A dissemination barrier is a symmetric barrier implementation in which threads spin on statically assigned locally cached locations using only load sand stores. As illustrated in Fig.18.20, the...

A dissemination barrier is a symmetric barrier implementation in which threads spin on statically assigned locally cached locations using only load sand stores. As illustrated in Fig.18.20, the algorithm runs in a series of rounds. At round r, thread in o tifies threadi+2r(mod n)(where n is the number of threads)and waits for notification from threadi−2r(mod n).For how many rounds must this protocol run to implement a barrier? What if n is not a power of 2? Justify your answers.