Instructions

Given the two semaphore operations illustrated below;

wait (x) { while x <= 0 // No Operation x-- }

Signal (x) { x++ }

And using (as an example and basis) the producer-consumer code as illustrated below;

Producer() { while (true) { item = produceitem() wait(empty) wait(binary) additemtobuffer(item) signal(binary) signal(full) } }

Consumer() { while (true) { wait(full); wait(binary); takeitemfrombuffer(item); signal(binary); signal(empty); consumeitem(item) } }

Then given the following information;

Three processes are involved in printing a file (pictured below);

Process A reads the file data from the disk to Buffer 1

Process B copies the data from Buffer 1 to Buffer 2

Process C takes the data from Buffer 2 and prints it

Assume all three processes operate on one (file) record at a time, both buffers' capacity are one record.

Write pseudo code (in the style of the producer-consumer) to coordinate the three processes using semaphores and successfully print a file.