Hi, On Sat, Sep 10, 2011 at 3:38 AM, Bernd Blaauw <bbla...@home.nl> wrote: > Op 10-9-2011 9:47, Jim Michaels schreef: >> I could see multithreading support in 7-zip. >> but then again files aren't usually very big in DOS. I don't know if >> OpenWATCOM or DJGPP has support for POSIX threads. > > Programs that are multithreaded either have to implement their own SMP > support or rely on the operating system's kernel/architecture to do so. > As DOS by default doesn't support SMP, 7zip would have to implement > their own DOS support for speaking to multiple processors. I'm not aware > of any DOS program accessing multiple processors. Maybe a > "Distributed.net" client, but that's about it.
There are multitasking DOSes (DR-DOS, RDOS, TSX-32 ??, etc.), but most of them I haven't tried. And of course Windows and OS/2 or Linux's DOSEMU "sorta" count, at least the 32-bit versions. Normal vanilla DOS (API) doesn't have SMP or threading, but some of these variants have their own. (I've never tried RDOS, but it sounds really good. DR-DOS is okay if you can live with the old tools, bugs, and 64 MB per task limitation.) Of course, that doesn't help us, but whatever. ;-) p7zip 9.13 has been ported to DOS via DJGPP. Unlike older versions (used GNU pth), this one uses FSU pthreads (initially written for Ada/GNAT, though ironically latest Ada for DJGPP doesn't support tasks at all, probably because FSU was basically abandoned a long time ago). Unlike GNU pth, you don't need a socket lib (libsocket, Watt-32), so it's easier to use, allegedly. But no, it's not real threads, just faking it so that p7zip compiles (as the "p" stands for POSIX, which obviously needs a lot more than minimal DOS/DJGPP services to run). HX works with Win32's 7ZA.EXE with (fake) threading, but no SMP support (yet), which is super complicated anyways. Besides, 7-Zip doesn't use much multithreading except to offload some file management, so it doesn't really help that much anyways, not 10x (nor even 2x) at least. Most home computers don't have many cores anyways, and it's hard to properly scale upwards in speed. ------------------------------------------------------------------------------ Malware Security Report: Protecting Your Business, Customers, and the Bottom Line. Protect your business and customers by understanding the threat from malware and how it can impact your online business. http://www.accelacomm.com/jaw/sfnl/114/51427462/ _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
