public void run() {
pr.println("Reader " + id + " trying to get into CR");
mutex.semWait(); // semWait on mutex, only one reader can adjust count
readCount++;
if (readCount == 1) S.semWait(); // semWait on S
mutex.semSignal(); // semSignal on mutex
pr.println("Reader " + id + " is reading");
try {
sleep((long) (Math.random() * 1000));
} catch (InterruptedException e) {
}
;
pr.println("Reader " + id + " is done reading");
mutex.semWait();
readCount--;
if (readCount == 0) S.semSignal(); // semSignal on S
mutex.semSignal(); // semSignal on mutex
}
public void run() {
pr.println("Writer " + id + " is trying to write");
S.semWait(); // semWait on S, see if allowed in critical section
pr.println("Writer " + id + " is starting to write");
try {
sleep((long) (Math.random() * 1000)); // "writing"
} catch (InterruptedException e) {
}
;
pr.println("Writer " + id + " is done writing");
S.semSignal(); // semSignal on S, done writing critical section
pr.println("Writer " + id + " is wrapping things up");
}