BS_Events_Proc

BS_event_proc.c

 #include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <time.h>
#include <semaphore.h>

void error_handler(char* msg){perror(msg);exit(EXIT_FAILURE);}
void askTicketsOnEvent(int index,int tickets);
void serverReadsEvents();
void create_shm(void);
void close_shm(void);
void handler_usig1(int sig);
void exit_handeler(int sig);

#define EVENTS 30

char* NAME = "/arr";
char* SEMA = "/semaphore";
sem_t* sem_fd[EVENTS];
sem_t* sem_fd_complete;
int* arr;
int* par_pid;
int* new;



int main(int argc, char const *argv[])
{
	signal(SIGINT,exit_handeler);
	signal(SIGUSR1,handler_usig1);
	//int status;
	
	if (argc!=2)
	{
		error_handler("USAGE: PRG INT");
	}

	//exit_handeler(1);
	int tmp = getpid();
	par_pid = &tmp;
	printf("%d \n", *par_pid);

	int n;
	sscanf(argv[1],"%d", &n);
	if((sem_fd_complete = sem_open(SEMA,O_CREAT| O_EXCL ,0660,1))==SEM_FAILED)error_handler("sem_open");
	char tmpString[100];
	for (int i = 0; i < EVENTS; ++i)
	{
		sprintf(tmpString, "%s%d",SEMA,i);
		if((sem_fd[i]=sem_open(tmpString,O_CREAT| O_EXCL ,0660,1))==SEM_FAILED)error_handler("sem_open");
	}

	create_shm();

	srand(time(NULL));

	int pid;
	int tick;
	int index;
	if(fork()!=0){
		srand(time(NULL));

		for (int j = 0; j < n; ++j){
			
			if((pid=fork())== 0)
			{
				while(1)
				{
					tick = rand() % 20 + 1;
					index = rand() % EVENTS;
					askTicketsOnEvent(index, tick);
				}
			}
		}
		while(1);
			//printf("running \n");
		/*{
			for (int i = 0; i < EVENTS; ++i)
			{
				fprintf(stderr,"Veranstaltung %d hat %d karten \n",i,arr[i]);
			}
		}*/
	}

	close_shm();
	exit_handeler(1);
	return EXIT_SUCCESS;
}

void askTicketsOnEvent(int index,int tickets){
	signal(SIGUSR1,handler_usig1);
	signal(SIGINT,exit_handeler);
	sem_wait(sem_fd_complete);
	sem_wait(sem_fd[index]);
	sem_post(sem_fd_complete);
	if(tickets <= arr[index]){
		arr[index] = arr[index] - tickets;
		//printf("%p, %d, %d\n", sem_fd[index],index,getpid());
		printf("Prozess %5d hat %3d Freikarten für Veanstaltung %3d erhalten\n", getpid(), tickets, index);
	}
	else{
		printf("Veanstaltung %3d hat nurmehr %2d < %2d Freikarten\n", index, arr[index], tickets);
	}

	if(arr[index] == 0)
	{
		sem_post(sem_fd[index]);	
		//raise(/**par_pid,*/SIGUSR1);
		//printf("%d \n", *par_pid);
		kill(*par_pid,SIGUSR1);
	}
	else
		sem_post(sem_fd[index]);
		
}

void serverReadsEvents(){
	signal(SIGUSR1,handler_usig1);
	signal(SIGINT,exit_handeler);
	sem_wait(sem_fd_complete);
	for (int i = 0; i < EVENTS; ++i)
	{
		if(arr[i]==0){
			arr[i] = rand() % 120 + 30;
		}

		printf("Veranstaltung %d hat noch %d tickets\n", i, arr[i]);

	}
	sem_post(sem_fd_complete);

}


void create_shm(void){
	int fd;
	if((fd = shm_open(NAME, O_RDWR | O_CREAT, 0660))==-1)error_handler("shm_open ");
	if(ftruncate(fd,sizeof(int)*30)==-1)error_handler("ftruncate");
	if((arr = (int*) mmap(NULL,sizeof(int)*30, PROT_WRITE, MAP_SHARED, fd, 0))==MAP_FAILED)error_handler("mmap ");
	for (int i = 0; i < 30; ++i)
	{
		serverReadsEvents();
	}
	close(fd);
}

void close_shm(void){
	munmap(NAME,sizeof(int)*30);
	shm_unlink(NAME);

}


void handler_usig1(int sig){
	serverReadsEvents();
}

void exit_handeler(int sig){
	close_shm();
	sem_unlink(SEMA);
	char tmpString[100];
	for (int i = 0; i < EVENTS; ++i)
	{

		sprintf(tmpString, "%s%d",SEMA,i);
		sem_unlink(tmpString);	
	}
	exit(EXIT_SUCCESS);
}