Buffer buffer .... // only accessed by operations push/pull
Semaphore num = 0; // synchronization of consumers/producers
Semaphore bufferAccess = 1; // critical region: buffer access

// Producer:
while (true) {
  newdata = produce();
  P(bufferAccess);
  push(newdata,buffer);
  V(bufferAccess);
  V(num);
}

// Consumer:
while (true) {
  P(num);
  P(bufferAccess);
  mydata = pull(buffer);
  V(bufferAccess);
  consume(mydata);
}