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C++11 实现生产者消费者双缓冲

时间:2017-11-09 23:38:30      阅读:301      评论:0      收藏:0      [点我收藏+]

基础的生产者消费者模型,生产者向公共缓存区写入数据,消费者从公共缓存区读取数据进行处理,两个线程访问公共资源,加锁实现数据的一致性。

通过加锁来实现

 1 class Produce_1 {
 2 public:
 3     Produce_1(std::queue<int> * que_, std::mutex * mt_) {
 4         m_mt = mt_;
 5         m_que = que_;
 6         m_stop = false;
 7     }
 8     void runProduce() {
 9         while (!m_stop) {
10             std::this_thread::sleep_for(std::chrono::seconds(1));
11             std::lock_guard<std::mutex> lgd(*m_mt);
12             m_que->push(1);
13             std::cout << "Produce_1 produce 1" << std::endl;
14         }
15     }
16     void join() {
17         m_trd->join();
18         m_trd.reset();
19     }
20     void start() {
21         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Produce_1::runProduce), this)));
22     }
23     void stop() {
24         m_stop = true;
25     }
26 private:
27     std::mutex * m_mt;
28     std::queue<int> * m_que;
29     volatile bool m_stop;
30     std::shared_ptr<std::thread> m_trd;
31 };
32 
33 
34 /*
35 *单缓冲一个同步队列 效率较低
36 */
37 class Consume_1 {
38 public:
39     Consume_1(std::queue<int> * que_, std::mutex * mt_) {
40         m_mt = mt_;
41         m_que = que_;
42         m_stop = false;
43     }
44 
45     void runConsume() {
46         while (!m_stop) {
47             std::this_thread::sleep_for(std::chrono::seconds(1));
48             std::lock_guard<std::mutex> lgd(*m_mt);
49             if (!m_que->empty()) {
50                 m_que->pop();
51             }
52             std::cout << "Consume_1 consume" << std::endl;
53         }
54     }
55     void join() {
56         m_trd->join();
57         m_trd.reset();
58     }
59     void start() {
60         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Consume_1::runConsume), this)));
61     }
62     void stop() {
63         m_stop = true;
64     }
65 private:
66     std::mutex * m_mt;
67     std::queue<int> * m_que;
68     volatile bool m_stop;
69     std::shared_ptr<std::thread> m_trd;
70 };

 

通过条件变量来实现

 1 typedef struct Mutex_Condition{
 2     std::mutex mt;
 3     std::condition_variable cv;
 4 }Mutex_Condition;
 5 
 6 class Produce {
 7 public:
 8     Produce(std::queue<int> * que_, Mutex_Condition * mc_) {
 9         m_que = que_;
10         m_mc = mc_;
11         m_stop = false;
12     }
13     void join() {
14         m_trd->join();
15         m_trd.reset();
16     }
17     void produce(int enter) {
18         std::lock_guard<std::mutex> lgd(m_mc->mt);
19         m_que->push(enter);
20         m_mc->cv.notify_one();
21     }
22 
23     void runProduce() {
24         while (!m_stop) {
25             std::this_thread::sleep_for(std::chrono::seconds(1));
26             produce(1);
27             std::cout << "Produce Thread produce 1 " << std::endl;
28         }
29     }
30 
31     void start() {
32         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Produce::runProduce), this)));
33     }
34     void stop() {
35         m_stop = true;
36     }
37 
38 private:
39     std::queue<int> * m_que;
40     Mutex_Condition * m_mc;
41     std::shared_ptr<std::thread> m_trd;
42     volatile bool m_stop;
43 };
44 
45 
46 class Consume {
47 public:
48     Consume(std::queue<int> * que_, Mutex_Condition * mc_) {
49         m_que = que_;
50         m_mc = mc_;
51         m_stop = false;
52     }
53     void join() {
54         m_trd->join();
55         m_trd.reset();
56     }
57     void consume() {
58         std::unique_lock<std::mutex> lgd(m_mc->mt);
59         while (m_que->empty()) {
60             int i = 0;
61             m_mc->cv.wait(lgd);
62         }
63         m_que->pop();
64         std::cout << "Consume Thread consume " << std::endl;
65     }
66     void runConsume() {
67         while (!m_stop) {
68             std::this_thread::sleep_for(std::chrono::seconds(1));
69             consume();
70         }
71     }
72     void start() {
73         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Consume::runConsume), this)));
74     }
75     void stop() {
76         m_stop = true;
77     }
78 
79 private:
80     std::queue<int> * m_que;
81     Mutex_Condition * m_mc;
82     std::shared_ptr<std::thread> m_trd;
83     volatile bool m_stop;
84 
85 };

 

二、生产者消费者-双缓冲

一个公共缓存区,由于多线程访问的锁冲突较大,可以采取双缓冲手段来解决锁的冲突

双缓冲的关键:双缓冲队列的数据交换

1)生产者线程不断的向生产者队列A写入数据,当队列中有数据时,进行数据的交换,交换开始启动时通过条件变量通知交换线程来处理最先的数据交换。

2)数据交换完成后,通过条件变量通知消费者处理数据,此时交换线程阻塞到消费者数据处理完成时通知的条件变量上。

3)消费者收到数据交换后的通知后,进行数据的处理,数据处理完成后,通知交换线程进行下一轮的双缓冲区的数据交换。

要点:

生产者除了在数据交换时,其余时刻都在不停的生产数据。

数据交换队列需要等待消费者处理数据完成的通知,以进行下一轮交换。

消费者处理数据时,不进行数据交换,生产者同时会不断的生产数据,消费者需要等待数据交换完成的通知,并且发送消费完成的通知给交换线程

 

 

  1 typedef struct Mutex_Condition{
  2     std::mutex mt;
  3     std::condition_variable cv;
  4 }Mutex_Condition;
  5 
  6 class Produce_1 {
  7 public:
  8     Produce_1(std::queue<int> * que_1, std::queue<int> * que_2, Mutex_Condition * mc_1 , Mutex_Condition * mc_2) {
  9         m_read_que   = que_1;
 10         m_writer_que = que_2;
 11         m_read_mc    = mc_1;
 12         m_writer_mc  = mc_2;
 13         m_stop       = false;
 14 
 15     }
 16     void runProduce() {
 17         while (!m_stop) {
 18             std::this_thread::sleep_for(std::chrono::microseconds(20 * 1000));
 19             std::lock_guard<std::mutex> lgd(m_writer_mc->mt);
 20             m_writer_que->push(1);
 21             m_writer_mc->cv.notify_one();
 22             std::cout << "m_writer push" << std::endl;
 23         }
 24         
 25     }
 26     void join() {
 27         m_trd->join();
 28         m_trd.reset();
 29     }
 30     void start() {
 31         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Produce_1::runProduce), this)));
 32     }
 33     void stop() {
 34         m_stop = true;
 35     }
 36 private:
 37     Mutex_Condition * m_read_mc;
 38     Mutex_Condition * m_writer_mc;
 39     std::queue<int> * m_read_que;
 40     std::queue<int> * m_writer_que;
 41     volatile bool m_stop;
 42     std::shared_ptr<std::thread> m_trd;
 43 };
 44 
 45 
 46 class Consume_1 {
 47 public:
 48     Consume_1(std::queue<int> * que_1, std::queue<int> * que_2, Mutex_Condition * mc_1,Mutex_Condition * mc_2,Mutex_Condition * switch_mc) {
 49         m_read_que    = que_1;
 50         m_writer_que  = que_2;
 51         m_read_mc     = mc_1;
 52         m_writer_mc   = mc_2;
 53         m_stop        = false;
 54         m_switch_mc = switch_mc;
 55     }
 56 
 57     void runConsume() {
 58         while (!m_stop) {
 59             while (true) {
 60                 std::this_thread::sleep_for(std::chrono::microseconds(20 * 1000));
 61                 std::unique_lock<std::mutex> ulg(m_read_mc->mt);
 62                 while (m_read_que->empty()) {
 63                     m_read_mc->cv.wait(ulg);
 64                 }
 65                 //deal data
 66                 //std::lock_guard<std::mutex> ulg(m_read_mc->mt);
 67                 while (!m_read_que->empty()) {
 68                     m_read_que->pop();
 69                     std::cout << "m_read_queue pop" << std::endl;
 70                 }
 71                 m_switch_mc->cv.notify_one();
 72             }
 73         }
 74     }
 75     void join() {
 76         m_trd->join();
 77         m_trd.reset();
 78     }
 79     void start() {
 80         m_trd.reset(new std::thread(std::bind(std::mem_fun(&Consume_1::runConsume), this)));
 81     }
 82     void stop() {
 83         m_stop = true;
 84     }
 85 private:
 86     Mutex_Condition * m_read_mc;
 87     Mutex_Condition * m_writer_mc;
 88     Mutex_Condition * m_switch_mc;
 89     std::queue<int> * m_read_que;
 90     std::queue<int> * m_writer_que;
 91     volatile bool m_stop;
 92     std::shared_ptr<std::thread> m_trd;
 93 };
 94 void que_switch_trd(std::queue<int> * read_que, std::queue<int> * writer_que, Mutex_Condition * read_mc, Mutex_Condition * writer_mc,Mutex_Condition * switch_mc) {
 95     while (true) {
 96         std::this_thread::sleep_for(std::chrono::microseconds(20*1000));
 97         {
 98             std::unique_lock<std::mutex> ulg(writer_mc->mt);
 99             while (writer_que->empty()) {
100                 writer_mc->cv.wait(ulg);
101             }
102             std::lock_guard<std::mutex> ulg_2(read_mc->mt);
103             std::swap(*read_que, *writer_que);
104             std::cout << "switch queue" << std::endl;
105             if (!read_que->empty()) {
106                 read_mc->cv.notify_one();
107             }
108         }
109         std::unique_lock<std::mutex> ulg_2(switch_mc->mt);
110         while (!read_que->empty()) {
111             switch_mc->cv.wait(ulg_2);
112         }
113     }
114 }
115 int main(){
116 
117     Mutex_Condition mc_1;
118     Mutex_Condition mc_2;
119     Mutex_Condition mc_3;
120     std::queue<int> que_1;
121     std::queue<int> que_2;
122 
123     Produce_1 produce_1(&que_1, &que_2, &mc_1, &mc_2);
124     Consume_1 consume_1(&que_1, &que_2, &mc_1, &mc_2,&mc_3);
125 
126     std::thread trd(std::bind(&que_switch_trd, &que_1, &que_2, &mc_1, &mc_2,&mc_3));
127     produce_1.start();
128     consume_1.start();
129     
130     produce_1.join();
131     consume_1.join();
132     trd.join();
133 
134     return 0;
135 }

 

C++11 实现生产者消费者双缓冲

原文:http://www.cnblogs.com/Forever-Kenlen-Ja/p/7811943.html

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