Stuff

/****************************//*	Subway.c	    *//*Ubahn Simulations Programm*//*	V 1.0 21.5.05	    *//****************************/#include <stdio.h>#include <stdlib.h>#include <pthread.h>#include <string.h>#include <time.h>#include <unistd.h>#define LINE_LEN 12pthread_cond_t cond;pthread_mutex_t mutex;typedef struct timetable{	double distance;	double speed;	double time;		}timetable_t;timetable_t line[4];double position[4];int stopit = 0;int counter;/*Funktion zum starten der Threads*/void *subwaytohell(void *arg){	int status;	int index = counter;		fprintf(stdout, "Subway %d: goin to work\n", index);		while(position[index] <= 500)	{		 		if(stopit == 0)		{							status = pthread_mutex_lock(&mutex);      			if (status != 0)   			{       				fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());       				exit (EXIT_FAILURE);       			}    						position[index] += line[index].speed;			fprintf(stdout, "Subway %lf: workin\n", line[index].speed);				status = pthread_mutex_unlock(&mutex);						if (status != 0)   			{       				fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());       				exit (EXIT_FAILURE);       			}  						sleep(1);			}		else		{			fprintf(stdout, "Subway %d: waitin\n", index);			pthread_cond_wait(&cond, &mutex);			}				}		if(position[index] >= 500 && position[index] < line[index].distance)	{		fprintf(stdout, "Subway %d: reached critical section\n", index);		stopit = 1;		   					while(position [index] <= 700)		{			status = pthread_mutex_lock(&mutex);      			if (status != 0)   			{       				fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());       				exit (EXIT_FAILURE);       				}							position[index] += line[index].speed;						status = pthread_mutex_unlock(&mutex);				if (status != 0)   			{       				fprintf (stdout, "Error on mutex_unlock with Thread%ld\n", pthread_self());       				exit (EXIT_FAILURE);       				}			sleep(1);			}		 		stopit = 0;		pthread_cond_signal(&cond);			}	while(position[index] <= line[index].distance)	{		pthread_mutex_lock(&mutex);		position[index] += line[index].speed;		pthread_mutex_unlock(&mutex);		sleep(1);		}		if(position[index] == line[index].distance)	{		fprintf(stdout, "Destination Reached\n");				pthread_exit((void *)0);line[index].time = line[index].distance / line[index].speed;		}return (0);}int thread_start(){	pthread_t th[4];	int i;	counter = 0;	for (i = 0; i < 4; i++) 	{				if(pthread_create(&th[i], NULL, &subwaytohell, NULL) != 0) 		{			fprintf (stderr, "Error creating Thread %d ...\n",i+1);			return EXIT_FAILURE;			}		counter++;	}   	/*Es wird für jeden Thread gewartet bis er beendet hat*/	for( i=0; i <= 3; i++)	{		pthread_join(th[i], NULL);		}		fprintf(stdout, "All Subways reached their Destinatons!\n");	return (0);} int main(int argc, char *argv[]){	FILE *fp;	char buffer[LINE_LEN];	int i;	if(argc < 1){				/*usage();*/		return EXIT_FAILURE;				}	if( (fp=fopen(argv[1], "r")) == NULL){				fprintf(stdout, "File couldn't be opened!\n");		return EXIT_FAILURE;				}	fprintf(stdout, "reading file\n");	for(i = 0; i < 3; i++)        {        	if(fgets(buffer, LINE_LEN -1, fp) == NULL)        	{        		fprintf(stderr, "%s: invalid file layout %s\n", argv[0], argv[1]);        		return EXIT_FAILURE;        	}      		sscanf(buffer,"%lf %lf", &line[i].distance, &line[i].speed);       		fprintf(stdout, "speed: %lf", line[i].speed);		line[i].speed = line[i].speed/3.6;fprintf(stdout, "speed: %lf", line[i].speed);       		line[i].time = line[i].distance / line[i].speed;			}				thread_start();return (0);}