Function put

examples/libc/ex2.c:41–56

Store an integer in the buffer */

/* Store an integer in the buffer */
static void put(struct prodcons * b, int data)
{
  pthread_mutex_lock(&b->lock);
  /* Wait until buffer is not full */
  while ((b->writepos + 1) % BUFFER_SIZE == b->readpos) {
    pthread_cond_wait(&b->notfull, &b->lock);
    /* pthread_cond_wait reacquired b->lock before returning */
  }
  /* Write the data and advance write pointer */
  b->buffer[b->writepos] = data;
  b->writepos++;
  if (b->writepos >= BUFFER_SIZE) b->writepos = 0;
  /* Signal that the buffer is now not empty */
  pthread_cond_signal(&b->notempty);
  pthread_mutex_unlock(&b->lock);
}

/* Read and remove an integer from the buffer */