Question

我从以下C ++脚本获取内存堆消息。如果我删除数组释放，则错误消失。所以bug可能在代码的deallocation部分。我无法弄清楚

if(harmonic_type =='a')
{
    double ** harmonic_content = new double *[number_of_harmonics_required_to_monitor](); 
    for (int i=0;i<number_of_harmonics_required_to_monitor+1;i++) 
    {                                                           
        harmonic_content[i] = new double [2]();                 
    }
    harmonic_content =  harmonic_detector(waveformdata,number_of_samples,samplingrate_Hz, fundamental_frequency_Hz, number_of_harmonics_required_to_monitor,harmonic_type);

    for (int i=1;i<number_of_harmonics_required_to_monitor+1;i++)
    {                                   
        cout<<" Harmonic order "<< i << "::::" << harmonic_content[i][0] << " Hz ::::"<<harmonic_content[i][1] << " :::: "<<harmonic_content[i][2]<<endl;
    }

    for (int i=0;i<number_of_harmonics_required_to_monitor+1;i++) 
    {   
        delete [] harmonic_content [i];                 
    }
    delete [] harmonic_content;
}

Answer 1

在

    new double *[number_of_harmonics_required_to_monitor]()

创建的总元素：number_of_harmonics_required_to_monitor

在

    for (int i=0;i<number_of_harmonics_required_to_monitor+1;i++)

写入的总元素：number_of_harmonics_required_to_monitor+1（从0到number_of_harmonics_required_to_monitor）

在

    for (int i=1;i<number_of_harmonics_required_to_monitor+1;i++)

最后一个读取元素不存在：它具有索引number_of_harmonics_required_to_monitor+1

Answer 2

你正在使用c ++。所以利用它的优势。如果number_of_harmonics_required_to_monitor是编译时常量，则整个代码可缩小为：

#include <array>
//...

auto* harmonic_content = new std::array<std::array<double, number_of_harmonics_required_to_monitor>, number_of_harmonics_required_to_monitor>;

for (int i=1;i<number_of_harmonics_required_to_monitor+1;i++)
{                                   
    cout<<" Harmonic order "<< i << " :::: " << (*harmonic_content)[i][0] << "Hz"
                                 << " :::: " << (*harmonic_content)[i][1] 
                                 << " :::: " << (*harmonic_content)[i][2] 
                                 <<endl;
}


delete harmonic_content;

如果它不是常数，你可以使用sdt :: vector。

更好的方法是使用一些跟踪自己内存的矩阵实现。

内存堆问题C ++，动态分配多维数组

2 个答案: