SH_TAILQ_HEAD
SH_TAILQ_HEAD(hash_head) *headp;
typedef SH_TAILQ_HEAD(hash_head) DB_HASHTAB;
SH_TAILQ_HEAD(lock_header) free_locks; /* free lock header */
SH_TAILQ_HEAD(obj_header) free_objs; /* free obj header */
SH_TAILQ_HEAD(_wait) _waiters; /* List of waiting locks. */
SH_TAILQ_HEAD(_hold) _holders; /* List of held locks. */
SH_TAILQ_HEAD(__fq) fq; /* List of file names. */
SH_TAILQ_HEAD(__bhq) bhq; /* LRU list of buckets. */
SH_TAILQ_HEAD(__bhfq) bhfq; /* Free buckets. */
SH_TAILQ_HEAD(__mpfq) mpfq; /* List of MPOOLFILEs. */
SH_TAILQ_HEAD(_active) active_txn; /* active transaction list */