#include <thread.h>
#include <thread-sync.h>

#define N 5

sem_t table;
sem_t avail[N];

void Tphilosopher(int id) {
    int lhs = (id + N - 1) % N;
    int rhs = id % N;

    while (1) {
        // Come to table
        // P(&table);

        P(&avail[lhs]);
        printf("+ %d by T%d\n", lhs, id);
        P(&avail[rhs]);
        printf("+ %d by T%d\n", rhs, id);

        // Eat.
        // Philosophers are allowed to eat in parallel.

        printf("- %d by T%d\n", lhs, id);
        printf("- %d by T%d\n", rhs, id);
        V(&avail[lhs]);
        V(&avail[rhs]);

        // Leave table
        // V(&table);
    }
}

int main() {
    SEM_INIT(&table, N - 1);

    for (int i = 0; i < N; i++) {
        SEM_INIT(&avail[i], 1);
    }

    for (int i = 0; i < N; i++) {
        create(Tphilosopher);
    }
}