Manipulating C Global Variables Using DPI

I'm sharing this code as an example of how two different DPI calls (calls to same function in two different parts of the hierarchy) can both manipulate a C global variable.
----file: my_dpi.c---- #include "stdio.h" #include "svdpi.h" // any function or variable declared 'static' - which is outside the // scope of any DPI function, is a global func/var. static int my_global_int = 4; // FYI - VPI function io_printf() will print to ncsim.log file // This function can be called from any Verilog Hierarchy // and manipulate my_global_in int c_func () { my_global_int++; // increment the global variable via DPI call io_printf("C: Function Calling HDL scope is %s \n", svGetNameFromScope(svGetScope() ) ); io_printf("C: increment my_global_in to %d \n", my_global_int); return my_global_int; } --------------- ----file: test_dut.sv // this example developed to test if DPI can manipulate // a C global variable from different hierarchies module dut (); import "DPI-C" context c_func = function int sv_func (); int b; initial begin b = sv_func(); $display("Verilog: %m %d", b); end endmodule // ------------------------ module test(); import "DPI-C" context c_func = function int sv_func (); int b; initial begin b = sv_func(); $display("Verilog: %m %d", b); end endmodule // ------------------------ module top(); test U1(); dut U2(); endmodule ---------------- ncsim: 05.83-s006: (c) Copyright 1995-2007 Cadence Design Systems, Inc. ncsim> run C: Function Calling HDL scope is top.U1 C: increment my_global_in to 5 Verilog: top.U1 5 C: Function Calling HDL scope is top.U2 C: increment my_global_in to 6 Verilog: top.U2 6 ncsim: *W,RNQUIE: Simulation is complete. ncsim> exit -------script: ------------- ncvlog -sv -linedebug test_dut.sv ncelab top gcc -m32 -fPIC -g -shared -o my_dpi.so my_dpi.c -I/`ncroot`/tools/inca/include ncsim top -sv_lib ./my_dpi.so