#include <stdio.h>

#include <stdlib.h>

#include <pthread.h>

#include <math.h>

#include <string.h>

#include <time.h>

#define BUF 255

#define MAX_X 1024



/*Zählvariable für Threads*/

int counter = 0; 

int counter2 = 0;



/*Mutex wird initialisiert*/

pthread_mutex_t mutex=PTHREAD_MUTEX_INITIALIZER;



/*Struktur für die Werte aus Datei und Berechnung*/

typedef struct

{

    long a;

    long n;

    long x[MAX_X];

    long erg[MAX_X];

    long sum;

}data_t;



data_t input;



void *multi(void *arg);

void *add(void *arg);



/*Thread-Funktion für Multiplikation*/

void *multi(void *arg) 

{

   int status;

   

   /*Daten werden gelockt*/

   status = pthread_mutex_lock(&mutex);

   

   if (status != 0) 

   {

      fprintf (stdout, "Fehler bei lock in Thread:%ld\n",pthread_self());

      exit (EXIT_FAILURE);

   }

   

   /*Berechnung wird durchgeführt für jedes x und in Struct zwischengespeichert*/

   input.erg[counter] = input.a * input.x[counter];

   counter++;

   

   /*Daten werden unlocked*/

   status = pthread_mutex_unlock(&mutex);

   

   if (status != 0)

   {

       fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());

       exit (EXIT_FAILURE);

       }    

   /*Thread wird beendet*/

   pthread_exit ((void *) 0);

}



/*Thread-Funktion für Addition*/

void *add(void *arg)

{

   int status;

   

   /*Daten werden gelockt*/ 

   status = pthread_mutex_lock(&mutex);

   

   if (status != 0) 

   {

      fprintf (stdout, "Fehler bei lock in Thread:%ld\n",pthread_self());

      exit (EXIT_FAILURE);

         }

   

   /*Berechnung*/

   input.sum += input.erg[counter2];

   counter2++;

   

   status = pthread_mutex_unlock(&mutex);

   

   if (status != 0)

   {

       fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());

       exit (EXIT_FAILURE);

       }    

   /*Daten werden entlocked*/

   pthread_exit ((void *) 0);



}



/*Funktion zum starten der Threads*/

int thread_start()

{

    pthread_t th[input.n];

    int i;

    

    fprintf(stdout, "Threads for Multi started\n");

    

    for (i = 0; i < input.n; i++) 

    {

    /*Thread wird n mal gestartet um x mit a zu multiplizieren*/

    if(pthread_create(&th[i], NULL, &multi, NULL) != 0) 

      {

         fprintf (stderr, "Error creating Thread %d ...\n",i+1);

         return EXIT_FAILURE;

         }

    }   

    

    /*Es wird für jeden Thread gewartet bis er beendet hat*/

    for( i=0; i < input.n; i++)

    {

	pthread_join(th[i], NULL);

    	}

    

    fprintf(stdout, "Threads for Multi ended\n");

    

    fprintf(stdout, "Threads for Add started\n");

    

    for (i = 0; i < input.n; i++)

    {

    	if(pthread_create(&th[i], NULL, &add, NULL) != 0)

      	{

        	fprintf (stderr, "Error creating Thread %d ...!\n", i+2);

		return EXIT_FAILURE;

          	}

   	} 

   

   for( i=0; i < input.n; i++)

   {	   

	pthread_join(th[i], NULL);

   	}

   

   fprintf(stdout, "Threads for Add ended\n");

   

   return (0);

} 

    

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

   

   FILE *fp;

   char *token = NULL;

   char delim[] = " ";

   char string[BUF];

   int i=0;

   long temp;

   clock_t start, stop;

   

   start=clock();

   

   input.sum = 0;

   

   /*Aufruf überprüfen*/

   if(argc < 2)

   {

       fprintf(stderr, "Usage: %s file\n", argv[0]);

       return (EXIT_FAILURE);

       }

   

   /*Datei zum lesen öffnen*/

   if( (fp = fopen(argv[1], "r") ) == NULL)

   {

       fprintf(stderr, "%s: File '%s' couldn't be opened!\n", argv[0], argv[1]);

       return (EXIT_FAILURE);

       }

   

   /* a und n aus erster Zeile lesen*/

   if( fgets(string, BUF, fp) != NULL)

   {

       token = strtok(string, delim);

       input.a = strtol(token, NULL, 10);

       

       if( (token = strtok(NULL, delim)) == NULL)

       {

	       fprintf(stderr, "Wrong fileformat\n");

	       return EXIT_FAILURE;

       	       }

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

       }

   

   if(input.n > 1024)

   {

	fprintf(stderr, "Maximum for n is 1024!\n");

	return EXIT_FAILURE;

	}

   

   /* x ins array einlesen*/

   while(fgets(string, BUF, fp) != NULL)

   {

       temp = strtol(string, NULL, 10);

       input.x[i] = temp;

       i++;

       }

   

   /* sollte es zu wenig x geben wird abgebrochen*/

   if (i < input.n)

   {

       fprintf(stderr, "%s: Not enough entries for x in file!", argv[0]);

       return EXIT_FAILURE;

       }

  /* Funktion für die Threads wird aufgerufen*/             

  thread_start();

  

  stop = clock();

  

  /*Ausgabe*/

  fprintf(stdout, "***************************\n");

  fprintf(stdout, "E = a*xi ( i = 1 -> n)\n");

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

  fprintf(stdout, "Result: %ld\n", input.sum);

  fprintf(stdout, "Time needed : %lf\n", (float)(stop - start) / CLOCKS_PER_SEC);

  fprintf(stdout, "***************************\n");



fclose(fp);

           

return (0);

  

}