/*
   +-------------+---------+-----------------------+
   | John Breaux | jab0910 | JohnBreaux@my.unt.edu |
   +-------------+---------+-----------------------+
   |                  2022-04-04                   |
   +-----------------------------------------------+
*/
#include <semaphore.h> // POSIX semaphores!
#include "list.hpp"    // list implementation
#include "globals.hpp" // lists, sems, muts
#include "transformer.hpp"

void transform(block *x, block *y);

void *transformer (void *) {
   block *x, *y;
   while (true) {
      // wait for element on list1
      wait(sem_list1);
      // mutual exclusion for list1
      wait(mut_list1);
      //* x:=unlink(list1);
      x = unlink(list1);
      // mutual exclusion for list1
      signal(mut_list1);

      // wait for element on freelist
      wait(sem_freelist);
      // mutual exclusion for freelist
      wait(mut_freelist);
      //* y:=unlink(freelist);
      y = unlink(freelist);
      // mutual exclusion for freelist
      signal(mut_freelist);

      //* use_block_x_to_produce_info_in_y(x,y)
      transform(x, y);

      // mutual exclusion for freelist
      wait(mut_freelist);
      //* link(x, freelist);
      link(x, freelist);
      // mutual exclusion for freelist
      signal(mut_freelist);
      // freelist++
      signal(sem_freelist);

      // mutual exclusion for list2
      wait(mut_list2);
      //* link(y, list2);
      link(y, list2);
      // mutual exclusion for list2
      signal(mut_list2);
      // signal new element on list2
      signal(sem_list2);
   }
   return nullptr;
}

void transform(block *x, block *y) {
   return;
}