is it possible to use "virtual public sc_module"?

[gkmike68]

Hi All,

 

I have a case using "diamond inheritance" sc_module as below figure

 

   base

   /      \

 A       B

   \       /

     top

 

base=> struct to share A and B

A => a systemc module (virtual public sc_module)

B => a systemc module (virtual public sc_module)

top=> a systemc module (virtual public A, virtual public B )

 

it work fine.

 

But when I using SC_THREAD. 

 

the compiler shows error, "pointer to member conversion via virtual base".

 

is it possible to fix the error?

 

Thanks

[kartikkg]

Hi,

You can try to inherit Class Base as virtual in Class A & Class B.  Will that work for you ?

[gkmike68]

Hi Kartik,

 

Actually I did.

 

I modified my question to make it clearer

 

sorry for the mistake

[gkmike68]

Hi All,

 

I solved this problem by using only one sc_module

 

base=> struct to share A and B

A => normal c++ class

B =>  normal c++ class

top=> a systemc module (virtual public A, virtual public B )

 

SC_THREAD should be written in top only

[David Black]

It looks like you solved your problem; however, just a C++ note as to using of the keyword 'virtual' with classes and the infamous diamond problem.

// Example demonstrating proper use virtual class inheritance to solve the dreaded diamond problem.
// Only a problem when base class contains data.
#include <iostream>
#include <systemc>

struct Base { int m_i; Base():m_i(42){} };

// Only one of the following two required to use 'virtual' keyword, but two is safer
struct A : virtual Base { int m_a; A(): m_a(1){} };
struct B : virtual Base { int m_b; B(): m_b(2){} };

// The following will only have one copy of 'var' from Base
struct Final: A, B
{
  Final() { std::cout << "Constructed Final with m_i=" << m_i << std::endl; }
};

int sc_main(int argc, char* argv[]) {
  Final f;
  sc_assert( f.m_i == 42 );
  return 0;
}
// Copyright 2015 by David Black
// License: Apache 2.0

[Philipp A Hartmann]

As a final remark: No, you can't use sc_module as a virtual base class, not only due to the required casts to start/create the embedded SystemC processes. Your solution to split the implementation is correct.

 

hth,
  Philipp