Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!comp.vuw.ac.nz!actrix!templar!jbickers
From: jbickers@templar.actrix.gen.nz (John Bickers)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: How do we change the scheduler? (Was Re: Multitasking at home...)
Message-ID: <10682.tnews@templar.actrix.gen.nz>
Date: 24 Jan 91 02:15:58 GMT
References: <1991Jan18.231330.16290@Neon.Stanford.EDU> <7553@sugar.hackercorp.com> 
 <1991Jan21.004720.25985@ncsuvx.ncsu.edu> <12880@life.ai.mit.edu> 
 <1991Jan21.072642.23587@Neon.Stanford.EDU> <10620.tnews@templar.actrix.gen.nz>
 <1991Jan22.215801.4557@Neon.Stanfor
Organization: TAP, NZAmigaUG.
Lines: 78

Quoted from <1991Jan22.215801.4557@Neon.Stanford.EDU> by torrie@cs.stanford.edu (Evan J Torrie):
> jbickers@templar.actrix.gen.nz (John Bickers) writes:
> >    No. Programs can set their own priorities, however, and the input
> >    handling task runs at a higher priority than anything else (so if

>   Can you explain the "input handling" task?  Do programs spin off an
> input-handler thread (this is how OS/2 programs are written if I

    Consider that there are two levels to input handling. One is handling
    receipt of the users actions (buffering keystrokes, moving the mouse
    pointer, resizing windows, swapping screens, etc). The other is the
    application actually getting around to doing something with the input.

    The 1st level is handled by a single task. The following is a list
    of tasks currently running on my machine...

    CPU:68020/68881     CPU activity:  25.0% 
    Dispat/Sec: 19.4    I/O Ints/Sec:  11.7
 
        ID     TYPE      STATE    PRI  CPUSE NUM TASKNAME
     -----------------------------------------------------
     0025d190 Process   Running     0   6.7% --- Xoper
     00202748 Process   Waiting     4   0.0%   0 RexxMaster
     0020b4a8 Process   Waiting     4   0.0% --- WSH_Completer
     002185b0 Process   Waiting     1   0.6% --- JDMouse
     00219b78 Process   Waiting     5   0.0% --- PopUpMenu
     0021f450 Process   Waiting     4   0.0% --- Snap
     00222b50 Process   Waiting    10   4.1% --- MISC
     00225b90 Process   Waiting     0   0.0%   1 New_WShell
     0022eac8 Process   Waiting     5   0.0% --- CON
     0023c5b8 Process   Waiting     0   2.0%   2 [ getty ]
     0023db38 Process   Waiting     5   0.0% --- NULL
     0023df40 Process   Waiting     0   0.0%   3 [ dcron ]
     0024019c Task      Waiting     0   0.0% --- narrator.device
     00242d98 Process   Waiting    10   0.0% --- PATH
     00251510 Process   Waiting     0   0.0%   4 [ tnews ]
     0025ef20 Process   Waiting    10   4.4% --- FAST
     0027c810 Process   Waiting     1   0.0%   0 CygnusEd
     00c00bd8 Process   Waiting    10   8.3% --- File System
 +-> 00c0270a Task      Waiting    20  47.7% --- input.device
 |   00c0482e Task      Waiting     5   8.5% --- trackdisk.device
 |   00c05d08 Process   Waiting    10   4.4% --- File System
 |   00c06266 Task      Waiting     5   8.5% --- trackdisk.device
 |   00c13e48 Process   Waiting     0   0.0% --- RAM
 |   00c15360 Process   Waiting    10   4.1% --- DH0
 |   00c169cc Task      Waiting     5   0.0% --- hddisk.device
 |
 +- See input.device, the one with a priority of 20? That's it.

    This gets input from the user, and funnels each event through a
    chain of input handlers. The program JDMouse is one such, which
    does screen blanking (timer events), mouse acceleration (mouse
    events), and what-not. PopUpMenu and Snap are another two.

    The 2nd level can be handled in a variety of ways (some programs
    do use input-handlers as well as normal mechanisms), and varies
    from program to program.

> >    A number of programs display some intelligence about what priority
> >    to use automatically (like editors that edit at priority 1, or
> >    executable packers that crunch at priority -1, etc). And some can
> >    be configured.
> 
>   "Some" can be configured?  Is there an all-purpose "nice" command?

    By configured I mean can be set to use a particular priority through
    a configuration file.

    By "nice" command I assume you mean a command that can change
    task priorities on the fly (that's not what I meant by configured,
    sorry). Anyhow, yes, the program that produced the task list
    above can also be used to change priorities (amongst other things,
    including pausing or killing tasks).

> Evan Torrie.  Stanford University, Class of 199?       torrie@cs.stanford.edu   
--
*** John Bickers, TAP, NZAmigaUG.        jbickers@templar.actrix.gen.nz ***
***         "Patterns multiplying, re-direct our view" - Devo.          ***