class ResourceMgr{
  private:
    Lock lock;
    CV cv;
    int r;          // Number of resources
    int t;          // Number of threads
    int avail[];    // avail[i]: instances of resource i available
    int max[][];    // max[i][j]: max of resource i needed by thread j
    int alloc[][];  // alloc[i][j]: current allocation of resource i to thread j
  ...
}