Spaces:
Paused
Paused
File size: 15,217 Bytes
9792ea7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 | # -*- coding: utf-8 -*-
"""The background task manager."""
import asyncio
import json
import time
from collections import OrderedDict
from dataclasses import dataclass, field
from typing import Any, Self, TYPE_CHECKING
import shortuuid
from pydantic import BaseModel, Field
from agentscope.message import TextBlock, ToolResultState
from agentscope.permission import (
PermissionContext,
PermissionDecision,
PermissionBehavior,
)
from agentscope.tool import ToolBase, ToolChunk
from agentscope._logging import logger
from ..message_bus import MessageBusKeys
if TYPE_CHECKING:
from ..message_bus import MessageBus
@dataclass
class BackgroundTask:
"""Metadata for a single background task.
Attributes:
asyncio_task (`asyncio.Task`):
The running asyncio task.
session_id (`str`):
The session id of the originating request.
agent_id (`str`):
The name of the agent that created the task.
user_id (`str`):
The user id of the originating request.
tool_name (`str`):
The name of the tool that was offloaded.
id (`str`):
Auto-generated unique task identifier.
"""
asyncio_task: asyncio.Task
"""The running asyncio task."""
session_id: str
"""The session id of the background task."""
agent_id: str
"""The agent that created the background task."""
user_id: str
"""The user id of the originating request."""
tool_name: str
"""The name of the offloaded tool."""
id: str = field(default_factory=shortuuid.uuid)
"""The background task id."""
class _ToolStopParams(BaseModel):
"""The params of the stop tool."""
task_id: str = Field(
description="The task id of the background tool to stop.",
)
class ToolStop(ToolBase):
"""A tool to stop a running background tool execution."""
name: str = "ToolStop"
"""The tool name."""
description: str = (
"Stop a background tool execution by its task id. "
"Use this when you want to cancel a previously offloaded tool "
"that is still running in the background."
)
"""The tool description."""
input_schema: dict = _ToolStopParams.model_json_schema()
"""The input schema."""
is_concurrency_safe: bool = True
is_read_only: bool = False
is_state_injected: bool = False
is_external_tool: bool = False
is_mcp: bool = False
mcp_name: str | None = None
def __init__(
self,
background_tasks: dict[str, BackgroundTask],
message_bus: "MessageBus",
session_id: str,
) -> None:
"""Initialize the ToolStop tool.
Args:
background_tasks (`dict[str, BackgroundTask]`):
A reference to the local background tasks managed by
the :class:`BackgroundTaskManager`.
message_bus (`MessageBus`):
The application message bus, used to check the global
registry and broadcast cross-worker cancel requests.
session_id (`str`):
The current session id, used to scope Redis registry
lookups.
"""
self.background_tasks = background_tasks
self._message_bus = message_bus
self._session_id = session_id
async def check_permissions(
self,
tool_input: dict[str, Any],
context: PermissionContext,
) -> PermissionDecision:
"""Check permission for the tool usage.
Args:
tool_input (`dict[str, Any]`):
The tool input parameters.
context (`PermissionContext`):
The permission context.
Returns:
`PermissionDecision`:
Always returns ALLOW.
"""
return PermissionDecision(
behavior=PermissionBehavior.ALLOW,
message=f"{self.name} is always allowed to be called.",
)
async def __call__(self, task_id: str) -> ToolChunk:
"""Stop the background task.
Args:
task_id (`str`):
The task id.
Returns:
`ToolChunk`:
The tool chunk.
"""
# Path 1: task is on this worker — cancel directly.
# Only cancel when the task belongs to the same session as this
# ToolStop instance, so a leaked/guessed task_id from another
# session cannot trigger cross-session cancellation on a shared
# worker.
local_task = self.background_tasks.get(task_id)
if (
local_task is not None
and local_task.session_id == self._session_id
):
self.background_tasks.pop(task_id, None)
local_task.asyncio_task.cancel()
logger.info(
"Background task stopped via ToolStop (local): task_id=%s, "
"session_id=%s, agent_id=%s",
task_id,
local_task.session_id,
local_task.agent_id,
)
return ToolChunk(
content=[
TextBlock(text=f"Task {task_id} stopped successfully."),
],
state=ToolResultState.SUCCESS,
)
# Path 2: task exists in the global registry (another worker, or
# a different session on this worker).
if await self._message_bus.registry_exists(
MessageBusKeys.bg_tasks(self._session_id),
task_id,
):
await self._message_bus.publish(
MessageBusKeys.task_cancel_channel(),
{"task_id": task_id},
)
logger.info(
"Background task cancel broadcast via ToolStop (remote): "
"task_id=%s, session_id=%s",
task_id,
self._session_id,
)
return ToolChunk(
content=[
TextBlock(
text=f"Cancel request sent for task {task_id}. "
f"The owning worker will stop it shortly.",
),
],
state=ToolResultState.SUCCESS,
)
# Path 3: task not found anywhere.
return ToolChunk(
content=[
TextBlock(
text=f"TaskNotFoundError: The task {task_id} "
f"does not exist.",
),
],
state=ToolResultState.ERROR,
)
class BackgroundTaskManager:
"""Tracks background asyncio task lifecycle within the agent service.
Responsibilities:
- **Global registry**: register/unregister tasks in Redis so any
process can query which tasks are alive for a session.
- **Local handle cache**: hold ``asyncio.Task`` references for
cancel and shutdown.
- **Task scheduling**: convenience method for creating a task from
a plain coroutine with a done callback that cleans up both sides.
Completion results are delivered via the :class:`MessageBus` inbox
+ wakeup path (same as team messages), so any process's
:class:`WakeupDispatcher` can pick up the result.
"""
def __init__(self, message_bus: "MessageBus") -> None:
"""Initialise the background task manager.
Args:
message_bus (`MessageBus`):
The application message bus; used for the global BG
task registry (Redis Hash) and task-level cancel
broadcasts.
"""
self._message_bus = message_bus
self.tasks: OrderedDict[str, BackgroundTask] = OrderedDict()
# ------------------------------------------------------------------
# Task registration
# ------------------------------------------------------------------
async def register_task(
self,
asyncio_task: asyncio.Task,
session_id: str,
agent_id: str,
user_id: str,
tool_name: str = "",
) -> str:
"""Register an already-running asyncio task.
Writes to both the local handle cache and the global Redis
registry. The task auto-removes from both when it finishes
(via ``add_done_callback``).
Args:
asyncio_task (`asyncio.Task`):
The already-running task to register.
session_id (`str`):
The originating session id.
agent_id (`str`):
The agent record id that owns the task.
user_id (`str`):
The user id of the originating request.
tool_name (`str`, optional):
The name of the offloaded tool.
Returns:
`str`:
The generated task id.
"""
bg_task = BackgroundTask(
asyncio_task=asyncio_task,
session_id=session_id,
agent_id=agent_id,
user_id=user_id,
tool_name=tool_name,
)
task_id = bg_task.id
self.tasks[task_id] = bg_task
# Register in the global Redis registry.
metadata = json.dumps(
{
"tool_name": tool_name,
"agent_id": agent_id,
"started_at": time.time(),
},
ensure_ascii=False,
)
await self._message_bus.registry_set(
MessageBusKeys.bg_tasks(session_id),
task_id,
metadata,
ttl_secs=MessageBusKeys.BG_TASKS_TTL_SECS,
)
logger.info(
"Background task registered: task_id=%s, session_id=%s, "
"agent_id=%s, tool_name=%s",
task_id,
session_id,
agent_id,
tool_name,
)
def _on_done(_t: asyncio.Task) -> None:
self.tasks.pop(task_id, None)
# Schedule async Redis cleanup (fire-and-forget). Wrap in a
# coroutine that logs failures so the bus error (e.g. Redis
# connection drop) does not surface as
# ``Task exception was never retrieved``.
try:
asyncio.ensure_future(
self._safe_bg_task_unregister(session_id, task_id),
)
except RuntimeError:
# Event loop already closed during shutdown.
pass
asyncio_task.add_done_callback(_on_done)
return task_id
async def _safe_bg_task_unregister(
self,
session_id: str,
task_id: str,
) -> None:
"""Unregister a finished background task, logging any failure.
Args:
session_id (`str`):
The session id of the finished task.
task_id (`str`):
The task id to unregister from the global registry.
"""
try:
await self._message_bus.registry_del(
MessageBusKeys.bg_tasks(session_id),
task_id,
)
except Exception as e: # pylint: disable=broad-except
logger.exception(
"Failed to unregister background task from the global "
"registry: task_id=%s, session_id=%s, error=%s",
task_id,
session_id,
str(e),
)
# ------------------------------------------------------------------
# Tool listing
# ------------------------------------------------------------------
async def list_tools(self, session_id: str) -> list[ToolBase]:
"""List the background task tools for a given session.
Args:
session_id (`str`):
The current session id (for ToolStop's registry
lookups).
Returns:
`list[ToolBase]`:
A list containing the :class:`ToolStop` tool.
"""
return [ToolStop(self.tasks, self._message_bus, session_id)]
# ------------------------------------------------------------------
# Session-scoped cancel
# ------------------------------------------------------------------
def cancel_session_tasks(self, session_id: str) -> int:
"""Cancel every locally-tracked task whose owner session matches.
Called by :class:`CancelDispatcher` on each incoming session
cancel broadcast. Returns the number of tasks cancelled on this
process.
Args:
session_id (`str`):
The session whose tasks should be cancelled.
Returns:
`int`:
Number of tasks cancelled locally.
"""
cancelled = 0
for bg_task in list(self.tasks.values()):
if bg_task.session_id != session_id:
continue
logger.info(
"Cancelling background task for session cancel: "
"task_id=%s, session_id=%s, agent_id=%s",
bg_task.id,
bg_task.session_id,
bg_task.agent_id,
)
bg_task.asyncio_task.cancel()
cancelled += 1
return cancelled
# ------------------------------------------------------------------
# Single-task cancel (called by CancelDispatcher on bus signal)
# ------------------------------------------------------------------
def cancel_task(self, task_id: str) -> bool:
"""Cancel a single locally-tracked task by its id.
Called by :class:`CancelDispatcher` when a task-level cancel
broadcast arrives. Returns whether the task was found and
cancelled on this process.
Args:
task_id (`str`):
The task to cancel.
Returns:
`bool`:
``True`` if the task was found locally and cancelled.
"""
bg_task = self.tasks.get(task_id)
if bg_task is None:
return False
logger.info(
"Cancelling background task via bus signal: "
"task_id=%s, session_id=%s, agent_id=%s",
task_id,
bg_task.session_id,
bg_task.agent_id,
)
bg_task.asyncio_task.cancel()
return True
# ------------------------------------------------------------------
# Lifecycle
# ------------------------------------------------------------------
async def __aenter__(self) -> Self:
"""Enter the async context. No setup required.
Returns:
`Self`: This manager instance.
"""
return self
async def __aexit__(self, *exc: object) -> None:
"""Cancel all running background tasks on context exit."""
count = len(self.tasks)
logger.info(
"Shutting down BackgroundTaskManager: cancelling %d task(s).",
count,
)
for bg_task in list(self.tasks.values()):
logger.info(
"Cancelling background task on shutdown: task_id=%s, "
"session_id=%s, agent_id=%s",
bg_task.id,
bg_task.session_id,
bg_task.agent_id,
)
bg_task.asyncio_task.cancel()
self.tasks.clear()
|