// A state is safe iff there exists a safe sequence of grants that would allow 
// all threads to eventually receive their maximum resource needs.
//
// avail[] holds free resource count 
// alloc[][] holds current allocation
// request[][] holds currently-blocked requests
bool
ResourceMgr::isDeadlocked() {
    int j;
    int toBeAvail[] = copy avail[];
    bool finish[] = [false, false, false, ...]; // finish[j] is true if thread 
                                                // j is guaranteed to finish

    while(true) {
        j = any threadID such that (finish[j] == false) && 
                                (forall i: request[i][j] <= toBeAvail[i]);
        if (no such j exists) {
            if (forall j: finish[j] == true) {
                return false;
            } else {
                return true;
            }
        } else {
            // Thread j *may* eventually finish and 
            // return its current allocation to the pool.
            finish[j] = true;
            forall i: toBeAvail[i] = toBeAvail[i] + alloc[i][j];
        }
    }
}