Per module: prints a one-line summary to stderr when the import
completes or fails:
[warmup 1] google.genai on controller-io_0 (id=18636): 1218.6ms
[warmup 2] anthropic on controller-io_1 (id=5500): 1148.3ms
[warmup 3] openai on controller-io_2 (id=34376): 1144.2ms
...
When the entire warmup completes, prints an aggregate:
[warmup done] 9 modules: 9 completed (sum of per-module elapsed: 3591.7ms)
If ANY canary ran on the main thread (main-thread-purity violation),
the per-module line is tagged with [MAIN-THREAD] AND a final WARNING
is printed:
[warmup WARNING] N module(s) loaded on the MAIN THREAD: google.genai
Default is log_to_stderr=True so production runs get the observability
for free. Tests opt out via WarmupManager(pool, log_to_stderr=False)
in the _build_warmup helper.
5 new tests (4 stderr logging + 1 quiet). All 13 canary tests pass.
Use case: 'did my heavy import run on the GUI thread when it shouldnt
have?' is now answered by grepping stderr for [warmup ...] [MAIN-THREAD]
lines. No hook server required.
Adds a canary record for each module submitted to the warmup, tracking:
canary_id, module, thread_name, thread_id, submit_ts, start_ts,
end_ts, elapsed_ms, status, error.
Surface:
- WarmupManager.canaries() returns list[dict] (defensive copy)
- AppController.warmup_canaries() returns list[dict] (delegation)
- GET /api/warmup_canaries Hook API endpoint
- ApiHookClient.get_warmup_canaries() returns list[dict]
Example: the warmup of google.genai records a 1187ms canary on
thread controller-io_0 with thread_id 50420, canary_id 1.
11 new tests (8 unit in test_warmup_canaries + 3 in test_api_hooks_warmup).
All pass; live_gui smoke test confirms endpoint returns real data.
Phase 2 Tasks T2.1-T2.4 of the startup_speedup_20260606 track.
NEW: src/io_pool.py
make_io_pool() factory: 4-worker ThreadPoolExecutor with
thread_name_prefix='controller-io'. The sanctioned way for any
background work. Replaces ad-hoc threading.Thread() calls per
the 'no new threads' rule.
NEW: src/warmup.py
WarmupManager: manages a list of modules to import on the shared
pool. Public API:
.submit(modules) - start warmup (call once)
.status() - {pending, completed, failed}
.is_done() - bool
.wait(timeout) - block until done
.on_complete(callback) - register completion callback
.reset() - clear state
Thread-safe (lock-guarded). 10 tests cover all paths.
NEW: tests/test_io_pool.py (4 tests):
- ThreadPoolExecutor returned
- 4 workers
- Threads named 'controller-io-*'
- Jobs run in parallel (barrier test)
NEW: tests/test_warmup.py (10 tests):
- One job per module submitted
- Initial pending list correct
- Failed imports tracked
- Done event set after all complete
- wait() blocks until done
- on_complete callback fires (and immediately if already done)
- Modules actually end up in sys.modules
- reset() clears state
- Jobs run concurrently (not serially)
All 14 tests pass. AppController integration is the next commit.
ed