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：
struct ItemRepository
{
int item_buffer[kItemRepositorySize]; // 产品缓冲区, 配合 read_position 和 write_position 模型环形队列.
size_t read_position; // 消费者读取产品位置.
size_t write_position; // 生产者写入产品位置.
std::mutex mtx; // 互斥量,保护产品缓冲区
std::condition_variable repo_not_full; // 条件变量, 指示产品缓冲区不为满.
std::condition_variable repo_not_empty; // 条件变量, 指示产品缓冲区不为空.
} gItemRepository; // 产品库全局变量, 生产者和消费者操作该变量. typedef struct ItemRepository ItemRepository; void ProduceItem(ItemRepository * ir, int item)
{
std::unique_lock<std::mutex> lock(ir->mtx);
while (((ir->write_position + ) % kItemRepositorySize)
== ir->read_position)
{ // item buffer is full, just wait here.
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区满，等待缓冲区不满\n";
}
(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.
} (ir->item_buffer)[ir->write_position] = item; // 写入产品.
(ir->write_position)++; // 写入位置后移. 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.
ir->write_position = ; (ir->repo_not_empty).notify_all(); // 通知消费者产品库不为空.
lock.unlock(); // 解锁.
} int ConsumeItem(ItemRepository *ir)
{
int data;
std::unique_lock<std::mutex> lock(ir->mtx);
// item buffer is empty, just wait here.
while (ir->write_position == ir->read_position)
{
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区空，等待生产者生成产品\n";
}
(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.
} data = (ir->item_buffer)[ir->read_position]; // 读取某一产品
(ir->read_position)++; // 读取位置后移 if (ir->read_position >= kItemRepositorySize) // 读取位置若移到最后，则重新置位.
ir->read_position = ; (ir->repo_not_full).notify_all(); // 通知消费者产品库不为满.
lock.unlock(); // 解锁. return data; // 返回产品.
} void ProducerTask() // 生产者任务
{
for (int i = ; i <= kItemsToProduce; ++i)
{
// sleep(1);
ProduceItem(&gItemRepository, i); // 循环生产 kItemsToProduce 个产品.
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "生产第 " << i << "个产品" << std::endl;
}
}
} void ConsumerTask() // 消费者任务
{
static int cnt = ;
while ()
{
std::this_thread::sleep_for(std::chrono::seconds());
int item = ConsumeItem(&gItemRepository); // 消费一个产品.
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费第" << item << "个产品" << std::endl;
}
if (++cnt == kItemsToProduce) break; // 如果产品消费个数为 kItemsToProduce, 则退出.
}
} void InitItemRepository(ItemRepository *ir)
{
ir->write_position = ; // 初始化产品写入位置.
ir->read_position = ; // 初始化产品读取位置.
} void test()
{
InitItemRepository(&gItemRepository);
std::thread producer(ProducerTask); // 创建生产者线程.
std::thread consumer(ConsumerTask); // 创建消费之线程. producer.join();
consumer.join();
}
单生产者多消费者模式：
struct ItemRepository
{
int item_buffer[kItemRepositorySize];
size_t read_position;
size_t write_position;
size_t item_counter;
std::mutex mtx;
std::mutex item_counter_mtx;
std::condition_variable repo_not_full;
std::condition_variable repo_not_empty;
} gItemRepository; typedef struct ItemRepository ItemRepository; void ProduceItem(ItemRepository *ir, int item)
{
std::unique_lock<std::mutex> lock(ir->mtx);
while (((ir->write_position + ) % kItemRepositorySize)
== ir->read_position)
{
// item buffer is full, just wait here.
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区满，等待缓冲区不满\n";
}
(ir->repo_not_full).wait(lock);
} (ir->item_buffer)[ir->write_position] = item;
(ir->write_position)++; if (ir->write_position == kItemRepositorySize)
ir->write_position = ; (ir->repo_not_empty).notify_all();
lock.unlock();
} int ConsumeItem(ItemRepository *ir)
{
int data;
std::unique_lock<std::mutex> lock(ir->mtx);
// item buffer is empty, just wait here.
while (ir->write_position == ir->read_position)
{
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区空，等待生产者生产产品\n";
}
(ir->repo_not_empty).wait(lock);
} data = (ir->item_buffer)[ir->read_position];
(ir->read_position)++; if (ir->read_position >= kItemRepositorySize)
ir->read_position = ; (ir->repo_not_full).notify_all();
lock.unlock(); return data;
} void ProducerTask()
{
for (int i = ; i <= kItemsToProduce; ++i)
{
std::this_thread::sleep_for(std::chrono::milliseconds());
ProduceItem(&gItemRepository, i);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "生产线程" << std::this_thread::get_id()
<< "生产第" << i << "个产品" << std::endl;
}
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "生产线程" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void ConsumerTask()
{
bool ready_to_exit = false;
while ()
{
// std::this_thread::sleep_for(std::chrono::milliseconds(6));
std::unique_lock<std::mutex> lock(gItemRepository.item_counter_mtx);
if (gItemRepository.item_counter < kItemsToProduce)
{
int item = ConsumeItem(&gItemRepository);
++(gItemRepository.item_counter);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费线程" << std::this_thread::get_id()
<< "正在消费第" << item << "个产品" << std::endl;
}
}
else
{
ready_to_exit = true;
}
lock.unlock(); if (ready_to_exit == true)
{
break;
}
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费线程" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void InitItemRepository(ItemRepository *ir)
{
ir->write_position = ;
ir->read_position = ;
ir->item_counter = ;
} void test()
{
InitItemRepository(&gItemRepository);
std::thread producer(ProducerTask);
std::thread consumer1(ConsumerTask);
std::thread consumer2(ConsumerTask);
std::thread consumer3(ConsumerTask);
std::thread consumer4(ConsumerTask); producer.join();
consumer1.join();
consumer2.join();
consumer3.join();
consumer4.join();
}
多消费者单生产者模式：
struct ItemRepository
{
int item_buffer[kItemRepositorySize];
size_t read_position;
size_t write_position;
size_t item_counter;
std::mutex mtx;
std::mutex item_counter_mtx;
std::condition_variable repo_not_full;
std::condition_variable repo_not_empty;
} gItemRepository; typedef struct ItemRepository ItemRepository; void ProduceItem(ItemRepository *ir, int item)
{
std::unique_lock<std::mutex> lock(ir->mtx);
while (((ir->write_position + ) % kItemRepositorySize)
== ir->read_position)
{
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区满，等待缓冲区不满\n";
}
(ir->repo_not_full).wait(lock);
} (ir->item_buffer)[ir->write_position] = item;
(ir->write_position)++; if (ir->write_position == kItemRepositorySize)
ir->write_position = ; (ir->repo_not_empty).notify_all();
lock.unlock();
} int ConsumeItem(ItemRepository *ir)
{
int data;
std::unique_lock<std::mutex> lock(ir->mtx);
// item buffer is empty, just wait here.
while (ir->write_position == ir->read_position)
{
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者等待产品中。。。\n";
}
(ir->repo_not_empty).wait(lock);
} data = (ir->item_buffer)[ir->read_position];
(ir->read_position)++; if (ir->read_position >= kItemRepositorySize)
ir->read_position = ; (ir->repo_not_full).notify_all();
lock.unlock(); return data;
} void ProducerTask()
{
bool ready_to_exit = false;
while ()
{
std::this_thread::sleep_for(std::chrono::milliseconds());
std::unique_lock<std::mutex> lock(gItemRepository.item_counter_mtx);
if (gItemRepository.item_counter < kItemsToProduce)
{
++(gItemRepository.item_counter);
ProduceItem(&gItemRepository, gItemRepository.item_counter);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "正在生产第" << gItemRepository.item_counter
<< "个产品" << std::endl;
}
}
else
{
ready_to_exit = true;
}
lock.unlock();
if (ready_to_exit == true) break;
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void ConsumerTask()
{
static int item_consumed = ;
while ()
{
std::this_thread::sleep_for(std::chrono::milliseconds());
++item_consumed;
if (item_consumed <= kItemsToProduce)
{
int item = ConsumeItem(&gItemRepository);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "正在消费第" << item << "个产品" << std::endl;
}
}
else break;
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void InitItemRepository(ItemRepository *ir)
{
ir->write_position = ;
ir->read_position = ;
ir->item_counter = ;
} void test()
{
InitItemRepository(&gItemRepository);
std::thread producer1(ProducerTask);
std::thread producer2(ProducerTask);
std::thread producer3(ProducerTask);
std::thread producer4(ProducerTask);
std::thread consumer(ConsumerTask); producer1.join();
producer2.join();
producer3.join();
producer4.join();
consumer.join();
}
多消费者多生产者模式：
struct ItemRepository
{
int item_buffer[kItemRepositorySize];
size_t read_position;
size_t write_position;
size_t produced_item_counter;
size_t consumed_item_counter;
std::mutex mtx;
std::mutex produced_item_counter_mtx;
std::mutex consumed_item_counter_mtx;
std::condition_variable repo_not_full;
std::condition_variable repo_not_empty;
} gItemRepository; typedef struct ItemRepository ItemRepository; void ProduceItem(ItemRepository *ir, int item)
{
std::unique_lock<std::mutex> lock(ir->mtx);
while (((ir->write_position + ) % kItemRepositorySize)
== ir->read_position)
{
// item buffer is full, just wait here.
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区满，生产者等待中\n";
}
(ir->repo_not_full).wait(lock);
} (ir->item_buffer)[ir->write_position] = item;
(ir->write_position)++; if (ir->write_position == kItemRepositorySize)
ir->write_position = ; (ir->repo_not_empty).notify_all();
lock.unlock();
} int ConsumeItem(ItemRepository *ir)
{
int data;
std::unique_lock<std::mutex> lock(ir->mtx);
// item buffer is empty, just wait here.
while (ir->write_position == ir->read_position)
{
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "缓冲区空，消费者等待中\n";
}
(ir->repo_not_empty).wait(lock);
} data = (ir->item_buffer)[ir->read_position];
(ir->read_position)++; if (ir->read_position >= kItemRepositorySize)
ir->read_position = ; (ir->repo_not_full).notify_all();
lock.unlock(); return data;
} void ProducerTask()
{
bool ready_to_exit = false;
while ()
{
std::this_thread::sleep_for(std::chrono::milliseconds());
std::unique_lock<std::mutex> lock(gItemRepository.produced_item_counter_mtx);
if (gItemRepository.produced_item_counter < kItemsToProduce)
{
++(gItemRepository.produced_item_counter);
ProduceItem(&gItemRepository, gItemRepository.produced_item_counter);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "生产者" << std::this_thread::get_id()
<< "正在生产第" << gItemRepository.produced_item_counter
<< "个产品" << std::endl;
}
}
else
{
ready_to_exit = true;
} lock.unlock();
if (ready_to_exit == true)
{
break;
}
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "生产者" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void ConsumerTask()
{
bool ready_to_exit = false;
while ()
{
std::this_thread::sleep_for(std::chrono::milliseconds());
std::unique_lock<std::mutex> lock(gItemRepository.consumed_item_counter_mtx);
if (gItemRepository.consumed_item_counter < kItemsToProduce)
{
int item = ConsumeItem(&gItemRepository);
++(gItemRepository.consumed_item_counter);
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "正在消费第" << item << "个产品" << std::endl;
}
}
else
{
ready_to_exit = true;
}
lock.unlock();
if (ready_to_exit == true)
{
break;
}
}
{
std::lock_guard<std::mutex> lock(mutex);
std::cout << "消费者" << std::this_thread::get_id()
<< "退出" << std::endl;
}
} void InitItemRepository(ItemRepository *ir)
{
ir->write_position = ;
ir->read_position = ;
ir->produced_item_counter = ;
ir->consumed_item_counter = ;
} void test()
{
InitItemRepository(&gItemRepository);
std::thread producer1(ProducerTask);
std::thread producer2(ProducerTask);
std::thread producer3(ProducerTask);
std::thread producer4(ProducerTask); std::thread consumer1(ConsumerTask);
std::thread consumer2(ConsumerTask);
std::thread consumer3(ConsumerTask);
std::thread consumer4(ConsumerTask); producer1.join();
producer2.join();
producer3.join();
producer4.join(); consumer1.join();
consumer2.join();
consumer3.join();
consumer4.join();
}
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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