Files
deb-python-eventlet/eventlet/hubs/twistedr.py

304 lines
10 KiB
Python

import sys
import threading
import weakref
from twisted.internet.base import DelayedCall as TwistedDelayedCall
from eventlet.hubs.hub import _g_debug
from eventlet import greenlib
from eventlet.support.greenlet import greenlet
import traceback
class DelayedCall(TwistedDelayedCall):
"fix DelayedCall to behave like eventlet's Timer in some respects"
def cancel(self):
if self.cancelled or self.called:
self.cancelled = True
return
return TwistedDelayedCall.cancel(self)
def callLater(reactor, _seconds, _f, *args, **kw):
# the same as original but creates fixed DelayedCall instance
assert callable(_f), "%s is not callable" % _f
assert sys.maxint >= _seconds >= 0, \
"%s is not greater than or equal to 0 seconds" % (_seconds,)
tple = DelayedCall(reactor.seconds() + _seconds, _f, args, kw,
reactor._cancelCallLater,
reactor._moveCallLaterSooner,
seconds=reactor.seconds)
reactor._newTimedCalls.append(tple)
return tple
class socket_rwdescriptor:
#implements(IReadWriteDescriptor)
def __init__(self, fileno, read, write, error):
self._fileno = fileno
self.read = read
self.write = write
self.error = error
def doRead(self):
if self.read:
self.read(self)
def doWrite(self):
if self.write:
self.write(self)
def connectionLost(self, reason):
if self.error:
self.error(self, reason)
def fileno(self):
return self._fileno
logstr = "XXXfixme"
def logPrefix(self):
return self.logstr
class BaseTwistedHub(object):
"""This hub does not run a dedicated greenlet for the mainloop (unlike TwistedHub).
Instead, it assumes that the mainloop is run in the main greenlet.
This makes running "green" functions in the main greenlet impossible but is useful
when you want to call reactor.run() yourself.
"""
def __init__(self, mainloop_greenlet):
self.greenlet = mainloop_greenlet
self.waiters_by_greenlet = {}
self.timers_by_greenlet = {}
def switch(self):
assert greenlet.getcurrent() is not self.greenlet, 'Impossible to switch() from the mainloop greenlet'
try:
greenlet.getcurrent().parent = self.greenlet
except ValueError, ex:
pass
return greenlib.switch(self.greenlet)
def stop(self):
from twisted.internet import reactor
reactor.stop()
def add_descriptor(self, fileno, read=None, write=None, exc=None):
from twisted.internet import reactor
descriptor = socket_rwdescriptor(fileno, read, write, exc)
if read:
reactor.addReader(descriptor)
if write:
reactor.addWriter(descriptor)
# XXX exc will not work if no read nor write
self.waiters_by_greenlet[greenlet.getcurrent()] = descriptor
return descriptor
def remove_descriptor(self, descriptor):
from twisted.internet import reactor
reactor.removeReader(descriptor)
reactor.removeWriter(descriptor)
self.waiters_by_greenlet.pop(greenlet.getcurrent(), None)
def exc_greenlet(self, gr, exception_object):
fileno = self.waiters_by_greenlet.pop(gr, None)
if fileno is not None:
self.remove_descriptor(fileno)
greenlib.switch(gr, None, exception_object)
# required by GreenSocket
def exc_descriptor(self, _fileno):
pass # XXX do something sensible here
def schedule_call_local(self, seconds, func, *args, **kwargs):
from twisted.internet import reactor
def call_with_timer_attached(*args1, **kwargs1):
try:
return func(*args1, **kwargs1)
finally:
if seconds:
self.timer_finished(timer)
timer = callLater(reactor, seconds, call_with_timer_attached, *args, **kwargs)
if seconds:
self.track_timer(timer)
return timer
schedule_call = schedule_call_local
def schedule_call_global(self, seconds, func, *args, **kwargs):
from twisted.internet import reactor
return callLater(reactor, seconds, func, *args, **kwargs)
def track_timer(self, timer):
try:
current_greenlet = greenlet.getcurrent()
timer.greenlet = current_greenlet
self.timers_by_greenlet.setdefault(
current_greenlet,
weakref.WeakKeyDictionary())[timer] = True
except:
print 'track_timer failed'
traceback.print_exc()
raise
def timer_finished(self, timer):
try:
greenlet = timer.greenlet
del self.timers_by_greenlet[greenlet][timer]
if not self.timers_by_greenlet[greenlet]:
del self.timers_by_greenlet[greenlet]
except (AttributeError, KeyError):
pass
except:
print 'timer_finished failed'
traceback.print_exc()
raise
def cancel_timers(self, greenlet, quiet=False):
try:
if greenlet not in self.timers_by_greenlet:
return
for timer in self.timers_by_greenlet[greenlet].keys():
if not timer.cancelled and not timer.called and hasattr(timer, 'greenlet'):
## If timer.seconds is 0, this isn't a timer, it's
## actually eventlet's silly way of specifying whether
## a coroutine is "ready to run" or not.
## TwistedHub: I do the same, by not attaching 'greenlet' attribute to zero-timers QQQ
try:
# this might be None due to weirdness with weakrefs
timer.cancel()
except TypeError:
pass
if _g_debug and not quiet:
print 'Hub cancelling left-over timer %s' % timer
try:
del self.timers_by_greenlet[greenlet]
except KeyError:
pass
except:
print 'cancel_timers failed'
import traceback
traceback.print_exc()
if not quiet:
raise
def abort(self):
from twisted.internet import reactor
reactor.crash()
@property
def running(self):
from twisted.internet import reactor
return reactor.running
# for debugging:
def get_readers(self):
from twisted.internet import reactor
readers = reactor.getReaders()
readers.remove(getattr(reactor, 'waker'))
return readers
def get_writers(self):
from twisted.internet import reactor
return reactor.getWriters()
def get_excs(self):
return []
def get_timers_count(self):
from twisted.internet import reactor
return len(reactor.getDelayedCalls())
class TwistedHub(BaseTwistedHub):
# wrapper around reactor that runs reactor's main loop in a separate greenlet.
# whenever you need to wait, i.e. inside a call that must appear
# blocking, call hub.switch() (then your blocking operation should switch back to you
# upon completion)
# unlike other eventlet hubs, which are created per-thread,
# this one cannot be instantiated more than once, because
# twisted doesn't allow that
# 0-not created
# 1-initialized but not started
# 2-started
# 3-restarted
state = 0
installSignalHandlers = False
def __init__(self):
assert Hub.state==0, ('This hub can only be instantiated once', Hub.state)
Hub.state = 1
make_twisted_threadpool_daemonic() # otherwise the program would hang after the main greenlet exited
BaseTwistedHub.__init__(self, None)
def switch(self):
if not self.greenlet:
self.greenlet = greenlib.tracked_greenlet()
args = ((self.run,),)
else:
args = ()
try:
greenlet.getcurrent().parent = self.greenlet
except ValueError, ex:
pass
return greenlib.switch(self.greenlet, *args)
def run(self, installSignalHandlers=None):
if installSignalHandlers is None:
installSignalHandlers = self.installSignalHandlers
# main loop, executed in a dedicated greenlet
from twisted.internet import reactor
assert Hub.state in [1, 3], ('run function is not reentrant', Hub.state)
if Hub.state == 1:
reactor.startRunning(installSignalHandlers=installSignalHandlers)
elif not reactor.running:
# if we're here, then reactor was explicitly stopped with reactor.stop()
# restarting reactor (like we would do after an exception) in this case
# is not an option.
raise AssertionError("reactor is not running")
try:
self.mainLoop(reactor)
except:
# an exception in the mainLoop is a normal operation (e.g. user's
# signal handler could raise an exception). In this case we will re-enter
# the main loop at the next switch.
Hub.state = 3
raise
# clean exit here is needed for abort() method to work
# do not raise an exception here.
def mainLoop(self, reactor):
Hub.state = 2
# Unlike reactor's mainLoop, this function does not catch exceptions.
# Anything raised goes into the main greenlet (because it is always the
# parent of this one)
while reactor.running:
# Advance simulation time in delayed event processors.
reactor.runUntilCurrent()
t2 = reactor.timeout()
t = reactor.running and t2
reactor.doIteration(t)
Hub = TwistedHub
class DaemonicThread(threading.Thread):
def _set_daemon(self):
return True
def make_twisted_threadpool_daemonic():
from twisted.python.threadpool import ThreadPool
if ThreadPool.threadFactory != DaemonicThread:
ThreadPool.threadFactory = DaemonicThread