semaphores.cpp

来自「精通QT4编程书籍光盘中的源码」· C++ 代码 · 共 58 行

#include <QtCore>

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

const int DataSize = 100000;
const int BufferSize = 8192;
int buffer[BufferSize];

QSemaphore freeBytes(BufferSize);
QSemaphore usedBytes(0);

class Producer : public QThread
{
public:
    void run();
};

void Producer::run()
{
    for (int i = 0; i < DataSize; ++i) {
        freeBytes.acquire();
        buffer[i % BufferSize] = (i % BufferSize);
        usedBytes.release();
    }
}

class Consumer : public QThread
{
public:
    void run();
};

void Consumer::run()
{
    for (int i = 0; i < DataSize; ++i) {
        usedBytes.acquire();
        fprintf(stderr, "%d ", buffer[i % BufferSize]);
				if(i % 16 ==0 && i!=0)
					fprintf(stderr, "\n");
        freeBytes.release();
    }
    fprintf(stderr, "\n");
}

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