ECE 426 Lab 3

lab3a.c

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

int main()
{
    int n = 8; //35
    pid_t pid;

    pid = fork();
    if (pid == 0) { /* child process */
        while(n > 1){
		printf("%d - ", n);
		if(n % 2 == 0){
			//even
			n = n/2;
		}else{
			n = 3*n + 1;
		}
	}
	printf("%d\n", n);
        return 0;
    }
    else if (pid > 0) { /* parent process */
        wait(NULL);
        printf ("Child Exited\n");
        return 0;
    }
}

lab3b.c

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

int main(int argc, char* argv[])
{
    if(argc == 1){
	    printf("Usage: ./lab3b <Number>\n");
	    return -1;
    }
    int n = atoi(argv[1]);
    pid_t pid;

    pid = fork();
    if (pid == 0) { /* child process */
        while(n > 1){
		printf("%d - ", n);
		if(n % 2 == 0){
			//even
			n = n/2;
		}else{
			n = 3*n + 1;
		}
	}
	printf("%d\n", n);
        return 0;
    }
    else if (pid > 0) { /* parent process */
        wait(NULL);
        printf ("Child Exited\n");
        return 0;
    }
}

lab3c-prod.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <sys/mman.h>

int main(int argc, char* argv[])
{
	if(argc == 1){
	    printf("Usage: ./lab3c-prod <Number>\n");
	    return -1;
    }
	const int SIZE = 4096;
	const char *name = "OS";
  int n = atoi(argv[1]);
	int shm_fd;
	void *ptr;

	shm_fd = shm_open(name, O_CREAT | O_RDWR, 0666);

	ftruncate(shm_fd,SIZE);

	ptr = mmap(0,SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, shm_fd, 0);
	if (ptr == MAP_FAILED) {
		printf("Map failed\n");
		return -1;
	}

  while(n > 1){
		sprintf(ptr, "%d - ", n);
    ptr += snprintf(NULL, 0,  "%d - ", n);
		if(n % 2 == 0){
			//even
			n = n/2;
		}else{
			n = 3*n + 1;
		}
	}
	sprintf(ptr,"%d\n", n);
  ptr += snprintf(NULL, 0,  "%d\n", n);

	return 0;
}

The generic consumer program from the book can consume lab3c.