Ludovic Marie
cb19660fbe
Add version-bound core, world data, geometry, generation and feature implementations with native client/server comparison tools and scoped evidence reports. Apply Horizon project branding. Workspace tests, Clippy and 147 Python tests passed. Full 51-family survival and expanded provider comparisons are still running; complete gameplay parity and a playable Rust client remain unfinished. Private game artifacts and the isolated simple-block placement work are excluded.
71 lines
4.5 KiB
Markdown
71 lines
4.5 KiB
Markdown
# Rejected dispatch retry experiment
|
|
|
|
A local game recording showed allocation samples repeatedly entering DH's
|
|
`ThreadPoolExecutor.AbortPolicy`, exception construction and diagnostic strings.
|
|
The direct allocation counters showed substantial allocation on render-loader
|
|
workers. This was a scheduler retry path, rather than evidence of useful terrain
|
|
generation. Inspecting the pinned DH 3.3.4 dispatcher confirmed that rejection
|
|
requeues the same tracked task and immediately tries it again while retaining
|
|
the dispatcher lock. A busy or unavailable physical pool can make that loop
|
|
allocate and prevent other executors from progressing.
|
|
|
|
The optional `dispatch-retry` profile uses balanced graphics, mods, distances,
|
|
worker count and heap guidance. It enables only the new dispatcher hook; adaptive
|
|
budgeting, precise worker pacing and queue waiting stay disabled. Other profiles
|
|
explicitly disable the new hook, so existing isolated comparisons remain useful.
|
|
It requires exact DH 3.3.4. Set `enabled=false` in
|
|
`config/horizon-dispatch-retry.properties` and restart to disable it.
|
|
|
|
After one rejection for an executor in a dispatch pass, the hook ends that
|
|
executor's inner submission loop. Other executors can consume available logical
|
|
slots in the same pass. The original catch still requeues the original task or
|
|
clears it during shutdown. The original lock, priority ordering, occupied-slot
|
|
increments/decrements, exception handling and scheduled-future cancellation
|
|
remain in use. A rejected pass requests a later retry after 1 ms; a pass with
|
|
only paused executors retains DH's original 1000 ms interval. Shutdown prevents
|
|
new retry scheduling. OS timers and lock contention can delay the requested retry.
|
|
|
|
This bounds repeated rejection within each pass. It still constructs an exception
|
|
for a rejected submission, and frequent callers can cause additional passes.
|
|
It is not a complete replacement scheduler or proof of faster terrain completion.
|
|
No simulation rule, server tick rate, render distance or voxel content is changed.
|
|
|
|
## Applied-hook integration test
|
|
|
|
Build with `python tools/build_mod.py`, then run `python tools/test_dispatch.py`.
|
|
On Linux the latter uses Xvfb; `--native-display` uses an existing display.
|
|
The tool builds a private fixture mod under `.local/mod-build`, runs two isolated
|
|
Fabric clients with the dispatcher hook disabled and enabled, and exits before
|
|
opening a world. It uses the local demo launcher and requires no account.
|
|
Official game libraries/assets and publisher mods remain private downloads.
|
|
The fixture never enters a release pack or production JAR.
|
|
|
|
The fixture creates an actual publisher dispatcher with two executors. It replaces
|
|
one executor's physical pool with a one-worker, one-slot pool and deliberately
|
|
fills it with blocking work outside the dispatcher. This reproduces rejection
|
|
while logical slots remain free. Upstream retains the caller in the retry loop
|
|
during a 200 ms observation window and stalls independent queued work. With the
|
|
hook, the caller returns and the other executor progresses before releasing the
|
|
blocked physical worker. Both runs then require each tracked task to run exactly
|
|
once, empty logical queues, zero occupied slots and physical-worker shutdown.
|
|
|
|
The sanitized output reports the submission caller's wall time, CPU time and
|
|
allocated bytes, plus total observed physical-pool rejections. Retry-scheduler
|
|
CPU/allocation is excluded from the caller counters. The observation window and
|
|
earlier patched return produce different caller durations; these measurements
|
|
describe the rejected-submission path, not normal task throughput. Linux CI runs
|
|
the applied hooks; Windows and ARM Mac CI compile the fixture and production mod.
|
|
|
|
In [Linux CI run 37158922187](https://github.com/ludovic111/Horizon/actions/runs/37158922187),
|
|
[the raw fixture result](../benchmarks/dispatch-retry-2026-10-04/linux-applied-hooks.json)
|
|
reported 216,987,192 caller allocation bytes and 63,790 rejections upstream,
|
|
versus 103,384 caller bytes and 6 rejections with the hook. Caller wall times were
|
|
401.549 ms and 0.959 ms respectively. These are single, unwarmed failure-path
|
|
observations, including initialization/JIT effects, rather than normal throughput
|
|
or a fixed-duration whole-process comparison. Both modes completed two tasks.
|
|
|
|
An initial patched Linux game also loaded, recorded 120 seconds and shut down
|
|
normally. Its subsequent JFR capture avoided the earlier allocation storm.
|
|
The captures had different cache histories; they do not establish an FPS or
|
|
whole-game memory improvement, and this is not an M2 graphics benchmark.
|