Files
deb-python-eventlet/eventlet/kqueuehub.py
2007-08-23 19:57:41 -04:00

220 lines
7.3 KiB
Python

"""\
@file kqueuehub.py
@author Donovan Preston
Copyright (c) 2006-2007, Linden Research, Inc.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
"""
import sys
import select
import kqueue
import traceback
from errno import EBADF
from eventlet import greenlib
from eventlet.runloop import RunLoop, Timer
import greenlet
class Hub(object):
def __init__(self):
self.runloop = RunLoop(self.wait)
self.descriptor_queue = {}
self.descriptors = {}
self.greenlet = None
self.kfd = None
def stop(self):
self.process_queue()
self.descriptors, self.descriptor_queue = self.descriptor_queue, {}
os.close(self.kfd)
self.kfd = None
self.runloop.abort()
if self.greenlet is not greenlet.getcurrent():
self.switch()
def schedule_call(self, *args, **kw):
return self.runloop.schedule_call(*args, **kw)
def switch(self):
if not self.greenlet:
self.greenlet = greenlib.tracked_greenlet()
args = ((self.runloop.run,),)
else:
args = ()
try:
greenlet.getcurrent().parent = self.greenlet
except ValueError:
pass
return greenlib.switch(self.greenlet, *args)
def add_descriptor(self, fileno, read=None, write=None, exc=None):
self.descriptor_queue[fileno] = read, write, exc
def remove_descriptor(self, fileno):
self.descriptor_queue[fileno] = None, None, None
def exc_descriptor(self, fileno):
# We must handle two cases here, the descriptor
# may be changing or removing its exc handler
# in the queue, or it may be waiting on the queue.
exc = None
try:
exc = self.descriptor_queue[fileno][2]
except KeyError:
try:
exc = self.descriptors[fileno][2]
except KeyError:
pass
if exc is not None:
try:
exc()
except self.runloop.SYSTEM_EXCEPTIONS:
self.squelch_exception(fileno, sys.exc_info())
def squelch_exception(self, fileno, exc_info):
traceback.print_exception(*exc_info)
print >>sys.stderr, "Removing descriptor: %r" % (fileno,)
try:
self.remove_descriptor(fileno)
except Exception, e:
print >>sys.stderr, "Exception while removing descriptor! %r" % (e,)
def process_queue(self):
if self.kfd is None:
self.kfd = kqueue.kqueue()
d = self.descriptors
E_R = kqueue.EVFILT_READ
E_W = kqueue.EVFILT_WRITE
E = kqueue.Event
E_ADD = kqueue.EV_ADD
E_DEL = kqueue.EV_DELETE
kevent = kqueue.kevent
kfd = self.kfd
for fileno, rwe in self.descriptor_queue.iteritems():
read, write, exc = rwe
if read is None and write is None and exc is None:
try:
read, write, exc = d.pop(fileno)
except KeyError:
pass
else:
l = []
if read is not None:
l.append(E(fileno, E_R, E_DEL))
if write is not None:
l.append(E(fileno, E_W, E_DEL))
if l:
try:
kevent(kfd, l, 0, 0)
except OSError, e:
if e[0] != EBADF:
raise
else:
l = []
try:
oldr, oldw, olde = d[fileno]
except KeyError:
pass
else:
if oldr is not None:
if read is None:
l.append(E(fileno, E_R, E_DEL))
else:
read = None
if oldw is not None:
if write is None:
l.append(E(fileno, E_W, E_DEL))
else:
write = None
if read is not None:
l.append(E(fileno, E_R, E_ADD))
if write is not None:
l.append(E(fileno, E_W, E_ADD))
if l:
try:
kevent(kfd, l, 0, 0)
except OSError, e:
if e[0] != EBADF:
raise
try:
del d[fileno]
except KeyError:
pass
if exc is not None:
try:
exc(fileno)
except SYSTEM_EXCEPTIONS:
raise
except:
self.squelch_exception(fileno, sys.exc_info())
continue
d[fileno] = rwe
self.descriptor_queue.clear()
def wait(self, seconds=None):
self.process_queue()
if seconds is not None:
seconds *= 1000000000.0
dct = self.descriptors
events = kqueue.kevent(self.kfd, [], len(dct), seconds)
SYSTEM_EXCEPTIONS = self.runloop.SYSTEM_EXCEPTIONS
E_R = kqueue.EVFILT_READ
E_W = kqueue.EVFILT_WRITE
E_EOF = kqueue.EV_EOF
for e in events:
fileno = e.ident
event = e.filter
try:
read, write, exc = dct[fileno]
except KeyError:
continue
if read is not None and event == E_R:
try:
read(fileno)
except SYSTEM_EXCEPTIONS:
raise
except:
self.squelch_exception(fileno, sys.exc_info())
elif exc is not None and e.fflags & E_EOF:
try:
exc(fileno)
except SYSTEM_EXCEPTIONS:
raise
except:
self.squelch_exception(fileno, sys.exc_info())
if write is not None and event == E_W:
try:
write(fileno)
except SYSTEM_EXCEPTIONS:
raise
except:
self.squelch_exception(fileno, sys.exc_info())