Re: [Twisted-Python] blocking and threads
Thanks, how embarassing... I suggest adding it to the
"using threads" howto (I'd do it myself if I knew
how). Another idea: make an asynchronous file-handling
module that wraps Python's file IO with something that
has a deferred-oriented interface. Is there already
something like that too?
Joe
--- Jp Calderone
Hi all,
I am just wondering: from the Twisted how-tos, it appears that doing anything that could possibly take arbitrarily long to execute should not be done in
reactor's main thread; i.e. it should be done using an asynchronous library (such as Twisted's network communication facilities), or in a different
On Wed, 27 Apr 2005 05:49:01 -0700 (PDT), Joachim Boomberschloss
wrote: the thread, using the reactor's thread pool.
So it would seem that many things that may be considered "primitive" in Python, such as file IO, require some kind of patching if they are to be immediately usable by a Twisted application. I came up with the following solution, which enables calling any function in a different thread with a deferred interface; I just wanted to make sure that I'm not completely missing some point:
def deferToThread(func, *args, **kargs): """executes the given function in a thread, and passes the return value to the deferred we return""" d = defer.Deferred() reactor.callInThread(_calledInThread, d, func, *args, **kargs) return d
def _calledInThread(d, func, *args, **kargs): try: retval = func(*args, **kargs) except Exception, x: reactor.callFromThread(d.errback, x) else: reactor.callFromThread(d.callback, retval)
Looks like you've got a pretty firm understanding. The one thing you did miss is the twisted.internet.threads module, which provides the deferToThread function.
Jp
_______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com
http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
participants (5)
-
Eugene Coetzee
-
Itamar Shtull-Trauring
-
jarrod roberson
-
Joachim Boomberschloss
-
Jp Calderone