Visual Analysis of DeadLock

Everyone may have seen traffic jams. A large number of cars are fighting for the right to exercise the traffic intersections, causing traffic jams, or because the vehicles break down or two cars collide, causing traffic jams.In this case, all cars are stopped and no one can move forward. This is a deadlock.

Two people crossing a single-plank bridge is an example of a deadlock:

Or if a busy intersection + traffic is paralyzed, look at the pictures and talk, which direction is the first traffic jam?

The situation in the picture below is not a deadlock. Because a vehicle irresponsibly occupies the right of way (which can be considered as a resource), the following vehicles are waiting, but this waiting state can be changed, as long as the whiteAs the vehicle moves on, the system status is updated.

There are many exclusive resources in the operating system. Semaphores and mutual exclusion locks are tools to provide multi-threaded resource protection and synchronization in RTOS or Linux systems. If used correctly, our programs will run safely, stably and reliably. However,If used incorrectly, it can also cause deadlocks, which in operating systems are when a group of threads are blocked, waiting for a condition that will never be true.After entering the deadlock, the status of all parties involved in the deadlock