1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
# Copyright (c) Twisted Matrix Laboratories.
# See LICENSE for details.
from twisted.internet import _threadedselect
_threadedselect.install()
from itertools import count
from twisted.internet import reactor
from twisted.internet.defer import Deferred
from twisted.python.failure import Failure
from twisted.python.runtime import seconds
try:
# Python 3
from queue import Empty, Queue
except ImportError:
# Python 2
from Queue import Empty, Queue
class TwistedManager:
def __init__(self):
self.twistedQueue = Queue()
self.key = count()
self.results = {}
def getKey(self):
# get a unique identifier
return next(self.key)
def start(self):
# start the reactor
reactor.interleave(self.twistedQueue.put)
def _stopIterating(self, value, key):
self.results[key] = value
def stop(self):
# stop the reactor
key = self.getKey()
reactor.addSystemEventTrigger(
"after", "shutdown", self._stopIterating, True, key
)
reactor.stop()
self.iterate(key)
def getDeferred(self, d):
# get the result of a deferred or raise if it failed
key = self.getKey()
d.addBoth(self._stopIterating, key)
res = self.iterate(key)
if isinstance(res, Failure):
res.raiseException()
return res
def poll(self, noLongerThan=1.0):
# poll the reactor for up to noLongerThan seconds
base = seconds()
try:
while (seconds() - base) <= noLongerThan:
callback = self.twistedQueue.get_nowait()
callback()
except Empty:
pass
def iterate(self, key=None):
# iterate the reactor until it has the result we're looking for
while key not in self.results:
callback = self.twistedQueue.get()
callback()
return self.results.pop(key)
def fakeDeferred(msg):
d = Deferred()
def cb():
print("deferred called back")
d.callback(msg)
reactor.callLater(2, cb)
return d
def fakeCallback():
print("twisted is still running")
def main():
m = TwistedManager()
print("starting")
m.start()
print("setting up a 1sec callback")
reactor.callLater(1, fakeCallback)
print("getting a deferred")
res = m.getDeferred(fakeDeferred("got it!"))
print("got the deferred:", res)
print("stopping")
m.stop()
print("stopped")
if __name__ == "__main__":
main()
|
