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Re: [function] timing trivia
by matt＠finray.com 15 Feb '04

15 Feb '04

"Pavel Vozenilek" wrote in message news:c0nfp0$pp5$1@sea.gmane.org... > > "Hurd, Matthew" <hurdm(a)sig.com> wrote > > > This is an Intel P43.2 I'm running on now and I'm getting output like: > > > > boost function measurements: median time = 250.698 microseconds > > direct in-line: median time = 250.691 microseconds > > > > You see here I look at the median time for boost function and > > direct-inline and see only a 7 ns difference which is probably smaller > > than I can truly measure I suspect... > > > I wrote my own test (the most simple one, call function/boost::fn > in loop and measuring total time). > > The numbers I got give me ~18 microseconds overhead per single > boost::function call (raw call takes ~404 microseconds). > > I use Intel C++ 8.0 plugged in VC6 IDE,, release mode, > Athlon XP 2200+, W2K. > > /Pavel > <snipped code> > ---------------------------------- > > test1() and test2() took each 30-40 seconds. > GetTickCount() resolution is at least 10 milliseconds. Thanks Pavel. I ran your test with vc7.1 in an optimised form as is with the only change being test1 and test1 returning tick2-tick1 as a long. Similar ball park figures for overall run time as you. test1 = 33312 ms test2 = 30625 ms Yep, boost function call based loop is faster. vc7.1, athlon 2800+, xp1a Also the 18 microseconds cost you measured, or roughly 30 microseconds benefit measured with my optimisation settings, can't just be put down to the boost::function difference I think as 18 microseconds is 36,000 cycles at 2 GHz and I don't think boost function could possibly cost that. If I crank the loop down to #define MAX_FN_LOOP 1e2 with 10,000,000 iterations in the test fn's I get test1 = 3578 ms test2 = 3219 ms Still curiously faster. Though the overhead indicated is 3.6 nanoseconds... If I turn my optimisations off for the last case, but still run in release mode I get: test1 = 8594 ms test2 = 8797 ms Which is the way around you'd expect it to be with boost::function being slower given some kind of abstraction penalty. So, I guess the insight is, your mileage may vary, optimisers are strange beasts, benchmarks are often misleading and weird... cliches are cliches. By the way, I have a slightly improved little bench harness that correctly measures emptiness at zero nanoseconds for an instrusive style of benchmark now if you or any one is interested I can email it to you. That is it correctly measures: inline double blank( matt::timer& t ) { double now; t.restart(); now = t.elapsed(); return now; } to be zero ns consistently for me. Thanks again for your numbers Pavel. Regards, Matt Hurd.

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Re: [boost] Re: A VC6 bug in const_reverse_iterator implementation?
by RGProlog＠aol.com 15 Feb '04

15 Feb '04

I am talking about 1.30.2 version of Boost Libraries. I tried the following in the VC6 enviroment: array<int, 3> arr = {{1, 2, 3}}; array<int, 3>::const_iterator ci = arr.begin(); // works fine array<int, 3>::const_reverse_iterator cri = arr.rbegin(); // fails to ompile

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RE: [boost] Re: [function] timing trivia
by Hurd, Matthew 15 Feb '04

15 Feb '04

> On Behalf Of Pavel Vozenilek > Subject: [boost] Re: [function] timing trivia > > > "Matthew Hurd" <matt(a)finray.net> wrote > > [snip boost::function benchmark info] > > > Can't explain it. Boost function can't be faster for the 10 million > loop > by > > more than a millisecond. I see none of this whacky behaviour with > release > > optimized code. > > > Can you post complete test code somewhere? > > /Pavel Probably small enough to post here... (12KB) Open the .sln, compile and run the "test" project and you should see something similar to: This is an Intel P43.2 I'm running on now and I'm getting output like: --------------------------------------------------------------------- quick time before overhead estimate= 393.5650855126686 nanoseconds time including previous console output = 1.157412246893155 milliseconds overhead estimate = 127.8459831920134 nanoseconds quick time after overhead estimation = 95.25779139797076 nanoseconds time including previous console output = 1.160907957159062 milliseconds --------------------------------------------------------------------- new timer for checking static carry --------------------------------------------------------------------- quick time -1.253391992078558 nanoseconds quick time -5.013567968314233 nanoseconds overhead estimate = 127.8459831920134 nanoseconds quick time 2.506783984157143 nanoseconds quick time -5.013567968314233 nanoseconds --------------------------------------------------------------------- check timing jitter on a simple loop --------------------------------------------------------------------- --------------------------------------------------------------------- estimating indirect function call overhead --------------------------------------------------------------------- --------------------------------------------------------------------- boost function measurements --------------------------------------------------------------------- median time = 250.698 microseconds 90% range size = 6.26696 nanoseconds widest range size (max - min) = 149443 nanoseconds minimum time = 250.695 microseconds maximum time = 400.138 microseconds 50% range = (250.695, 250.701) microseconds 50% range size = 6.26696 nanoseconds stop the optimiser eliding garbage = 3.33328e+017 stop the optimiser eliding garbage = 3.33328e+017 --------------------------------------------------------------------- direct in-line --------------------------------------------------------------------- median time = 250.691 microseconds 90% range size = 6.26696 nanoseconds widest range size (max - min) = 29324.4 nanoseconds minimum time = 250.688 microseconds maximum time = 280.013 microseconds 50% range = (250.688, 250.692) microseconds 50% range size = 3.76018 nanoseconds stop the optimiser eliding garbage = 3.33328e+017 stop the optimiser eliding garbage = 3.33328e+017 Press any key to continue . . . You see here I look at the median time for boost function and direct-inline and see only a 7 ns difference which is probably smaller than I can truly measure I suspect... At the top of looper.hpp there is #define MAX_FN_LOOP 1e5 which controls the iterations in the timing loop. If my hacked up untidy code is buggy or if you have some insight I would love to hear about it. Regards, Matt Hurd _______________________ Susquehanna Pacific P/L hurdm(a)sig.com +61.2.8226.5029 _______________________ IMPORTANT: The information contained in this email and/or its attachments is confidential. If you are not the intended recipient, please notify the sender immediately by reply and immediately delete this message and all its attachments. Any review, use, reproduction, disclosure or dissemination of this message or any attachment by an unintended recipient is strictly prohibited. Neither this message nor any attachment is intended as or should be construed as an offer, solicitation or recommendation to buy or sell any security or other financial instrument. Neither the sender, his or her employer nor any of their respective affiliates makes any warranties as to the completeness or accuracy of any of the information contained herein or that this message or any of its attachments is free of viruses.

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Boost Filesystem Build On GCC
by Stephan T. Lavavej 15 Feb '04

15 Feb '04

When Boost Filesystem is built with bjam "-sTOOLS=gcc" or bjam "-sTOOLS=mingw" on MinGW, the resulting static library is a .lib consisting of .obj files. However, it is traditional for gcc to use .a files which consist of .o files. I fix this by hand by renaming the .obj files to .o and then executing ar rvs libboost_filesystem.a *.o , but it would be nice if bjam would get it correctly by itself. Stephan T. Lavavej http://nuwen.net

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[Boost-bugs] [ boost-Bugs-897250 ] boost::mutable_queue constructor with iterators
by SourceForge.net 14 Feb '04

14 Feb '04

Bugs item #897250, was opened at 2004-02-14 22:45 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=897250&group_i… Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Cromwell Enage (expaler) Assigned to: Nobody/Anonymous (nobody) Summary: boost::mutable_queue constructor with iterators Initial Comment: Constructing a mutable_queue using container.begin() and container.end() causes the elements in container to be inserted twice into the mutable_queue. This is because the mutable_queue's internal container c is first initialized with the same iterators, thus already inserting the elements into c, and then the while loop inserts the elements into c again. Changing c(first, last) to c() in the constructor should fix the bug. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=897250&group_i… ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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indirect_pmap
by Cromwell Enage 14 Feb '04

14 Feb '04

Does anybody remember (or, is anybody actively) using the indirect_pmap functor class template defined at <boost/pending/indirect_cmp.hpp>? A Google search within the Boost site turned up empty. Sifting through most of the graph source code (haven't yet looked at the detail subfolder) was also fruitless. Nevertheless, my documentation quest continues... Cromwell Enage __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html

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future of boost.threads
by Burc Arpat 14 Feb '04

14 Feb '04

i was actually waiting for the rush of the new release to go away to ask this question: i have seen some recent discussions regarding the threads library and from what i gathered there are plans to start working on it again. but, it also seems the original owner of the lib has disappeared from the list here at the petroleum eng. dept. of stanford university, we use boost rather heavily and lately we started into looking parallelization issues. we, of course, would like to use a cross-platform library such as boost.threads but are a bit worried about the future of it so, i guess, the questions are: is there gonna be a new release of boost.threads? if so, are there any plans to change the interface to a degree that it will require significant changes in the user code? with that said, let me also state that, i will be more than glad to give full test support for the library if any changes are being considered burch - - - G. Burc ARPAT Ph.D. Candidate Dept. of Petroleum Engineering Stanford University Stanford, CA 94305 Internet: www.burcarpat.com

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[BGL] [boost-sandbox] make_random_paths
by Cromwell Enage 14 Feb '04

14 Feb '04

<http://groups.yahoo.com/group/boost/files/bgl_algo/make_random_paths.zip> Changes made: * Now uses concept checking. * No more fat from in_edges, cout_utility, etc. * New unit test added. * Documentation mistakes fixed. Cromwell Enage __________________________________ Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html

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Building boost::filesystem without bjam
by Joe Gottman 14 Feb '04

14 Feb '04

I just upgraded to boost 1.31. I use filesystem with MSVC 6.0, but I don't use the jamfiles to create my .dsp and .dsw files. I just created simple projects myself. It worked previously, but now when I try to include the filesystem.dll file, I get the error LINK : fatal error LNK1104: cannot open file "libboost_filesystem-vc6-mt-gd-1_31.lib" Do you have any suggestions?

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Got a boost-request email with MyDoom in it...
by Dan W. 14 Feb '04

14 Feb '04

My antivirus killed it so fast I can't remember if it was a, b or c variant. It was appended to the last message, which starts like, ------------------------------ Date: Thu, 12 Feb 2004 08:36:48 +0800 From: kevlin(a)curbralan.com To: boost(a)lists.boost.org Subject: [boost] Mail Transaction Failed Message-ID: <200402120032.i1C0Wq529796(a)heart-of-gold.osl.iu.edu> Content-Type: multipart/mixed; boundary="----=_NextPart_000_0006_642BC3B6.52190D69" MIME-Version: 1.0 Precedence: list Message: 10 This is a multi-part message in MIME format. ------=_NextPart_000_0006_642BC3B6.52190D69 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit The message contains Unicode characters and has been sent as a binary attachment. ------=_NextPart_000_0006_642BC3B6.52190D69 Content-Type: application/octet-stream; name="message.pif" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="message.pif" TVqQAAMAAAAEAAAA//8AALgAAAAAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA ........................ ------------------------------ I guess the SMTP server doesn't scan what it sends... Not that that I have much of an issue with the spirit of it... ;-) The microsoft server is kind of slow tonight, trying to get all those patches between the DOS cracks... Cheers!

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