user_controller.c

#include "user_controller.h"
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static UserController *users = NULL;
static int sem_user; // Keep only user semaphore

#if defined(__linux__)
union semun { int val; };
#endif

static void sem_lock(int sem_id) {
    struct sembuf op = {0, -1, SEM_UNDO};
    semop(sem_id, &op, 1);
}

static void sem_unlock(int sem_id) {
    struct sembuf op = {0, 1, SEM_UNDO};
    semop(sem_id, &op, 1);
}

void init_user_controller() {
    int shm_id = shmget(SHM_KEY_USERS, sizeof(UserController), IPC_CREAT | 0666);
    users = (UserController*)shmat(shm_id, NULL, 0);
    memset(users, 0, sizeof(UserController));

    // Only create user semaphore (removed balance semaphore)
    sem_user = semget(SHM_KEY_USERS + 1, 1, IPC_CREAT | 0666);

    union semun arg;
    arg.val = 1;
    semctl(sem_user, 0, SETVAL, arg);

    printf("✓ User controller initialized\n");
}

int check_and_register_login(int role, int user_id) {
    sem_lock(sem_user);

    for (int i = 0; i < MAX_USERS; i++) {
        if (users->users[i].active &&
            users->users[i].role == role &&
            users->users[i].user_id == user_id) {
            sem_unlock(sem_user);
            return 0;
        }
    }

    for (int i = 0; i < MAX_USERS; i++) {
        if (!users->users[i].active) {
            users->users[i].role = role;
            users->users[i].user_id = user_id;
            users->users[i].active = 1;
            sem_unlock(sem_user);
            return 1;
        }
    }

    sem_unlock(sem_user);
    return 0;
}

void register_logout(int role, int user_id) {
    sem_lock(sem_user);
    for (int i = 0; i < MAX_USERS; i++) {
        if (users->users[i].role == role &&
            users->users[i].user_id == user_id) {
            users->users[i].active = 0;
            break;
        }
    }
    sem_unlock(sem_user);
}