fix: don't hang if tracer crashed

kxxt · Aug 6, 2024 · ed36cea · ed36cea
1 parent 9121977
commit ed36cea
Show file tree

Hide file tree

Showing 5 changed files with 81 additions and 35 deletions.
diff --git a/src/event.rs b/src/event.rs
@@ -51,6 +51,7 @@ pub enum Event {
 pub enum TracerMessage {
   Event(TracerEvent),
   StateUpdate(ProcessStateUpdateEvent),
+  FatalError(String),
 }
 
 impl From<TracerEvent> for TracerMessage {

diff --git a/src/main.rs b/src/main.rs
@@ -138,14 +138,22 @@ async fn main() -> color_eyre::Result<()> {
       )?);
       let tracer_thread = tracer.spawn(cmd, Some(output), req_rx);
       loop {
-        if let Some(TracerMessage::Event(TracerEvent {
-          details: TracerEventDetails::TraceeExit { exit_code, .. },
-          ..
-        })) = tracer_rx.recv().await
-        {
-          tracing::debug!("Waiting for tracer thread to exit");
-          tracer_thread.await??;
-          process::exit(exit_code);
+        match tracer_rx.recv().await {
+          Some(TracerMessage::Event(TracerEvent {
+            details: TracerEventDetails::TraceeExit { exit_code, .. },
+            ..
+          })) => {
+            tracing::debug!("Waiting for tracer thread to exit");
+            tracer_thread.await??;
+            process::exit(exit_code);
+          }
+          // channel closed abnormally.
+          None | Some(TracerMessage::FatalError(_)) => {
+            tracing::debug!("Waiting for tracer thread to exit");
+            tracer_thread.await??;
+            process::exit(1);
+          }
+          _ => (),
         }
       }
     }
@@ -282,6 +290,12 @@ async fn main() -> color_eyre::Result<()> {
               })) => {
                 json.events.push(JsonExecEvent::new(id, *exec));
               }
+              // channel closed abnormally.
+              None | Some(TracerMessage::FatalError(_)) => {
+                tracing::debug!("Waiting for tracer thread to exit");
+                tracer_thread.await??;
+                process::exit(1);
+              }
               _ => (),
             }
           }
@@ -307,6 +321,12 @@ async fn main() -> color_eyre::Result<()> {
                 output.write_all(&[b'\n'])?;
                 output.flush()?;
               }
+              // channel closed abnormally.
+              None | Some(TracerMessage::FatalError(_)) => {
+                tracing::debug!("Waiting for tracer thread to exit");
+                tracer_thread.await??;
+                process::exit(1);
+              }
               _ => (),
             }
           }

diff --git a/src/tracer.rs b/src/tracer.rs
@@ -227,10 +227,15 @@ impl Tracer {
           let current_thread = pthread_self();
           pthread_setname_np(current_thread, "tracer\0\0\0\0\0\0\0\0\0\0".as_ptr().cast());
         }
-        tokio::runtime::Handle::current().block_on(async move {
+        let tx = self.msg_tx.clone();
+        let result = tokio::runtime::Handle::current().block_on(async move {
           self.printer.init_thread_local(output);
           self.run(args, req_rx).await
-        })
+        });
+        if let Err(e) = &result {
+          tx.send(TracerMessage::FatalError(e.to_string())).unwrap();
+        }
+        result
       }
     })
   }

diff --git a/src/tui.rs b/src/tui.rs
@@ -36,7 +36,7 @@ use tokio::{
 use tokio_util::sync::CancellationToken;
 use tracing::{error, trace};
 
-use crate::event::{Event, TracerMessage};
+use crate::event::{Event, TracerEvent, TracerEventDetails, TracerEventMessage, TracerMessage};
 
 pub mod app;
 mod breakpoint_manager;
@@ -112,33 +112,42 @@ impl Tui {
         let crossterm_event = reader.next().fuse();
         let tracer_event = tracer_rx.recv();
         tokio::select! {
-            _ = _cancellation_token.cancelled() => {
-                break;
-            }
-            Some(tracer_event) = tracer_event => {
-              trace!("TUI event: tracer message!");
+          _ = _cancellation_token.cancelled() => {
+              break;
+          }
+          tracer_event = tracer_event => {
+            trace!("TUI event: tracer message!");
+            if let Some(tracer_event) = tracer_event {
               _event_tx.send(Event::Tracer(tracer_event)).unwrap();
+            } else {
+              // channel closed abnormally
+              _event_tx.send(Event::Tracer(TracerMessage::Event(TracerEvent {
+                details: TracerEventDetails::Error(TracerEventMessage {
+                  pid: None,
+                  msg: "The connection between TUI and tracer shutdown abnormally. Tracer is probably died.".to_string()
+                }), id: u64::MAX }))).unwrap();
             }
-            Some(event) = crossterm_event => {
-              #[cfg(debug_assertions)]
-              trace!("TUI event: crossterm event {event:?}!");
-              match event {
-                Ok(evt) => {
-                  match evt {
-                    CrosstermEvent::Key(key) => {
-                        if key.kind == KeyEventKind::Press {
-                            _event_tx.send(Event::Key(key)).unwrap();
-                        }
-                    },
-                    CrosstermEvent::Resize(cols, rows) => {
-                        _event_tx.send(Event::Resize(Size {
-                            width: cols,
-                            height: rows,
-                        })).unwrap();
-                    },
-                    _ => {},
-                  }
+          }
+          Some(event) = crossterm_event => {
+            #[cfg(debug_assertions)]
+            trace!("TUI event: crossterm event {event:?}!");
+            match event {
+              Ok(evt) => {
+                match evt {
+                  CrosstermEvent::Key(key) => {
+                      if key.kind == KeyEventKind::Press {
+                          _event_tx.send(Event::Key(key)).unwrap();
+                      }
+                  },
+                  CrosstermEvent::Resize(cols, rows) => {
+                      _event_tx.send(Event::Resize(Size {
+                          width: cols,
+                          height: rows,
+                      })).unwrap();
+                  },
+                  _ => {},
                 }
+              }
               Err(_) => {
                 _event_tx.send(Event::Error).unwrap();
               }

diff --git a/src/tui/app.rs b/src/tui/app.rs
@@ -503,6 +503,17 @@ impl App {
                   self.event_list.update(update);
                 }
               }
+              TracerMessage::FatalError(e) => {
+                action_tx.send(Action::SetActivePopup(ActivePopup::InfoPopup(
+                  InfoPopupState::error(
+                    "FATAL ERROR in tracer thread".to_string(),
+                    vec![
+                      Line::raw("The tracer thread has died abnormally! error: "),
+                      e.into(),
+                    ],
+                  ),
+                )))?;
+              }
             }
             // action_tx.send(Action::Render)?;
           }