Coverage for src/lilbee/runtime/shard_process.py: 100%

1"""What a fan-out worker process was told about its own slice of the machine. 

2 

3A worker pins its card, its engine slot and its CPU share. These values live 

4here, in plain Python state, and not in ``os.environ``: ``setenv`` reallocates 

5the C ``environ`` array, and a native thread that reads it at that moment 

6(pyarrow, lancedb) can fault. A worker has native threads as soon as its 

7imports finish, so no variable can be written in it safely. 

8 

9The readers take the value from here. An engine child gets the card pin in its 

10own ``env=`` at spawn. 

11""" 

12 

13from __future__ import annotations 

14 

15from dataclasses import dataclass, field 

16from pathlib import Path 

17 

18 

19@dataclass 

20class ShardProcessState: 

21 """The slice values of this process; every field is unset outside a worker.""" 

22 

23 engine_dir: Path | None = None 

24 cpu_quota: int | None = None 

25 visible_devices: dict[str, str] = field(default_factory=dict) 

26 

27 def bind(self, engine_dir: Path, cpu_quota: int, visible_devices: dict[str, str]) -> None: 

28 """Record the slice. Called once, first, by the worker's main thread.""" 

29 self.engine_dir = engine_dir 

30 self.cpu_quota = cpu_quota 

31 self.visible_devices = dict(visible_devices) 

32 

33 

34shard_process = ShardProcessState()