Question

我在Pebble应用程序中使用自定义向量。 Pebble在调用realloc时崩溃了。

的main.c

#include <pebble.h>
#include "movement.h"

static PointArray point_array;

int main(void) {;
    point_array_create(&point_array, 1);
    GPoint point1 = (GPoint){.x = 1, .y = 1};
    GPoint point2 = (GPoint){.x = 2, .y = 2};
    GPoint point3 = (GPoint){.x = 3, .y = 3};

    point_array_push(&point_array, point1);
    point_array_push(&point_array, point2);
    point_array_push(&point_array, point3);
    APP_LOG(APP_LOG_LEVEL_DEBUG, "Done\n");
}

movement.c

#include "movement.h"
#include "pebble.h"


static void point_array_resize(PointArray *point_array){
  point_array->capacity *= 2;
  size_t new_size = point_array->capacity * sizeof(GPoint) + sizeof(GPoint);
  point_array->points = (GPoint*)realloc(point_array->points, new_size);
}


void point_array_create(PointArray *arr, int capacity) {
    arr->points = (GPoint*)malloc(capacity * sizeof(GPoint));
    arr->length = 0;
    arr->capacity = capacity;
}

void point_array_push(PointArray *point_array, GPoint point) {

  APP_LOG(APP_LOG_LEVEL_DEBUG, "pushing");

  if (point_array->length > point_array->capacity) {
    APP_LOG(APP_LOG_LEVEL_DEBUG, "resizing");
    point_array_resize(point_array);
    APP_LOG(APP_LOG_LEVEL_DEBUG, "successful resize");
  }
  point_array->points[point_array->length] = point;
  point_array->length++;
  APP_LOG(APP_LOG_LEVEL_DEBUG, "+ length");
}

movement.h

#include <pebble.h>
#include <stdlib.h>
#include <math.h>

typedef struct {
  GPoint *points;
  int length;
  int capacity;
} PointArray;

void point_array_create(PointArray *arr, int capacity);

void point_array_push(PointArray *point_array, GPoint point);

void point_array_destroy(PointArray *point_array, GPoint point);

GPoint move(GPoint point, float distance, float degrees);

日志显示应用程序在调用realloc时崩溃：

[DEBUG] movement.c:20: pushing
[DEBUG] movement.c:29: + length
[DEBUG] movement.c:20: pushing
[DEBUG] movement.c:29: + length
[DEBUG] movement.c:20: pushing
[DEBUG] movement.c:23: resizing

这是我试过的：

代码在GCC和Clang（！）上运行良好。
我确认point_array和point_array->points不为空且
new_size大于point_array->points的现有尺寸。
我看了this issue，这似乎不适用。
我尝试在realloc的底部调用point_array_create，它运行正常。它只是在point_array_resize。

Answer 1

在point_array_push中，您测试是否需要调整顶部的点数，但测试是错误的。只有在长度超出容量时才会调整大小，这意味着您已经超出了阵列。

相反，请检查长度是否已达到容量。

  if (point_array->length == point_array->capacity) {
    APP_LOG(APP_LOG_LEVEL_DEBUG, "resizing");
    point_array_resize(point_array);
    APP_LOG(APP_LOG_LEVEL_DEBUG, "successful resize");
  }

Pebble在`realloc`上崩溃，但只在某个函数中崩溃

1 个答案: