circular buffer

i have a buffer that i like to write to and read from at the same time so that no data gets lost.
could you give an example of such scenario?.

such scenario is possible for infinite and bounded buffer of finite length,such that production of data > consumption of data.

In synchronization problems, you can have your read and write operations work simulataneously.

Or if RW operations are in serialized form.

any example code to cover each case if it is not too much to ask?.