11 /* Circular buffer of integers. */
14   int buffer[BUFFER_SIZE];      /* the actual data */  member
15   pthread_mutex_t lock;         /* mutex ensuring exclusive access to buffer */
17   pthread_cond_t notempty;      /* signaled when buffer is not empty */
18   pthread_cond_t notfull;       /* signaled when buffer is not full */
21 /* Initialize a buffer */
32 /* Store an integer in the buffer */
36   /* Wait until buffer is not full */  in put()
42   b->buffer[b->writepos] = data;  in put()
45   /* Signal that the buffer is now not empty */  in put()
50 /* Read and remove an integer from the buffer */
56   /* Wait until buffer is not empty */  in get()
61   data = b->buffer[b->readpos];  in get()
64   /* Signal that the buffer is now not full */  in get()
75 struct prodcons buffer;  variable
82     put(&buffer, n);  in producer()
84   put(&buffer, OVER);  in producer()
92     d = get(&buffer);  in consumer()
104   init(&buffer);  in libc_ex2()