[myhdl-list] MyHDL / ModelSim cosim

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

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?

Chris