Files
hermes-agent/tui_gateway/synthetic_turn.py

125 lines
6.7 KiB
Python

"""Synthetic GIL-heavy turn driver for the AC-4 isolation certify harness. The regime under test is
interpreter-wide GIL starvation (serving-process turn threads park the WebSocket loop in ``take_gil``),
so the driver must hold the GIL with sustained pure-Python CPU — a network/sleep stub releases the GIL
and a green off it is fake. Test seam: dead unless ``HERMES_ISO_CERTIFY_SYNTH_TURN=1``; when armed,
``server._make_agent`` returns a :class:`SyntheticHeavyAgent` on both the in-process and compute-host
paths, so the isolation boundary is the only variable. Per-turn intensity rides in the prompt text as
a JSON object; any other prompt falls back to env / built-in defaults."""
from __future__ import annotations
import contextlib
import json
import os
import threading
import time
from typing import Any, Callable, Optional
from tui_gateway._env import env_float as _env_float, env_int as _env_int
# Per-turn intensity spec: (key, caster, default source). ``chunk`` = pure-Python ops per interrupt
# check (ms-level interrupt latency, still hot on the GIL); ``delta_interval_s`` = streamed-delta
# cadence (each delta is a loop wakeup marshalling a frame); ``tokens_per_delta`` drives the 100K+-token
# heavy-turn proxy; ``sleep_s`` = optional per-chunk sleep for a mixed regime (0 = pure burn; --dry-run
# shortens duration instead, so it still exercises the real seam).
_SPEC_FIELDS = (
("duration_s", float, lambda: _env_float("HERMES_ISO_CERTIFY_DURATION_S", 8.0)),
("chunk", int, lambda: _env_int("HERMES_ISO_CERTIFY_CHUNK", 20_000)),
("delta_interval_s", float, lambda: _env_float("HERMES_ISO_CERTIFY_DELTA_S", 0.05)),
("tokens_per_delta", int, lambda: _env_int("HERMES_ISO_CERTIFY_TPD", 512)),
("sleep_s", float, lambda: 0.0),
)
def synth_turn_armed() -> bool:
"""True when the synthetic-turn test seam is armed via env."""
return os.environ.get("HERMES_ISO_CERTIFY_SYNTH_TURN") == "1"
class SyntheticHeavyAgent:
"""An AIAgent-shaped object whose turn is a GIL-holding CPU burn. Presents only the surface
``tui_gateway.server``'s turn path and status helpers read (``run_conversation``/``interrupt``/
``clear_interrupt`` plus the ``model``/``provider``/``session_*`` attributes consumed by
``_get_usage`` and ``_session_info``). Never opens a socket or spawns a subprocess."""
def __init__(self, session_id: str, *, model: str = "synthetic-heavy") -> None:
self.session_id, self.model, self.provider, self.api_mode = session_id, model, "synthetic", "chat_completions"
self.base_url = self.api_key = self.platform = self._cached_system_prompt = ""
self.tools: list[Any] = []
self.reasoning_config = self.service_tier = self.context_compressor = None
self._config_context_length = 200_000
# Cumulative session counters (read by _get_usage → status bar).
self.session_input_tokens = self.session_output_tokens = self.session_prompt_tokens = 0
self.session_completion_tokens = self.session_reasoning_tokens = self.session_total_tokens = 0
self.session_api_calls = 0
self.history: list[dict[str, str]] = []
self._interrupt = threading.Event()
# interrupt contract (mirrors AIAgent); close() is a no-op teardown that also stops the burn
def clear_interrupt(self) -> None:
self._interrupt.clear()
def interrupt(self) -> None:
self._interrupt.set()
close = interrupt
def _has_stream_consumers(self) -> bool: # defensive; not used by our loop
return True
@staticmethod
def _parse_spec(message: Any) -> dict[str, Any]:
spec: dict[str, Any] = {}
if isinstance(message, str) and message.strip().startswith("{"):
with contextlib.suppress(ValueError, TypeError):
parsed = json.loads(message.strip())
spec = parsed if isinstance(parsed, dict) else {}
return {key: cast(spec.get(key, default())) for key, cast, default in _SPEC_FIELDS}
def run_conversation(
self, message: Any, *, conversation_history: Optional[list[dict[str, str]]] = None,
stream_callback: Optional[Callable[[str], None]] = None, task_id: Optional[str] = None, **_kwargs: Any,
) -> dict[str, Any]:
spec = self._parse_spec(message)
duration, chunk = max(0.0, spec["duration_s"]), max(1, spec["chunk"])
interval, tokens_per_delta, sleep_s = max(0.001, spec["delta_interval_s"]), max(0, spec["tokens_per_delta"]), max(0.0, spec["sleep_s"])
base_history = list(conversation_history if conversation_history is not None else self.history)
start = last_delta = time.monotonic()
acc = deltas = 0
while not (interrupted := self._interrupt.is_set()) and (now := time.monotonic()) - start < duration:
# A tight integer loop never releases the GIL — the exact contention that starves the serving loop.
for _ in range(chunk):
acc = (acc * 1_000_003 + 12_345) & 0xFFFFFFFFFFFFFFFF
if sleep_s:
time.sleep(sleep_s)
if now - last_delta >= interval:
deltas += 1
self.session_output_tokens += tokens_per_delta
self.session_completion_tokens += tokens_per_delta
self.session_total_tokens += tokens_per_delta
if stream_callback is not None:
stream_callback(f"synthtok-{deltas:05d} ")
last_delta = now
self.session_api_calls += 1
# Fold the checksum into the reply so the loop can't be eliminated and the turn is deterministic.
final = (
f"[synthetic heavy turn] deltas={deltas} out_tokens={self.session_output_tokens} "
f"interrupted={interrupted} checksum={acc & 0xFFFF:04x}"
)
self.history = [*base_history, {"role": "user", "content": str(message)[:200]}, {"role": "assistant", "content": final}]
return {"final_response": final, "messages": self.history, "interrupted": interrupted, "error": None, "last_reasoning": None}
def maybe_build_synthetic_agent(session_id: str, model_override: Any = None) -> SyntheticHeavyAgent | None:
"""Return a :class:`SyntheticHeavyAgent` when the seam is armed, else ``None``. ``model_override``
(dict or str) only influences the reported ``model`` label; it never changes the compute."""
if not synth_turn_armed():
return None
if isinstance(model_override, dict):
model_override = str(model_override["model"]) if model_override.get("model") else ""
return SyntheticHeavyAgent(session_id, model=model_override if isinstance(model_override, str) and model_override else "synthetic-heavy")
__all__ = ["SyntheticHeavyAgent", "maybe_build_synthetic_agent", "synth_turn_armed"]