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

#define shm_path "shm123"
#define sem_path "sem123"
#define MAX_MSG_LENGTH      50

struct msg_s {
    int type;
    int content;
};


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

    int deskryptor;
    int rozmiar = (1 * sizeof(struct msg_s));
    struct msg_s *shared_msg;

    sem_t * sem = sem_open(sem_path, 0);
	sem_wait(sem);

    deskryptor = shm_open(shm_path, O_RDWR, S_IRWXU | S_IRWXG);

    printf("Otwarto pamiec wspoldzielona %s\n", shm_path);

    shared_msg = (struct msg_s *)mmap(NULL, rozmiar, PROT_READ | PROT_WRITE, MAP_SHARED, deskryptor, 0);

    printf("Odczytany pid w SHM: %d\n",  shared_msg->content);

	shared_msg->content=getpid();

    printf("Ustawianie pid w SHM na: %d\n",  shared_msg->content);

    munmap(0, rozmiar);

	sem_post(sem);

    return 0;

}