这个模式的详细解释请参考:http://blog.csdn.net/program_think/archive/2009/03/25/4022087.aspx
简要的说明一下这个模式:
消费者线程从缓冲区中获得物品,然后释放缓冲区。当生产者线程生产物品时,如果没有空缓冲区可用,那么生产者线程必须等待消费者线程释放出一个空缓冲区。当消费者线程消费物品时,如果没有满的缓冲区,那么消费者线程将被阻塞,直到新的物品被生产出来。
生产者/消费者模式实现:
- #include <windows.h>
- #include <iostream>
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- const unsigned short SIZE_OF_BUFFER = 10;
- unsigned short ProductID = 0;
- unsigned short ConsumeID = 0;
- unsigned short in = 0;
- unsigned short out = 0;
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- int g_buffer[SIZE_OF_BUFFER];
- bool g_continue = true;
- HANDLE g_hMutex;
- HANDLE g_hFullSemaphore;
- HANDLE g_hEmptySemaphore;
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- DWORD WINAPI Producer(LPVOID);
- DWORD WINAPI Consumer(LPVOID);
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- int main()
- {
- g_hMutex = CreateMutex(NULL,FALSE,NULL);
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- g_hFullSemaphore = CreateSemaphore(NULL,SIZE_OF_BUFFER-1,SIZE_OF_BUFFER-1,NULL);
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- g_hEmptySemaphore = CreateSemaphore(NULL,0,SIZE_OF_BUFFER-1,NULL);
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- const unsigned short PRODUCERS_COUNT = 3;
- const unsigned short CONSUMERS_COUNT = 1;
- const unsigned short THREADS_COUNT = PRODUCERS_COUNT+CONSUMERS_COUNT;
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- HANDLE hThreads[PRODUCERS_COUNT];
- DWORD producerID[CONSUMERS_COUNT];
- DWORD consumerID[THREADS_COUNT];
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- for (int i=0;i<PRODUCERS_COUNT;++i){
- hThreads[i]=CreateThread(NULL,0,Producer,NULL,0,&producerID[i]);
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- if (hThreads[i]==NULL) return -1;
- }
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- for ( int i=0;i<CONSUMERS_COUNT;++i){
- hThreads[PRODUCERS_COUNT+i]=
- CreateThread(NULL,0,Consumer,NULL,0,&consumerID[i]);
- if (hThreads[i]==NULL) return -1;
- }
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- while(g_continue){
- if(getchar()){
- g_continue = false;
- }
- }
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- return 0;
- }
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- void Produce()
- {
- std::cerr << "Producing " << ++ProductID << " ... ";
- std::cerr << "Succeed" << std::endl;
- }
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- void Append()
- {
- std::cerr << "Appending a product ... ";
- g_buffer[in] = ProductID;
- in = (in+1)%SIZE_OF_BUFFER;
- std::cerr << "Succeed" << std::endl;
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- for (int i=0;i<SIZE_OF_BUFFER;++i){
- std::cout << i <<": " << g_buffer[i];
- if (i==in) std::cout << " <-- 生产";
- if (i==out) std::cout << " <-- 消费";
- std::cout << std::endl;
- }
- }
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- void Take()
- {
- std::cerr << "Taking a product ... ";
- ConsumeID = g_buffer[out];
- out = (out+1)%SIZE_OF_BUFFER;
- std::cerr << "Succeed" << std::endl;
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- for (int i=0;i<SIZE_OF_BUFFER;++i){
- std::cout << i <<": " << g_buffer[i];
- if (i==in) std::cout << " <-- 生产";
- if (i==out) std::cout << " <-- 消费";
- std::cout << std::endl;
- }
- }
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- void Consume()
- {
- std::cerr << "Consuming " << ConsumeID << " ... ";
- std::cerr << "Succeed" << std::endl;
- }
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- DWORD WINAPI Producer(LPVOID lpPara)
- {
- while(g_continue){
- WaitForSingleObject(g_hFullSemaphore,INFINITE);
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- WaitForSingleObject(g_hMutex,INFINITE);
- Produce();
- Append();
- Sleep(1500);
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- ReleaseMutex(g_hMutex);
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- ReleaseSemaphore(g_hEmptySemaphore,1,NULL);
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- return 0;
- }
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- DWORD WINAPI Consumer(LPVOID lpPara)
- {
- while(g_continue){
- WaitForSingleObject(g_hEmptySemaphore,INFINITE);
- WaitForSingleObject(g_hMutex,INFINITE);
- Take();
- Consume();
- Sleep(1500);
- ReleaseMutex(g_hMutex);
- ReleaseSemaphore(g_hFullSemaphore,1,NULL);
- }
- return 0;
- }
(yfqvip) |