Question

我使用Boost线程库编写了一些多线程代码。我使用占位符_1作为成员函数fillSample（int num）所需的参数，在构造函数中初始化了两个线程。但是这不能在我的Visual Studio 2010中编译。以下是代码：

#include<boost/thread.hpp>
#include<boost/thread/condition.hpp>
#include<boost/bind/placeholders.hpp>

#define SAMPLING_FREQ 250
#define MAX_NUM_SAMPLES 5*60*SAMPLING_FREQ
#define BUFFER_SIZE 8

class ECG
{
private:
    int sample[BUFFER_SIZE];
    int sampleIdx;
    int readIdx, writeIdx;
    boost::thread m_ThreadWrite;
    boost::thread m_ThreadRead;
    boost::mutex m_Mutex;
    boost::condition bufferNotFull, bufferNotEmpty;
public:
    ECG();
    void fillSample(int num);   //get sample from the data stream
    void processSample();   //process ECG sample, return the last processed 

};


ECG::ECG() : readyFlag(false), sampleIdx(0), readIdx(0), writeIdx(0)
{
    m_ThreadWrite=boost::thread((boost::bind(&ECG::fillSample, this, _1)));
    m_ThreadRead=boost::thread((boost::bind(&ECG::processSample, this)));
}

void ECG::fillSample(int num)
{
    boost::mutex::scoped_lock lock(m_Mutex);
    while( (writeIdx-readIdx)%BUFFER_SIZE == BUFFER_SIZE-1 )
    {
        bufferNotFull.wait(lock);
    }

    sample[writeIdx] = num;
    writeIdx = (writeIdx+1) % BUFFER_SIZE;
    bufferNotEmpty.notify_one();

}

void ECG::processSample()
{
    boost::mutex::scoped_lock lock(m_Mutex);
    while( readIdx == writeIdx )
    {
        bufferNotEmpty.wait(lock);
    }

    sample[readIdx] *= 2;
    readIdx = (readIdx+1) % BUFFER_SIZE;
    ++sampleIdx;
    bufferNotFull.notify_one();
}

我已经包含了placeholders.hpp头文件，但它仍然没有编译。如果我将_1替换为0，那么它将起作用。但这会用0初始化线程函数，这不是我想要的。关于如何使这项工作的任何想法？

Answer 1

将创建移动到初始化列表： m_ThreadWrite（boost :: bind（＆amp; ECG :: fillSample，this，_1）），...

thread对象不可复制，并且您的编译器不支持其移动构造函数。

为什么这个提升线程创建不能编译？

1 个答案: