Re: [myhdl-list] MyHDL / ModelSim cosim

[Christopher F. <chr...@gm...>]

Many months later ...

Attached is the patch for the modelsim memory leak issues.  Created a 
separate directory and Makefile for modelsim.

General modelsim items:
   When (if) running the cosimulation unittests make sure to
   first build the shared library and copy to the test directory.
   Then execute the following two modelsim commands

   >> vlib work
   >> vmap work work

If the above are not executed errors will ensue.

{plug for my friends, I have been transitioning to CVC instead of 
modelsim and all is working well and faster (thus far).  But I had these 
changes laying around so I thought I would share them for other modelsim 
users}.

Regards,
Chris Felton

On 5/6/11 2:37 PM, Jan Decaluwe wrote:
> On 05/05/2011 02:48 PM, Christopher Felton wrote:
>> There was an old thread (last post 31 May 2005, same subject line) that
>> addressed a memory leak in Modelsim which also occurred in cver and
>> Icarus.  I don't know if this was resolved but the issue still exists in
>> the current releases with Modelsim.
>>
>> In a cosimulations that I was running a simulation would exceed 10GB of
>> resident memory usage.  And the simulation would crawl along when this
>> occurred.
>>
>> The fix was to release the handles created by vpi_scan, example
>>
>> ~~~~~~~~~~~ Code Snip ~~~~~~~~~~~~~~~~~~
>> // ~line 416 of myhdl_vpi.c
>> while ((value_s.value.str = strtok(NULL, " ")) != NULL) {
>>        reg_handle = vpi_scan(reg_iter);
>>        vpi_put_value(reg_handle,&value_s, NULL, vpiNoDelay);
>>        vpi_free_object(reg_handle);  // **<-- Added line
>> }
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> This had to be added in four spots (~line 125, 198, 301, 416).  The
>> reg_handle and net_handle in the reg and net iterator loops had to be
>> released for each object retrieved (at least for modelsim).  After this
>> change my memory usage top out at 222MB (no more leak).
>>
>> I did not create a patch because I didn't have time to regression test
>> cver and Icarus.
>>
>> I can provide a patch if desired.  Should a separate directory and
>> myhdl_vpi.c and Makefile be created for mti in the Cosimulation directory?
>
> Yes, that's the right way, and thanks for debugging this.
>
>
>