What are the necessary conditions for a computer to generate a deadlock?

The cause of the deadlock is as follows: (1) due to insufficient system resources. (2) The order in which the process is promoted is inappropriate. (3) improper resource allocation. If the system resources are sufficient,All process resource requests can be satisfied, and the possibility of deadlock is very low. Otherwise, a deadlock will occur due to competition for limited resources. Second, the process running promotion orderDifferent from the speed, deadlock may also occur. Four Conditions for deadlock: (1) mutex: A resource can only be used by one process at a time. (2) Requests andCondition: when a process is blocked by requesting resources, it does not store the obtained resources. (3) Non-deprivation condition: resources obtained by the process, before the end of use,Cannot be forcibly deprived. (4) Cyclic waiting condition: a cyclic waiting resource relationship is formed between several processes that are connected at the beginning and end. These four conditions are necessary for deadlock, as longWhen a deadlock occurs in the system, these conditions must be met.