Network Reception

receive interrupt handler

packetArrival->V()

packetArrival->P()

while (systemActive) {

packetArrival->P();

disable interrupts;

pkt = GetRcvPacket();

enable interrupts;

HandleRcvPacket(pkt);

}

interrupt

TCP/IP reception

HTTP request handler

This example illustrates use of a semaphore by an interrupt handler to pass incoming data to waiting threads.