#!/usr/bin/python # -*- coding: utf-8 -*- # # Copyright 2013-2015 clowwindy # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. # from ssloop # https://github.com/clowwindy/ssloop from __future__ import absolute_import, division, print_function, \ with_statement import os import socket import select import errno import logging from collections import defaultdict __all__ = ['EventLoop', 'POLL_NULL', 'POLL_IN', 'POLL_OUT', 'POLL_ERR', 'POLL_HUP', 'POLL_NVAL', 'EVENT_NAMES'] POLL_NULL = 0x00 POLL_IN = 0x01 POLL_OUT = 0x04 POLL_ERR = 0x08 POLL_HUP = 0x10 POLL_NVAL = 0x20 EVENT_NAMES = { POLL_NULL: 'POLL_NULL', POLL_IN: 'POLL_IN', POLL_OUT: 'POLL_OUT', POLL_ERR: 'POLL_ERR', POLL_HUP: 'POLL_HUP', POLL_NVAL: 'POLL_NVAL', } class EpollLoop(object): def __init__(self): self._epoll = select.epoll() def poll(self, timeout): return self._epoll.poll(timeout) def add_fd(self, fd, mode): self._epoll.register(fd, mode) def remove_fd(self, fd): self._epoll.unregister(fd) def modify_fd(self, fd, mode): self._epoll.modify(fd, mode) class KqueueLoop(object): MAX_EVENTS = 1024 def __init__(self): self._kqueue = select.kqueue() self._fds = {} def _control(self, fd, mode, flags): events = [] if mode & POLL_IN: events.append(select.kevent(fd, select.KQ_FILTER_READ, flags)) if mode & POLL_OUT: events.append(select.kevent(fd, select.KQ_FILTER_WRITE, flags)) for e in events: self._kqueue.control([e], 0) def poll(self, timeout): if timeout < 0: timeout = None # kqueue behaviour events = self._kqueue.control(None, KqueueLoop.MAX_EVENTS, timeout) results = defaultdict(lambda: POLL_NULL) for e in events: fd = e.ident if e.filter == select.KQ_FILTER_READ: results[fd] |= POLL_IN elif e.filter == select.KQ_FILTER_WRITE: results[fd] |= POLL_OUT return results.items() def add_fd(self, fd, mode): self._fds[fd] = mode self._control(fd, mode, select.KQ_EV_ADD) def remove_fd(self, fd): self._control(fd, self._fds[fd], select.KQ_EV_DELETE) del self._fds[fd] def modify_fd(self, fd, mode): self.remove_fd(fd) self.add_fd(fd, mode) class SelectLoop(object): def __init__(self): self._r_list = set() self._w_list = set() self._x_list = set() def poll(self, timeout): r, w, x = select.select(self._r_list, self._w_list, self._x_list, timeout) results = defaultdict(lambda: POLL_NULL) for p in [(r, POLL_IN), (w, POLL_OUT), (x, POLL_ERR)]: for fd in p[0]: results[fd] |= p[1] return results.items() def add_fd(self, fd, mode): if mode & POLL_IN: self._r_list.add(fd) if mode & POLL_OUT: self._w_list.add(fd) if mode & POLL_ERR: self._x_list.add(fd) def remove_fd(self, fd): if fd in self._r_list: self._r_list.remove(fd) if fd in self._w_list: self._w_list.remove(fd) if fd in self._x_list: self._x_list.remove(fd) def modify_fd(self, fd, mode): self.remove_fd(fd) self.add_fd(fd, mode) class EventLoop(object): def __init__(self): self._iterating = False if hasattr(select, 'epoll'): self._impl = EpollLoop() model = 'epoll' elif hasattr(select, 'kqueue'): self._impl = KqueueLoop() model = 'kqueue' elif hasattr(select, 'select'): self._impl = SelectLoop() model = 'select' else: raise Exception('can not find any available functions in select ' 'package') self._fd_to_f = {} self._handlers = [] self._ref_handlers = [] self._handlers_to_remove = [] logging.debug('using event model: %s', model) def poll(self, timeout=None): events = self._impl.poll(timeout) return [(self._fd_to_f[fd], fd, event) for fd, event in events] def add(self, f, mode): fd = f.fileno() self._fd_to_f[fd] = f self._impl.add_fd(fd, mode) def remove(self, f): fd = f.fileno() del self._fd_to_f[fd] self._impl.remove_fd(fd) def modify(self, f, mode): fd = f.fileno() self._impl.modify_fd(fd, mode) def add_handler(self, handler, ref=True): self._handlers.append(handler) if ref: # when all ref handlers are removed, loop stops self._ref_handlers.append(handler) def remove_handler(self, handler): if handler in self._ref_handlers: self._ref_handlers.remove(handler) if self._iterating: self._handlers_to_remove.append(handler) else: self._handlers.remove(handler) def run(self): events = [] while self._ref_handlers: try: events = self.poll(1) except (OSError, IOError) as e: if errno_from_exception(e) in (errno.EPIPE, errno.EINTR): # EPIPE: Happens when the client closes the connection # EINTR: Happens when received a signal # handles them as soon as possible logging.debug('poll:%s', e) else: logging.error('poll:%s', e) import traceback traceback.print_exc() continue self._iterating = True for handler in self._handlers: # TODO when there are a lot of handlers try: handler(events) except (OSError, IOError) as e: logging.error(e) import traceback traceback.print_exc() if self._handlers_to_remove: for handler in self._handlers_to_remove: self._handlers.remove(handler) self._handlers_to_remove = [] self._iterating = False # from tornado def errno_from_exception(e): """Provides the errno from an Exception object. There are cases that the errno attribute was not set so we pull the errno out of the args but if someone instatiates an Exception without any args you will get a tuple error. So this function abstracts all that behavior to give you a safe way to get the errno. """ if hasattr(e, 'errno'): return e.errno elif e.args: return e.args[0] else: return None # from tornado def get_sock_error(sock): error_number = sock.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR) return socket.error(error_number, os.strerror(error_number))