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From: jmunkki@kampi.hut.fi (Juri Munkki)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Locking executable resources
Keywords: lock init executable patch
Message-ID: <21859@santra.UUCP>
Date: 8 May 89 23:27:40 GMT
References: <4170@druco.ATT.COM> <1591@hub.ucsb.edu> <1476@murtoa.cs.mu.oz.au>
Sender: news@santra.UUCP
Reply-To: jmunkki@kampi.hut.fi (Juri Munkki)
Distribution: comp
Organization: Helsinki University of Technology, Finland
Lines: 37

In article <1476@murtoa.cs.mu.oz.au> jkjl@munmurra.UUCP (John Lim) writes:
>You do not have to lock any executable resource if you are
>not calling code that will move handles in the *same* system heap.
						^^^^^^^
						Not strictly true. :-)

How do you know that allocating a block from the system heap will not
cause changes in the application heap? You think it doesn't happen,
but how can you be sure? I'm pretty sure you are correct in assuming
this, but since Apple doesn't say anything about the affected zones,
it might change in the future! Never assume anything.

>I have seen several articles in MacTutor that are fairly
>laughable concerning VBL tasks. The idiots use GetCursor()
>and GetIcon() in the VBL tasks which move memory during interrupts 

It was relatively easy to predict what would happen to MacTutor
after a few years. It was a very good magazine for the first two
or three years, but after that the technical quality of most of
the articles has declined. However: I don't think that calling
the authours "idiots" will help the magazine. Simply point out
the bugs and leave out the insults. Insulting people is a very
good way of making enemies.

The reason for what has happened to MacTutor does not lie in the
people who are making it. I think it was caused by the way the
Macintosh programmer community has evolved. Good books are finally
available and electronical communication satisfies the needs of
the most advanced programmers.

As to the question of locking or not locking: It doesn't take any
extra code to lock down your INITs. Why not do it?

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|     Juri Munkki jmunkki@hut.fi  jmunkki@fingate.bitnet        I Want   Ne   |
|     Helsinki University of Technology Computing Centre        My Own   XT   |
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