1 // operator_system.cpp: 定义控制台应用程序的入口点。
2 //
3
4 #include "stdafx.h"
5 #include<iostream>
6 #include <mutex>
7 #include <condition_variable>
8 #include <windows.h>
9 #include <thread>
10
11 using namespace std;
12
13 static const int buffer_size = 10; // 缓存大小
14 static const int item_total = 100; //总共要生产 item_total个item
15
16 // 缓存结构体, 使用循环队列当做缓存
17 struct Buffer
18 {
19 int buffer[buffer_size];
20 size_t read_position; // 当前读位置
21 size_t write_position; // 当前写位置
22 mutex mtx; // 读写互斥
23 //条件变量
24 condition_variable not_full;
25 condition_variable not_empty;
26 }buffer_res;
27
28 typedef struct Buffer Buffer;
29
30 void porduce_item(Buffer *b, int item)
31 {
32 unique_lock<mutex> lock(b->mtx);//设置互斥锁
33
34 while(((b->write_position + 1) % buffer_size) == b->read_position) {
35 //当前缓存已经满了
36 cout << "buffer is full now, producer is wating....." << endl;
37 (b->not_full).wait(lock); // 等待缓存非full
38 }
39 // 向缓存中添加item
40 (b->buffer)[b->write_position] = item;
41 (b->write_position)++;
42
43 // 若到达最后一个, 写位置置位0
44 if (b->write_position == buffer_size)
45 b->write_position = 0;
46
47 (b->not_empty).notify_all();
48 lock.unlock();
49 }
50
51 int consume_item(Buffer *b)
52 {
53 int data;
54 unique_lock <mutex> lock(b->mtx);
55 while (b->write_position == b->read_position)
56 { // 当前buffer 为空
57 cout << "buffer is empty , consumer is waiting....." << endl;
58 (b->not_empty).wait(lock);
59 }
60
61 data = (b->buffer)[b->read_position];
62 (b->read_position)++;
63
64 if (b->read_position >= buffer_size)
65 b->read_position = 0;
66
67 (b->not_full).notify_all();
68 lock.unlock();
69
70 return data;
71 }
72
73 //生产者任务
74 void producer() {
75 for (int i = 1; i<= item_total;i++) {
76 cout << "prodece the " << i << "^th item ..." << endl;
77 porduce_item(&buffer_res, i);
78 }
79 }
80
81 //消费者任务
82 void consumer()
83 {
84 static int cnt = 0;
85 while(1) {
86 Sleep(1);
87 int item = consume_item(&buffer_res);
88 cout << "consume the " << item << "^th item" << endl;
89 if (++cnt == item_total)
90 break;
91 }
92 }
93
94 //初始化 buffer
95 void init_buffer(Buffer *b)
96 {
97 b->write_position = 0;
98 b->read_position = 0;
99 }
100
101 int main()
102 {
103 init_buffer(&buffer_res);
104 thread prodece(producer);
105 thread consume(consumer);
106 prodece.join();
107 consume.join();
108 getchar();
109 }
