From: Karsten Blees Date: Thu, 05 Jun 2014 20:03:42 GMT Subject: Re: [PATCH v2] Add a Windows-specific fallback to getenv("HOME"); Message-ID: <5390CD1E.5080500@gmail.com> In-Reply-To: Am 05.06.2014 15:39, schrieb Johannes Schindelin: > And in particular with your changes to Unicodify the complete environment, > I am *highly* doubtful that child processes will be able to handle > themselves properly, unless we spend a whole lot of time converting back > and forth the environment when calling children. The unicode version _does_ convert back and forth, in mingw_startup and make_environment_block, respectively. However, as the unicode environment is sorted, this is actually much faster than the original version. To put things in perspective *: entire mingw_startup: ~450 µs * _wgetmainargs: 25 µs * allocate+convert args and environment: 25 µs * qsort environment: 15 µs * winansi_init: 393 µs entire mingw_spawnve_fd: ~1250 µs * make_environment_block: 25 µs * CreateProcessW: 690 µs Now, the unicode mingw_getenv is O(log n) (~0.15 µs per call) and MSVCRT's getenv is O(n) (~3.6 µs per call). A git command that just launches a script (e.g. git gui) calls getenv ~25 times. (3.6 µs - 0.15 µs) * 25 = 86 µs, i.e. this compensates the additional startup time (including qsort) more than twice. (*) Measurements done via QueryPerformanceCounter, with 75 environment entries, on a Core i7 960, Windows 7 x64 -- -- *** Please reply-to-all at all times *** *** (do not pretend to know who is subscribed and who is not) *** *** Please avoid top-posting. *** The msysGit Wiki is here: https://github.com/msysgit/msysgit/wiki - Github accounts are free. You received this message because you are subscribed to the Google Groups "msysGit" group. To post to this group, send email to msysgit@googlegroups.com To unsubscribe from this group, send email to msysgit+unsubscribe@googlegroups.com For more options, and view previous threads, visit this group at http://groups.google.com/group/msysgit?hl=en_US?hl=en --- You received this message because you are subscribed to the Google Groups "msysGit" group. To unsubscribe from this group and stop receiving emails from it, send an email to msysgit+unsubscribe@googlegroups.com. For more options, visit https://groups.google.com/d/optout.