Question

我尝试使用动态数组，当我完成使用它时，我尝试释放使用的内存，我收到此错误。

free(): invalid next size (fast): 0x00652098

这是struct变量的声明：

struct player {
int played_time;
int min_time;
int max_time;
int errors;
int color;
};

struct Players {
struct player *array;
size_t player_number;
size_t size;
};
typedef struct Players Player_list;

这是用于管理动态数组的方法：

void initArray(Player_list *list, size_t initialSize) {
  list->array = (struct player *) malloc(initialSize * sizeof(struct player));
  list->player_number = 0;
  list->size = initialSize;
}

void insertArray(Player_list *list, struct player element) {
  if (list->player_number == list->size) {
    list->size *= 2;
    list->array = (struct player *) realloc(list->array,
            list->size * sizeof(struct player));
  }
  list->array[list->player_number++] = element;
}

void freeArray(Player_list *list) {
  free(list->array);
  list->array = NULL;
  list->player_number = list->size = 0;
 }

int disqualified(Player_list *list, int errors) {
  int i = 0;
  for (i = 0; i < list->player_number; i++) {
    if (list->array[i].errors >= errors) {
        return 1;
    }
  }
  return 0;
  }

以下是我在主要方面的使用方法：

/**
 * When button is pressed 1 add an error to a random player
 */
void button_s_isr(void) {
    int index = rand() % (players.player_number);
    point_players->array[index].errors = point_players->array[index].errors      + 1;

}

      ... 

int main(void) {

      ...
// set up of GPIO
// get with scanf NUMBER_OF_PLAYERS and MAX_ERRORS values

int i;
for (i = 0; i < NUMBER_OF_PLAYERS; i++) {
    struct player player;
    player.color = PLAYER_COLORS[i];
    player.errors = 0;
    player.max_time = 0;
    player.min_time = 0;
    player.played_time = 0;
    insertArray(&players, player);
}

while (disqualified(&players, MAX_ERRORS) != 1) {
// wait
}
printf("\n  Se ha acabdo el juego: ");
freeArray(point_players);
return EXIT_SUCCESS;
}

我必须说我对C很新，对不起，如果难以理解的话。我想要做的是结构（玩家）的动态列表，其中每个玩家都有自己的参数（playing_time，min_time，max_time，错误，颜色）。在主要内部我希望有一个游戏，我可以从每个玩家控制这些参数。任何改进代码的帮助都表示赞赏。

Answer 1

这样的错误通常会发生，因为您正在写入已声明的内存的末尾。虽然我们可以通过仔细地倾注每一行代码来找到错误，但valgrind会为你找到它更快。

尝试在没有优化的情况下在调试模式下编译代码（如果使用gcc，请使用gcc -g -O0）并在valgrind下运行程序（例如，valgrind myprog -my-prog-options）。它应该立即标记错误。

所有这些假设您正在运行linux的变体。如果您使用的是visual studio，可能会有类似的内存检查程序，但我不知道它是什么或如何运行它。祝你好运！

Answer 2

发布的代码：

无法编译
缺少PLAYER_COLORS [i]的定义，这是一个坏主意，因为玩家数量可能会超过阵列中的可用颜色。
错误地计算realloc()
未能检查malloc()和realloc()
包含令人困惑的（即使是OP）命名变量和结构实例
缺少num_jugadores
错误地尝试分配结构而不是复制结构
未能声明struct Players

现在，纠正了干净地编译的代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>  // memcpy()

struct player
{
    int played_time;
    int min_time;
    int max_time;
    int errors;
    int color;
};

struct Players
{
    struct player *array;
    size_t player_number;
    size_t numPlayers;
};


//This are the method used to manage the dynamic array:

void freeArray(struct Players *pArray)
{
    free(pArray->array);
    pArray->array = NULL;
    pArray->player_number = pArray->numPlayers = 0;
}


void initArray( struct Players *pArray )
{
    if( NULL == (pArray->array = malloc(sizeof(struct player)) ) )
    { // then malloc failed
        freeArray( pArray );
        exit( EXIT_FAILURE );
    }

    // implied else, malloc successful

    pArray->player_number = 0;
    pArray->numPlayers = 1;
}


size_t sizeof_array(size_t size)
{
    return  size * sizeof(struct player);
}


void insertArray(struct Players *pArray, struct player *element)
{
    if (pArray->player_number == pArray->numPlayers)
    { // then currently allocated memory for array of players is full

        struct player *temp = NULL;
        if( NULL == (temp = realloc(pArray->array, sizeof_array(pArray->numPlayers)*2) ) )
        { // then, realloc failed
            freeArray( pArray );
            exit( EXIT_FAILURE );
        }

        // implied else, realloc successful

        pArray->numPlayers *= 2;
        pArray->array = temp;
    }

    memcpy( &(pArray->array[pArray->player_number]), element, sizeof( struct player ) );
    pArray->player_number++;
}

//and here is how i use it in the main method:

#define num_jugadores (20)

int main( void )
{
    int i;
    struct Players playerList;

    initArray(&playerList);

    for (i = 0; i < num_jugadores; i++)
    {
        struct player myPlayer;
        //player.color = PLAYER_COLORS[i];
        myPlayer.errors = 0;
        myPlayer.max_time = 0;
        myPlayer.min_time = 0;
        myPlayer.played_time = 0;
        insertArray(&playerList, &myPlayer);
    }


    //...

    freeArray(&playerList);
} // end function: main

结构的空闲内存，里面有一个其他结构数组--C

2 个答案: