unsloth/studio/backend/utils
Daniel Han 8e0d082c92
Reap Studio child processes when the parent dies abnormally (#6425)
* Reap Studio child processes when the parent dies abnormally

Standalone `unsloth studio` launches orphaned cloudflared and llama-server when
the parent exited without running the cooperative shutdown path (terminal-window
close, Task Manager End Task, SIGKILL): the children reparented to init and kept
running, leaving an authenticated Cloudflare tunnel up for days.

Add utils/process_lifetime.py: a parent-owned Windows Job Object
(JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE, children auto-inherit) plus Linux
PR_SET_PDEATHSIG, behind a best-effort helper that mirrors the desktop app's
windows_job.rs. initialize_parent_lifetime() runs at the top of run_server;
long-lived spawns (cloudflared, llama-server, RAG embedder, llama.cpp updater)
get the PDEATHSIG preexec, multiprocessing workers are adopted into the job, and
_graceful_shutdown plus atexit gain a terminate_all() backstop sweep. The
cooperative shutdown path is otherwise unchanged.

Verified on Linux: killing the parent now reaps cloudflared and llama-server
within ~2s instead of orphaning them.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* test: add real Windows kill-on-job-close integration test

Spawn a parent that installs the job and a child that inherits it, terminate
the parent, and assert the child is reaped. Skipped off Windows. Also make the
liveness probe Windows-safe (os.kill(pid, 0) terminates on Windows).

* Fix Win64 handle truncation in the Job Object calls

Set explicit argtypes so the 64-bit job/process handles are not marshaled as
c_int (which truncated them on Win64, failing AssignProcessToJobObject). Assert
install success in the Windows integration test.

* Bind multiprocessing workers to parent death; harden the sweep

Review follow-ups:
- Multiprocessing workers (inference/export/training/data-recipe/Xet) cannot be
  given a preexec_fn by the parent, so adopt_pid alone left them orphanable on a
  Linux SIGKILL. They now bind themselves with PR_SET_PDEATHSIG at startup via
  bind_current_process_to_parent_lifetime(), wired into the shared
  run_without_native_path_secret entrypoint and the Xet child entry.
- Wire the previously-missed data-recipe worker through adopt_pid.
- terminate_all now honors its timeout: SIGTERM, wait, then SIGKILL the
  survivors, so cooperative children can exit cleanly.
- Track adopted pids with a /proc starttime identity and add forget_pid, so the
  shutdown sweep never signals a recycled pid.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Michael Han <michaelhan2050@gmail.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
2026-06-18 05:51:22 -07:00
..
datasets Studio: training survives a non-writable HF datasets cache (#6148) 2026-06-10 08:22:47 -07:00
hardware Studio: scale export GGUF size estimates from the real model size (#6418) 2026-06-18 05:44:17 -07:00
inference Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00
models Harden model fetching (#6391) 2026-06-18 05:39:52 -07:00
paths Studio: fix training output dir escaping outputs root for models on another drive (#6293) 2026-06-13 04:06:17 -07:00
security Harden model fetching (#6391) 2026-06-18 05:39:52 -07:00
.gitkeep root studio folder 2026-02-02 09:13:49 +00:00
__init__.py Final cleanup 2026-03-12 18:28:04 +00:00
_studio_release_build.py Add Studio web update banner and release version display (#5308) 2026-05-11 18:24:01 +04:00
api_errors.py Studio: improve OpenAI- and Anthropic-compatible API spec compliance (#6010) 2026-06-09 17:13:25 +02:00
cache_cleanup.py Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00
cpu_threads.py Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00
downsample.py Formatting: ruff line-length 100, kwarg-spacing passes, drop blank after short local imports (#6079) 2026-06-08 04:24:13 -07:00
helper_precache_settings.py Studio: make Helper LLM startup pre-cache opt in (#6113) 2026-06-09 15:28:34 +02:00
hf_xet_fallback.py Reap Studio child processes when the parent dies abnormally (#6425) 2026-06-18 05:51:22 -07:00
host_policy.py Studio: enable stdio MCP servers on a loopback bind (#6295) 2026-06-15 03:02:32 +01:00
lifespan_shutdown.py Studio: make lifespan shutdown resilient to a dead default executor (#6307) 2026-06-15 22:51:46 -07:00
llama_cpp_freshness.py Studio: stop the llama.cpp update banner flickering and show the download size (#6338) 2026-06-17 21:28:54 -07:00
llama_cpp_update.py Reap Studio child processes when the parent dies abnormally (#6425) 2026-06-18 05:51:22 -07:00
native_path_leases.py Reap Studio child processes when the parent dies abnormally (#6425) 2026-06-18 05:51:22 -07:00
process_lifetime.py Reap Studio child processes when the parent dies abnormally (#6425) 2026-06-18 05:51:22 -07:00
studio_version.py Studio: llama.cpp update banner redesign, About tab license info, UI polish (#6196) 2026-06-11 09:27:34 -07:00
subprocess_compat.py Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00
transformers_version.py Harden model fetching (#6391) 2026-06-18 05:39:52 -07:00
update_status.py Studio: make code comments and docstrings more succinct (#6029) 2026-06-08 23:07:28 -07:00
upload_limits.py Formatting: ruff line-length 100, kwarg-spacing passes, drop blank after short local imports (#6079) 2026-06-08 04:24:13 -07:00
utils.py Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00
wheel_utils.py Reduce and tighten code comments and docstrings repo-wide (#6095) 2026-06-08 23:09:51 -07:00