Removed a couple deadlocks

crates/librqbit/src/torrent_state.rs

@@ -543,6 +543,8 @@ impl TorrentState {
             }
             PeerState::Queued | PeerState::Dead | PeerState::NotNeeded => {
                 warn!("bug: peer was in a wrong state, ignoring it forever");
+                // Prevent deadlocks.
+                drop(pe);
                 self.peers.drop_peer(handle);
                 return;
             }
@@ -563,6 +565,9 @@ impl TorrentState {
         pe.value_mut().state = PeerState::Dead;
         let backoff = pe.value_mut().stats.backoff.next_backoff();
 
+        // Prevent deadlocks.
+        drop(pe);
+
         if let Some(dur) = backoff {
             let state = self.clone();
             spawn(

crates/rqbit/Cargo.toml

@@ -30,6 +30,7 @@ tracing-subscriber = {version = "0.3", features = ["env-filter"]}
 regex = "1"
 futures = "0.3"
 parse_duration = "2"
+parking_lot = {version = "0.12", features = ["deadlock_detection"]}
 reqwest = "0.11"
 serde = {version = "1", features=["derive"]}
 serde_json = "1"

crates/rqbit/src/main.rs

@@ -160,10 +160,35 @@ fn init_logging(opts: &Opts) {
         .init();
 }
 
+fn _start_deadlock_detector_thread() {
+    use parking_lot::deadlock;
+    use std::thread;
+
+    // Create a background thread which checks for deadlocks every 10s
+    thread::spawn(move || loop {
+        thread::sleep(Duration::from_secs(10));
+        let deadlocks = deadlock::check_deadlock();
+        if deadlocks.is_empty() {
+            continue;
+        }
+
+        println!("{} deadlocks detected", deadlocks.len());
+        for (i, threads) in deadlocks.iter().enumerate() {
+            println!("Deadlock #{}", i);
+            for t in threads {
+                println!("Thread Id {:#?}", t.thread_id());
+                println!("{:#?}", t.backtrace());
+            }
+        }
+        std::process::exit(42);
+    });
+}
+
 fn main() -> anyhow::Result<()> {
     let opts = Opts::parse();
 
     init_logging(&opts);
+    // start_deadlock_detector_thread();
 
     let (mut rt_builder, spawner) = match opts.single_thread_runtime {
         true => (