[Zope] Re: Zope is a POS.

[Josef Meile]

>> Not necessary. For example what if you want to manage concurrency? You 
>> will need row locking and perhaps table locking, thing, which I 
>> haven't figured out how to do with zope.
> 
> 
> Concurrency do not exists. Computers simulate concurrency but nothing 
> can't do 2 things at time overcoat if you have only 1 HD or 1 CPU
What if you have two CPUs trying to access the same HD? I agree, one CPU 
will have the access first, but somehow you will have to block the 
resorce. If you try to simulate this with zope, you could think about a 
lock attribute on the object, but one thing could happen:

Three CPUs: A, B, and C are trying to access object D on Hardisk E.

1) CPU A Arives first and takes Object D and checks lock, which is zero.
2) CPU B, which was late, takes Object D just right after A, so, lock is 
still zero.
3) CPU A sets lock to one and modifies D on a html form.
4) CPU B sets lock to one and modifies D on a html form.
5) CPU A saves modifications and sets lock to one.
6) CPU C arives and takes D because lock is zero.

As you see, CPU B and C are working with the false information. This is 
difficult to simulate with zope. That's why I think the row locking of a 
DB like mysql or postgres will do it better. The locking, if I'm not 
wrong, happens while accessing the data the first time.

Regards,
Josef