LockHead LockRequest LockRequest LockHead LockRequest LockHead LockRequest LockRequest Granted Modeの遷移 S lock S lock S lock S lock S lock S lock X lock X lock X lock X lock S lock (granted_mode) S X (Timestamp) (ts: 1) (ts: 2) (ts: 4) (ts: 3) (ts: 6) (ts: 5) S S S X
S lock S lock S -> X S lock LockHead LockRequest LockRequest LockRequest S -> X S lock X lock LockHead LockRequest S -> X LockHead LockRequest LockRequest LockRequest S S lock S lock S lock LockHead LockRequest LockRequest X S -> X X lock Lock Conversion to X Lock (convert_modeに変換先のlock_modeを保持) LockRequest X lock LockRequest X lock (Timestamp) (ts: 1) X lock LockRequest LockRequest S lock (ts: 2) (ts: 4) (ts: 3) (ts: 6) (ts: 5) S S S S