Elaborato_SO/src/custom_shm.c

#include <stdio.h>
#include <sys/shm.h>
#include <sys/stat.h>
#include <custom_shm.h>

#include <errExit.h>
#include <forza4.h>

int _SHMID;

int getShmid();
tile_t *shmServerAt();

void setupServerShm() {
    _SHMID = getShmid();
    _BOARD = shmServerAt();

    for (int i=0; i < _ROWS * _COLLUMS; i++) {
        _BOARD[i] = EMPTY;
    }
}

int getShmid() {
    int shmid = shmget(ftok(KEYFILE, 'h'), _ROWS * _COLLUMS * sizeof(tile_t), IPC_CREAT | S_IRUSR | S_IWUSR);
    if (shmid == -1) {
        errExit("shmget", "getShmid");
    }

    return shmid;
}

tile_t *shmServerAt() { //FIXME: si possono fare void
    tile_t *board = (tile_t *)shmat(_SHMID, NULL, 0); 
    if (board == SHMERR) {
        errExit("shmat", "shmServerAt");
    }
    
    return board;
}

tile_t * shmClientAt() {
    tile_t *board = (tile_t *)shmat(_SHMID, NULL, SHM_RDONLY);
    perror("perche");

    if (board == SHMERR) {
        errExit("shmat", "shmClientAt");
    }

    return board;
} 

void shmDt(void *shm_ptr) { //FIXME: sono tutte var globali
    if (shmdt(shm_ptr) == -1) {
        errExit("shmdt", "shmDt");
    }
}

void shmServerRm(int shmid) {
    if (shmctl(shmid, IPC_RMID, NULL) == -1) {
        errExit("shmctl", "shmServerRm");
    } 
}