Re: [myhdl-list] MyHDL / ModelSim cosim

[Jan D. <ja...@ja...>]

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.



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