Miscellany

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