c++ - 损坏的双链表 : 0x0804d0c0 (C++)?

Question

注意:我以前从来没有遇到过这种规模的问题，也不知道如何布局，如果我布局错误，请解释我应该如何布局。如果您不能或不愿意帮助该程序，我很乐意了解这个问题。

我一直在写一段代码来练习面向对象的编程，但是我遇到了一个我以前从未见过的错误(我只做了几个月并且没有得到很多没有时间学习，因为我的时间都浪费在了义务教育上)。内核本身(显然)在我的代码中产生了这个错误。但是运行 gdb(带有调试符号)并没有让我知道行号。放入 printf 语句显示它正在循环 while 循环，即使不再满足条件？这对我来说似乎很奇怪，因为它似乎不满足条件，但它一直在循环。它在发生这种情况时出现错误的原因(我认为)是因为在“Stack”类中的某个地方它为整数数组重新分配了负大小的内存 - 虽然，当我向 Stack::reloc 添加一个 if 语句以便防止它重新分配负数数组大小它仍然通过错误。往下看它显示了其他几条信息，(引用 gdb):

程序收到信号 SIGABRT，已中止。__kernel_vsyscall() 中的 0x0012d422

我并没有从 SIGABRT 的 wiki 页面学到很多东西，而且我认为十六进制数对我来说没有任何意义。这是我的代码，分为两个类和主要部分:

标题:

#include <cstdio>
#include <cstdlib>

类堆栈:

class Stack {
private:
    int *stack;
    int size;
    void init(int *top) {
        *top = 0;
    }

    void push2(int *s,int* top, int element) {
        s[(*top)++] = element;
    }

    int pop2(int *s,int *top) {
        return s[--(*top)];
    }
    void reloc(int diff) {
        if ((top+diff)>1) {
            realloc(stack, (size+diff));
            size = size+diff;
        }
    }

public:
    int top;
    Stack() {
        init(&top);
        size = 100;
        stack = (int *)malloc(100 * sizeof(int));
    }
    void push(int element) {
        if (top>=(size-1)) reloc(100);
        push2(stack, &top, element);
    }
    int pop() {
        if ((top<(size-120)) && (top>100)) reloc(-100);
        return (pop2(stack, &top));
    }
    int sth() {
        return size;
    }

};

宇宙类:

/*Universe is the casual layout for the universe*/
class Universe {
    private:
        int y_cog; //y axis center of gravity
        int x_cog; //x axis "
        int force; //weight of universe
        int fps; //frames per second
        int g; //acceleration under gravity
        int G; //gravitational constant

        //NB: velocity in d/s
        //all stacks defined
        Stack y_pos; //y axis position
        Stack x_pos; //x axis "
        Stack mass; //mass of object
        Stack y_vel; //velocity on y axis
        Stack x_vel; //velocity on x axis
        Stack y_pos2; //stacks for repeating
        Stack x_pos2;
        Stack mass2;
        Stack y_vel2;
        Stack x_vel2;

        //function 'increments' the center of gravity
        void cog(int y, int x, int m) {
            //ratio is offset of universe cog
            //where 100 is exectly half way
            int ratio = ((m*100)/(force))/2;
            //set the center of gravity the ratio beween the objects
            y_cog = y_cog-(((y_cog-y)/100)*ratio);
            x_cog = x_cog-(((x_cog-x)/100)*ratio);
            force = m+force;
        }

        /*moves the object at the top of the stack and alters velocity
        according to previouse velocity and force towards the universe
        center of gravity*/
        void move() {
            int yp, xp, m, yv, xv, vi, yvi, xvi, rm;
            yp = y_pos2.pop();
            xp = x_pos2.pop();
            m = mass2.pop();
            yv = y_vel2.pop();
            xv = x_vel2.pop();
            //important part
            //set the position according to velocity and frame rate
            yp = yp+(yv/fps);
            xp = xp+(xv/fps);
            //find the ratio share of velocity
            vi = ((g*100)/fps); //velocity increase
            rm = ((y_cog-yp)+(x_cog-xp)); //ratio maximum
            if (rm==0) rm = 1;
            yvi = ((vi/rm)*(y_cog-yp))/100;
            xvi = ((vi/rm)*(x_cog-xp))/100;
            yv = yvi;
            xv = xvi;
            //push everything back
            y_pos.push(yp);
            x_pos.push(xp);
            mass.push(m);
            y_vel.push(yv);
            x_vel.push(xv);
        }

    public:
        Universe() {
            y_cog = 0;
            x_cog = 0;
            force = 0;
            fps = 10;
            g = 10;
            //all stacks initialised
            y_pos = Stack();
            x_pos = Stack();
            mass = Stack();
            y_vel = Stack();
            x_vel = Stack();
        }

        void add(int yp, int xp, int m, int yv, int xv) { //adds object to stack
            y_pos.push(yp);
            x_pos.push(xp);
            mass.push(m);
            y_vel.push(yv);
            x_vel.push(xv);
        }

        void run() {
            int yp, xp, m, yv, xv;
            while (y_pos.top<=0) { //reposition center of gravity
                //mainly pushing things around
                yp = y_pos.pop();
                xp = x_pos.pop();
                m = mass.pop();
                yv = y_vel.pop();
                xv = x_vel.pop();
                cog(yp, xp, m); //the important part
                y_pos2.push(yp);
                x_pos2.push(xp);
                mass2.push(m);
                y_vel2.push(yv);
                x_vel2.push(xv);
            }
            while (y_pos2.top<1) {
                move();
            }
        }

        void outh() { //human output
            int yp, xp, m, yv, xv;
            while (y_pos.top<=0) {
                yp = y_pos.pop();
                xp = x_pos.pop();
                m = mass.pop();
                yv = y_vel.pop();
                xv = x_vel.pop();
                y_pos2.push(yp);
                x_pos2.push(xp);
                mass2.push(m);
                y_vel2.push(yv);
                x_vel2.push(xv);
                printf("%d, %d\t%d\t%d\n", yp, xp, m, yv+xv);
            }
            while (y_pos2.top<=0) {
                y_pos.push(y_pos2.pop());
                x_pos.push(x_pos2.pop());
                mass.push(mass.pop());
                y_vel.push(y_vel.pop());
                x_vel.push(x_vel.pop());
            }
        }       
};

主要功能:

int main() {
    Universe main = Universe();
    main.add(10, 10, 10, 0, 0);
    main.add(5, 5, 5, 0, 0);
    int i;
    for (i = 1; i<100; i++) {
        main.run();
        main.outh();
        printf("\n");
    }
    return 0;
}

GDB运行结果(带调试符号):

Starting program: /home/james/Desktop/coding/Universe/debug 
*** glibc detected *** /home/james/Desktop/coding/Universe/debug: corrupted double-linked list: 0x0804d0c0 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6(+0x6b591)[0x2d4591]
/lib/tls/i686/cmov/libc.so.6(+0x70ce3)[0x2d9ce3]
/lib/tls/i686/cmov/libc.so.6(realloc+0xdd)[0x2d9f9d]
/home/james/Desktop/coding/Universe/debug[0x80486b2]
/home/james/Desktop/coding/Universe/debug[0x804872c]
/home/james/Desktop/coding/Universe/debug[0x80489b0]
/home/james/Desktop/coding/Universe/debug[0x8048cec]
/home/james/Desktop/coding/Universe/debug[0x80485fd]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe6)[0x27fbd6]
/home/james/Desktop/coding/Universe/debug[0x80484d1]
======= Memory map: ========
00110000-0012b000 r-xp 00000000 08:01 393241     /lib/ld-2.11.1.so
0012b000-0012c000 r--p 0001a000 08:01 393241     /lib/ld-2.11.1.so
0012c000-0012d000 rw-p 0001b000 08:01 393241     /lib/ld-2.11.1.so
0012d000-0012e000 r-xp 00000000 00:00 0          [vdso]
0012e000-00217000 r-xp 00000000 08:01 2625203    /usr/lib/libstdc++.so.6.0.13
00217000-00218000 ---p 000e9000 08:01 2625203    /usr/lib/libstdc++.so.6.0.13
00218000-0021c000 r--p 000e9000 08:01 2625203    /usr/lib/libstdc++.so.6.0.13
0021c000-0021d000 rw-p 000ed000 08:01 2625203    /usr/lib/libstdc++.so.6.0.13
0021d000-00224000 rw-p 00000000 00:00 0 
00224000-00248000 r-xp 00000000 08:01 525255     /lib/tls/i686/cmov/libm-2.11.1.so
00248000-00249000 r--p 00023000 08:01 525255     /lib/tls/i686/cmov/libm-2.11.1.so
00249000-0024a000 rw-p 00024000 08:01 525255     /lib/tls/i686/cmov/libm-2.11.1.so
0024a000-00267000 r-xp 00000000 08:01 393299     /lib/libgcc_s.so.1
00267000-00268000 r--p 0001c000 08:01 393299     /lib/libgcc_s.so.1
00268000-00269000 rw-p 0001d000 08:01 393299     /lib/libgcc_s.so.1
00269000-003bc000 r-xp 00000000 08:01 525247     /lib/tls/i686/cmov/libc-2.11.1.so
003bc000-003bd000 ---p 00153000 08:01 525247     /lib/tls/i686/cmov/libc-2.11.1.so
003bd000-003bf000 r--p 00153000 08:01 525247     /lib/tls/i686/cmov/libc-2.11.1.so
003bf000-003c0000 rw-p 00155000 08:01 525247     /lib/tls/i686/cmov/libc-2.11.1.so
003c0000-003c3000 rw-p 00000000 00:00 0 
08048000-0804a000 r-xp 00000000 08:01 132105     /home/james/Desktop/coding/Universe/debug
0804a000-0804b000 r--p 00001000 08:01 132105     /home/james/Desktop/coding/Universe/debug
0804b000-0804c000 rw-p 00002000 08:01 132105     /home/james/Desktop/coding/Universe/debug
0804c000-0806d000 rw-p 00000000 00:00 0          [heap]
b7e00000-b7e21000 rw-p 00000000 00:00 0 
b7e21000-b7f00000 ---p 00000000 00:00 0 
b7fed000-b7fef000 rw-p 00000000 00:00 0 
b7ffe000-b8000000 rw-p 00000000 00:00 0 
bffeb000-c0000000 rw-p 00000000 00:00 0          [stack]

Program received signal SIGABRT, Aborted.
0x0012d422 in __kernel_vsyscall ()

Answer 1

一个大问题，realloc() 行应该是:

stack = realloc(stack, (size+diff));