Oh and one more note, just FYI: Sync errors are not related to timing. The patches should be 100% safe to apply. What will cause sync errors is when the same code gives a different result on one client as on another client. This can happen for various reasons:
- Broken code (either in Spring itself or any library it uses) overwrites random memory that happens to be used in "synced" calculations - Different compiler optimizations - in particular ones that reduce / improve floating point accuracy - or change from X87 math to SSE math or vice versa Note though that with GCC 4.0 up to at least 4.4 the normal optimization options (-O0..-O3) all synced perfectly. - Miscompilations - Our "known good" build flags are overridden by something unsafe. - Different floating point accuracy selected in the processor. Spring typically ensures the correct mode is selected, but some libraries like to reset it... - Bugs in Spring or any libs used for synced calculations that make the results of those synced calculations depend on unsynced data. I hope that was useful :-) Regards, Tobi On 5 June 2011 13:45, Tobi Vollebregt <tobivollebr...@gmail.com> wrote: > Hi, > > I've actually noticed a few days ago that on Fedora 15 I also desync > with current release build. I am a developer but I am kind of inactive > so I didn't play online since Fedora 13. > > So if new Debian packages also desync that suggests to me that > something in the whole stack has been upgraded during this time which > breaks sync. > > I already did some tests (although on Fedora of course, but it looks > like this affects all distros): > > - self compiled spring with distro's gcc 4.6 : desync > - packaged spring (compiled with gcc 4.6) : desync > - self compiled spring using self compiled gcc 4.5 : desync > - someone else on Ubuntu (unknown version), using a self-compiled gcc > 4.6 : NO desync > - yet someone else on latest Ubuntu, using packaged gcc 4.6 : desync > > So to me this suggests that probably some upgraded library is to > blame, or gcc 4.6 contains some miscompile but only with certain > compilation options, but the search space is huge :-/ > > I'll keep you informed if I figure out more on why it happens / how to > solve it on Fedora, as the solution would probably apply to Debian > too. > > Regards, > > Tobi > > > On 5 June 2011 12:11, Jan Dittberner <ja...@debian.org> wrote: >> On Sun, Jun 05, 2011 at 10:16:39AM +0200, Piotr Majkrzak wrote: >>> Package: spring >>> Version: 0.82.7.1+dfsg1-3 >>> Severity: important >>> >>> Hi, >>> I have problem when I'm trying to play on-line, because I have lot of "sync >>> errors". >>> http://springrts.com/wiki/Build_from_source says that it can be caused by >>> wrong build. >>> Yours sincerely >>> Piotr Majkrzak >> >> I just checked a network game and got (few) sync errors too. Maybe this is >> related to the patch [1] added recently to fix the GCC 4.6 build failures. >> Upstream did not have objections to use this patch but maybe it introduces >> some minor timing issues. >> >> [1] >> http://anonscm.debian.org/gitweb/?p=pkg-games/spring.git;a=history;f=debian/patches/ftbfs-fix-625097.patch >> >> Thanks for reporting the issue. >> >> >> Jan Dittberner >> >>> -- System Information: >>> Debian Release: wheezy/sid >>> APT prefers unstable >>> APT policy: (500, 'unstable') >>> Architecture: amd64 (x86_64) >>> >>> Kernel: Linux 2.6.39-1-amd64 (SMP w/2 CPU cores) >>> Locale: LANG=pl_PL.UTF-8, LC_CTYPE=pl_PL.UTF-8 (charmap=UTF-8) >>> Shell: /bin/sh linked to /bin/dash >>> >>> Versions of packages spring depends on: >>> ii libboost-program-option 1.46.1-5 program options library for C++ >>> ii libboost-regex1.46.1 1.46.1-5 regular expression library for >>> C++ >>> ii libboost-signals1.46.1 1.46.1-5 managed signals and slots >>> library >>> ii libboost-system1.46.1 1.46.1-5 Operating system (e.g. >>> diagnostics >>> ii libboost-thread1.46.1 1.46.1-5 portable C++ multi-threading >>> ii libc6 2.13-4 Embedded GNU C Library: Shared >>> lib >>> ii libdevil1c2 1.7.8-6+b1 Cross-platform image loading >>> and m >>> ii libfreetype6 2.4.4-1 FreeType 2 font engine, shared >>> lib >>> ii libgcc1 1:4.6.0-11 GCC support library >>> ii libgl1-mesa-glx [libgl1 7.10.2-3 free implementation of the >>> OpenGL >>> ii libglew1.5 1.5.8-3 The OpenGL Extension Wrangler >>> - ru >>> ii libglu1-mesa [libglu1] 7.10.2-3 The OpenGL utility library >>> (GLU) >>> ii libogg0 1.2.2~dfsg-1 Ogg bitstream library >>> ii libopenal1 1:1.13-2 Software implementation of the >>> Ope >>> ii libsdl1.2debian 1.2.14-6.4 Simple DirectMedia Layer >>> ii libstdc++6 4.6.0-11 The GNU Standard C++ Library v3 >>> ii libvorbis0a 1.3.2-1 The Vorbis General Audio >>> Compressi >>> ii libvorbisfile3 1.3.2-1 The Vorbis General Audio >>> Compressi >>> ii libx11-6 2:1.4.3-1 X11 client-side library >>> ii libxcursor1 1:1.1.11-1 X cursor management library >>> ii otf-freefont 20100919-1 Freefont Serif, Sans and Mono >>> Open >>> ii spring-common 0.82.7.1+dfsg1-3 a modern full-3D RTS game >>> engine ( >>> ii zlib1g 1:1.2.3.4.dfsg-3 compression library - runtime >>> >>> Versions of packages spring recommends: >>> ii springlobby [spring-lobby] 0.130-1 single/multiplayer lobby for >>> the S >>> >>> Versions of packages spring suggests: >>> pn libtxc-dxtn0 <none> (no description available) >>> pn spring-javaai <none> (no description available) >>> pn spring-maps-deltasiege | spri <none> (no description available) >>> pn spring-mods-kernelpanic | spr <none> (no description available) >>> >>> -- no debconf information >>> >>> >>> >>> _______________________________________________ >>> Pkg-games-devel mailing list >>> pkg-games-de...@lists.alioth.debian.org >>> http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-games-devel >>> >> >> -- >> Jan Dittberner - Debian Developer >> GPG-key: 4096R/558FB8DD 2009-05-10 >> B2FF 1D95 CE8F 7A22 DF4C F09B A73E 0055 558F B8DD >> http://ddportfolio.debian.net/ - http://people.debian.org/~jandd/ >> >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.10 (GNU/Linux) >> >> iQIcBAEBCAAGBQJN61ZGAAoJEKc+AFVVj7jd1IEP/jm1RLiVcsmoIU3zbWBjNToK >> BSBwxzgeHo4geX8dkwmMZq5IILkIOv968HPLYp+RP01Hvd6oREAmu1bFeVZ5xEEB >> lSTikarnlD53mJ2IvFDMZFPAH2Ak87mJisGJmmSS23+DNuoVVDVDyByysVovTkWk >> vlg1w+nOE6OqW3l1v1tv5HAP5sEo9StU+wr/yhPQTr4rcCSSNbJ1qBfY4fLHnxC5 >> C+bOjX2fcWnBcrxJzshbeXuFAHAe15hcpA2O9dL7nKRVheBb0uZwklS7ehtH3n04 >> ol0xopD8ZUSnwIjOo/sfX4EBjSK2M8IEIDrWG4fOkpxSocvBIKdmXOYaxuq+R1m3 >> fD5keFCNIS3zDhxR81BuLHpOReO0ni1VJfm7TIF7qokLDwKGsx5HqY72+mdbtTsg >> K+HGL3UNB87vEzX6bcsqKT1VwrDLGNi17YASXgcSD9itXcYgWYH/F0iV/sOOz+JL >> olyIkS4tCfZA8t/Bqn+lJj5W+zLPcnIQ+RpJkdHo0ieokzBswM8N9CqHs//Hzlrh >> aqDuinP55XTVjnfpmf4u3dlmo++ZOqTvNPekUCBZ/HCnCqKRRf2TLNMZNB4cddbQ >> O6F/uNF3MCql9LaIVLCHD9HW+lX8uhnUIz79Lgomb0mMPQtWSzt7TdOb0PxXLTHr >> 12Kz4Nr+CoBWOk8SaIeN >> =AX/D >> -----END PGP SIGNATURE----- >> >> _______________________________________________ >> Pkg-games-devel mailing list >> pkg-games-de...@lists.alioth.debian.org >> http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-games-devel >> > -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". 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