Krzysztof kuhy Rudnicki
a9b65812d7
On 2026-07-25 the PC appeared frozen and needed an SSH rescue. Three defects
stacked:
1. DP-0 came up `connected` with a valid EDID and no mode/CRTC -- physically
dark, while X still reserved its 3840px slice of the root window.
2. diet-guard-gate and workout-locker each mapped an override-redirect window
spanning the WHOLE root (6400x1440+0+0), centring their controls on the
primary output -- the dark one. The escape UI was invisible.
3. They deadlocked on the X grab, and the loser logged "another app -- e.g. a
fullscreen game -- holds it". No game was running; the holder was the other
locker. That guess sent the diagnosis the wrong way for the whole outage.
The library had no concept of an individual output: setup() sized the window
from winfo_screenwidth(), the union bounding box of every output.
What changes:
* _outputs.py An output is LIVE only if connected AND has a mode/CRTC.
RandR (crtc==0 or mode==0) and an xrandr --query parser derive
that predicate independently; verified to agree exactly on the
real DP-0/HDMI-0 layout. Fails closed three distinct ways.
* _surfaces.py One window per live output at its own geometry, and the only
module allowed to create/move/destroy windows. Explicit
geometry replaces attributes(fullscreen=True), which an
override-redirect window is invisible to anyway.
* _detect.py RandR events + Tk <Configure> + xrandr polling, coalesced. The
RandR thread runs on a private X connection and may only call
queue.put -- Tk is not thread-safe.
* _recovery.py Re-asserts coverage, placement, grab and VT on a timer. Proven
monotonic: it may only ADD coverage or RE-ACQUIRE the grab. An
ast test asserts the file contains none of grab_release /
restore_vt_switching / close / destroy / quit / withdraw, while
disable_vt_switching and grab_set_global ARE present. Yanking
every cable therefore does not unlock anything.
* _arbiter.py N-app priority: wake_alarm > screen_locker > diet_guard.
Liveness is proved by flock-on-death -- no heartbeat, no PID
scan, no clock. A two-axis strength check stops rank ever
weakening the lock: an app stands down only for an incumbent
at least as strong on BOTH grab kind and VT disabling.
* _guards.py wait_for_x_server replaces wait_for_display and gates ONLY on
an X server existing. Output count must never gate arming:
zero live outputs means lock without showing, not decline to
lock. That inversion is what left the machine unlocked.
* _window.py Arms first, renders second. Names the real grab holder instead
of blaming a fullscreen game. Releases the arbiter on close so
the alarm -> workout handoff cannot strand the next app.
Two bugs found by running it, not reading it:
* acquire_holder() opened the holder file "w", which truncates at open() --
before the lock attempt. A losing contender erased the incumbent's claim, so
the app that most needed to know who held the screen found an empty file.
* tk.Toplevel over a MagicMock sends real tkinter into infinite mock recursion;
the suite hung instead of failing, and an unpatched setup() would have run
setxkbmap against the developer's own machine. conftest now has an autouse
hermetic fixture; the suite went from >120s to 0.7s.
235 tests, 100% branch coverage, ruff (select=ALL) and mypy --strict clean.
No suppressions added: Protocols replace Any for python-xlib, public attribute
access replaces ._data, and type-only Protocols live under TYPE_CHECKING.
Consumers still pin gatelock-v0.1.1 and are unmigrated; nothing ships until a
tag and a reinstall into system python.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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|---|---|---|
| .github/workflows | ||
| crdt_sync_dart | ||
| crdt-sync | ||
| gatelock | ||
| guard-lib | ||
| unified-design-system | ||
| LICENSE | ||
| README.md | ||
utils
Shared libraries used across kuhyx's other projects. Each subdirectory is a
formerly-standalone repo, folded in here with full commit history preserved
(see each subdirectory's own git log for its pre-merge history).
crdt_sync_dart/
Dart/Flutter CRDT sync library (pub package name: crdt_sync, not published
to pub.dev — consumed via a git dependency). Mirrors crdt-sync (below)
module-for-module and test-for-test. Consumed by diet_guard's app,
screen-locker's workout_app, wake_alarm's phone_app, and todo (whose
notes are stored in the v0.2.0 LogStore).
Consume via:
dependencies:
crdt_sync:
git:
url: https://github.com/kuhyx/utils
ref: crdt_sync_dart-v0.2.0
path: crdt_sync_dart
crdt-sync/
Python CRDT sync library (package: crdt_sync, not published to PyPI). Same
design as crdt_sync_dart (HLC clocks, per-field LWW, sticky-delete
tombstones). Consumed by diet-guard and screen-locker.
Consume via:
crdt-sync @ git+https://github.com/kuhyx/utils@crdt-sync-v0.2.0#subdirectory=crdt-sync
guard-lib/
Bash tamper-resistance primitives (guardctl: chattr + bind-mount + systemd
watcher + pacman hooks). Not a package — installed by running
guard-lib/install.sh as root, which copies files onto the system
(/usr/local/bin, /usr/local/lib/guard-lib, systemd units, pacman hooks).
Consumed by steam-backlog-enforcer (expects a guard-lib/install.sh
sibling clone) and referenced by screen-locker.
gatelock/
Python lock-window + HMAC log-integrity backend (package: gatelock, not
published to PyPI). Consumed via pip by screen-locker, diet-guard, and
wake-alarm:
gatelock @ git+https://github.com/kuhyx/utils@gatelock-v0.1.0#subdirectory=gatelock
unified-design-system/
Not a package — the frozen design tokens (colors, spacing, type, radius,
shadow policy) and per-stack (Flutter/web/Tkinter) implementation patterns
that keep every one of kuhy's repos visually identical, plus annotated
component references (components.html, button.html). Read
unified-design-system/README.md and
tokens.md before touching any theme/CSS/style file in any repo. The
unified-design-system Claude Code skill is a thin pointer here, not a
duplicate.