QWaitCondition 示例代码

最新推荐文章于 2024-10-14 14:24:36 发布

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这个示例展示了使用C++实现的生产者消费者模型，通过QWaitCondition和QMutex同步多个线程。生产者线程生成随机DNA序列字符并填满缓冲区，消费者线程则从缓冲区读取并打印这些字符。

#include

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

const int DataSize = 100000;

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

QWaitCondition bufferNotEmpty;
QWaitCondition bufferNotFull;
QMutex mutex;
int numUsedBytes = 0;

class Producer : public QThread
{
public:
Producer(QObject *parent = NULL) : QThread(parent)
{
}

  void run() override
  {
      qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));

      for (int i = 0; i < DataSize; ++i) {
          mutex.lock();
          if (numUsedBytes == BufferSize)
              bufferNotFull.wait(&mutex);
          mutex.unlock();

          buffer[i % BufferSize] = "ACGT"[(int)qrand() % 4];

          mutex.lock();
          ++numUsedBytes;
          bufferNotEmpty.wakeAll();
          mutex.unlock();
      }
  }

};

class Consumer : public QThread
{
Q_OBJECT
public:
Consumer(QObject *parent = NULL) : QThread(parent)
{
}

  void run() override
  {
      for (int i = 0; i < DataSize; ++i) {
          mutex.lock();
          if (numUsedBytes == 0)
              bufferNotEmpty.wait(&mutex);
          mutex.unlock();

          fprintf(stderr, "%c", buffer[i % BufferSize]);

          mutex.lock();
          --numUsedBytes;
          bufferNotFull.wakeAll();
          mutex.unlock();
      }
      fprintf(stderr, "\n");
  }

signals:
void stringConsumed(const QString &text);
};

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