生成时钟置换算法python代码

以下是Python实现的时钟置换算法代码：

def clock_replacement(pages, frames):
    """
    :param pages: list of page references
    :param frames: number of available frames
    :return: number of page faults
    """
    frame_list = []
    ref_bits = []
    page_faults = 0
    clock_hand = 0

    for page in pages:
        if page in frame_list:
            ref_bits[frame_list.index(page)] = 1  # update reference bit
        else:
            page_faults += 1
            if len(frame_list) < frames:
                frame_list.append(page)
                ref_bits.append(1)
            else:
                while True:
                    if ref_bits[clock_hand] == 1:
                        ref_bits[clock_hand] = 0  # reset reference bit
                    else:
                        frame_list[clock_hand] = page
                        ref_bits[clock_hand] = 1
                        clock_hand = (clock_hand + 1) % frames
                        break

    return page_faults

使用方法：

pages = [1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5]
frames = 3
page_faults = clock_replacement(pages, frames)
print("Number of page faults:", page_faults)

输出结果：

Number of page faults: 9