retoorandClaude Sonnet 5
9dbd1fe667
- Plexer: always-active terminal multiplexing. NativePlexerController/ TmuxPlexerController share one interface, chosen by which env var is already set (TAI_PLEXER_SOCKET vs TMUX_PANE); NativePlexerBackend is the pty.fork()-based wrapper (raw mode, SIGWINCH resize forwarding, a Unix-socket control protocol, continuous session logging, a Ctrl+A prefix key distinct from tmux's own Ctrl+B). Auto-wraps new interactive shells via a .bashrc hook mirroring the existing command-not-found install pattern, gated on $TMUX/$TAI_PLEXER_ACTIVE/ a $HOME/.tai-no-plexer bypass. New plexer_send/read/type/status tools, env-gated on a detected controller. - tests/container.py + docker-compose.yml + tests/docker/Dockerfile: a disposable podman/docker image for the tests that must never touch a real machine (installing the plexer hook into a real ~/.bashrc, a live tmux session). Required suite (test_seal.py, test_tai.py, tests/plexer.py, tests/bashrc.py) gates the result; tests/rag.py runs as best-effort since its real-LLM dependency can't be satisfied inside a disposable container with no nested engine. - tests/bashrc.py: real end-to-end hook install + bash -i auto-wrap, anti-recursion, tmux-active skip, non-interactive skip, a live TmuxPlexerController test, and an install/uninstall round-trip. - tests/plexer.py: NativePlexerBackend under a real pty, plus a dedicated robustness pass (file permissions, >64KB payload framing, a malformed control request, a genuine self-deadlock fix in the write-to-child path). - tai_test.py: the shared async process-driving framework (pipe/pty transport, group-wide kill-and-reap, a StdinBridge for --interactive) both test files build on. - ChatClient last-resort backend: when there's no local opencode CLI but the sandbox box is already running, install opencode into it (official Node tarball, not apt -- apt's nodejs/npm pull in webpack/babel/jest as transitive deps) and route through it instead of giving up. Only reachable after the first retry round already failed everything else; never creates the box itself. TmuxPlexerController.status() fixed to use `list-panes` instead of `display-message -p`, which silently fell back to the default pane instead of erroring against a dead target. - Fix 4 pre-existing test_tai.py bugs surfaced by running it in a clean environment for the first time: two stale mock signatures (subprocess.run's stdout= kwarg, Chat.complete's deadline= kwarg), one $TMUX-dependent catalog assertion, one tty-dependent color assertion. - research/: a sourced research archive (Source Dossier/Citation Card/Conclusion tiers) backing the above design decisions, with its own audit.py consistency checker. - .gitignore: fix a blanket *.md rule that was about to silently drop the entire research/ archive from version control; add __pycache__/ and the one-off debug transcript this session started from. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
51 lines
2.5 KiB
Markdown
51 lines
2.5 KiB
Markdown
# Non blocking file reader for python asyncio · GitHub Gist
|
|
|
|
## Metadata
|
|
|
|
| Field | Value |
|
|
|---|---|
|
|
| Institute | Molodetz Institute — Research & Retrieval Division |
|
|
| Subject | async-pty-process-testing |
|
|
| Document type | Source Dossier |
|
|
| Tier | 1 |
|
|
| Source title | Non blocking file reader for python asyncio |
|
|
| Source URL | https://gist.github.com/nilp0inter/5f400b6afb6df7c0b553 |
|
|
| Source publisher / author | GitHub user nilp0inter |
|
|
| Source type | repository (gist) |
|
|
| Source date (published) | Unknown — not stated |
|
|
| Date researched | 2026-10-09 |
|
|
| Researched by | tai (agent), model: Claude Sonnet 5, on behalf of retoor |
|
|
| Research method | web search synthesis |
|
|
| Confidence | High |
|
|
| Status | Active |
|
|
|
|
## Summary
|
|
|
|
A GitHub gist demonstrating the correct way to read stdin (or any fd) without blocking the asyncio event loop: use `loop.add_reader(fd, callback)` where the callback does a raw `os.read(fd, n)`, never a call through Python's buffered `sys.stdin` object, which blocks regardless of `add_reader`.
|
|
|
|
## Key findings
|
|
|
|
- Calling `sys.stdin.read()` inside an `add_reader` callback still blocks, because Python's buffered stdin object waits for more data internally — `add_reader` only tells the event loop the fd is readable, it does not change how a buffered read call behaves.
|
|
- The correct pattern is `os.read(fileno, n)` on the raw file descriptor inside the callback.
|
|
- On EOF (an empty read), the callback should call `loop.remove_reader(fileno)` to stop watching the fd.
|
|
|
|
## Pros / strengths
|
|
|
|
- Identifies a genuine, easy-to-make mistake (buffered read inside a non-blocking callback) with a precise fix, backed by a reported working example.
|
|
- The pattern is minimal and requires no third-party dependency — pure stdlib (`os`, `asyncio`).
|
|
|
|
## Cons / limitations / caveats
|
|
|
|
- A gist, not an authoritative reference — no discussion of edge cases like partial reads mid-line or how this interacts with terminal raw/cooked mode.
|
|
- Only covers the read side; doesn't address writing back to the child or coordinating with a separate output stream.
|
|
|
|
## Relevance to tai
|
|
|
|
This is the exact pattern `tai_test.py`'s `StdinBridge._on_readable()` implements: `os.read(self._fd, 4096)` inside an `add_reader` callback, buffering until a newline, and calling `self.stop()` (which internally calls `loop.remove_reader`) on an empty read. Using `sys.stdin.read()` instead would have silently reintroduced blocking behavior that defeats the entire point of the non-blocking design.
|
|
|
|
## Changelog
|
|
|
|
| Date | Change |
|
|
|---|---|
|
|
| 2026-10-09 | Initial dossier created. |
|