C++11 实现生产者消费者模式

代码都类似，看懂一个，基本都能理解了。

共有代码：

#include <cstdlib>
#include <condition_variable>
#include <iostream>
#include <mutex>
#include <thread>

static const int kItemRepositorySize = 10; // Item buffer size.
static const int kItemsToProduce = 1000; // How many items we plan to produce.
std::mutex mutex;//多线程标准输出同步锁

单生产者单消费者模式：

  1 struct ItemRepository
  2     {
  3         int item_buffer[kItemRepositorySize]; // 产品缓冲区, 配合 read_position 和 write_position 模型环形队列.
  4         size_t read_position; // 消费者读取产品位置.
  5         size_t write_position; // 生产者写入产品位置.
  6         std::mutex mtx; // 互斥量,保护产品缓冲区
  7         std::condition_variable repo_not_full; // 条件变量, 指示产品缓冲区不为满.
  8         std::condition_variable repo_not_empty; // 条件变量, 指示产品缓冲区不为空.
  9     } gItemRepository; // 产品库全局变量, 生产者和消费者操作该变量.
 10 
 11     typedef struct ItemRepository ItemRepository;
 12 
 13     void ProduceItem(ItemRepository * ir, int item)
 14     {
 15         std::unique_lock<std::mutex> lock(ir->mtx);
 16         while (((ir->write_position + 1) % kItemRepositorySize)
 17             == ir->read_position)
 18         { // item buffer is full, just wait here.
 19             {
 20                 std::lock_guard<std::mutex> lock(mutex);
 21                 std::cout << "缓冲区满，等待缓冲区不满
";
 22             }
 23             (ir->repo_not_full).wait(lock); // 生产者等待"产品库缓冲区不为满"这一条件发生.
 24         }
 25 
 26         (ir->item_buffer)[ir->write_position] = item; // 写入产品.
 27         (ir->write_position)++; // 写入位置后移.
 28 
 29         if (ir->write_position == kItemRepositorySize) // 写入位置若是在队列最后则重新设置为初始位置.
 30             ir->write_position = 0;
 31 
 32         (ir->repo_not_empty).notify_all(); // 通知消费者产品库不为空.
 33         lock.unlock(); // 解锁.
 34     }
 35 
 36     int ConsumeItem(ItemRepository *ir)
 37     {
 38         int data;
 39         std::unique_lock<std::mutex> lock(ir->mtx);
 40         // item buffer is empty, just wait here.
 41         while (ir->write_position == ir->read_position)
 42         {
 43             {
 44                 std::lock_guard<std::mutex> lock(mutex);
 45                 std::cout << "缓冲区空，等待生产者生成产品
";
 46             }
 47             (ir->repo_not_empty).wait(lock); // 消费者等待"产品库缓冲区不为空"这一条件发生.
 48         }
 49 
 50         data = (ir->item_buffer)[ir->read_position]; // 读取某一产品
 51         (ir->read_position)++; // 读取位置后移
 52 
 53         if (ir->read_position >= kItemRepositorySize) // 读取位置若移到最后，则重新置位.
 54             ir->read_position = 0;
 55 
 56         (ir->repo_not_full).notify_all(); // 通知消费者产品库不为满.
 57         lock.unlock(); // 解锁.
 58 
 59         return data; // 返回产品.
 60     }
 61 
 62 
 63     void ProducerTask() // 生产者任务
 64     {
 65         for (int i = 1; i <= kItemsToProduce; ++i)
 66         {
 67             // sleep(1);
 68             ProduceItem(&gItemRepository, i); // 循环生产 kItemsToProduce 个产品.
 69             {
 70                 std::lock_guard<std::mutex> lock(mutex);
 71                 std::cout << "生产第 " << i << "个产品" << std::endl;
 72             }
 73         }
 74     }
 75 
 76     void ConsumerTask() // 消费者任务
 77     {
 78         static int cnt = 0;
 79         while (1)
 80         {
 81             std::this_thread::sleep_for(std::chrono::seconds(1));
 82             int item = ConsumeItem(&gItemRepository); // 消费一个产品.
 83             {
 84                 std::lock_guard<std::mutex> lock(mutex);
 85                 std::cout << "消费第" << item << "个产品" << std::endl;
 86             }
 87             if (++cnt == kItemsToProduce) break; // 如果产品消费个数为 kItemsToProduce, 则退出.
 88         }
 89     }
 90 
 91     void InitItemRepository(ItemRepository *ir)
 92     {
 93         ir->write_position = 0; // 初始化产品写入位置.
 94         ir->read_position = 0; // 初始化产品读取位置.
 95     }
 96 
 97     void test()
 98     {
 99         InitItemRepository(&gItemRepository);
100         std::thread producer(ProducerTask); // 创建生产者线程.
101         std::thread consumer(ConsumerTask); // 创建消费之线程.
102 
103         producer.join();
104         consumer.join();
105     }

View Code

单生产者多消费者模式：

  1 struct ItemRepository
  2     {
  3         int item_buffer[kItemRepositorySize];
  4         size_t read_position;
  5         size_t write_position;
  6         size_t item_counter;
  7         std::mutex mtx;
  8         std::mutex item_counter_mtx;
  9         std::condition_variable repo_not_full;
 10         std::condition_variable repo_not_empty;
 11     } gItemRepository;
 12 
 13     typedef struct ItemRepository ItemRepository;
 14 
 15     void ProduceItem(ItemRepository *ir, int item)
 16     {
 17         std::unique_lock<std::mutex> lock(ir->mtx);
 18         while (((ir->write_position + 1) % kItemRepositorySize)
 19             == ir->read_position)
 20         {
 21             // item buffer is full, just wait here.
 22             {
 23                 std::lock_guard<std::mutex> lock(mutex);
 24                 std::cout << "缓冲区满，等待缓冲区不满
";
 25             }
 26             (ir->repo_not_full).wait(lock);
 27         }
 28 
 29         (ir->item_buffer)[ir->write_position] = item;
 30         (ir->write_position)++;
 31 
 32         if (ir->write_position == kItemRepositorySize)
 33             ir->write_position = 0;
 34 
 35         (ir->repo_not_empty).notify_all();
 36         lock.unlock();
 37     }
 38 
 39     int ConsumeItem(ItemRepository *ir)
 40     {
 41         int data;
 42         std::unique_lock<std::mutex> lock(ir->mtx);
 43         // item buffer is empty, just wait here.
 44         while (ir->write_position == ir->read_position)
 45         {
 46             {
 47                 std::lock_guard<std::mutex> lock(mutex);
 48                 std::cout << "缓冲区空，等待生产者生产产品
";
 49             }
 50             (ir->repo_not_empty).wait(lock);
 51         }
 52 
 53         data = (ir->item_buffer)[ir->read_position];
 54         (ir->read_position)++;
 55 
 56         if (ir->read_position >= kItemRepositorySize)
 57             ir->read_position = 0;
 58 
 59         (ir->repo_not_full).notify_all();
 60         lock.unlock();
 61 
 62         return data;
 63     }
 64 
 65 
 66     void ProducerTask()
 67     {
 68         for (int i = 1; i <= kItemsToProduce; ++i)
 69         {
 70             std::this_thread::sleep_for(std::chrono::milliseconds(6));
 71             ProduceItem(&gItemRepository, i);
 72             {
 73                 std::lock_guard<std::mutex> lock(mutex);
 74                 std::cout << "生产线程" << std::this_thread::get_id()
 75                     << "生产第" << i << "个产品" << std::endl;
 76             }
 77         }
 78         {
 79             std::lock_guard<std::mutex> lock(mutex);
 80             std::cout << "生产线程" << std::this_thread::get_id()
 81                 << "退出" << std::endl;
 82         }
 83     }
 84 
 85     void ConsumerTask()
 86     {
 87         bool ready_to_exit = false;
 88         while (1)
 89         {
 90         //    std::this_thread::sleep_for(std::chrono::milliseconds(6));
 91             std::unique_lock<std::mutex> lock(gItemRepository.item_counter_mtx);
 92             if (gItemRepository.item_counter < kItemsToProduce)
 93             {
 94                 int item = ConsumeItem(&gItemRepository);
 95                 ++(gItemRepository.item_counter);
 96                 {
 97                     std::lock_guard<std::mutex> lock(mutex);
 98                     std::cout << "消费线程" << std::this_thread::get_id()
 99                         << "正在消费第" << item << "个产品" << std::endl;
100                 }
101             }
102             else
103             {
104                 ready_to_exit = true;
105             }
106             lock.unlock();
107 
108             if (ready_to_exit == true)
109             {
110                 break;
111             }
112         }
113         {
114             std::lock_guard<std::mutex> lock(mutex);
115             std::cout << "消费线程" << std::this_thread::get_id()
116                 << "退出" << std::endl;
117         }
118     }
119 
120     void InitItemRepository(ItemRepository *ir)
121     {
122         ir->write_position = 0;
123         ir->read_position = 0;
124         ir->item_counter = 0;
125     }
126 
127     void test()
128     {
129         InitItemRepository(&gItemRepository);
130         std::thread producer(ProducerTask);
131         std::thread consumer1(ConsumerTask);
132         std::thread consumer2(ConsumerTask);
133         std::thread consumer3(ConsumerTask);
134         std::thread consumer4(ConsumerTask);
135 
136         producer.join();
137         consumer1.join();
138         consumer2.join();
139         consumer3.join();
140         consumer4.join();
141     }

View Code

多消费者单生产者模式：

  1 struct ItemRepository
  2     {
  3         int item_buffer[kItemRepositorySize];
  4         size_t read_position;
  5         size_t write_position;
  6         size_t item_counter;
  7         std::mutex mtx;
  8         std::mutex item_counter_mtx;
  9         std::condition_variable repo_not_full;
 10         std::condition_variable repo_not_empty;
 11     } gItemRepository;
 12 
 13     typedef struct ItemRepository ItemRepository;
 14 
 15     void ProduceItem(ItemRepository *ir, int item)
 16     {
 17         std::unique_lock<std::mutex> lock(ir->mtx);
 18         while (((ir->write_position + 1) % kItemRepositorySize)
 19             == ir->read_position)
 20         { 
 21             {
 22                 std::lock_guard<std::mutex> lock(mutex);
 23                 std::cout << "缓冲区满，等待缓冲区不满
";
 24             }
 25             (ir->repo_not_full).wait(lock);
 26         }
 27 
 28         (ir->item_buffer)[ir->write_position] = item;
 29         (ir->write_position)++;
 30 
 31         if (ir->write_position == kItemRepositorySize)
 32             ir->write_position = 0;
 33 
 34         (ir->repo_not_empty).notify_all();
 35         lock.unlock();
 36     }
 37 
 38     int ConsumeItem(ItemRepository *ir)
 39     {
 40         int data;
 41         std::unique_lock<std::mutex> lock(ir->mtx);
 42         // item buffer is empty, just wait here.
 43         while (ir->write_position == ir->read_position)
 44         {
 45             {
 46                 std::lock_guard<std::mutex> lock(mutex);
 47                 std::cout << "消费者等待产品中。。。
";
 48             }
 49             (ir->repo_not_empty).wait(lock);
 50         }
 51 
 52         data = (ir->item_buffer)[ir->read_position];
 53         (ir->read_position)++;
 54 
 55         if (ir->read_position >= kItemRepositorySize)
 56             ir->read_position = 0;
 57 
 58         (ir->repo_not_full).notify_all();
 59         lock.unlock();
 60 
 61         return data;
 62     }
 63 
 64     void ProducerTask()
 65     {
 66         bool ready_to_exit = false;
 67         while (1)
 68         {
 69             std::this_thread::sleep_for(std::chrono::milliseconds(1000));
 70             std::unique_lock<std::mutex> lock(gItemRepository.item_counter_mtx);
 71             if (gItemRepository.item_counter < kItemsToProduce) 
 72             {
 73                 ++(gItemRepository.item_counter);
 74                 ProduceItem(&gItemRepository, gItemRepository.item_counter);
 75                 {
 76                     std::lock_guard<std::mutex> lock(mutex);
 77                     std::cout << "消费者" << std::this_thread::get_id()
 78                         << "正在生产第" << gItemRepository.item_counter
 79                         << "个产品" << std::endl;
 80                 }
 81             }
 82             else
 83             {
 84                 ready_to_exit = true;
 85             }
 86             lock.unlock();
 87             if (ready_to_exit == true) break;
 88         }
 89         {
 90             std::lock_guard<std::mutex> lock(mutex);
 91             std::cout << "消费者" << std::this_thread::get_id()
 92                 << "退出" << std::endl;
 93         }
 94     }
 95 
 96     void ConsumerTask()
 97     {
 98         static int item_consumed = 0;
 99         while (1) 
100         {
101             std::this_thread::sleep_for(std::chrono::milliseconds(1000));
102             ++item_consumed;
103             if (item_consumed <= kItemsToProduce)
104             {
105                 int item = ConsumeItem(&gItemRepository);
106                 {
107                     std::lock_guard<std::mutex> lock(mutex);
108                     std::cout << "消费者" << std::this_thread::get_id()
109                         << "正在消费第" << item << "个产品" << std::endl;
110                 }
111             }
112             else break;
113         }
114         {
115             std::lock_guard<std::mutex> lock(mutex);
116             std::cout << "消费者" << std::this_thread::get_id()
117                 << "退出" << std::endl;
118         }
119     }
120 
121     void InitItemRepository(ItemRepository *ir)
122     {
123         ir->write_position = 0;
124         ir->read_position = 0;
125         ir->item_counter = 0;
126     }
127 
128     void test()
129     {
130         InitItemRepository(&gItemRepository);
131         std::thread producer1(ProducerTask);
132         std::thread producer2(ProducerTask);
133         std::thread producer3(ProducerTask);
134         std::thread producer4(ProducerTask);
135         std::thread consumer(ConsumerTask);
136 
137         producer1.join();
138         producer2.join();
139         producer3.join();
140         producer4.join();
141         consumer.join();
142     }

View Code

多消费者多生产者模式：

  1 struct ItemRepository 
  2     {
  3         int item_buffer[kItemRepositorySize];
  4         size_t read_position;
  5         size_t write_position;
  6         size_t produced_item_counter;
  7         size_t consumed_item_counter;
  8         std::mutex mtx;
  9         std::mutex produced_item_counter_mtx;
 10         std::mutex consumed_item_counter_mtx;
 11         std::condition_variable repo_not_full;
 12         std::condition_variable repo_not_empty;
 13     } gItemRepository;
 14 
 15     typedef struct ItemRepository ItemRepository;
 16 
 17     void ProduceItem(ItemRepository *ir, int item)
 18     {
 19         std::unique_lock<std::mutex> lock(ir->mtx);
 20         while (((ir->write_position + 1) % kItemRepositorySize)
 21             == ir->read_position)
 22         { 
 23             // item buffer is full, just wait here.
 24             {
 25                 std::lock_guard<std::mutex> lock(mutex);
 26                 std::cout << "缓冲区满，生产者等待中
";
 27             }
 28             (ir->repo_not_full).wait(lock);
 29         }
 30 
 31         (ir->item_buffer)[ir->write_position] = item;
 32         (ir->write_position)++;
 33 
 34         if (ir->write_position == kItemRepositorySize)
 35             ir->write_position = 0;
 36 
 37         (ir->repo_not_empty).notify_all();
 38         lock.unlock();
 39     }
 40 
 41     int ConsumeItem(ItemRepository *ir)
 42     {
 43         int data;
 44         std::unique_lock<std::mutex> lock(ir->mtx);
 45         // item buffer is empty, just wait here.
 46         while (ir->write_position == ir->read_position) 
 47         {
 48             {
 49                 std::lock_guard<std::mutex> lock(mutex);
 50                 std::cout << "缓冲区空，消费者等待中
";
 51             }
 52             (ir->repo_not_empty).wait(lock);
 53         }
 54 
 55         data = (ir->item_buffer)[ir->read_position];
 56         (ir->read_position)++;
 57 
 58         if (ir->read_position >= kItemRepositorySize)
 59             ir->read_position = 0;
 60 
 61         (ir->repo_not_full).notify_all();
 62         lock.unlock();
 63 
 64         return data;
 65     }
 66 
 67     void ProducerTask()
 68     {
 69         bool ready_to_exit = false;
 70         while (1) 
 71         {
 72             std::this_thread::sleep_for(std::chrono::milliseconds(1000));
 73             std::unique_lock<std::mutex> lock(gItemRepository.produced_item_counter_mtx);
 74             if (gItemRepository.produced_item_counter < kItemsToProduce) 
 75             {
 76                 ++(gItemRepository.produced_item_counter);
 77                 ProduceItem(&gItemRepository, gItemRepository.produced_item_counter);
 78                 {
 79                     std::lock_guard<std::mutex> lock(mutex); 
 80                     std::cout << "生产者" << std::this_thread::get_id()
 81                         << "正在生产第" << gItemRepository.produced_item_counter
 82                         << "个产品" << std::endl;
 83                 }
 84             }
 85             else
 86             {
 87                 ready_to_exit = true;
 88             }
 89 
 90             lock.unlock();
 91             if (ready_to_exit == true)
 92             {
 93                 break;
 94             }
 95         }
 96         {
 97             std::lock_guard<std::mutex> lock(mutex);
 98             std::cout << "生产者" << std::this_thread::get_id()
 99                 << "退出" << std::endl;
100         }
101     }
102 
103     void ConsumerTask()
104     {
105         bool ready_to_exit = false;
106         while (1) 
107         {
108             std::this_thread::sleep_for(std::chrono::milliseconds(1000));
109             std::unique_lock<std::mutex> lock(gItemRepository.consumed_item_counter_mtx);
110             if (gItemRepository.consumed_item_counter < kItemsToProduce) 
111             {
112                 int item = ConsumeItem(&gItemRepository);
113                 ++(gItemRepository.consumed_item_counter);
114                 {
115                     std::lock_guard<std::mutex> lock(mutex);
116                     std::cout << "消费者" << std::this_thread::get_id()
117                         << "正在消费第" << item << "个产品" << std::endl;
118                 }
119             }
120             else
121             {
122                 ready_to_exit = true;
123             }
124             lock.unlock();
125             if (ready_to_exit == true)
126             {
127                 break;
128             }
129         }
130         {
131             std::lock_guard<std::mutex> lock(mutex);
132             std::cout << "消费者" << std::this_thread::get_id()
133                 << "退出" << std::endl;
134         }
135     }
136 
137     void InitItemRepository(ItemRepository *ir)
138     {
139         ir->write_position = 0;
140         ir->read_position = 0;
141         ir->produced_item_counter = 0;
142         ir->consumed_item_counter = 0;
143     }
144 
145     void test()
146     {
147         InitItemRepository(&gItemRepository);
148         std::thread producer1(ProducerTask);
149         std::thread producer2(ProducerTask);
150         std::thread producer3(ProducerTask);
151         std::thread producer4(ProducerTask);
152 
153         std::thread consumer1(ConsumerTask);
154         std::thread consumer2(ConsumerTask);
155         std::thread consumer3(ConsumerTask);
156         std::thread consumer4(ConsumerTask);
157 
158         producer1.join();
159         producer2.join();
160         producer3.join();
161         producer4.join();
162 
163         consumer1.join();
164         consumer2.join();
165         consumer3.join();
166         consumer4.join();
167     }

View Code

注：

1、当缓存容量为n时，其实只能存放n-1个产品，主要原因是，当缓存满和空时，用取余无法区分

2、当单单模式变成多多模式时，只是针对单变多的某一方多添加一个读写锁

3、向标准缓冲区输出字符串时，由于是多线程的，所以需要使用读写锁来同步

完整实例下载：http://files.cnblogs.com/files/swarmbees/Producer_Consumer.zip

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原文地址：https://www.cnblogs.com/swarmbees/p/5889297.html