/* thread2.c */
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <math.h>
#include <string.h>
#define BUF 255
#define MAX_X 1024

static pthread_cond_t cond;
pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;

typedef struct
{
    long a;
    long n;
    long x[MAX_X];
    long erg;
    long sum;
}data_t;

data_t input;

void *multi(void *arg);
void *add(void *arg);

void *multi(void *arg) {
   int status;
   long temp;

   fprintf(stdout, "Thread multi gestartet: %ld\n", pthread_self());

   status = pthread_mutex_lock(&mutex);

   fprintf(stdout, "Daten multi gelockt\n");
   if (status != 0)
   {
      fprintf (stdout, "Fehler bei lock in Thread:%ld\n",pthread_self());       exit (EXIT_FAILURE);
         }

   temp = (long)arg;
   input.erg = input.a * temp;
   fprintf(stdout, "Thread multi temp = %ld\n", temp);
   fprintf(stdout, "Thread multi erg = %ld\n", input.erg);
   fprintf(stdout, "Thread multi sendet condition\n");

   pthread_cond_signal(&cond);
status = pthread_mutex_unlock(&mutex);

   fprintf(stdout, "Daten multi unlocked\n");
   if (status != 0)
   {
       fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());
       exit (EXIT_FAILURE);
       }
   fprintf(stdout, "Thread multi beendet: %ld\n", pthread_self());
   pthread_exit ((void *) 0);
}

void *add(void *arg)
{
   int status;

   fprintf (stdout, "Thread add : %ld wartet auf die Condition Variable\n", pthread_self ());

   pthread_cond_wait (&cond, &mutex);
   fprintf (stdout, "Thread add: %ld gestartet ...\n", pthread_self ());

   status = pthread_mutex_lock(&mutex);

   fprintf(stdout, "Daten add gelockt\n");

   if (status != 0)
   {
      fprintf (stdout, "Fehler bei lock in Thread:%ld\n",pthread_self());
      exit (EXIT_FAILURE);
         }

   input.sum = input.sum + input.erg;

   status = pthread_mutex_unlock(&mutex);

   fprintf(stdout, "Daten add unlocked\n");

   if (status != 0)
   {
       fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());
       exit (EXIT_FAILURE);
       }
   fprintf(stdout, "Thread multi beendet\n");
   pthread_exit ((void *) 0);

}
int thread_start(long max_threads)
{
    pthread_t th[max_threads+1];
    int i;
    fprintf(stdout, "input.n = %ld", max_threads);
    for (i = 0; i < max_threads; i++) {


    if(pthread_create(&th[i], NULL, &multi, &input.x[i]) != 0)
      {
         fprintf (stderr, "Error creating Thread %d ...\n",i+1);
         return EXIT_FAILURE;
         }

    if(pthread_create(&th[i+1], NULL, &add, NULL) != 0)
      {
          fprintf (stderr, "Error creating Thread %d ...!\n", i+2);
          return EXIT_FAILURE;
          }
   for (i=0; i < max_threads; i++)
   {
           pthread_join(th[i], NULL);
           pthread_join(th[i+1], NULL);
       fprintf(stdout, "pthread_join %d", i);
   }
    }
   return (0);
}

int main (int argc, char *argv[]) {

   FILE *fp;
   char *token = NULL;
   char delim[] = " ";
   char string[BUF];
   int i=0;
   long temp;

   input.erg = 0;
   input.sum = 0;

   if(argc < 2)
   {
       fprintf(stderr, "Usage: %s file\n", argv[0]);
       return (EXIT_FAILURE);
       }

   if( (fp = fopen(argv[1], "r") ) == NULL)
   {
fprintf(stderr, "%s: File '%s' couldn't be opened!\n", argv[0], argv[1]);
       return (EXIT_FAILURE);
       }

   if( fgets(string, BUF, fp) != NULL)
   {
       token = strtok(string, delim);
       input.a = strtol(token, NULL, 10);

       token = strtok(NULL, delim);
       input.n = strtol(token, NULL, 10);
       }

   while(fgets(string, BUF, fp) != NULL)
   {
       temp = strtol(string, NULL, 10);
       input.x[i] = temp;
       fprintf(stdout, "input.x[%d] = %ld\n", i, input.x[i]);
       i++;
       }

   if (i < input.n)
   {
       fprintf(stderr, "%s: Not enough entries for x in file!", argv[0]);
       return EXIT_FAILURE;
   }

  thread_start(input.n);

  fprintf(stdout, "a = %ld, n = %ld, Summe = %ld\n", input.a, input.n, input.sum);

fclose(fp);

return (0);

}