn hints(buf: &str) -> Option<(String, i32, bool)> {
 
 /// Auxiliary function to start provided Drk as an interactive shell.
 /// Only sane/linenoise terminals are suported.
-pub async fn interactive(drk: &Drk, history_path: &str) {
+pub async fn interactive(drk: &Drk, history_path: &str, ex: &ExecutorPtr) {
     // Expand the history file path
     let history_path = match expand_path(history_path) {
         Ok(p) => p,
@@ -127,87 +134,14 @@ pub async fn interactive(drk: &Drk, history_path: &str) {
     let mut subscription_active = false;
     let subscription_task = StoppableTask::new();
 
-    // Create two bounded smol channels, so we can have 2 way
-    // communication between the shell thread and the background task.
-    let (_shell_sender, shell_receiver) = smol::channel::bounded::<()>(1);
-    let (background_sender, _background_receiver) = smol::channel::bounded::<()>(1);
+    // Create an unbounded smol channel, so we can have a printing
+    // queue the background task can submit messages to the shell.
+    let (shell_sender, shell_receiver) = unbounded();
 
     // Start the interactive shell
     loop {
-        // Generate the linoise state structure
-        let mut state = match LinenoiseState::edit_start(-1, -1, "drk> ") {
-            Ok(s) => s,
-            Err(e) => {
-                eprintln!("Error while generating linenoise state: {e}");
-                break
-            }
-        };
-
-        // Read until we get a line to process
-        let mut line = None;
-        loop {
-            let retval = unsafe {
-                // Setup read buffers
-                let mut readfds: fd_set = zeroed();
-                FD_ZERO(&mut readfds);
-                FD_SET(state.get_fd(), &mut readfds);
-
-                // Setup a 1 second timeout to check if background
-                // process wants to print.
-                let mut tv = timeval { tv_sec: 1, tv_usec: 0 };
-
-                // Wait timeout or input
-                select(state.get_fd() + 1, &mut readfds, null_mut(), null_mut(), &mut tv)
-            };
-
-            // Handle error
-            if retval == -1 {
-                eprintln!("Error while reading linenoise buffers");
-                break
-            }
-
-            // Check if background process wants to print anything
-            if shell_receiver.is_full() {
-                // Consume the channel message
-                if let Err(e) = shell_receiver.recv().await {
-                    eprintln!("Error while reading shell receiver channel: {e}");
-                    break
-                }
-
-                // Signal background task it can start printing
-                let _ = state.hide();
-                if let Err(e) = background_sender.send(()).await {
-                    eprintln!("Error while sending to background task channel: {e}");
-                    break
-                }
-
-                // Wait signal that it finished
-                if let Err(e) = shell_receiver.recv().await {
-                    eprintln!("Error while reading shell receiver channel: {e}");
-                    break
-                }
-                let _ = state.show();
-            }
-
-            // Check if we have a line to process
-            if retval <= 0 {
-                continue
-            }
-
-            // Process linenoise feed
-            match state.edit_feed() {
-                Ok(Some(l)) => line = Some(l),
-                Ok(None) => { /* Do nothing */ }
-                Err(e) if e.kind() == ErrorKind::Interrupted => { /* Do nothing */ }
-                Err(e) if e.kind() == ErrorKind::WouldBlock => {
-                    // Need more input, continue
-                    continue;
-                }
-                Err(e) => eprintln!("Error while reading linenoise feed: {e}"),
-            }
-            break
-        }
-        let _ = state.edit_stop();
+        // Wait for next line to process
+        let line = listen_for_line(&shell_receiver).await;
 
         // Grab input or end if Ctrl-D or Ctrl-C was pressed
         let Some(line) = line else { break };
@@ -233,7 +167,14 @@ pub async fn interactive(drk: &Drk, history_path: &str) {
             "ping" => handle_ping(drk).await,
             "completions" => handle_completions(&parts),
             "subscribe" => {
-                handle_subscribe(drk, &mut subscription_active, &subscription_task).await
+                handle_subscribe(
+                    drk,
+                    &mut subscription_active,
+                    &subscription_task,
+                    &shell_sender,
+                    ex,
+                )
+                .await
             }
             "unsubscribe" => handle_unsubscribe(&mut subscription_active, &subscription_task).await,
             "scan" => handle_scan(drk, &subscription_active, &parts).await,
@@ -250,6 +191,97 @@ pub async fn interactive(drk: &Drk, history_path: &str) {
     let _ = linenoise_history_save(history_file);
 }
 
+/// Auxiliary function to listen for linenoise input line and handle
+/// background task messages.
+async fn listen_for_line(shell_receiver: &Receiver<Vec<String>>) -> Option<String> {
+    // Generate the linoise state structure
+    let mut state = match LinenoiseState::edit_start(-1, -1, "drk> ") {
+        Ok(s) => s,
+        Err(e) => {
+            eprintln!("Error while generating linenoise state: {e}");
+            return None
+        }
+    };
+
+    // Set stdin to non-blocking mode
+    let fd = state.get_fd();
+    unsafe {
+        let flags = fcntl(fd, F_GETFL, 0);
+        fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+    }
+
+    // Read until we get a line to process
+    let mut line = None;
+    loop {
+        // Future that polls stdin for input
+        let input_future = async {
+            loop {
+                match state.edit_feed() {
+                    Ok(Some(l)) => {
+                        line = Some(l);
+                        break
+                    }
+                    Ok(None) => break,
+                    Err(e) if e.kind() == ErrorKind::Interrupted => break,
+                    Err(e) if e.kind() == ErrorKind::WouldBlock => {
+                        // No data available, yield and retry
+                        msleep(10).await;
+                        continue
+                    }
+                    Err(e) => {
+                        eprintln!("Error while reading linenoise feed: {e}");
+                        break
+                    }
+                }
+            }
+        };
+
+        // Future that polls the channel
+        let channel_future = async {
+            loop {
+                if !shell_receiver.is_empty() {
+                    break
+                }
+                msleep(1000).await;
+            }
+        };
+
+        // Manage the futures
+        select! {
+            // When input is ready we break out the loop
+            _ = input_future.fuse() => break,
+            // Manage filled channel
+            _ = channel_future.fuse() => {
+                while !shell_receiver.is_empty() {
+                    match shell_receiver.recv().await {
+                        Ok(msg) => {
+                            // Hide prompt, print output, show prompt again
+                            let _ = state.hide();
+                            for line in msg {
+                                println!("{line}\r");
+                            }
+                            let _ = state.show();
+                        }
+                        Err(e) => {
+                            eprintln!("Error while reading shell receiver channel: {e}");
+                            break
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    // Restore blocking mode
+    unsafe {
+        let flags = fcntl(fd, F_GETFL, 0);
+        fcntl(fd, F_SETFL, flags & !O_NONBLOCK);
+    }
+
+    let _ = state.edit_stop();
+    line
+}
+
 /// Auxiliary function to define the ping command handling.
 async fn handle_ping(drk: &Drk) {
     if let Err(e) = drk.ping().await {
@@ -274,7 +306,9 @@ fn handle_completions(parts: &[&str]) {
 async fn handle_subscribe(
     drk: &Drk,
     subscription_active: &mut bool,
-    _subscription_task: &StoppableTask,
+    subscription_task: &StoppableTaskPtr,
+    shell_sender: &Sender<Vec<String>>,
+    ex: &ExecutorPtr,
 ) {
     if *subscription_active {
         println!("Subscription is already active!")
@@ -286,13 +320,41 @@ async fn handle_subscribe(
     }
     println!("Finished scanning blockchain");
 
-    // TODO: subscribe
+    // Start the subcristion task
+    // TODO: use actual subscribe not a dummy task
+    let shell_sender_ = shell_sender.clone();
+    subscription_task.clone().start(
+        async move {
+            loop {
+                msleep(750).await;
+                let line = String::from("This is a single line dummy message");
+                if shell_sender_.send(vec![line]).await.is_err() {
+                    break;
+                }
+                msleep(750).await;
+                let line0 = String::from("This is the first line of a multiline dummy message");
+                let line1 = String::from("This is the second line of a multiline dummy message");
+                if shell_sender_.send(vec![line0, line1]).await.is_err() {
+                    break;
+                }
+            }
+            Ok(())
+        },
+        |res| async {
+            match res {
+                Ok(()) | Err(Error::DetachedTaskStopped) => { /* Do nothing */ }
+                Err(e) => println!("Failed starting dnet subs task: {e}"),
+            }
+        },
+        Error::DetachedTaskStopped,
+        ex.clone(),
+    );
 
     *subscription_active = true;
 }
 
 /// Auxiliary function to define the unsubscribe command handling.
-async fn handle_unsubscribe(subscription_active: &mut bool, subscription_task: &StoppableTask) {
+async fn handle_unsubscribe(subscription_active: &mut bool, subscription_task: &StoppableTaskPtr) {
     if !*subscription_active {
         println!("Subscription is already inactive!")
     }

bin/drk/src/lib.rs

@@ -16,11 +16,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-use std::{fs, sync::Arc};
+use std::fs::create_dir_all;
 
 use url::Url;
 
-use darkfi::{rpc::client::RpcClient, util::path::expand_path, Error, Result};
+use darkfi::{rpc::client::RpcClient, system::ExecutorPtr, util::path::expand_path, Error, Result};
 
 /// Error codes
 pub mod error;
@@ -85,7 +85,7 @@ impl Drk {
         wallet_path: String,
         wallet_pass: String,
         endpoint: Option<Url>,
-        ex: Arc<smol::Executor<'static>>,
+        ex: &ExecutorPtr,
         fun: bool,
     ) -> Result<Self> {
         // Initialize blockchain cache database
@@ -99,7 +99,7 @@ impl Drk {
         let wallet_path = expand_path(&wallet_path)?;
         if !wallet_path.exists() {
             if let Some(parent) = wallet_path.parent() {
-                fs::create_dir_all(parent)?;
+                create_dir_all(parent)?;
             }
         }
         let Ok(wallet) = WalletDb::new(Some(wallet_path), Some(&wallet_pass)) else {
@@ -108,7 +108,7 @@ impl Drk {
 
         // Initialize rpc client
         let rpc_client = if let Some(endpoint) = endpoint {
-            Some(RpcClient::new(endpoint, ex).await?)
+            Some(RpcClient::new(endpoint, ex.clone()).await?)
         } else {
             None
         };

bin/drk/src/main.rs

@@ -20,7 +20,6 @@ use std::{
     io::{stdin, Read},
     process::exit,
     str::FromStr,
-    sync::Arc,
 };
 
 use log::info;
@@ -32,6 +31,7 @@ use url::Url;
 
 use darkfi::{
     async_daemonize, cli_desc,
+    system::ExecutorPtr,
     util::{
         encoding::base64,
         parse::{decode_base10, encode_base10},
@@ -625,7 +625,7 @@ async fn new_wallet(
     wallet_path: String,
     wallet_pass: String,
     endpoint: Option<Url>,
-    ex: Arc<smol::Executor<'static>>,
+    ex: &ExecutorPtr,
     fun: bool,
 ) -> Drk {
     // Script kiddies protection
@@ -644,7 +644,7 @@ async fn new_wallet(
 }
 
 async_daemonize!(realmain);
-async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
+async fn realmain(args: Args, ex: ExecutorPtr) -> Result<()> {
     // Grab blockchain network configuration
     let blockchain_config = match args.network.as_str() {
         "localnet" => parse_blockchain_config(args.config, "localnet").await?,
@@ -663,11 +663,11 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
-            interactive(&drk, &blockchain_config.history_path).await;
+            interactive(&drk, &blockchain_config.history_path, &ex).await;
             drk.stop_rpc_client().await
         }
 
@@ -686,7 +686,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -729,7 +729,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 None,
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -970,7 +970,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 None,
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -1006,7 +1006,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 None,
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -1024,7 +1024,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -1105,7 +1105,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1139,7 +1139,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1168,7 +1168,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1188,7 +1188,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1241,7 +1241,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1307,7 +1307,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1329,7 +1329,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1347,7 +1347,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1365,7 +1365,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1417,7 +1417,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1447,7 +1447,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1529,7 +1529,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1574,7 +1574,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1601,7 +1601,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1809,7 +1809,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1876,7 +1876,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1906,7 +1906,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -1966,7 +1966,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -1996,7 +1996,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -2030,12 +2030,12 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint.clone()),
-                ex.clone(),
+                &ex,
                 args.fun,
             )
             .await;
 
-            if let Err(e) = drk.subscribe_blocks(blockchain_config.endpoint, ex).await {
+            if let Err(e) = drk.subscribe_blocks(blockchain_config.endpoint, &ex).await {
                 eprintln!("Block subscription failed: {e:?}");
                 exit(2);
             }
@@ -2049,7 +2049,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                 blockchain_config.wallet_path,
                 blockchain_config.wallet_pass,
                 Some(blockchain_config.endpoint),
-                ex,
+                &ex,
                 args.fun,
             )
             .await;
@@ -2079,7 +2079,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2121,7 +2121,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2146,7 +2146,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2205,7 +2205,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2224,7 +2224,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2290,7 +2290,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2319,7 +2319,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2348,7 +2348,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2384,7 +2384,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2400,7 +2400,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2418,7 +2418,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2471,7 +2471,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2549,7 +2549,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2582,7 +2582,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2601,7 +2601,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     None,
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2638,7 +2638,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;
@@ -2667,7 +2667,7 @@ async fn realmain(args: Args, ex: Arc<smol::Executor<'static>>) -> Result<()> {
                     blockchain_config.wallet_path,
                     blockchain_config.wallet_pass,
                     Some(blockchain_config.endpoint),
-                    ex,
+                    &ex,
                     args.fun,
                 )
                 .await;

bin/drk/src/rpc.rs

@@ -18,7 +18,6 @@
 
 use std::{
     collections::{BTreeMap, HashMap},
-    sync::Arc,
     time::Instant,
 };
 
@@ -31,7 +30,7 @@ use darkfi::{
         jsonrpc::{ErrorCode, JsonError, JsonRequest, JsonResult},
         util::JsonValue,
     },
-    system::{Publisher, StoppableTask},
+    system::{ExecutorPtr, Publisher, StoppableTask},
     tx::Transaction,
     util::encoding::base64,
     Error, Result,
@@ -136,11 +135,7 @@ impl Drk {
     /// to its previous height and then scan it. We assume that the blocks
     /// up to that point are unchanged, since darkfid will just broadcast
     /// the sequence after the reorg.
-    pub async fn subscribe_blocks(
-        &self,
-        endpoint: Url,
-        ex: Arc<smol::Executor<'static>>,
-    ) -> Result<()> {
+    pub async fn subscribe_blocks(&self, endpoint: Url, ex: &ExecutorPtr) -> Result<()> {
         // Grab last confirmed block height
         let (last_confirmed_height, _) = self.get_last_confirmed_block().await?;
 
@@ -204,7 +199,7 @@ impl Drk {
                 }
             },
             Error::RpcServerStopped,
-            ex,
+            ex.clone(),
         );
         println!("Detached subscription to background");
         println!("All is good. Waiting for block notifications...");