semaphores.cpp Example File

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 #include <QtGui>

 #include <stdio.h>
 #include <stdlib.h>

 const int DataSize = 100000;

 const int BufferSize = 8192;
 char buffer[BufferSize];

 QSemaphore freeBytes(BufferSize);
 QSemaphore usedBytes;

 class Producer : public QThread
 {
 public:
     void run()
     {
         qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
         for (int i = 0; i < DataSize; ++i) {
             freeBytes.acquire();
             buffer[i % BufferSize] = "ACGT"[(int)qrand() % 4];
             usedBytes.release();
         }
     }
 };

 class Consumer : public QThread
 {
     Q_OBJECT
 public:
     void run()
     {
         for (int i = 0; i < DataSize; ++i) {
             usedBytes.acquire();
             fprintf(stderr, "%c", buffer[i % BufferSize]);
             freeBytes.release();
         }
         fprintf(stderr, "\n");
     }

 signals:
     void stringConsumed(const QString &text);

 protected:
     bool finish;
 };

 int main(int argc, char *argv[])
 {
     QCoreApplication app(argc, argv);
     Producer producer;
     Consumer consumer;
     producer.start();
     consumer.start();
     producer.wait();
     consumer.wait();
     return 0;
 }

 #include "semaphores.moc"