I think we still need to make sure that a call to float (and other numeric primitives) uses light weight exceptions as well for this scenario to completely be fast but that should be pretty easy.
> -----Original Message----- > From: users-boun...@lists.ironpython.com [mailto:users- > boun...@lists.ironpython.com] On Behalf Of Dave Fugate > Sent: Tuesday, August 03, 2010 10:03 AM > To: Discussion of IronPython > Subject: Re: [IronPython] Exception Performance > > Yup, I think you'll find the situation in IronPython 2.7A1 to be a bit better > in this respect: > D:\rft\vsl\dlr\bin>type blah.py > from System.Diagnostics import Stopwatch > t = Stopwatch() > > try: > t.Start() > x = 1/0 > except Exception, e: > t.Stop() > > print t.Elapsed.TotalMilliseconds > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.6\ipy.exe" > blah.py > 2.6096 > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.6\ipy.exe" > blah.py > 2.4518 > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.6\ipy.exe" > blah.py > 2.4622 > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.7\ipy.exe" > blah.py > 0.7887 > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.7\ipy.exe" > blah.py > 0.7633 > > D:\rft\vsl\dlr\bin>"C:\Program Files (x86)\IronPython 2.7\ipy.exe" > blah.py > 0.7683 > > Dave > > > -----Original Message----- > From: users-boun...@lists.ironpython.com [mailto:users- > boun...@lists.ironpython.com] On Behalf Of Jeff Hardy > Sent: Tuesday, August 03, 2010 8:41 AM > To: Discussion of IronPython > Subject: Re: [IronPython] Exception Performance > > Hi Cory, > > On Mon, Aug 2, 2010 at 12:41 PM, Cory Brostowicz <cory.brostow...@gmail.com> > wrote: > > Hello, > > I noticed the performance in one of my python scripts has really bad > > performance, so I started profiling different sections of the script > > to find out where the issue is. It turns out, the exception handle > > seems to add the biggest chunk of time. > > IronPython 2.6 and earlier rely on the .NET exception mechanism. > .NET's exception handling is extremely slow, whereas CPython has an extremely > fast exception handling system. I don't know the details of why each is the > way it is, though - engineering tradeoffs, I guess. > > IronPython 2.7 will have a 'lightweight' exception mechanism that should be > closer to the performance of CPython. > > > I've fairly new to the Python language, so if there is a better way to > > do what I'm doing, then please let me know. > > Unfortunately, I think that's pretty much idiomatic Python, which often relies > on it's very fast exception handling. In .NET you use the > Try* methods instead, which don't throw exceptions. > > If you don't need CPython compatibility, you could use System.Double.TryParse > (http://msdn.microsoft.com/en-us/library/994c0zb1.aspx), but I don't know how > to use out parameters from IronPython off the top of my head. > > On an unrelated note, you can write your print statement as: > > print "Total: %s RateGet: %s RateSets: %s Exception Handle: %s > Rate: %s" % (t.Elapsed.TotalMilliseconds, rateGet, rateSet, > e.Elapsed.TotalMilliseconds, Rate) > > - Jeff > _______________________________________________ > Users mailing list > Users@lists.ironpython.com > http://lists.ironpython.com/listinfo.cgi/users-ironpython.com > > _______________________________________________ > Users mailing list > Users@lists.ironpython.com > http://lists.ironpython.com/listinfo.cgi/users-ironpython.com _______________________________________________ Users mailing list Users@lists.ironpython.com http://lists.ironpython.com/listinfo.cgi/users-ironpython.com
