lock out

verb4

1. •
   To inadvertently prevent (a person, particularly oneself) from entering a place, by leaving it locked.

   • I've locked myself out of my room again!
2. •
   To prevent from accessing a data structure.

   • The synchronize keyword locks out all other threads trying to access the object.
3. •
   (industrial) To prevent (a person, including oneself) from powering up or turning on a machine when doing so would be dangerous (accomplished with objects such as padlocks or zip ties placed through the switch handle, for example)
4. •
   (colloquial, sometimes humorous) To be unable to concentrate.

   • Bro, I am totally locked out on this assignment.