[Twisted-Python] Wrapping blocking code

[Justin Johnson]

Since I'm running on win2k (ugh!) I followed the instructions to use
win32eventreactor instead of the default posix reactor.  I did read
through the docstrings, and it does mention that process calling can be
problematic.  I ran the code below and got the following error.  Is it
possible to get this working on windows?  It is marked as semi-stable. 
Man I hate windows!  Unfortunately the servers I support are all windows
boxes.


C:\Python22\Lib\site-packages\twisted\internet\win32eventreactor.py:198:
Depreca
tionWarning: Foolish capitalist!  Your opulent toilet will be your
undoing!!
  log.logOwner.own(fd)
C:\Python22\Lib\site-packages\twisted\internet\win32eventreactor.py:213:
Depreca
tionWarning: The proletariat is victorious.
  log.logOwner.disown(fd)


[snip]
from twisted.internet import protocol
from twisted.internet import win32eventreactor
win32eventreactor.install()
from twisted.internet import reactor

class MyProcessProtocol(protocol.ProcessProtocol):
	finished = 0

	def connectionMade(self):
		self.data = ''
		self.err = ''
		self.transport.write("connectionMade")

	def outReceived(self, data):
		self.data = self.data + data

	def outConnectionLost(self):
		self.transport.write("outConnectionLost")

	def errReceived(self, data):
		self.err = self.err + data
		self.transport.write("errReceived")

	def errConnectionLost(self):
		self.transport.write("errConnectionLost")

	def inConnectionLost(self):
		self.transport.write("inConnectionLost")

	def processEnded(self, reason):
		self.finished = 1
		self.reason = reason
		self.transport.write("processEnded")


exe = r"c:\program files\rational\clearcase\bin\cleartool.exe"
p = MyProcessProtocol()
reactor.spawnProcess(p, exe, [exe, "lsview", "-s"], env=None)
while not p.finished:
	reactor.iterate()
[/snip]


On Wed, 23 Jul 2003 14:42:15 -0600, "Dave Smith" <dizzyd at jabber.org>
said:
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> Sounds to me like you want to use a deferToThread(...), to pass the 
> calls off to the reactor's thread pool so they can run there without 
> holding up the reactor's runloop.
> 
> See also: 
> http://www.itamarst.org/writings/OSCON03/twisted_internet-95.html
> 
> Hope that helps. :)
> 
> Diz
> 
> On Wednesday, Jul 23, 2003, at 10:16 America/Denver, Justin Johnson 
> wrote:
> 
> > I have some code in my xmlrpc service that executes commands using
> > process.py (http://starship.python.net/crew/tmick/).  The service 
> > appears
> > to block this code, thus only allowing one connection to get any work
> > done at a time, at least while the commands are being executed.  
> > Should I
> > be wrapping this up in a Deferred somehow to avoid blocking?
> >
> > Slowly but surely this is starting to make sense to me.  Twisted rocks!
> >
> > Thanks.
> > -Justin
> >
> > _______________________________________________
> > Twisted-Python mailing list
> > Twisted-Python at twistedmatrix.com
> > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
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