Files
deb-python-eventlet/eventlet/hubs/poll.py
Sergey Shepelev 203e629212 PEP-8 fixes
2014-08-27 10:21:55 +04:00

124 lines
4.0 KiB
Python

import errno
import sys
from eventlet import patcher
select = patcher.original('select')
time = patcher.original('time')
sleep = time.sleep
from eventlet.hubs.hub import BaseHub, READ, WRITE, noop
from eventlet.support import get_errno, clear_sys_exc_info
EXC_MASK = select.POLLERR | select.POLLHUP
READ_MASK = select.POLLIN | select.POLLPRI
WRITE_MASK = select.POLLOUT
class Hub(BaseHub):
def __init__(self, clock=time.time):
super(Hub, self).__init__(clock)
self.poll = select.poll()
# poll.modify is new to 2.6
try:
self.modify = self.poll.modify
except AttributeError:
self.modify = self.poll.register
def add(self, evtype, fileno, cb, tb, mac):
listener = super(Hub, self).add(evtype, fileno, cb, tb, mac)
self.register(fileno, new=True)
return listener
def remove(self, listener):
super(Hub, self).remove(listener)
self.register(listener.fileno)
def register(self, fileno, new=False):
mask = 0
if self.listeners[READ].get(fileno):
mask |= READ_MASK | EXC_MASK
if self.listeners[WRITE].get(fileno):
mask |= WRITE_MASK | EXC_MASK
try:
if mask:
if new:
self.poll.register(fileno, mask)
else:
try:
self.modify(fileno, mask)
except (IOError, OSError):
self.poll.register(fileno, mask)
else:
try:
self.poll.unregister(fileno)
except (KeyError, IOError, OSError):
# raised if we try to remove a fileno that was
# already removed/invalid
pass
except ValueError:
# fileno is bad, issue 74
self.remove_descriptor(fileno)
raise
def remove_descriptor(self, fileno):
super(Hub, self).remove_descriptor(fileno)
try:
self.poll.unregister(fileno)
except (KeyError, ValueError, IOError, OSError):
# raised if we try to remove a fileno that was
# already removed/invalid
pass
def do_poll(self, seconds):
# poll.poll expects integral milliseconds
return self.poll.poll(int(seconds * 1000.0))
def wait(self, seconds=None):
readers = self.listeners[READ]
writers = self.listeners[WRITE]
if not readers and not writers:
if seconds:
sleep(seconds)
return
try:
presult = self.do_poll(seconds)
except (IOError, select.error) as e:
if get_errno(e) == errno.EINTR:
return
raise
SYSTEM_EXCEPTIONS = self.SYSTEM_EXCEPTIONS
if self.debug_blocking:
self.block_detect_pre()
# Accumulate the listeners to call back to prior to
# triggering any of them. This is to keep the set
# of callbacks in sync with the events we've just
# polled for. It prevents one handler from invalidating
# another.
callbacks = set()
for fileno, event in presult:
if event & READ_MASK:
callbacks.add((readers.get(fileno, noop), fileno))
if event & WRITE_MASK:
callbacks.add((writers.get(fileno, noop), fileno))
if event & select.POLLNVAL:
self.remove_descriptor(fileno)
continue
if event & EXC_MASK:
callbacks.add((readers.get(fileno, noop), fileno))
callbacks.add((writers.get(fileno, noop), fileno))
for listener, fileno in callbacks:
try:
listener.cb(fileno)
except SYSTEM_EXCEPTIONS:
raise
except:
self.squelch_exception(fileno, sys.exc_info())
clear_sys_exc_info()
if self.debug_blocking:
self.block_detect_post()