---

1）
in = 0, out = 0
buffer[k]
semaphore empty = k, full = 0；//缓冲区空闲和非空闲数量
semaphore mutex_in = 1, mutex_out = 1//生产者之间互斥访问缓冲区、消费者之间互斥访问缓冲区；

2）

Process Producer_i:
while true:
    produce data;
    P(empty);
    P(mutex_in);
    write to buffer[in];
    in = (in + 1) % k;
    V(mutex_in);
    V(full);

3）

Process Consumer_j:
while true:
    P(full);
    P(mutex_out);
    read from buffer[out];
    out = (out + 1) % k;
    V(mutex_out);
    V(empty);

---