fix(exec-server): retain output until streams close

codex-rs/exec-server/src/local_process.rs

@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 use std::collections::VecDeque;
+use std::collections::hash_map::Entry;
 use std::sync::Arc;
 use std::time::Duration;
 
@@ -628,16 +629,7 @@ async fn watch_exit(
             .await;
     }
 
-    maybe_emit_closed(process_id.clone(), Arc::clone(&inner)).await;
-
-    tokio::time::sleep(EXITED_PROCESS_RETENTION).await;
-    let mut processes = inner.processes.lock().await;
-    if matches!(
-        processes.get(&process_id),
-        Some(ProcessEntry::Running(process)) if process.exit_code == Some(exit_code)
-    ) {
-        processes.remove(&process_id);
-    }
+    maybe_emit_closed(process_id, Arc::clone(&inner)).await;
 }
 
 async fn finish_output_stream(process_id: ProcessId, inner: Arc<Inner>) {
@@ -656,7 +648,7 @@ async fn finish_output_stream(process_id: ProcessId, inner: Arc<Inner>) {
 }
 
 async fn maybe_emit_closed(process_id: ProcessId, inner: Arc<Inner>) {
-    let notification = {
+    let (notification, output_notify) = {
         let mut processes = inner.processes.lock().await;
         let Some(ProcessEntry::Running(process)) = processes.get_mut(&process_id) else {
             return;
@@ -671,15 +663,30 @@ async fn maybe_emit_closed(process_id: ProcessId, inner: Arc<Inner>) {
         process.next_seq += 1;
         let _ = process.wake_tx.send(seq);
         process.events.publish(ExecProcessEvent::Closed { seq });
-        Some(ExecClosedNotification {
-            process_id: process_id.clone(),
-            seq,
-        })
+        (
+            ExecClosedNotification {
+                process_id: process_id.clone(),
+                seq,
+            },
+            Arc::clone(&process.output_notify),
+        )
     };
 
-    let Some(notification) = notification else {
-        return;
-    };
+    output_notify.notify_waiters();
+    let cleanup_process_id = process_id.clone();
+    let cleanup_inner = Arc::clone(&inner);
+    tokio::spawn(async move {
+        tokio::time::sleep(EXITED_PROCESS_RETENTION).await;
+        let mut processes = cleanup_inner.processes.lock().await;
+        match processes.entry(cleanup_process_id) {
+            Entry::Occupied(entry) => {
+                if matches!(entry.get(), ProcessEntry::Running(process) if process.closed) {
+                    entry.remove();
+                }
+            }
+            Entry::Vacant(_) => {}
+        }
+    });
 
     if let Some(notifications) = notification_sender(&inner) {
         let _ = notifications
@@ -700,6 +707,10 @@ fn notification_sender(inner: &Inner) -> Option<RpcNotificationSender> {
 mod tests {
     use super::*;
     use codex_config::types::ShellEnvironmentPolicyInherit;
+    use codex_utils_pty::ProcessDriver;
+    use pretty_assertions::assert_eq;
+    use tokio::sync::oneshot;
+    use tokio::time::timeout;
 
     fn test_exec_params(env: HashMap<String, String>) -> ExecParams {
         ExecParams {
@@ -748,4 +759,222 @@ mod tests {
 
         assert_eq!(child_env(&params), expected);
     }
+
+    #[tokio::test]
+    async fn exited_process_retains_late_output_past_retention() {
+        let backend = LocalProcess::default();
+        let mut process = spawn_test_process(&backend, "proc-late-output").await;
+
+        process.exit(/*exit_code*/ 0);
+        let exit_response =
+            read_process_until_change(&backend, &process.process_id, /*after_seq*/ None).await;
+        assert_eq!(
+            exit_response,
+            ReadResponse {
+                chunks: Vec::new(),
+                next_seq: 2,
+                exited: true,
+                exit_code: Some(0),
+                closed: false,
+                failure: None,
+            }
+        );
+
+        tokio::time::sleep(EXITED_PROCESS_RETENTION + Duration::from_millis(10)).await;
+        process
+            .stdout_tx
+            .send(b"late output after retention\n".to_vec())
+            .await
+            .expect("send late stdout");
+
+        let late_response =
+            read_process_until_change(&backend, &process.process_id, /*after_seq*/ Some(1)).await;
+        assert_eq!(
+            late_response.chunks,
+            vec![ProcessOutputChunk {
+                seq: 2,
+                stream: ExecOutputStream::Stdout,
+                chunk: b"late output after retention\n".to_vec().into(),
+            }]
+        );
+        assert_eq!(late_response.exit_code, Some(0));
+        assert!(!late_response.closed);
+
+        drop(process.stdout_tx);
+        drop(process.stderr_tx);
+        let _closed_response = timeout(
+            Duration::from_secs(1),
+            read_process_until_closed(&backend, &process.process_id),
+        )
+        .await
+        .expect("process should close");
+        backend.shutdown().await;
+    }
+
+    #[tokio::test]
+    async fn closed_process_is_evicted_after_retention() {
+        let backend = LocalProcess::default();
+        let mut process = spawn_test_process(&backend, "proc-closed-eviction").await;
+        let process_id = process.process_id.clone();
+
+        process.exit(/*exit_code*/ 0);
+        drop(process.stdout_tx);
+        drop(process.stderr_tx);
+
+        let closed_response = timeout(
+            Duration::from_secs(1),
+            read_process_until_closed(&backend, &process_id),
+        )
+        .await
+        .expect("process should close");
+        assert!(closed_response.closed);
+
+        timeout(Duration::from_secs(1), async {
+            loop {
+                {
+                    let processes = backend.inner.processes.lock().await;
+                    if !processes.contains_key(&process_id) {
+                        break;
+                    }
+                }
+                tokio::time::sleep(Duration::from_millis(5)).await;
+            }
+        })
+        .await
+        .expect("closed process should be evicted");
+        backend.shutdown().await;
+    }
+
+    struct TestProcess {
+        process_id: ProcessId,
+        stdout_tx: mpsc::Sender<Vec<u8>>,
+        stderr_tx: mpsc::Sender<Vec<u8>>,
+        exit_tx: Option<oneshot::Sender<i32>>,
+    }
+
+    impl TestProcess {
+        fn exit(&mut self, exit_code: i32) {
+            self.exit_tx
+                .take()
+                .expect("process should not have exited")
+                .send(exit_code)
+                .expect("send process exit");
+        }
+    }
+
+    async fn spawn_test_process(backend: &LocalProcess, process_id: &str) -> TestProcess {
+        let process_id = ProcessId::from(process_id);
+        let (stdout_tx, stdout_rx) = mpsc::channel(16);
+        let (stderr_tx, stderr_rx) = mpsc::channel(16);
+        let (exit_tx, exit_rx) = oneshot::channel();
+        let output_notify = Arc::new(Notify::new());
+        let (wake_tx, _wake_rx) = watch::channel(0);
+        let events = ExecProcessEventLog::new(
+            PROCESS_EVENT_CHANNEL_CAPACITY,
+            RETAINED_OUTPUT_BYTES_PER_PROCESS,
+        );
+
+        let mut processes = backend.inner.processes.lock().await;
+        let previous = processes.insert(
+            process_id.clone(),
+            ProcessEntry::Running(Box::new(RunningProcess {
+                session: dummy_session(),
+                tty: false,
+                pipe_stdin: false,
+                output: VecDeque::new(),
+                retained_bytes: 0,
+                next_seq: 1,
+                exit_code: None,
+                wake_tx: wake_tx.clone(),
+                events: events.clone(),
+                output_notify: Arc::clone(&output_notify),
+                open_streams: 2,
+                closed: false,
+            })),
+        );
+        assert!(previous.is_none());
+        drop(processes);
+
+        tokio::spawn(stream_output(
+            process_id.clone(),
+            ExecOutputStream::Stdout,
+            stdout_rx,
+            Arc::clone(&backend.inner),
+            Arc::clone(&output_notify),
+        ));
+        tokio::spawn(stream_output(
+            process_id.clone(),
+            ExecOutputStream::Stderr,
+            stderr_rx,
+            Arc::clone(&backend.inner),
+            Arc::clone(&output_notify),
+        ));
+        tokio::spawn(watch_exit(
+            process_id.clone(),
+            exit_rx,
+            Arc::clone(&backend.inner),
+            output_notify,
+        ));
+
+        TestProcess {
+            process_id,
+            stdout_tx,
+            stderr_tx,
+            exit_tx: Some(exit_tx),
+        }
+    }
+
+    fn dummy_session() -> ExecCommandSession {
+        let (writer_tx, _writer_rx) = mpsc::channel(1);
+        let (_stdout_tx, stdout_rx) = tokio::sync::broadcast::channel(1);
+        let (_stderr_tx, stderr_rx) = tokio::sync::broadcast::channel(1);
+        let (_exit_tx, exit_rx) = oneshot::channel();
+
+        codex_utils_pty::spawn_from_driver(ProcessDriver {
+            writer_tx,
+            stdout_rx,
+            stderr_rx: Some(stderr_rx),
+            exit_rx,
+            terminator: None,
+            writer_handle: None,
+            resizer: None,
+        })
+        .session
+    }
+
+    async fn read_process_until_change(
+        backend: &LocalProcess,
+        process_id: &ProcessId,
+        after_seq: Option<u64>,
+    ) -> ReadResponse {
+        timeout(
+            Duration::from_secs(1),
+            backend.exec_read(ReadParams {
+                process_id: process_id.clone(),
+                after_seq,
+                max_bytes: None,
+                wait_ms: Some(1_000),
+            }),
+        )
+        .await
+        .expect("process read should finish")
+        .expect("process read")
+    }
+
+    async fn read_process_until_closed(
+        backend: &LocalProcess,
+        process_id: &ProcessId,
+    ) -> ReadResponse {
+        let mut after_seq = None;
+        loop {
+            let response = read_process_until_change(backend, process_id, after_seq).await;
+            if response.closed {
+                return response;
+            }
+            for chunk in &response.chunks {
+                after_seq = Some(chunk.seq);
+            }
+            after_seq = response.next_seq.checked_sub(1).or(after_seq);
+        }
+    }
 }

codex-rs/exec-server/src/server/handler/tests.rs

@@ -170,13 +170,12 @@ async fn long_poll_read_fails_after_session_resume() {
         .expect("initialize");
     first_handler.initialized().expect("initialized");
 
+    // Keep the process quiet and alive so the pending read can only complete
+    // after session resume, not because the process produced output or exited.
     first_handler
         .exec(exec_params_with_argv(
             "proc-long-poll",
-            shell_argv(
-                "sleep 0.1; printf resumed",
-                "ping -n 2 127.0.0.1 >NUL && echo resumed",
-            ),
+            shell_argv("sleep 5", "ping -n 6 127.0.0.1 >NUL"),
         ))
         .await
         .expect("start process");