Drobe :: The archives
About Drobe | Contact | RSS | Twitter | Tech docs | Downloads | BBC Micro

Reply to thread

"A thread can only be run on one core at one time. For an application to run on more than one core simultaneously, it must be multi threaded."

"Killermike has suggested giving each application its own OS context, and I have pointed out that this is a technique used in Unix systems (back in the mainframe era). It would require some rewriting of the OS and extension modules, but would it really need to be so extensive?"

Hugely extensive. I tried to make a list of contexts in RISC OS that would need to be replicated, but gave up when I reached 20.

Untrue; it may be multiprocess, or the compiler may do magic to make safe parts execute on different hyperthreads or cores.

"Rjek has rightly pointed out that a switch statement with a long list of case statements is less efficient than a jump table for handling the Wimp_Poll reason codes, but I have already agreed that any saving would be insignificant in itself."

No, myself and imj both said that a switch statement gets /compiled/ to a jump table anyway. (In ARM code, a jump table is a single instruction followed by a list of branch instructions).

"The Wimp_Poll idea was to allow applications to respond to more than one event at a time, in a multiprocessor system"

Other systems simply have a job dispatch thread; it would listen to Wimp_Poll, and dispatch jobs to handler threads. This is both simple, and good enough.

 is a RISC OS Userrjek on 29/5/09 12:12AM
[ Reply | Permalink | Report ]

Please login before posting a comment. Use the form on the right to do so or create a free account.

Search the archives

Today's featured article

  • Java and RISC OS
    Nick Brown explores the state of play and future options
     47 comments, latest by em2ac on 28/09/07 12:34AM. Published: 19 Sep 2007

  • Random article

  • Last of the serial port digital cameras
    Photodesk Ltd. slashes prices in special offers as new technology goes USB
     Discuss this. Published: 21 Sep 2001

  • Useful links

    News and media:
    IconbarMyRISCOSArcSiteRISCOScodeANSC.S.A.AnnounceArchiveQercusRiscWorldDrag'n'DropGAG-News

    Top developers:
    RISCOS LtdRISC OS OpenMW SoftwareR-CompAdvantage SixVirtualAcorn

    Dealers:
    CJE MicrosAPDLCastlea4X-AmpleLiquid SiliconWebmonster

    Usergroups:
    WROCCRONENKACCIRUGSASAUGROUGOLRONWUGMUGWAUGGAGRISCOS.be

    Useful:
    RISCOS.org.ukRISCOS.orgRISCOS.infoFilebaseChris Why's Acorn/RISC OS collectionNetSurf

    Non-RISC OS:
    The RegisterThe InquirerApple InsiderBBC NewsSky NewsGoogle Newsxkcddiodesign


    © 1999-2009 The Drobe Team. Some rights reserved, click here for more information
    Powered by MiniDrobeCMS, based on J4U | Statistics
    "Drobe's only failing is the sixth-form geek-journo tone with its lead balloon humour and occasional smugness and ugly personalty"
    Page generated in 0.0505 seconds.