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Re: New developer

From: Bas Wijnen
Subject: Re: New developer
Date: Wed, 10 Sep 2003 02:52:39 +0200 (CEST)


> > This doesn't seem entirely correct to me.  Guessing a thread ID will 
> > give you a random thread.
> This is not what guessing means.  "Foo can be guessed" means that you
> can find the right Foo by simply guessing it.  It doesn't matter if you
> know that it is the right Foo or not, it just matters that there is a 
> non-zero chance that you get the right Foo.  At least this is what I 
> meant to say ;)
> The point here is that L4 allows all threads to send messsages to any 
> other thread directly.  As the authentication can only be checked 
> _after_ accepting the message, there is no point in hding the thread ID.

I understand what you mean, but obviously didn't make that too clear ;-)  
What I meant is that there is information that can be secret, which is 
given away by the proc server if it responds to a PID query by returning 
the thread ID: the information that this thread ID is coupled to that PID.  

However, I don't see why this information should be secret.  So as far as 
I'm concerned, there is no problem :-)

> > I'd like to do some low level things, like the taskserver, or the auth 
> > server.
> These are high level.

Right.  What kind of things need to be done at the moment then?  I
understood from Marco (on IRC) that the design was about finished.  Does
that mean it's time to start coding, or am I missing some steps?  I
haven't seen any document with the proposed interfaces of various servers 
(L4-hurd specific ones I mean), which is something I would expect is 
needed as part of the design.  Did I miss them, or do they still need to 
be written?

> I doubt that much can come out of it in terms of real productivity in 
> these early stages if you don't become a jack of all trades.

Good :-)  I thought it would be better to start with a smaller part, and 
work into it, but if I need to read about everything before starting, 
that's no problem.  It actually makes sense, if I see how things are done 
with the Hurd.  Never quick and dirty, but always the Right Way.  I like 
that a lot :-)

> Well, you should read and understand the L4 specification, and the glibc 
> and the Hurd source code.

Right.  I'm almost through the L4 specification, you'll hear from me again 
in 5 years, when I'm done with all the source code ;-)

Bas Wijnen

/** mastermind. input 4 numbers 0-5. output <right>.<in the right place> **/

 main(){int  c[4]   ,x=3  ,l=getpid()  ,i;;   for(  srand(l);c[  x]=-   rand
()%6         ,x--   ;);;  for(         ;44>   x;){  char         a[9] ,*p=
 "%.1f\n",   b[9];x=i=0;  gets(a);for   (l=4 ;l--   ;)x+=-(a[l]  -=48)==
       (b[l  ]=c[   l]);  ;for           (l=0;16    >i;l         =++i %4)x
+=(b[i/4]+   a[l]   ?0:(  a[l]=b[i/4]     =10))     ;printf(p,x  *.1)   ;};}

/** This signature should be viewed in a monospaced font, e.g. courier.  **/

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