# adapted from vllm
# https://github.com/vllm-project/vllm/blob/main/vllm/executor/multiproc_worker_utils.py
import asyncio
import multiprocessing
import os
import socket
import sys
import threading
import traceback
import uuid
from dataclasses import dataclass
from multiprocessing import Queue
from multiprocessing.connection import wait
from typing import Any, Callable, Dict, Generic, List, Optional, TextIO, TypeVar, Union
from videosys.utils.logging import create_logger
T = TypeVar("T")
_TERMINATE = "TERMINATE" # sentinel
# ANSI color codes
CYAN = "\033[1;36m"
RESET = "\033[0;0m"
JOIN_TIMEOUT_S = 2
mp_method = "spawn" # fork cann't work
mp = multiprocessing.get_context(mp_method)
logger = create_logger()
def get_distributed_init_method(ip: str, port: int) -> str:
# Brackets are not permitted in ipv4 addresses,
# see https://github.com/python/cpython/issues/103848
return f"tcp://[{ip}]:{port}" if ":" in ip else f"tcp://{ip}:{port}"
def get_open_port() -> int:
# try ipv4
try:
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind(("", 0))
return s.getsockname()[1]
except OSError:
# try ipv6
with socket.socket(socket.AF_INET6, socket.SOCK_STREAM) as s:
s.bind(("", 0))
return s.getsockname()[1]
@dataclass
class Result(Generic[T]):
"""Result of task dispatched to worker"""
task_id: uuid.UUID
value: Optional[T] = None
exception: Optional[BaseException] = None
class ResultFuture(threading.Event, Generic[T]):
"""Synchronous future for non-async case"""
def __init__(self):
super().__init__()
self.result: Optional[Result[T]] = None
def set_result(self, result: Result[T]):
self.result = result
self.set()
def get(self) -> T:
self.wait()
assert self.result is not None
if self.result.exception is not None:
raise self.result.exception
return self.result.value # type: ignore[return-value]
def _set_future_result(future: Union[ResultFuture, asyncio.Future], result: Result):
if isinstance(future, ResultFuture):
future.set_result(result)
return
loop = future.get_loop()
if not loop.is_closed():
if result.exception is not None:
loop.call_soon_threadsafe(future.set_exception, result.exception)
else:
loop.call_soon_threadsafe(future.set_result, result.value)
class ResultHandler(threading.Thread):
"""Handle results from all workers (in background thread)"""
def __init__(self) -> None:
super().__init__(daemon=True)
self.result_queue = mp.Queue()
self.tasks: Dict[uuid.UUID, Union[ResultFuture, asyncio.Future]] = {}
def run(self):
for result in iter(self.result_queue.get, _TERMINATE):
future = self.tasks.pop(result.task_id)
_set_future_result(future, result)
# Ensure that all waiters will receive an exception
for task_id, future in self.tasks.items():
_set_future_result(future, Result(task_id=task_id, exception=ChildProcessError("worker died")))
def close(self):
self.result_queue.put(_TERMINATE)
class WorkerMonitor(threading.Thread):
"""Monitor worker status (in background thread)"""
def __init__(self, workers: List["ProcessWorkerWrapper"], result_handler: ResultHandler):
super().__init__(daemon=True)
self.workers = workers
self.result_handler = result_handler
self._close = False
def run(self) -> None:
# Blocks until any worker exits
dead_sentinels = wait([w.process.sentinel for w in self.workers])
if not self._close:
self._close = True
# Kill / cleanup all workers
for worker in self.workers:
process = worker.process
if process.sentinel in dead_sentinels:
process.join(JOIN_TIMEOUT_S)
if process.exitcode is not None and process.exitcode != 0:
logger.error("Worker %s pid %s died, exit code: %s", process.name, process.pid, process.exitcode)
# Cleanup any remaining workers
logger.info("Killing local worker processes")
for worker in self.workers:
worker.kill_worker()
# Must be done after worker task queues are all closed
self.result_handler.close()
for worker in self.workers:
worker.process.join(JOIN_TIMEOUT_S)
def close(self):
if self._close:
return
self._close = True
logger.info("Terminating local worker processes")
for worker in self.workers:
worker.terminate_worker()
# Must be done after worker task queues are all closed
self.result_handler.close()
def _add_prefix(file: TextIO, worker_name: str, pid: int) -> None:
"""Prepend each output line with process-specific prefix"""
prefix = f"{CYAN}({worker_name} pid={pid}){RESET} "
file_write = file.write
def write_with_prefix(s: str):
if not s:
return
if file.start_new_line: # type: ignore[attr-defined]
file_write(prefix)
idx = 0
while (next_idx := s.find("\n", idx)) != -1:
next_idx += 1
file_write(s[idx:next_idx])
if next_idx == len(s):
file.start_new_line = True # type: ignore[attr-defined]
return
file_write(prefix)
idx = next_idx
file_write(s[idx:])
file.start_new_line = False # type: ignore[attr-defined]
file.start_new_line = True # type: ignore[attr-defined]
file.write = write_with_prefix # type: ignore[method-assign]
def _run_worker_process(
worker_factory: Callable[[], Any],
task_queue: Queue,
result_queue: Queue,
) -> None:
"""Worker process event loop"""
# Add process-specific prefix to stdout and stderr
process_name = mp.current_process().name
pid = os.getpid()
_add_prefix(sys.stdout, process_name, pid)
_add_prefix(sys.stderr, process_name, pid)
# Initialize worker
worker = worker_factory()
del worker_factory
# Accept tasks from the engine in task_queue
# and return task output in result_queue
logger.info("Worker ready; awaiting tasks")
try:
for items in iter(task_queue.get, _TERMINATE):
output = None
exception = None
task_id, method, args, kwargs = items
try:
executor = getattr(worker, method)
output = executor(*args, **kwargs)
except BaseException as e:
tb = traceback.format_exc()
logger.error("Exception in worker %s while processing method %s: %s, %s", process_name, method, e, tb)
exception = e
result_queue.put(Result(task_id=task_id, value=output, exception=exception))
except KeyboardInterrupt:
pass
except Exception:
logger.exception("Worker failed")
logger.info("Worker exiting")
class ProcessWorkerWrapper:
"""Local process wrapper for handling single-node multi-GPU."""
def __init__(self, result_handler: ResultHandler, worker_factory: Callable[[], Any]) -> None:
self._task_queue = mp.Queue()
self.result_queue = result_handler.result_queue
self.tasks = result_handler.tasks
self.process = mp.Process( # type: ignore[attr-defined]
target=_run_worker_process,
name="VideoSysWorkerProcess",
kwargs=dict(
worker_factory=worker_factory,
task_queue=self._task_queue,
result_queue=self.result_queue,
),
daemon=True,
)
self.process.start()
def _enqueue_task(self, future: Union[ResultFuture, asyncio.Future], method: str, args, kwargs):
task_id = uuid.uuid4()
self.tasks[task_id] = future
try:
self._task_queue.put((task_id, method, args, kwargs))
except BaseException as e:
del self.tasks[task_id]
raise ChildProcessError("worker died") from e
def execute_method(self, method: str, *args, **kwargs):
future: ResultFuture = ResultFuture()
self._enqueue_task(future, method, args, kwargs)
return future
async def execute_method_async(self, method: str, *args, **kwargs):
future = asyncio.get_running_loop().create_future()
self._enqueue_task(future, method, args, kwargs)
return await future
def terminate_worker(self):
try:
self._task_queue.put(_TERMINATE)
except ValueError:
self.process.kill()
self._task_queue.close()
def kill_worker(self):
self._task_queue.close()
self.process.kill()