Epoll example: order of received event

[gftea]

For me on WSL2, I receive the events in below order

RECEIVED: Event { events: 1, epoll_data: 1 }
RECEIVED: Event { events: 1, epoll_data: 2 }
RECEIVED: Event { events: 1, epoll_data: 3 }
RECEIVED: Event { events: 1, epoll_data: 4 }
RECEIVED: Event { events: 1, epoll_data: 5 }
FINISHED

I guess the queue store events according to receiving order, so this seems correct for me, but the books says below

RECIEVED: Event { events: 1, epoll_data: 5 }
RECIEVED: Event { events: 1, epoll_data: 4 }
RECIEVED: Event { events: 1, epoll_data: 3 }
RECIEVED: Event { events: 1, epoll_data: 2 }
RECIEVED: Event { events: 1, epoll_data: 1 }
FINISHED