Merge of the "new ByNeed" branch

[Raphael Collet]

Hi Kostja,

> this issue apparently needs a boost.
> 
> First, I would like to separate the optimizations (in particular if
> they are considered for their own sake, if I may put it like that)
> from the important thing - which is to get the thing in. And here, as
> I understand it, everyone agrees "it is good enough". The benchmarking
> results and absense of any applications that "abuse" this stuff allow
> us to do so.
> 
> Of course we should keeping an eye open for suggested optimizations by
> {Raph,Kevin,Denys}. BTW I did not get the Denys' point about optimized
> ByNeedFuture that it "become very straightforward and semantically
> clean".

I agree.  I have spend (lost?) some time the last weeks evaluating some
proposed optimizations.  I have managed to test them on "serious" Oz
programs, i.e., not toy examples.  My results convinced me that Denys'
proposals will not make a real difference.  Except the emulator will be
harder to maintain...  I suggest to forget about those hacks, unless
clear evidence can be made about their usefulness.

> Now, I'm more concerned with the fact that the "by-need" branch failed
> on me while doing the "oztest" (Redhat 7.3, gcc 3.3.2 (compiled off
> sources), optimized emulator):
> 
> unix_write1: 
> Program received signal SIGSEGV, Segmentation fault.
> 0x401a9860 in getIPAddress() ()
>    from /home/kost/soft/mozart/cache/x-oz/boot/DPB.so-linux-i486
> (gdb) bt
> #0  0x401a9860 in getIPAddress() ()
>    from /home/kost/soft/mozart/cache/x-oz/boot/DPB.so-linux-i486
> #1  0x401b78e7 in BIinitIPConnection ()
>    from /home/kost/soft/mozart/cache/x-oz/boot/DPMisc.so-linux-i486
> #2  0x404d9eb8 in ?? ()
> Cannot access memory at address 0x18
> (gdb) 
> 
> Curiously - and worryingly - it works fine with the "gdb" emulator.
> Anyone dare to comment??!

I haven't been able to reproduce this.

> Then, *after* the thing is merged, I'd still like to see the emulator
> clean-ups (as we discussed before).

I was rather thinking to making those clean-ups in the byneed branch
first, and then deal with the merge...


Cheers,

raph
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