#include <stdio.h>
#include "pt.h"
#include "printqsim.h"

typedef struct {
  void (*f)();
  void *a;
  Spq *s;
  Job *j;
} Cont;

typedef struct {
  Job **b;
  int head;
  int tail;
  Gsem njobs;
  Gsem nslots;
} Buffer;
  
void initialize_v(Spq *s)
{
  Buffer *b;

  b = (Buffer *) malloc(sizeof(Buffer));
  b->b = (Job **) malloc(sizeof(Job *)*s->bufsize);
  b->head = 0;
  b->tail = 0;
  b->njobs = make_gsem(0);
  b->nslots = make_gsem(s->bufsize);
  s->v = (void *) b;
}

void submit_job_cont(c)
Cont *c;
{
  Spq *s;
  Job *j;
  void (*f)();
  void *a;
  Buffer *b;

  s = c->s;
  j = c->j;
  f = c->f;
  a = c->a;
  free(c);

  b = (Buffer *) s->v;

  b->b[b->head] = j;
  b->head = (b->head + 1) % s->bufsize;
  gsem_V(b->njobs);
  pt_yield(f, a);
}
      
void submit_job(s, j, f, a)
Spq *s;
Job *j;
void (*f)();
void *a;
{
  Buffer *b;
  Cont *c;

  c = (Cont *) malloc(sizeof(Cont));

  b = (Buffer *) s->v;

  c->f = f;
  c->a = a;
  c->s = s;
  c->j = j;

  gsem_P(b->nslots, submit_job_cont, c);
}


void get_print_job_cont(c)
Cont *c;
{
  Spq *s;
  void (*f)();
  void *a;
  Buffer *b;

  s = c->s;
  f = c->f;
  a = c->a;
  free(c);

  b = (Buffer *) s->v;

  s->j = b->b[b->tail];
  b->tail = (b->tail + 1) % s->bufsize;
  gsem_V(b->nslots);
  pt_yield(f, a);
}

get_print_job(s, f, a)
Spq *s;
void (*f)();
void *a;
{
  Buffer *b;

  Cont *c;

  c = (Cont *) malloc(sizeof(Cont));
  c->f = f;
  c->a = a;
  c->s = s;

  b = (Buffer *) s->v;
  gsem_P(b->njobs, get_print_job_cont, c);
}