（1）WAITING FOR THIS LOCK TO BE GRANTED

lock_mode X locks gap before rec insert intention waiting

这部分怎么理解，加的什么锁？

lock_mode X locks gap before rec insert intention 怎么断句

lock_mode X locks gap before rec 还是 lock_mode X locks gap before rec insert intention是一个整体？

(2) WAITING FOR THIS LOCK TO BE GRANTED:

lock_mode X insert intention waiting

这部分怎么理解，加的什么锁？ 

lock_mode X 一部分

insert intention waiting 一部分

还是lock_mode X insert intention 整体算？