1 files changed, 92 insertions, 0 deletions
diff --git a/doc/core/examples/threadedselect/blockingdemo.py b/doc/core/examples/threadedselect/blockingdemo.py
new file mode 100644
index 0000000..7dc98df
--- /dev/null
+++ b/doc/core/examples/threadedselect/blockingdemo.py
@@ -0,0 +1,92 @@
+# Copyright (c) Twisted Matrix Laboratories.
+# See LICENSE for details.
+
+
+from twisted.internet import _threadedselect
+_threadedselect.install()
+
+from twisted.internet.defer import Deferred
+from twisted.python.failure import Failure
+from twisted.internet import reactor
+from twisted.python.runtime import seconds
+from itertools import count
+from Queue import Queue, Empty
+
+class TwistedManager(object):
+    def __init__(self):
+        self.twistedQueue = Queue()
+        self.key = count()
+        self.results = {}
+
+    def getKey(self):
+        # get a unique identifier
+        return self.key.next()
+
+    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()