什么是内存访问冲突？ [英] What's causing the memory access violation?

问题描述

我遇到内存访问冲突

Swarm swarm;
while(true){
    const Particle * const pParticles = swarm.getParticles();
    for (int i = 0; i < swarm.N; i++)
    {   
        Particle particle = pParticles[i];
        int x = (particle.x+) * (screen.width/2);
        int y = (particle.y+1) * (screen.height/2); 
        screen.setPixel(x,y,255,255,255);
    }
    screen.update();
    if(!screen.processEvents())
        break;
}

在 pParticles [i] 。指针只是访问其分配的内存块（在构造函数中分配），我不会在代码中的任何地方篡改指针。这里是Swarm类：

at pParticles[i] . The pointer is just accessing its allocated memory block (allocated in the constructor) and I'm not tampering with the pointer anywhere in the code. here's the Swarm class:

// Sawrm.h
class Swarm
{
public:
    const static int N = 6000;

private:
    Particle * particles;

public:
    const Particle * const getParticles() { return particles; };

    Swarm::Swarm(void)
    {
        particles = new Particle[Swarm::N];
    }

    Swarm::~Swarm(void)
    {
        delete [] particles;
    }

};

// Swarm.cpp    
Swarm::Swarm(void)
{
    particles = new Particle[Swarm::N];
}

Swarm::~Swarm(void)
{
    delete [] particles;
}

如果N大于5000（说6000）我运行它几次，异常。但是如果我再次增加N，我再次得到异常等等。

if N is greater than 5000 (say 6000) I get the exception. I run it a couple times and the exception goes. but if I increase N again I get the exception again and so on. What's going on here?

这里是Particle类，只有两个 double 变量 x，y ：

Here's the Particle class which has nothing but two double variables x,y :

Particle::Particle(void)
{
    x = (1.0*rand())/RAND_MAX   ;
    y = (1.0*rand())/RAND_MAX   ;
}

Particle::~Particle(void)
{
}

推荐答案

我通过使字段N非静态，非const并初始化它在构造函数中修复了问题。不知道为什么这个工作。如果任何人都能提供证明为什么这样做的理由，我会很高兴。

I fixed the problem by making the field N non-static, non-const and initializing it in the constructor instead. Not sure why this works. I'll be happy if anyone can provide a justification as to why this works.

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