Fix torad hanging on add of torrent

crates/torad/src/torrents.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 use std::path::PathBuf;
 use std::sync::Arc;
 use std::time::Duration;
@@ -22,6 +22,7 @@ use crate::db::{self, TorrentRow, TorrentState};
 use crate::source::SourceResolver;
 
 const POLL_INTERVAL: Duration = Duration::from_secs(2);
+const ADD_TIMEOUT: Duration = Duration::from_secs(60);
 const BYTES_PER_MIB: f64 = 1_048_576.0;
 
 pub enum ResolveError {
@@ -36,6 +37,7 @@ pub struct TorrentManager {
     default_output_dir: PathBuf,
     source: SourceResolver,
     tracked: Mutex<HashMap<Uuid, Arc<ManagedTorrent>>>,
+    adding: Mutex<HashSet<Uuid>>,
 }
 
 impl TorrentManager {
@@ -56,6 +58,7 @@ impl TorrentManager {
             default_output_dir: download_dir,
             source,
             tracked: Mutex::new(HashMap::new()),
+            adding: Mutex::new(HashSet::new()),
         }))
     }
 
@@ -170,13 +173,13 @@ impl TorrentManager {
             let mut interval = tokio::time::interval(POLL_INTERVAL);
             loop {
                 interval.tick().await;
-                self.pick_up_pending().await;
+                Arc::clone(&self).pick_up_pending().await;
                 self.report_progress().await;
             }
         });
     }
 
-    async fn pick_up_pending(&self) {
+    async fn pick_up_pending(self: Arc<Self>) {
         let pending = match db::list_pending(&self.pool).await {
             Ok(rows) => rows,
             Err(err) => {
@@ -188,46 +191,74 @@ impl TorrentManager {
             return;
         }
 
-        let mut tracked = self.tracked.lock().await;
-        for row in pending {
-            if tracked.contains_key(&row.id) {
-                continue;
+        // Mark in-flight adds under brief locks so the poller doesn't re-spawn
+        // the same torrent on the next tick. The actual `add_torrent` call runs
+        // in a detached task WITHOUT holding either lock; otherwise a slow add
+        // (e.g. a magnet with no peers) would block every RPC that touches
+        // `tracked` indefinitely.
+        let to_start: Vec<TorrentRow> = {
+            let tracked = self.tracked.lock().await;
+            let mut adding = self.adding.lock().await;
+            let selected = pending
+                .into_iter()
+                .filter(|row| !tracked.contains_key(&row.id) && !adding.contains(&row.id))
+                .collect::<Vec<_>>();
+            for row in &selected {
+                adding.insert(row.id);
             }
-            let options = AddTorrentOptions {
-                output_folder: Some(row.output_path.clone()),
-                overwrite: true,
-                ..Default::default()
-            };
-            let add = match AddTorrent::from_cli_argument(&row.source) {
-                Ok(add) => add,
-                Err(err) => {
-                    error!(id = %row.id, source = %row.source, error = %err, "failed to parse torrent source");
-                    continue;
-                }
-            };
-            match self.session.add_torrent(add, Some(options)).await {
-                Ok(response) => match response.into_handle() {
-                    Some(handle) => {
-                        info!(id = %row.id, info_hash = %row.info_hash, "torrent added to session");
-                        tracked.insert(row.id, handle);
+            selected
+        };
+
+        for row in to_start {
+            let manager = Arc::clone(&self);
+            tokio::spawn(async move {
+                let options = AddTorrentOptions {
+                    output_folder: Some(row.output_path.clone()),
+                    overwrite: true,
+                    ..Default::default()
+                };
+                let add = match AddTorrent::from_cli_argument(&row.source) {
+                    Ok(add) => add,
+                    Err(err) => {
+                        error!(id = %row.id, source = %row.source, error = %err, "failed to parse torrent source");
+                        let message = err.to_string();
+                        persist_error(&manager.pool, row.id, &message).await;
+                        manager.adding.lock().await.remove(&row.id);
+                        return;
                     }
-                    None => warn!(id = %row.id, "add_torrent returned no handle"),
-                },
-                Err(err) => {
-                    error!(id = %row.id, error = %err, "failed to add torrent to session");
-                    let message = err.to_string();
-                    let progress = db::Progress {
-                        name: None,
-                        total_bytes: 0,
-                        downloaded_bytes: 0,
-                        state: TorrentState::Error,
-                        error_message: Some(message.as_str()),
-                    };
-                    if let Err(err) = db::update_progress(&self.pool, row.id, progress).await {
-                        error!(error = %err, "failed to persist torrent add error");
+                };
+
+                let add_result = tokio::time::timeout(
+                    ADD_TIMEOUT,
+                    manager.session.add_torrent(add, Some(options)),
+                )
+                .await;
+                match add_result {
+                    Ok(Ok(response)) => match response.into_handle() {
+                        Some(handle) => {
+                            info!(id = %row.id, info_hash = %row.info_hash, "torrent added to session");
+                            let mut tracked = manager.tracked.lock().await;
+                            tracked.insert(row.id, handle);
+                        }
+                        None => warn!(id = %row.id, "add_torrent returned no handle"),
+                    },
+                    Ok(Err(err)) => {
+                        error!(id = %row.id, error = %err, "failed to add torrent to session");
+                        let message = err.to_string();
+                        persist_error(&manager.pool, row.id, &message).await;
+                    }
+                    Err(_) => {
+                        warn!(id = %row.id, timeout = ?ADD_TIMEOUT, "timed out adding torrent to session");
+                        persist_error(
+                            &manager.pool,
+                            row.id,
+                            "metadata fetch timed out (no peers or unreachable trackers)",
+                        )
+                        .await;
                     }
                 }
-            }
+                manager.adding.lock().await.remove(&row.id);
+            });
         }
     }
 
@@ -270,6 +301,19 @@ struct LiveTorrentStats {
     seeds: u32,
 }
 
+async fn persist_error(pool: &PgPool, id: Uuid, message: &str) {
+    let progress = db::Progress {
+        name: None,
+        total_bytes: 0,
+        downloaded_bytes: 0,
+        state: TorrentState::Error,
+        error_message: Some(message),
+    };
+    if let Err(err) = db::update_progress(pool, id, progress).await {
+        error!(id = %id, error = %err, "failed to persist torrent add error");
+    }
+}
+
 fn extract_live_stats(tracked: &HashMap<Uuid, Arc<ManagedTorrent>>, id: &Uuid) -> LiveTorrentStats {
     let Some(handle) = tracked.get(id) else {
         return LiveTorrentStats::default();