program example();

// semaphores are a unique datatype in SV semaphore want_to_print;

// this is the "shared resource", would be a bus,

// but in this case its a $display

task write_bus(int addr, int data);

     $display("here is a write to the bus at addr %d", addr);

     #100;

endtask

int done = 0, i = 0;

initial

  begin

  // here we initialize the semaphore with one token  availabe to      //share. We could initialize

 // with more, if there were an interleaved bus, for  example

  want_to_print = new(1);

  fork

   begin

   /// here is one parallel thread competing

    while(!done)

     begin

      // wait for some random time

      #($random() % 100);

      // attempt to get the one semaphore token

      want_to_print.get(1);

      // got it!, lets use the bus

      write_bus(200, $random());

      i++;

      // we must return the semaphore token want_to_print.put(1);

     end

end