John Arbash Meinel wrote: > On 03/29/2011 08:24 AM, Andrew Bennetts wrote: > > John Arbash Meinel wrote: > > [...] > >> > >> Best case time, 350ms. Apparently those aren't the expensive exceptions. > >> So it does help (350ms is better than 480ms.) But not as much as > >> 'tb=None' ~180ms. > > > > Hmm, interesting. It might be worth patching Failure and Deferred on > > your system to see where the other calls to Failure() [i.e. with no > > args] are coming from. Specifically patch the part of > > Deferred._runCallbacks that calls Failure() to say which callback > > triggered it, and patch Failure.__init__ to report when it is called > > without args too, because there may be some places that don't happen > > directly in Deferred… > > I believe there are things like Failure.trap() and xmlrpc.trap_fault() > that can do a bare 'raise' to re-raise the original exception because it > doesn't match the exact type that the error handler can handle.
Neither of those is a problem, although I had to check earlier today to be sure :) Failure.trap() will re-raise the original Failure (it's an old-style class, which Python allows to be raised, like how it allows you to raise strs). Calling Failure() when the active exception is a Failure does some magic that ends up setting self.__dict__ = raised_failure.__dict__, so the result of Failure() in that case doesn't have self.tb set if the original failure didn't either. lp.services.twistedsupport.xmlrpc.trap_fault is the same: the only thing it raises is the failure given to it (either via Failure.trap or directly). So it's ok too. [...] > At least as I read that, if you pass an object for 'exc_value' but pass > None for 'exc_tb' it will find the traceback from sys.exc_info. I have > to actually audit the code to make sure that is the case. I have two strong pieces of evidence that my understanding is correct. 1) my patch sped up your benchmark :) 2) >>> from twisted.python.failure import Failure >>> try: ... 1/0 ... except ZeroDivisionError as e: ... f = Failure(e) ... f2 = Failure() ... >>> print f.tb None >>> f2.tb <traceback object at 0xb7508d4c> -Andrew. _______________________________________________ Mailing list: https://launchpad.net/~launchpad-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~launchpad-dev More help : https://help.launchpad.net/ListHelp
