/* Lecture_2/simple_sem.c
 * James S. Plank

Continuation-Based Thread Library - A non-preemptive, continuation-based thread library.
Copyright (C) 2009 James S. Plank

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

Original: October, 1995
Revised: January, 2009

James S. Plank
Department of Electrical Engineering and Computer Science
University of Tennessee
Knoxville, TN 37996
plank@cs.utk.edu
*/

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

typedef struct {
  cbthread_gsem semaphore;
  int counter;
} Tinfo; 

void consumer(Tinfo *t);

void producer(Tinfo *t)
{
  t->counter++;
  printf("%8.3lf Producer %d\n", cbthread_get_fake_time(), t->counter);
  cbthread_gsem_V(t->semaphore);
  cbthread_fake_sleep(drand48(), producer, t);
}

void consumer_unblocked(Tinfo *t)
{
  printf("%8.3lf Consumer %d finished\n", cbthread_get_fake_time(), t->counter);
  cbthread_fake_sleep(drand48(), consumer, t);
}

void consumer(Tinfo *t)
{
  t->counter++;
  printf("%8.3lf Consumer %d starting\n", cbthread_get_fake_time(), t->counter);
  cbthread_gsem_P(t->semaphore, consumer_unblocked, t);
}

main()
{
  int i;
  Tinfo *p, *c;
  cbthread_gsem s;
  
  srand48(time(0));

  s = cbthread_make_gsem(0);
  p = (Tinfo *) malloc(sizeof(Tinfo));
  p->semaphore = s;
  p->counter = 0;
  cbthread_fork(producer, p);

  c = (Tinfo *) malloc(sizeof(Tinfo));
  c->semaphore = s;
  c->counter = 0;
  cbthread_fork(consumer, c);
  
  cbthread_fake_sleep(3.00, exit, NULL);
}