c - 分配仅在释放时失败

Question

在调试程序时，程序会按预期运行。运行发行版时，它告诉我空间不足。为什么会发生这种情况，如何让它在发布 exe 中运行？

我找到了一些其他文章，但我不明白相似之处在哪里。 C malloc weird behavior on debug/release

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

#define AMOUNT  100000                              // amount of random numbers
#define RANDOM  (rand() & 0x1F) + (rand() << 16)    // 32 bit random number

struct sNumStruct {
    unsigned int uiNum;             // number
    struct sNumStruct *pNext;       // next
    struct sNumStruct *pPrev;       // previous
};

int main()
{
    /// initializing
    srand(time(NULL));              // rand() initializer
    unsigned int i = 0;             // counter
    struct sNumStruct * pNumbers;   // pointer to number structure
    struct sNumStruct * pStart;     // pointer to start of list
    struct sNumStruct * pLast;      // pointer to end of list

    /// random number generation
    printf("Generating %d random numbers ...\n", AMOUNT);

    pStart = (struct sNumStruct*)malloc(sizeof(struct sNumStruct*));    // allocating memory for first element
    if(pStart == NULL)              // allocation failed?
    {
        perror("-1");               // print error -1
        return -1;
    }
    pStart->pNext = NULL;           // next element is NULL
    pStart->pPrev = NULL;           // prev element is NULL

    pNumbers = pStart;              // point to number structure
    pNumbers->uiNum = RANDOM;       // get random number

    for(i = 0; i < AMOUNT; i++)     // repeat AMOUNT times
    {
        printf("%d,", i);           // <---------- DEBUG
        pNumbers->pNext = (struct sNumStruct*)malloc(sizeof(struct sNumStruct*));   // allocating memory for next element
        if(pNumbers->pNext == NULL) // allocation failed?
        {
            perror("-2");           // print error -2
            return -2;
        }
        (pNumbers->pNext)->pPrev = pNumbers;    // current element is previous from next
        pNumbers = pNumbers->pNext;             // next element
        pNumbers->uiNum = RANDOM;               // random number
        pNumbers->pNext = NULL;                 // next element is NULL
    }
    pLast = pNumbers;

    printf("\n... done generating numbers\n");

    // sort(&pNumbers);

    return 0;
}

我得到的输出是:“生成 100000 个随机数......0,1,-2: 空间不足

进程返回 -2 (0xFFFFFFFE)”

“0,1”是它分配了多少个元素。所以它在第一个“下一个元素”分配时失败。“-2”证实了上面的说法

希望看到:“生成 100000 个随机数......0,1, ....(不会输入所有数字)... 99998,99999,... ...完成生成数字

进程返回 0"

Answer 1

当你这样做时:

pStart = (struct sNumStruct*)malloc(sizeof(struct sNumStruct*));

你正在分配一个指针的大小，如果你在 64 位系统上，它可能是 8 个字节。你应该使用 :

pStart = (struct sNumStruct*)malloc(sizeof(struct sNumStruct));(没有指针)

这将为您的结构分配所需的大小。

也许这会有所帮助？