We would expect both programs to print something like ``` <x> execute <x> snoop <x+1> execute <x+1> snoop .... ``` However, this is not the case when using multiple threads within one ``SC_MODULE``` (see output of doesnotwork.cpp)

doesnotwork.cpp

#include "aca2013.h"
#include <systemc.h>
#include <iostream>

using namespace std;
SC_MODULE(Thing) {
  public:
    sc_in<bool> clk;

    SC_CTOR(Thing) {
      SC_THREAD(execute);
      SC_THREAD(snoop);
      sensitive << clk.pos();
      dont_initialize();
    }

    void execute() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " execute" << endl;
      }
    }

    void snoop() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " snoop" << endl;
      }
    }
};

int sc_main(int argc, char* argv[]) {
  sc_clock clk;

  Thing thing("meh");

  thing.clk(clk);
  sc_start();

  return 0;
}

updated_does_not_work_that_works.cpp

#include "aca2013.h"
#include <systemc.h>
#include <iostream>

using namespace std;
SC_MODULE(Thing) {
  public:
    sc_in<bool> clk;

    SC_CTOR(Thing) {
      SC_THREAD(execute);
      sensitive << clk.pos();
      SC_THREAD(snoop);
      sensitive << clk.pos();
      dont_initialize();
    }

    void execute() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " execute" << endl;
      }
    }

    void snoop() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " snoop" << endl;
      }
    }
};

int sc_main(int argc, char* argv[]) {
  sc_clock clk;

  Thing thing("meh");

  thing.clk(clk);
  sc_start();

  return 0;
}

works.cpp

#include "aca2013.h"
#include <systemc.h>
#include <iostream>

using namespace std;
SC_MODULE(Thing) {
  SC_MODULE(Snooper) {
    sc_in<bool> clk;
    SC_CTOR(Snooper) {
      SC_THREAD(snoop);
      sensitive << clk.pos();
    } 
      
    void snoop() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " snoop" << endl;
      }
    }
  };
  
  public:
    sc_in<bool> clk;
    Snooper *snooper;
  
    SC_CTOR(Thing) {
      SC_THREAD(execute);
      sensitive << clk.pos();
      this->snooper = new Snooper("hehe");
      dont_initialize();
    }

    void execute() {
      while(true) {
        wait(1);
        cout << sc_time_stamp() << " execute" << endl;
      }
    }
};  

int sc_main(int argc, char* argv[]) {
  sc_clock clk;
      
  Thing thing("meh");
      
  thing.clk(clk);
  thing.snooper->clk(clk);
  sc_start();
      
  return 0;
}