blomios/IdeA
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix(terminals): stop PTY output duplication on re-attach

Browse Source 
Each open/reattach spawned a pump thread feeding pty_bridge[session]. The
broadcast hub added a subscriber per attach without dropping the previous one,
and the stale pump thread kept delivering (its send_output still succeeded
against the new channel) — so every byte was delivered twice (more after
further re-attaches). Accumulated on each tab/layout/agent switch; window
resize made it glaring.

- Broadcast::subscribe() is now single-consumer: a new subscription supersedes
  the previous one, ending the old pump thread's stream.
- PtyBridge gains a per-session generation; register() returns it and
  unregister_if(session, gen) only removes when still current, so a dying
  superseded thread can't tear down the channel that replaced it.
- All three attach sites (open/reattach/agent launch) use unregister_if.

Tests: 6 added (generation guard + single-consumer broadcast). Workspace green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
Blomios
2026-06-07 11:52:24 +02:00
parent 9b92259429
commit b9fd2fb925
4 changed files with 140 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
crates/app-tauri/src/commands.rs
View File

@ -163,11 +163,11 @@ pub async fn open_terminal(
let session_id = output.session.id;
// (2) Register the xterm output channel for this session.
state.pty_bridge.register(session_id, on_output);
let gen = state.pty_bridge.register(session_id, on_output);
// (3) Subscribe to the PTY's byte stream and pump it to the channel. The
// stream is a blocking iterator, so it runs on a dedicated OS thread; it
// ends when the PTY hits EOF (process exit) or the bridge channel is gone.
// ends when the PTY hits EOF (process exit) or this attach is superseded.
let handle = PtyHandle { session_id };
match state.pty_port.subscribe_output(&handle) {
Ok(stream) => {
@ -178,8 +178,9 @@ pub async fn open_terminal(
break;
}
}
// Stream ended (process exited): drop the channel registration.
bridge.unregister(&session_id);
// Stream ended: drop the channel only if still ours (a re-attach
// may have superseded this generation — don't tear down its channel).
bridge.unregister_if(&session_id, gen);
});
}
Err(e) => {
@ -283,10 +284,12 @@ pub fn reattach_terminal(
.map_err(|e| ErrorDto::from(AppError::from(e)))?;
// (2) Register the new output channel for this session, replacing any stale
// one from a previous attach.
state.pty_bridge.register(sid, on_output);
// one from a previous attach (and bumping the generation).
let gen = state.pty_bridge.register(sid, on_output);
// (3) Subscribe afresh to the live byte stream and pump it to the channel.
// The fresh subscription supersedes the previous attach's, so its pump thread
// ends and stops double-delivering this session's bytes.
match state.pty_port.subscribe_output(&handle) {
Ok(stream) => {
let bridge: std::sync::Arc<PtyBridge> = std::sync::Arc::clone(&state.pty_bridge);
@ -296,7 +299,7 @@ pub fn reattach_terminal(
break;
}
}
bridge.unregister(&sid);
bridge.unregister_if(&sid, gen);
});
}
Err(e) => {
@ -767,11 +770,11 @@ pub async fn launch_agent(
let session_id = output.session.id;
// Register the xterm output channel for this session.
state.pty_bridge.register(session_id, on_output);
let gen = state.pty_bridge.register(session_id, on_output);
// Subscribe to the PTY's byte stream and pump it to the channel.
// The stream is a blocking iterator; it runs on a dedicated OS thread and
// ends when the PTY hits EOF or the bridge channel is gone.
// ends when the PTY hits EOF or this attach is superseded.
let handle = PtyHandle { session_id };
match state.pty_port.subscribe_output(&handle) {
Ok(stream) => {
@ -782,7 +785,7 @@ pub async fn launch_agent(
break;
}
}
bridge.unregister(&session_id);
bridge.unregister_if(&session_id, gen);
});
}
Err(e) => {