Qt线程的简单使用（四）——QSemaphore的使用

 1 #include <QtCore/QCoreApplication>
 2 #include <QSemaphore>
 3 #include <QThread>
 4 #include <iostream>
 5 #include <QTime>
 6 
 7 const int DataSize = 100;
 8 const int BufferSize = 10;
 9 char buffer[BufferSize];
10 QSemaphore freeSpace (BufferSize);
11 QSemaphore usedSpace(0);
12 //1.BufferSize = 1 ,DataSize = 100,生产一个，消费一个。
13 //2.BufferSize = 100,DataSize = 100;先是大量生产。
14 
15 
16 
17 //生产者
18 class Producer:public QThread
19 {
20 protected:
21     void run()
22     {
23         qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
24         qsrand(NULL);
25         for (int i = 0;i < DataSize;++i)
26         {
27             freeSpace.acquire();
28             std::cerr<<"P";
29             usedSpace.release();
30         }
31     }
32 };
33 //消费者
34 class Consumer:public QThread
35 {
36 protected:
37     void run()
38     {
39         for (int i = 0;i < DataSize;++i)
40         {
41             usedSpace.acquire();
42             std::cerr<<"C";
43             freeSpace.release();
44         }
45     }
46 };
47 
48 int main(int argc, char *argv[])
49 {
50     QCoreApplication a(argc, argv);
51 
52     Producer producer;
53     Consumer consumer;
54     producer.start();
55     consumer.start();
56     producer.wait();
57 
58     consumer.wait();
59 
60     return a.exec();
61 }