can clone a thread?

[Gianni Pisetta]

On Wednesday, 11 December 2013 at 08:54:18 UTC, Marco Leise wrote:
> Am Wed, 11 Dec 2013 09:10:09 +0100
> schrieb "Gianni Pisetta" <pisetta.gianni at alice.it>:
>
>> No, i think fork or something similar is the way i prefer to 
>> go.
>> I'm working on a simple top-down parser, so i save all the 
>> data references in the context of the function and at the end 
>> of it i create the syntax tree object with all his childrens. 
>> So i have the already allocated objects in the tls and the 
>> info on the realtionships of these objects plus the parser 
>> state in the call stack. I want to duplicate the parser 
>> because i want all the possible syntax trees as a result and 
>> when the tokenizer will find in the input two or more possible 
>> tokens, it must fork and return for each thread one token from 
>> the possible ones. At the end if one or more threads made to 
>> the end, each thread copy his syntax tree on a shared array 
>> and the main thread then can work on the results.
>> 
>> Another way to solve this is to move all the info from the 
>> call stack to a stack managed by me, have a standard procedure 
>> that fills the stack. When i must duplicate the thread i can 
>> create a new one, make a deep copy of the objects in the stack 
>> and the stack itself, then call the standard procedure again. 
>> But i think this is a bottom-up parser and a major change in 
>> the application design.
>>
>> For now i will stick with fork, if in the future a similar 
>> function is implemented in core.thread, i will use it.
>
> Alright, fork is optimized for this kind of stuff and it
> should work fine. Personally I would likely have tried a
> manged stack instead of cloning the whole application. How do
> you write back the results from the child processes? Do you
> use pipes or shared memory?

I also like the managed stack idea, but i think the main problem 
with that is that it is harder to understand what's going on when 
you have to debug.
I'm not at the point yet of passing the results to the main 
thread, but i think at the end i will make the entire tree 
immutable(or maybe already create it with immutable) and add the 
reference to a shared array or use a message passing pattern like 
the one in std.concurrency.

Gianni Pisetta