Files
codex/codex-rs/utils/pty
iceweasel-oai 5d5500650b Fix Windows PTY teardown by preserving ConPTY ownership (#20685)
## Why

On Windows, background terminals could stay visible after their shell
process had already exited. The elevated runner waits for the PTY output
reader to reach EOF before it sends the final exit message, but the
ConPTY helper was reducing ownership down to raw handles too early. That
left the pseudoconsole's borrowed pipe handles alive past teardown, so
EOF never propagated and the session stayed `running`.

## What changed

- change `utils/pty/src/win/conpty.rs` to hand off owned ConPTY
resources instead of leaking only raw handles
- make `windows-sandbox-rs/src/conpty/mod.rs` keep the pseudoconsole
owner and the backing pipe handles together until teardown
- update the elevated runner and the legacy unified-exec backend to keep
that `ConptyInstance` alive, take only the specific pipe handles they
need, and drop the owner at teardown instead of trying to close a
detached pseudoconsole handle later

## Testing

- desktop app in `Auto-review`: 11 x `cmd /c "ping -n 3 google.com"` all
exited cleanly and did not accumulate in the UI
- desktop app in `Auto-review`: 5 x `cmd /c "ping -n 30 google.com"`
appeared in the UI and drained back out on their own
2026-05-04 18:40:00 +00:00
..

codex-utils-pty

Lightweight helpers for spawning interactive processes either under a PTY (pseudo terminal) or regular pipes. The public API is minimal and mirrors both backends so callers can switch based on their needs (e.g., enabling or disabling TTY).

API surface

  • spawn_pty_process(program, args, cwd, env, arg0, size)SpawnedProcess
  • spawn_pipe_process(program, args, cwd, env, arg0)SpawnedProcess
  • spawn_pipe_process_no_stdin(program, args, cwd, env, arg0)SpawnedProcess
  • combine_output_receivers(stdout_rx, stderr_rx)broadcast::Receiver<Vec<u8>>
  • conpty_supported()bool (Windows only; always true elsewhere)
  • TerminalSize { rows, cols } selects PTY dimensions in character cells.
  • ProcessHandle exposes:
    • writer_sender()mpsc::Sender<Vec<u8>> (stdin)
    • resize(TerminalSize)
    • close_stdin()
    • has_exited(), exit_code(), terminate()
  • SpawnedProcess bundles session, stdout_rx, stderr_rx, and exit_rx (oneshot exit code).

Usage examples

use std::collections::HashMap;
use std::path::Path;
use codex_utils_pty::combine_output_receivers;
use codex_utils_pty::spawn_pty_process;
use codex_utils_pty::TerminalSize;

# tokio_test::block_on(async {
let env_map: HashMap<String, String> = std::env::vars().collect();
let spawned = spawn_pty_process(
    "bash",
    &["-lc".into(), "echo hello".into()],
    Path::new("."),
    &env_map,
    &None,
    TerminalSize::default(),
).await?;

let writer = spawned.session.writer_sender();
writer.send(b"exit\n".to_vec()).await?;

// Collect output until the process exits.
let mut output_rx = combine_output_receivers(spawned.stdout_rx, spawned.stderr_rx);
let mut collected = Vec::new();
while let Ok(chunk) = output_rx.try_recv() {
    collected.extend_from_slice(&chunk);
}
let exit_code = spawned.exit_rx.await.unwrap_or(-1);
# let _ = (collected, exit_code);
# anyhow::Ok(())
# });

Swap in spawn_pipe_process for a non-TTY subprocess; the rest of the API stays the same. Use spawn_pipe_process_no_stdin to force stdin closed (commands that read stdin will see EOF immediately).

Tests

Unit tests live in src/lib.rs and cover both backends (PTY Python REPL and pipe-based stdin roundtrip). Run with:

cargo test -p codex-utils-pty -- --nocapture