Question

Visual Studio 2008 - 在C中编译

我正在编写一个链表应用程序但是当我尝试释放每个节点时，我会抛出一个异常。我唯一能想到的是我在add函数中分配了我的内存，也许我不能在另一个函数中释放它。公寓，我什么都想不到。

非常感谢任何建议，

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

static struct convert_temp
{
    size_t cel;
    size_t fah;
    struct convert_temp *next;
} *head = NULL, *tail = NULL;

=======

/** Add the new converted temperatures on the list */
void add(size_t cel, size_t fah)
{
    struct convert_temp *node_temp = NULL; /* contain temp data */

    node_temp = malloc(sizeof(node_temp));

    if(node_temp == NULL)
    {
        fprintf(stderr, "Cannot allocate memory [ %s ] : [ %d ]\n",
            __FUNCTION__, __LINE__);
        exit(0);
    }

    /* Assign data */
    node_temp->cel = cel;
    node_temp->fah = fah;
    node_temp->next = NULL;

    if(head == NULL)
    {
        /* The list is at the beginning */
        head = node_temp;   /* Head is the first node = same node */
        tail = node_temp;   /* Tail is also the last node = same node */
    }
    else
    {
        /* Append to the tail */
        tail->next = node_temp;
        /* Point the tail at the end */
        tail = node_temp; 
    }
}

=====

/** Free all the memory that was used to allocate the list */
void destroy()
{
    /* Create temp node */
    struct convert_temp *current_node = head;

    /* loop until null is reached */
    while(current_node)
    {
        struct convert_temp *next = current_node->next;
        /* free memory */
        free(current_node);
        current_node = next;    
    }

    /* Set to null pointers */
    head = NULL;
    tail = NULL;
}

Answer 1

node_temp = malloc(sizeof(node_temp));分配结构指针的大小而不是结构，你应该使用sizeof(*node_temp)。

Answer 2

此行未分配正确的内存量：

node_temp = malloc(sizeof(node_temp));

它应该是这样的：

node_temp = malloc(sizeof *node_temp);

Answer 3

变化：

node_temp = malloc(sizeof(node_temp));

为：

node_temp = malloc(sizeof(struct convert_temp));

它会起作用。 sizeof(node_temp)是指针的大小（最可能是4或8个字节）;你想分配结构的大小

尝试释放内存时罚球错误

3 个答案: