What are the necessary conditions for deadlock to occur?

a. At least one resource should be occupied in a non-sharable condition.

b. A process holding at least one resource is waiting for more resources currently in use by other processes.

c. It is not possible to pre-empt the resource.

d. There exists a circular wait for processes.

Name the functions constituting the OS's memory management.

- Memory allocation and de-allocation

- Integrity maintenance

- Swapping

- Virtual memory