Jigal van Hemert <jigal@stripped> wrote on 10/31/2005 03:41:39 AM:
> SGreen@stripped wrote:
> > wang shuming <wangshuming01@stripped> wrote on 10/31/2005 01:11:06
AM:
> >>How could run mysqld-nt.exe in background on win2000/XP, not as a
> > would be useful in HIS operating system. AFAIK, there has never, ever,
> > been a Windows (or DOS) command or command modifier to launch an
> > executable in the background and I have been a Windows(DOS) user since
the
> > mid 80's. I believe I would have probably run across it a long time
ago if
> > it existed.
>
> Shawn,
>
> Back in the eighties we had several little utility programs that ran in
> the background. Does the name TSR (Terminate and Stay Resident)
> (http://en.wikipedia.org/wiki/Terminate_and_Stay_Resident) ring a bell?
>
> The ability to TSR was present from MS-DOS 2.0 until Windows ME, so
> there is no way to do this in Win2k/XP.
>
> Regards, Jigal.
TSR's weren't exactly in the background and they were tricky to setup to
behave correctly. I know, I wrote a few.
They injected themselved in the interrupt handling tree so that, for
example, whenever INT 1C (timer tick) was triggered it would funnel
through the TSR chain with each TSR in the chain performing a bit of it's
processing then calling the next link in the chain (whichever function had
the interrupt before it) until you eventually arrive at either the
original BIOS routine for that interrupt or a function that returned
without calling the routine that it replaced.
They only simulated background processing by interjecting themselves
between the "foreground" application and the system interrupt calls to the
BIOS. However, because DOS was not a multitasking OS, if you
mis-configured a TSR or if you designed it to do so, it could take over
and lock down the system (that's how DOS-level AV software worked in the
day). There was no concept of thread prioritization or time-slicing or
task switching or any of the other things that modern CPUs and OS's do
with _relative_ efficiency.
Yes, it does ring a bell :-)
However, you could not make an application into a TSR unless it was
already desiged to operate that way. In this case, TSRs would not meet
his need to "push" an executable into the background so that one Windows
CMD window can be executing more than one task at a time.
Shawn Green
Database Administrator
Unimin Corporation - Spruce Pine
