Atomic for two operations

Dear Sir;

I am facing a problem in atomic operations:
I would like the thread to do two things simultaneously
before the second thread operates on the content of the address?

For Example:
The first thread need to updated the content of the memory address, and then, increment the address

Then the second thread will do the same operation (update the content of the incremented address) and increment the incremented address

Thanks,
Saleh