emrg: offload remaining sync git probes from event loop (rant 2026-08-19T01:05:47)

Agent.md

@@ -118,7 +118,7 @@ Community needs voiced in HN agent-UI discussions map directly to EMRG's design:
 pkill -f "emrg.server"; rm -f ~/.emrg/emrgd.port; python -m emrg
 ```
 
-Python: `uv run pytest tests/ -v` (961) — import check: `uv run python -c "from emrg.client.app import run_client"`
+Python: `uv run pytest tests/ -v` (963) — import check: `uv run python -c "from emrg.client.app import run_client"`
 GUI: `cd emrg/gui && npm test` (260: 45 daemon_client + 19 conn-manager + 22 app-commands + 131 renderer smoke + 16 i18n + 7 integration + 3 commands + 8 build-config + 7 gui-state + 2 tool-group) — syntax: `node --check main.js preload.js daemon_client.js renderer/js/*.js`
 CI: `uv run pytest` (ubuntu + **windows-2025 matrix** — Windows pytest 回归在 PR CI 即失败，v0.2.29 教训 #725) + GUI tests + **actionlint workflow lint** (`rhysd/actionlint@v1.7.12` gate, #444 — workflow 解析错误在 PR CI 即失败，如 `if:` secrets 上下文)
 Re-trigger: `scripts/re-trigger-ci.sh [branch]` (workflow_dispatch, #527 — 替代空 commit 重触发：Actions outage 会整段丢弃 push 事件，dispatch 走 API 路径不受影响)

emrg/server/daemon.py

@@ -3000,12 +3000,20 @@ async def _latest_session_at(entry: dict) -> str:
 
  ats = await asyncio.gather(*(_latest_session_at(e) for e in entries))
  ordered = sorted(zip(entries, ats), key=lambda t: t[1], reverse=True)
+ # rant 2026-08-19T01:05:47 — _detect_git_remote runs a sync
+ # git subprocess per project; offload to worker threads so a
+ # slow git probe never freezes the event loop (websocket
+ # clients would otherwise time out during list_projects).
+ repos = await asyncio.gather(*(
+ asyncio.to_thread(_detect_git_remote, p.get("path", ""))
+ for p, _ in ordered
+ ))
  projects = [
  {"name": p.get("name", ""),
- "repo": _detect_git_remote(p.get("path", "")),
+ "repo": repo,
  "path": p.get("path", ""),
  "latest_session_at": at}
- for p, atin ordered
+ for (p, at), repo in zip(ordered, repos)
  ]
  except (yaml.YAMLError, OSError):
  logger.exception("Failed to read projects.yml")

emrg/server/scheduler.py

@@ -1270,16 +1270,40 @@ def _tasks_file(self) -> Path:
  def _tasks_file(self, value: Path | None) -> None:
  self.__tasks_file = value
 
- def _start_handler_for(self, cfg: dict) -> TaskHandler:
- """Create + start a handler for a task cfg; returns the handler."""
+ def _build_handler(self, cfg: dict) -> TaskHandler:
+ """Construct a TaskHandler for a task cfg (pure sync construction).
+
+ May block briefly (git remote detection in ``TaskHandler.__init__``
+ + template lookup) — callers in the event loop must offload via
+ ``asyncio.to_thread`` (rant 2026-08-19T01:05:47: no blocking calls
+ in the loop).
+ """
  template_path = _resolve_task_template(cfg["type"])
-handler = TaskHandler(
+return TaskHandler(
  name=cfg["name"],
  config=cfg.get("config", {}),
  interval=cfg.get("interval", DEFAULT_INTERVAL),
  identity=self.identity,
  template_path=template_path,
  )
+
+ def _start_handler_for(self, cfg: dict) -> TaskHandler:
+ """Create + start a handler for a task cfg; returns the handler.
+
+ Boot path (no websocket clients connected yet) — sync construction
+ is acceptable here.
+ """
+ handler = self._build_handler(cfg)
+ self._handlers.append(handler)
+ self._handler_cfgs[handler.name] = cfg
+ self._coros.append(asyncio.create_task(handler.run()))
+ return handler
+
+ async def _start_handler_async(self, cfg: dict) -> TaskHandler:
+ """Hot-reload path (apply_tasks, on the event loop while serving):
+ offload the sync handler construction to a worker thread so a slow
+ git probe never freezes the loop (rant 2026-08-19T01:05:47)."""
+ handler = await asyncio.to_thread(self._build_handler, cfg)
  self._handlers.append(handler)
  self._handler_cfgs[handler.name] = cfg
  self._coros.append(asyncio.create_task(handler.run()))
@@ -1666,13 +1690,13 @@ async def apply_tasks(self, tasks: list[dict]) -> dict:
  for name, cfg in enabled.items():
  if name not in current:
  added.append(name)
- self._start_handler_for(cfg)
+await self._start_handler_async(cfg)
  else:
  old = self._handler_cfgs.get(name)
  if old is not None and _task_cfg_signature(old) != _task_cfg_signature(cfg):
  updated.append(name)
  self._stop_handler(current[name])
- self._start_handler_for(cfg)
+await self._start_handler_async(cfg)
  return {"added": added, "removed": removed, "updated": updated}
 
  def list_templates(self) -> list[dict]:

tests/test_scheduler.py

@@ -2193,6 +2193,38 @@ async def _run():
  mod.config_dir = orig
 
 
+def test_hot_reload_offloads_handler_construction_to_thread():
+ """rant 2026-08-19T01:05:47 — apply_tasks (hot reload, on the event loop
+ while serving websockets) must not run TaskHandler's sync git probe on
+ the loop. Construction goes through _start_handler_async →
+ asyncio.to_thread(_build_handler); the boot path keeps the sync
+ _start_handler_for (no clients connected yet)."""
+ import inspect
+
+ from emrg.server import scheduler as mod
+
+ sched_src = inspect.getsource(mod.TaskScheduler)
+ # apply_tasks awaits the async start path
+ assert "await self._start_handler_async(cfg)" in sched_src
+ # async start path offloads the sync construction
+ assert "asyncio.to_thread(self._build_handler, cfg)" in sched_src
+ # boot path unchanged (sync, pre-serve)
+ assert "handler = self._build_handler(cfg)" in sched_src
+ assert "def _start_handler_for(self, cfg: dict) -> TaskHandler:" in sched_src
+
+
+def test_daemon_projects_list_offloads_git_probe_to_thread():
+ """rant 2026-08-19T01:05:47 — the daemon's projects_list handler probes
+ each project's git remote with a sync subprocess; it must run in worker
+ threads (asyncio.to_thread) so a slow git probe never freezes the loop."""
+ from pathlib import Path as _Path
+
+ src = _Path(__file__).resolve().parent.parent / "emrg" / "server" / "daemon.py"
+ content = src.read_text(encoding="utf-8")
+ assert "asyncio.to_thread(_detect_git_remote, p.get(\"path\", \"\"))" in content
+ assert "repos = await asyncio.gather(*(" in content
+
+
 def test_template_crud_and_guards(tmp_path):
  """Custom templates: create/list/update/delete; builtin read-only; delete-refused guard."""
  from emrg.server import scheduler as mod