Re: [sv-ec] RE: [sv-bc] Can a function contain a fork/join/any/none?

Another variant of the same issue is what happens if an
initializer does a fork/join_none?  Particularly in the
cases that were raised by Arturo and Dave (class construction),
there is no parent thread in a declaration.

     some_class decl = new;   // where "new" has a fork/join_none

When are these threads supposed to start?  If they use
fine-grained process control (semaphores or similar), are
those supposed to be guaranteed to complete before all
initial and always blocks (assuming they terminate without
other delays)?

I think the semantics of this needs some work if it is to be
considered legal.

Gord.



Bresticker, Shalom wrote:
> I see you're correct. I still have a lot to learn about SV.
> 
> So let me now ask the following. Suppose I have the following code: 
> 
> initial 
> begin
>   ...
>   fork
>     ...
>     ...
>   join_none
> end
> 
> And there is additional code so that the simulation does not end when
> this initial block finishes.
> 
> The LRM says about join_none,
> "The parent process continues to execute concurrently with all the
> processes spawned by the fork. The spawned processes do not start
> executing until the parent thread executes a blocking
> statement."
> 
> The parent thread is this initial block. Where does it execute a
> blocking statement? When do the threads in the fork...join_none execute?
> 
> Thanks,
> Shalom
> 
> 
>>-----Original Message-----
>>From: Steven Sharp [mailto:sharp@cadence.com]
>>Sent: Monday, February 20, 2006 10:19 PM
>>To: sharp@cadence.com; sv-ec@eda.org; sv-bc@eda.org;
>>Dave_Rich@mentor.com; Bresticker, Shalom
>>Subject: RE: [sv-ec] RE: [sv-bc] Can a function contain a
>>fork/join/any/none?
>>
>>
>>
>>>From: "Bresticker, Shalom" <shalom.bresticker@intel.com>
>>
>>>Who is the parent thread in this case? Could I argue that the
>>
>>parent
>>
>>>disappears and thus never reaches a blocking statement?
>>
>>No.  I don't believe that calling a function is considered by
>>the 1800
>>LRM to create a thread.  The thread executing in the function
>>is the
>>same thread that called the function and the same thread that
>>continues
>>after the return.
> 
> 
> 
> 

-- 
--------------------------------------------------------------------
Gordon Vreugdenhil                                503-685-0808
Model Technology (Mentor Graphics)                gordonv@model.com