278 lines
8.9 KiB
Python
278 lines
8.9 KiB
Python
import heapq
|
|
import sys
|
|
import traceback
|
|
|
|
from eventlet.support import greenlets as greenlet
|
|
from eventlet.hubs import timer
|
|
from eventlet import patcher
|
|
time = patcher.original('time')
|
|
|
|
READ="read"
|
|
WRITE="write"
|
|
|
|
class FdListener(object):
|
|
def __init__(self, evtype, fileno, cb):
|
|
assert (evtype is READ or evtype is WRITE)
|
|
self.evtype = evtype
|
|
self.fileno = fileno
|
|
self.cb = cb
|
|
def __call__(self, *args, **kw):
|
|
return self.cb(*args, **kw)
|
|
def __repr__(self):
|
|
return "%s(%r, %r, %r)" % (type(self).__name__, self.evtype, self.fileno, self.cb)
|
|
__str__ = __repr__
|
|
|
|
|
|
# in debug mode, track the call site that created the listener
|
|
class DebugListener(FdListener):
|
|
def __init__(self, evtype, fileno, cb):
|
|
self.where_called = traceback.format_stack()
|
|
self.greenlet = greenlet.getcurrent()
|
|
super(DebugListener, self).__init__(evtype, fileno, cb)
|
|
def __repr__(self):
|
|
return "DebugListener(%r, %r, %r, %r)\n%sEndDebugFdListener" % (self.evtype,
|
|
self.fileno,
|
|
self.cb,
|
|
self.greenlet,
|
|
''.join(self.where_called))
|
|
__str__ = __repr__
|
|
|
|
|
|
class BaseHub(object):
|
|
""" Base hub class for easing the implementation of subclasses that are
|
|
specific to a particular underlying event architecture. """
|
|
|
|
SYSTEM_EXCEPTIONS = (KeyboardInterrupt, SystemExit)
|
|
|
|
READ = READ
|
|
WRITE = WRITE
|
|
|
|
def __init__(self, clock=time.time):
|
|
self.listeners = {READ:{}, WRITE:{}}
|
|
|
|
self.clock = clock
|
|
self.greenlet = greenlet.greenlet(self.run)
|
|
self.stopping = False
|
|
self.running = False
|
|
self.timers = []
|
|
self.next_timers = []
|
|
self.lclass = FdListener
|
|
self.debug_exceptions = True
|
|
|
|
def add(self, evtype, fileno, cb):
|
|
""" Signals an intent to or write a particular file descriptor.
|
|
|
|
The *evtype* argument is either the constant READ or WRITE.
|
|
|
|
The *fileno* argument is the file number of the file of interest.
|
|
|
|
The *cb* argument is the callback which will be called when the file
|
|
is ready for reading/writing.
|
|
"""
|
|
listener = self.lclass(evtype, fileno, cb)
|
|
self.listeners[evtype].setdefault(fileno, []).append(listener)
|
|
return listener
|
|
|
|
def remove(self, listener):
|
|
listener_list = self.listeners[listener.evtype].pop(listener.fileno, [])
|
|
try:
|
|
listener_list.remove(listener)
|
|
except ValueError:
|
|
pass
|
|
if listener_list:
|
|
self.listeners[listener.evtype][listener.fileno] = listener_list
|
|
|
|
def remove_descriptor(self, fileno):
|
|
""" Completely remove all listeners for this fileno. For internal use
|
|
only."""
|
|
self.listeners[READ].pop(fileno, None)
|
|
self.listeners[WRITE].pop(fileno, None)
|
|
|
|
def stop(self):
|
|
self.abort()
|
|
if self.greenlet is not greenlet.getcurrent():
|
|
self.switch()
|
|
|
|
def switch(self):
|
|
cur = greenlet.getcurrent()
|
|
assert cur is not self.greenlet, 'Cannot switch to MAINLOOP from MAINLOOP'
|
|
switch_out = getattr(cur, 'switch_out', None)
|
|
if switch_out is not None:
|
|
try:
|
|
switch_out()
|
|
except:
|
|
self.squelch_generic_exception(sys.exc_info())
|
|
sys.exc_clear()
|
|
if self.greenlet.dead:
|
|
self.greenlet = greenlet.greenlet(self.run)
|
|
try:
|
|
current = greenlet.getcurrent()
|
|
if self.greenlet.parent is not current:
|
|
current.parent = self.greenlet
|
|
except ValueError:
|
|
pass # gets raised if there is a greenlet parent cycle
|
|
sys.exc_clear()
|
|
return self.greenlet.switch()
|
|
|
|
def squelch_exception(self, fileno, exc_info):
|
|
traceback.print_exception(*exc_info)
|
|
sys.stderr.write("Removing descriptor: %r\n" % (fileno,))
|
|
sys.stderr.flush()
|
|
try:
|
|
self.remove_descriptor(fileno)
|
|
except Exception, e:
|
|
sys.stderr.write("Exception while removing descriptor! %r\n" % (e,))
|
|
sys.stderr.flush()
|
|
|
|
def wait(self, seconds=None):
|
|
raise NotImplementedError("Implement this in a subclass")
|
|
|
|
def default_sleep(self):
|
|
return 60.0
|
|
|
|
def sleep_until(self):
|
|
t = self.timers
|
|
if not t:
|
|
return None
|
|
return t[0][0]
|
|
|
|
def run(self):
|
|
"""Run the runloop until abort is called.
|
|
"""
|
|
if self.running:
|
|
raise RuntimeError("Already running!")
|
|
try:
|
|
self.running = True
|
|
self.stopping = False
|
|
while not self.stopping:
|
|
self.prepare_timers()
|
|
self.fire_timers(self.clock())
|
|
self.prepare_timers()
|
|
wakeup_when = self.sleep_until()
|
|
if wakeup_when is None:
|
|
sleep_time = self.default_sleep()
|
|
else:
|
|
sleep_time = wakeup_when - self.clock()
|
|
if sleep_time > 0:
|
|
self.wait(sleep_time)
|
|
else:
|
|
self.wait(0)
|
|
else:
|
|
del self.timers[:]
|
|
del self.next_timers[:]
|
|
finally:
|
|
self.running = False
|
|
self.stopping = False
|
|
|
|
def abort(self):
|
|
"""Stop the runloop. If run is executing, it will exit after completing
|
|
the next runloop iteration.
|
|
"""
|
|
if self.running:
|
|
self.stopping = True
|
|
|
|
def squelch_generic_exception(self, exc_info):
|
|
if self.debug_exceptions:
|
|
traceback.print_exception(*exc_info)
|
|
sys.stderr.flush()
|
|
|
|
def squelch_timer_exception(self, timer, exc_info):
|
|
if self.debug_exceptions:
|
|
traceback.print_exception(*exc_info)
|
|
sys.stderr.flush()
|
|
|
|
def _add_absolute_timer(self, when, info):
|
|
# the 0 placeholder makes it easy to bisect_right using (now, 1)
|
|
self.next_timers.append((when, 0, info))
|
|
|
|
def add_timer(self, timer):
|
|
scheduled_time = self.clock() + timer.seconds
|
|
self._add_absolute_timer(scheduled_time, timer)
|
|
return scheduled_time
|
|
|
|
def timer_finished(self, timer):
|
|
pass
|
|
|
|
def timer_canceled(self, timer):
|
|
self.timer_finished(timer)
|
|
|
|
def prepare_timers(self):
|
|
heappush = heapq.heappush
|
|
t = self.timers
|
|
for item in self.next_timers:
|
|
heappush(t, item)
|
|
del self.next_timers[:]
|
|
|
|
def schedule_call_local(self, seconds, cb, *args, **kw):
|
|
"""Schedule a callable to be called after 'seconds' seconds have
|
|
elapsed. Cancel the timer if greenlet has exited.
|
|
seconds: The number of seconds to wait.
|
|
cb: The callable to call after the given time.
|
|
*args: Arguments to pass to the callable when called.
|
|
**kw: Keyword arguments to pass to the callable when called.
|
|
"""
|
|
t = timer.LocalTimer(seconds, cb, *args, **kw)
|
|
self.add_timer(t)
|
|
return t
|
|
|
|
def schedule_call_global(self, seconds, cb, *args, **kw):
|
|
"""Schedule a callable to be called after 'seconds' seconds have
|
|
elapsed. The timer will NOT be cancelled if the current greenlet has
|
|
exited before the timer fires.
|
|
seconds: The number of seconds to wait.
|
|
cb: The callable to call after the given time.
|
|
*args: Arguments to pass to the callable when called.
|
|
**kw: Keyword arguments to pass to the callable when called.
|
|
"""
|
|
t = timer.Timer(seconds, cb, *args, **kw)
|
|
self.add_timer(t)
|
|
return t
|
|
|
|
def fire_timers(self, when):
|
|
t = self.timers
|
|
heappop = heapq.heappop
|
|
|
|
i = 0
|
|
|
|
while t:
|
|
next = t[0]
|
|
|
|
exp = next[0]
|
|
timer = next[2]
|
|
|
|
if when < exp:
|
|
break
|
|
|
|
heappop(t)
|
|
|
|
try:
|
|
try:
|
|
timer()
|
|
except self.SYSTEM_EXCEPTIONS:
|
|
raise
|
|
except:
|
|
self.squelch_timer_exception(timer, sys.exc_info())
|
|
sys.exc_clear()
|
|
finally:
|
|
self.timer_finished(timer)
|
|
|
|
# for debugging:
|
|
|
|
def get_readers(self):
|
|
return self.listeners[READ].values()
|
|
|
|
def get_writers(self):
|
|
return self.listeners[WRITE].values()
|
|
|
|
def get_timers_count(hub):
|
|
return max(len(hub.timers), len(hub.next_timers))
|
|
|
|
def set_debug_listeners(self, value):
|
|
if value:
|
|
self.lclass = DebugListener
|
|
else:
|
|
self.lclass = FdListener
|
|
|
|
def set_timer_exceptions(self, value):
|
|
self.debug_exceptions = value
|