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Re: Slashdot: Providers Ignoring DNS TTL?


From: Valdis.Kletnieks () vt edu
Date: Sun, 24 Apr 2005 02:00:48 -0400

On Sat, 23 Apr 2005 16:13:22 EDT, Dean Anderson said:

I'm reminded of the arguments in the late 80's about threading:  People
(like you) said there are no multithreading operating systems, and
multiprocessor systems existed only in labs.  So designing threadsafe
libraries or writing multithreading capable languages was a total waste of
time.  And they showed as evidence all the programs written from 1975 to
1985.

Odd, seeing how IBM's OS/360 supported multithreading in the mid-60s (well, OK,
only the MVT variant did it really well - MFT had some restrictions, and PCP
was basically a program loader on steroids), as did Multics, early Unix, the
various PDP-8/11 and DEC-10/20 operating systems, and most supported
multiprocessor systems before 1970.

What you're actually talking about is the "I don't have to worry about *THAT*"
syndrome that's always been the bane of program portability.  Those of us who
were around at the time remember all too well "Not all the world's a VAX" when
programs that ran fine under BSD on a VAX would bomb out under SunOS 3.2 -
because the VAX allowed dereferencing a NULL pointer and SunOS didn't.

And anyhow, you're looking at it totally backwards - things like system libraries
didn't support multithreading well at first because nobody was *interested* in
doing it.  The support did happen once there was an actual demand for it.
Remember that there's a *cost* to supporting multithreading - you have to drag
along all this ugly locking code and stuff like that.  It's really hard to
justify putting in code that slows down the 95% of the applications that are
single-threaded for the 5% that are multi-threaded, and even harder to justify
putting the support in the library "just in case somebody wants to use it in
the future".

Well, PPLB isn't the end of the world. But PPLB is coming, and the smart 
people will be prepared for it.  They dumb people, well, they're dumb. 
What can be expected from dumb people?

What you seem to be missing is that the *really* smart people will be prepared
for it when it actually gets here - and will take advantage of it's lack of
arrival in the meantime.

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