According to Coffman deadlock refers to a specific condition when two or when more processes are each waiting for each other to release a resource, or more than two processes are waiting for resources in a circular chain.
It is evident that processes fall into “Deadlock” or no further progress state when all four of the following conditions are met, since there is no way to recover from such situation.
Serially reusable resource (Mutual exclusion)
Wait for cycle
The diagram below illustrates how the processes wait on a queue to acquire the lock to continue execution.