[sv-ec] Re: [sv-ac] Re: sv-ac: example error in "9.7 Fine-grain process control"?

I think that minor changes should be done for this code to work as
expected - they are bolded in below code

    task **do_n_way( int N );
    *automatic *process job[] = new[N];
         for ( int j = 1; j <= N; j++ )
         fork
    * automatic int k = j-1;*
             begin job[k] = process::self(); .... end
         join_none
         for( int j = 0; j < N; j++ ) // wait for all processes to start
             wait( job[j] != null );
         job[0].await(); // wait for first process to
    finish

         for ( int k = 0; k < N; k++ ) begin
             if ( job[k].status != process::FINISHED )
                 job[k].kill();
         end

    endtask

On 2/22/2012 7:41 PM, Arturo Salz wrote:
>
> I believe that the only things that need to change is the array (job)
> declaration to a dynamic array (and the corresponding indexing
> changes), which would make the example strictly correct:
>
> *task *do_n_way( *int *N );
>
> process job[] = *new*[N];
>
> *for *( *int *j = 1; j <= N; j++ )
>
> *fork*
>
> *automatic int *k = j;
>
> *begin *job[k] = process::self(); ... ; *end*
>
> *join_none*
>
> **
>
> *for*( *int *j = 0; j < N; j++ ) // wait for all processes to start
>
> *wait*( job[j] != *null *);
>
> job[0].await(); // wait for first process to finish
>
> **
>
> *for *( *int *k = 0; k < N; k++ ) *begin*
>
> *if *( job[k].status != process::FINISHED )
>
> job[k].kill();
>
> *end*
>
> *endtask*
>
> I don't agree with Ben's proposed change to add the fork in the second
> loop. The sequential check is indeed intended -- to wait for all
> processes to start. Ben's proposed change would break that intent and
> would wait for no process: the wait processes would simply execute
> concurrently but with no synchronization.
>
> Arturo
>
> *From:*owner-sv-ec@eda.org [mailto:owner-sv-ec@eda.org] *On Behalf Of
> *Bresticker, Shalom
> *Sent:* Wednesday, February 22, 2012 7:05 AM
> *To:* sv-ac@eda-stds.org; sv-ec@eda.org
> *Subject:* [sv-ec] RE: [sv-ac] Re: sv-ac: example error in "9.7
> Fine-grain process control"?
>
> Hi,
>
> This was previously reported in Mantis 2559.
>
> It has not been fixed.
>
> It could be a ballot comment.
>
> Shalom
>
> *From:*owner-sv-ac@eda.org <mailto:owner-sv-ac@eda.org>
> [mailto:owner-sv-ac@eda.org] <mailto:[mailto:owner-sv-ac@eda.org]> *On
> Behalf Of *ben cohen
> *Sent:* Sunday, January 01, 2012 5:58 PM
> *To:* sv-ac@eda-stds.org <mailto:sv-ac@eda-stds.org>;
> stuart@sutherland-hdl.com <mailto:stuart@sutherland-hdl.com>
> *Cc:* Korchemny, Dmitry
> *Subject:* [sv-ac] Re: sv-ac: example error in "9.7 Fine-grain process
> control"?
>
> After more thoughts, the model work without the fork join, even though
> it might be a better style. However, the first reported issue is
> still there:
>
> task do_n_way( int N ); // line 98
>
> process job[1:N]; // (99): Range must be bounded by constant
> expressions.
>
> Ben Cohen
>
> On Sat, Dec 31, 2011 at 8:47 PM, ben cohen <hdlcohen@gmail.com
> <mailto:hdlcohen@gmail.com>> wrote:
>
> In code below (copied mostly from LRM), I think that this statement is
> incorrect:
>
> for( int j = 1; j <= N; j++ ) // wait for all processes to start
>
> wait( job[j] != null );
>
> I think that this should be
>
> for( int j = 1; j <= N; j++ ) // wait for all processes to start
>
> fork
>
> wait( job[j] != null );
>
> join_none
>
> Without the fork, these wait(job...) are sequential.
>
> From 9.4.3 Level-sensitive event control
>
> The wait statement shall evaluate a condition; and, if it is not true
> (as defined in 12.4), the procedural statements
>
> following the wait statement shall remain blocked until that condition
> becomes true before continuing.
>
> Attached is a modified model that I constructed to test the LRM
> example using a simulator. The simulator yielded:
>
> run 100ns
>
> # @t= 0, waiting for jobs[ 1] to start
>
> # @t= 0, waiting for jobs[ 2] to start
>
> # @t= 0, waiting for jobs[ 3] to start
>
> # @t= 2, in task, k= 1
>
> # @t= 3, in task also, k= 1
>
> # @t= 3, killing job 2
>
> # @t= 3, killing job 3
>
> I suggest that the example be modified to reflect code that compiles
> and reflects the intent of the example.
>
> The way it is now, I believe that the LRM model is in error in 2
> respects.
>
> Ben Cohen
>
> systemverilog.us <http://systemverilog.us>
>
> On Sat, Dec 31, 2011 at 5:34 PM, ben cohen <hdlcohen@gmail.com
> <mailto:hdlcohen@gmail.com>> wrote:
>
> Below is code copied from LRM, draft 4 (slightly modified to comment
> out the "...;" and add a call to the task.
>
> A simulator cage me this error code upon compilation:
>
> (99): Range must be bounded by constant expressions
>
> Is LRM is error here?
>
> Thanks,
>
> Ben
>
> ----
>
> module mprocess; // line 96
>
> task do_n_way( int N ); // line 98
>
> process job[1:N]; // (99): Range must be bounded by constant
> expressions.
>
> for ( int j = 1; j <= N; j++ )
>
> fork
>
> automatic int k = j;
>
> begin job[k] = process::self();
>
> $display(" in task, k=%d", k);
>
> // ... ;
>
> end
>
> join_none
>
> for( int j = 1; j <= N; j++ ) // wait for all processes to start
>
> wait( job[j] != null );
>
> job[1].await(); // wait for first process to finish
>
> for ( int k = 1; k <= N; k++ ) begin
>
> if ( job[k].status != process::FINISHED )
>
> job[k].kill();
>
> end
>
> endtask
>
> initial begin : init
>
> do_n_way(3);
>
> end :init
>
> endmodule :mprocess
>
>
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