[Lazarus] Threads in Lazarus code base

[Florian Klaempfl]

Am 17.09.2010 13:33, schrieb Michael Schnell:
>  On 09/17/2010 11:48 AM, Juha Manninen (gmail) wrote:
>> On Friday 17 September 2010 11:47:12 Florian Klaempfl wrote:
>>> Same can be said about goto and labels. Very intuitive and simple why
>>> bother about while, for, repeat loops?
>> Well, it is a valid comparison. I remember reading about new syntax in
>> some
>> languages. One is a "future variable" which you calculate in one place
>> and
>> then use later. Actually the compiler creates a thread for the
>> calculation and
>> does "waitfor" when the result is used first time. Cool!
>>
>> Another was the "parallel" keyword for loops. Cool as well!
>>
>>
> 
> Since long I am raving about "Thread Events". (You might find some posts
> about this in the backlog of this list.)
> 
> Those are supposed to be procedural properties of objects. Currently
> those simply are called. When used as "Events", the Object calls them
> when appropriate and they are assigned to procedures by some code
> outside of the object. Thus they are used as "Callbacks".
> 
> This concept can be enhanced by assigning a thread to such an event with
> any call of same and execute the called procedure as this thread. Of
> course the function results and var parameters of such a beast would
> automatically be "futures"
> 
> This would make threads easy to create and use for the programmer, but
> of course it would not at all handle the potential complexity problems
> regarding mutual access, indeterminated code sequencing, and debugging.
> 

This is imo the real challenging part, besides mechanisms to abort
threads. Especially because using the current mechanisms of
synchronication, it is very hard to read multithreaded programs.