In order to control traffic, a network router, A periodically sends a message to its neighbor, B, telling it to increase or decrease the number of packets that it can handle. At some point in time, Router A is flooded with traffic and sends B a message telling it to cease sending traffic. It does this by specifying that the number of bytes B may send (A’s window size) is 0. As traffic surges decrease, A sends a new message, telling B to restart transmission. It does this by increasing the window size from 0 to a positive number. That message is lost. As described, neither side will ever transmit. State and explain this type of deadlock.

QUESTION FOUR

1. In order to control traffic, a network router, A periodically sends a message to its neighbor, B, telling it to increase or decrease the number of packets that it can handle. At some point in time, Router A is flooded with traffic and sends B a message telling it to cease sending traffic. It does this by specifying that the number of bytes B may send (A’s window size) is 0. As traffic surges decrease, A sends a new message, telling B to restart transmission. It does this by increasing the window size from 0 to a positive number. That message is lost. As described, neither side will ever transmit. State and explain this type of deadlock.
2. All precedence graph can be implemented by fork/join construct? Proof?

(i)Show by example that all precedence graphs cannot be implemented by cobegin/coend construct. Characterize the precedence graphs can be implemented using the cobegin/coend.

(ii)Explain how semaphore variables are used with cobegin/coend to be implemented in all precedence graphs.

(iii)Apply the fork-join structure to write a procedure for the graph below in figure 1.

Apply the cobegin/coend with the aid of the semaphore variables to write a procedure for the graph below in figure 1