1, set the bus, the driver and the conductor are respectively:

Driver's activities:

Start the vehicle;             

Normal driving;             

Stop at the station; 

Conductor's activities:

Shut the door;             

The ticket;             

The car door open; 

What is the synchronous relationship between the two activities as the car continues to arrive, stop and move?P, V operation to achieve their synchronization.

Solution: set two semaphores S and C with initial value S = 0.C = 0; 

Driver: English: normal conductor: L2: ticket

As the P (S)

V (S) drive door

P (C) shut the door

Start driving V (C)

GO TO L1 GO TO L2