#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cbthread.h"
#include "printqsim.h"

#define START 0
#define GOT_JOB 1
#define GOT_SLOT 2

typedef void (*func)();

typedef struct {
  void (*func)();
  Spq *s;
  Job *job;
  int state;
} Mycont;

void real_submit_job(Mycont *mc);
void real_get_print_job(Mycont *mc);

typedef struct {
  cbthread_gsem job_sem;
  cbthread_gsem slot_sem;
  Job **buffer;
  int head;
  int tail;
} Info;

void initialize_v(Spq *s)
{
  Info *info;

  info = (Info *) malloc(sizeof(Info));
  info->job_sem = cbthread_make_gsem(0);
  info->slot_sem = cbthread_make_gsem(s->bufsize);
  info->buffer = (Job **) malloc(sizeof(Job *)*s->bufsize);
  info->head = 0;
  info->tail = 0;
  s->v = (void *) info;
}

void submit_job(Spq *s, Job *j, void (*function)())
{
  Mycont *mc;

  mc = (Mycont *) malloc(sizeof(Mycont));
  mc->func = function;
  mc->job = j;
  mc->s = s;
  mc->state = START;
  
  real_submit_job(mc);
}

void real_submit_job(Mycont *mc) 
{
  Info *info;
  Spq *s;
  void (*func)();

  s = mc->s;
  info = (Info *) s->v;

  if (mc->state == START) {
    mc->state = GOT_SLOT;
    cbthread_gsem_P(info->slot_sem, real_submit_job, mc);

  } else if (mc->state == GOT_SLOT) {
    info->buffer[info->tail] = mc->job;
    info->tail = (info->tail + 1) % s->bufsize;
    cbthread_gsem_V(info->job_sem);
    func = mc->func;
    free(mc);
    (*func)(s);
    cbthread_exit();
  }
}

void get_print_job(Spq *s, void (*function)())
{
  Mycont *mc;

  mc = (Mycont *) malloc(sizeof(Mycont));
  mc->func = function;
  mc->s = s;
  mc->state = START;
  
  real_get_print_job(mc);
}

void real_get_print_job(Mycont *mc)
{
  Spq *s;
  Info *info;
  void (*func)();

  s = mc->s;
  info = (Info *) s->v;

  if (mc->state == START) {
    mc->state = GOT_JOB;
    cbthread_gsem_P(info->job_sem, real_get_print_job, mc);
  } else if (mc->state == GOT_JOB) {
    s->job = info->buffer[info->head];
    info->head = (info->head + 1) % s->bufsize;
    cbthread_gsem_V(info->slot_sem);
    func = mc->func;
    free(mc);
    (*func)(s);
    cbthread_exit();
  }
}