S01_SEMAFORY_07

/*
Zademonstruj działanie operacji SETALL, GETALL, IPC_STAT, GETPID, GETZCNT.
*/

#include <stdio.h>
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/types.h>
#include <sys/sem.h>
#include <time.h>

#define NUMBER_OF_SEMAPHORES 4

int main(void)
{
    srand(time(NULL));

    int semid;
    union semun arg;
    u_short *array_buffer;
    struct semid_ds buffer;
    pid_t pid;
    short semnum;

    arg.array = (u_short *)calloc(NUMBER_OF_SEMAPHORES, sizeof(u_short));
    array_buffer = (u_short *)calloc(NUMBER_OF_SEMAPHORES, sizeof(u_short));

    if((semid = semget(IPC_PRIVATE, NUMBER_OF_SEMAPHORES, 0775 | IPC_CREAT | IPC_EXCL)) == -1){
        perror("semget");
        return EXIT_FAILURE;
    }

    /* SETALL */
    for(int i = 0; i < NUMBER_OF_SEMAPHORES; i++)
        arg.array[i] = rand() % 10;

    if(semctl(semid, 0, SETALL, arg.array) == -1){
        perror("setall_semctl");
        return EXIT_FAILURE;
    }

    /* GETALL */
    if(semctl(semid, 0, GETALL, array_buffer) == -1){
        perror("getall_semctl");
        return EXIT_FAILURE;
    }
    printf("Wartosci semaforow: ");
    for(int i = 0; i < NUMBER_OF_SEMAPHORES; i++)
        printf("%hu ", array_buffer[i]);
    printf("\n");

    /* IPC_STAT */
    if(semctl(semid, 0, IPC_STAT, &buffer) == -1){
        perror("ipc_stat_semctl");
        return EXIT_FAILURE;
    }
    printf("Liczba semaforow: %hu\n", buffer.sem_nsems);

    /* GETPID */
    if(semctl(semid, 0, GETPID, &pid) == -1){
        perror("pid_semctl");
        return EXIT_FAILURE;
    }
    printf("Pid procesu, ktory ostatnio wykonywal operacje na semaforach: %d\n", pid);

    /* GETZCNT */
    if((semnum = semctl(semid, 0, GETZCNT)) == -1){
        perror("getzcnt_semctl");
        return EXIT_FAILURE;
    }
    printf("Ilosc czekajacych procesow: %hu\n", semnum);

    if(semctl(semid, 0, IPC_RMID) == -1){
        perror("ipc_rmid_semctl");
        return EXIT_FAILURE;
    }

    return EXIT_SUCCESS;
}