XIDHASH
#define DRHASH(dr) XIDHASH((dr)->dr_xid)
dr = drhashtbl[XIDHASH(xid)];
#define DRHASH(dr) XIDHASH((dr)->dr_xid)
dr = cotsdrhashtbl[XIDHASH(xid)];
#define DRHASH(dr) XIDHASH((dr)->dr_xid)
dr = rdmadrhashtbl[XIDHASH(xid)];