from abc import ABC, abstractmethod import functools import torch.multiprocessing as mp from multiprocessing.context import BaseContext import threading import queue import platform import traceback import uuid import time from ditk import logging from dataclasses import dataclass, field from typing import Any, Callable, Dict, List, Optional, Union from enum import Enum @functools.lru_cache(maxsize=1) def get_mp_ctx() -> BaseContext: context = 'spawn' if platform.system().lower() == 'windows' else 'fork' mp_ctx = mp.get_context(context) return mp_ctx @dataclass class SendPayload: proc_id: int # Use uuid1 here to include the timestamp req_id: str = field(default_factory=lambda: uuid.uuid1().hex) method: str = None args: List = field(default_factory=list) kwargs: Dict = field(default_factory=dict) @dataclass class RecvPayload: proc_id: int req_id: str = None method: str = None data: Any = None err: Exception = None extra: Any = None class ReserveMethod(Enum): SHUTDOWN = "_shutdown" GETATTR = "_getattr" class ChildType(Enum): PROCESS = "process" THREAD = "thread" class Child(ABC): """ Abstract class of child process/thread. """ def __init__(self, proc_id: int, init: Union[Callable, object], **kwargs) -> None: self._proc_id = proc_id self._init = init self._recv_queue = None self._send_queue = None @abstractmethod def start(self, recv_queue: Union[mp.Queue, queue.Queue]): raise NotImplementedError def restart(self): self.shutdown() self.start(self._recv_queue) @abstractmethod def shutdown(self, timeout: Optional[float] = None): raise NotImplementedError @abstractmethod def send(self, payload: SendPayload): raise NotImplementedError def _target( self, proc_id: int, init: Union[Callable, object], send_queue: Union[mp.Queue, queue.Queue], recv_queue: Union[mp.Queue, queue.Queue], shm_buffer: Optional[Any] = None, shm_callback: Optional[Callable] = None ): send_payload = SendPayload(proc_id=proc_id) if isinstance(init, Callable): child_ins = init() else: child_ins = init while True: try: send_payload: SendPayload = send_queue.get() if send_payload.method == ReserveMethod.SHUTDOWN: break if send_payload.method == ReserveMethod.GETATTR: data = getattr(child_ins, send_payload.args[0]) else: data = getattr(child_ins, send_payload.method)(*send_payload.args, **send_payload.kwargs) recv_payload = RecvPayload( proc_id=proc_id, req_id=send_payload.req_id, method=send_payload.method, data=data ) if shm_callback is not None and shm_buffer is not None: shm_callback(recv_payload, shm_buffer) recv_queue.put(recv_payload) except Exception as e: logging.warning(traceback.format_exc()) logging.warning("Error in child process! id: {}, error: {}".format(self._proc_id, e)) recv_payload = RecvPayload( proc_id=proc_id, req_id=send_payload.req_id, method=send_payload.method, err=e ) recv_queue.put(recv_payload) def __del__(self): self.shutdown() class ChildProcess(Child): def __init__( self, proc_id: int, init: Union[Callable, object], shm_buffer: Optional[Any] = None, shm_callback: Optional[Callable] = None, mp_ctx: Optional[BaseContext] = None, **kwargs ) -> None: super().__init__(proc_id, init, **kwargs) self._proc = None self._mp_ctx = mp_ctx self._shm_buffer = shm_buffer self._shm_callback = shm_callback def start(self, recv_queue: mp.Queue): if self._proc is None: self._recv_queue = recv_queue ctx = self._mp_ctx or get_mp_ctx() self._send_queue = ctx.Queue() proc = ctx.Process( target=self._target, args=( self._proc_id, self._init, self._send_queue, self._recv_queue, self._shm_buffer, self._shm_callback ), name="supervisor_child_{}_{}".format(self._proc_id, time.time()), daemon=True ) proc.start() self._proc = proc def shutdown(self, timeout: Optional[float] = None): if self._proc: self._send_queue.put(SendPayload(proc_id=self._proc_id, method=ReserveMethod.SHUTDOWN)) self._proc.terminate() self._proc.join(timeout=timeout) if hasattr(self._proc, "close"): # Compatible with 3.6 self._proc.close() self._proc = None self._send_queue.close() self._send_queue.join_thread() self._send_queue = None def send(self, payload: SendPayload): if self._send_queue is None: logging.warning("Child worker has been terminated or not started.") return self._send_queue.put(payload) class ChildThread(Child): def __init__(self, proc_id: int, init: Union[Callable, object], *args, **kwargs) -> None: super().__init__(proc_id, init, *args, **kwargs) self._thread = None def start(self, recv_queue: queue.Queue): if self._thread is None: self._recv_queue = recv_queue self._send_queue = queue.Queue() thread = threading.Thread( target=self._target, args=(self._proc_id, self._init, self._send_queue, self._recv_queue), name="supervisor_child_{}_{}".format(self._proc_id, time.time()), daemon=True ) thread.start() self._thread = thread def shutdown(self, timeout: Optional[float] = None): if self._thread: self._send_queue.put(SendPayload(proc_id=self._proc_id, method=ReserveMethod.SHUTDOWN)) self._thread.join(timeout=timeout) self._thread = None self._send_queue = None def send(self, payload: SendPayload): if self._send_queue is None: logging.warning("Child worker has been terminated or not started.") return self._send_queue.put(payload) class Supervisor: TYPE_MAPPING = {ChildType.PROCESS: ChildProcess, ChildType.THREAD: ChildThread} def __init__(self, type_: ChildType, mp_ctx: Optional[BaseContext] = None) -> None: self._children: List[Child] = [] self._type = type_ self._child_class = self.TYPE_MAPPING[self._type] self._running = False self.__queue = None self._mp_ctx = mp_ctx or get_mp_ctx() def register( self, init: Union[Callable, object], shm_buffer: Optional[Any] = None, shm_callback: Optional[Callable] = None ) -> None: proc_id = len(self._children) self._children.append( self._child_class(proc_id, init, shm_buffer=shm_buffer, shm_callback=shm_callback, mp_ctx=self._mp_ctx) ) @property def _recv_queue(self) -> Union[queue.Queue, mp.Queue]: if not self.__queue: if self._type is ChildType.PROCESS: self.__queue = self._mp_ctx.Queue() elif self._type is ChildType.THREAD: self.__queue = queue.Queue() return self.__queue @_recv_queue.setter def _recv_queue(self, queue: Union[queue.Queue, mp.Queue]): self.__queue = queue def start_link(self) -> None: if not self._running: for child in self._children: child.start(recv_queue=self._recv_queue) self._running = True def send(self, payload: SendPayload) -> None: """ Overview: Send message to child process. Arguments: - payload (:obj:`SendPayload`): Send payload. """ if not self._running: logging.warning("Please call start_link before sending any payload to child process.") return self._children[payload.proc_id].send(payload) def recv(self, ignore_err: bool = False, timeout: float = None) -> RecvPayload: """ Overview: Wait for message from child process Arguments: - ignore_err (:obj:`bool`): If ignore_err is True, put the err in the property of recv_payload. \ Otherwise, an exception will be raised. - timeout (:obj:`float`): Timeout for queue.get, will raise an Empty exception if timeout. Returns: - recv_payload (:obj:`RecvPayload`): Recv payload. """ recv_payload: RecvPayload = self._recv_queue.get(timeout=timeout) if recv_payload.err and not ignore_err: raise recv_payload.err return recv_payload def recv_all( self, send_payloads: List[SendPayload], ignore_err: bool = False, callback: Callable = None, timeout: Optional[float] = None ) -> List[RecvPayload]: """ Overview: Wait for messages with specific req ids until all ids are fulfilled. Arguments: - send_payloads (:obj:`List[SendPayload]`): Request payloads. - ignore_err (:obj:`bool`): If ignore_err is True, \ put the err in the property of recv_payload. Otherwise, an exception will be raised. \ This option will also ignore timeout error. - callback (:obj:`Callable`): Callback for each recv payload. - timeout (:obj:`Optional[float]`): Timeout when wait for responses. Returns: - recv_payload (:obj:`List[RecvPayload]`): Recv payload, may contain timeout error. """ assert send_payloads, "Req payload is empty!" recv_payloads = {} remain_payloads = {payload.req_id: payload for payload in send_payloads} unrelated_payloads = [] try: while remain_payloads: try: recv_payload: RecvPayload = self._recv_queue.get(block=True, timeout=timeout) if recv_payload.req_id in remain_payloads: del remain_payloads[recv_payload.req_id] recv_payloads[recv_payload.req_id] = recv_payload if recv_payload.err and not ignore_err: raise recv_payload.err if callback: callback(recv_payload, remain_payloads) else: unrelated_payloads.append(recv_payload) except queue.Empty: if ignore_err: req_ids = list(remain_payloads.keys()) logging.warning("Timeout ({}s) when receving payloads! Req ids: {}".format(timeout, req_ids)) for req_id in req_ids: send_payload = remain_payloads.pop(req_id) # If timeout error happens in timeout recover, there may not find any send_payload # in the original indexed payloads. recv_payload = RecvPayload( proc_id=send_payload.proc_id, req_id=send_payload.req_id, method=send_payload.method, err=TimeoutError("Timeout on req_id ({})".format(req_id)) ) recv_payloads[req_id] = recv_payload if callback: callback(recv_payload, remain_payloads) else: raise TimeoutError("Timeout ({}s) when receving payloads!".format(timeout)) finally: # Put back the unrelated payload. for payload in unrelated_payloads: self._recv_queue.put(payload) # Keep the original order of requests. return [recv_payloads[p.req_id] for p in send_payloads] def shutdown(self, timeout: Optional[float] = None) -> None: if self._running: for child in self._children: child.shutdown(timeout=timeout) self._cleanup_queue() self._running = False def _cleanup_queue(self): while True: while not self._recv_queue.empty(): self._recv_queue.get() time.sleep(0.1) # mp.Queue is not reliable. if self._recv_queue.empty(): break if hasattr(self._recv_queue, "close"): self._recv_queue.close() self._recv_queue.join_thread() self._recv_queue = None def __getattr__(self, key: str) -> List[Any]: assert self._running, "Supervisor is not running, please call start_link first!" send_payloads = [] for i, child in enumerate(self._children): payload = SendPayload(proc_id=i, method=ReserveMethod.GETATTR, args=[key]) send_payloads.append(payload) child.send(payload) return [payload.data for payload in self.recv_all(send_payloads)] def get_child_attr(self, proc_id: str, key: str) -> Any: """ Overview: Get attr of one child process instance. Arguments: - proc_id (:obj:`str`): Proc id. - key (:obj:`str`): Attribute key. Returns: - attr (:obj:`Any`): Attribute of child. """ assert self._running, "Supervisor is not running, please call start_link first!" payload = SendPayload(proc_id=proc_id, method=ReserveMethod.GETATTR, args=[key]) self._children[proc_id].send(payload) payloads = self.recv_all([payload]) return payloads[0].data def __del__(self) -> None: self.shutdown(timeout=5) self._children.clear()