Question

我的realloc（）没有重新分配更多内存。例如，我有一个方法：

void addInfo(LocationArray** myArray, int* count, int* numberOfLoc) {

    if(*count == *numberOfLoc) { // Checks if the array is already full
        printf("count is %d and numberOfLoc is %d\n", *count, *numberOfLoc);
        resizeArray(*myArray, numberOfLoc); //Resizes the array if it's full
    }
    .......
}

如果count值等于numberOfLoc，则resizeArray()应重新分配更多内存。但我得到了resizeArray()：

的输出

printf("The memory heap is exhausted!\n");

我在代码中做错了什么？

typedef struct Location {
    char locName[35];
    char locDesc[85];
    float latitude;
    float longitude;
} LocationArray;

int main() {
    printf("How many locations would you like to be inside the array?\n");
    int numberOfLoc = 0; //variable for storing the size of the LocationArray
    scanf(" %d", &numberOfLoc); //gets the user input and stores in numerOfLoc

    LocationArray* myArray; //declares a LocationArray with the size of numberOfLoc
    myArray = (LocationArray*)malloc(numberOfLoc * sizeof(LocationArray));

    int count = 0;
    while(1) {
        //Prints the menu
        printMenu(&myArray, &count, &numberOfLoc);
    }
    //Free the pointer
    free(myArray);
    return 0;
}

void addInfo(LocationArray** myArray, int* count, int* numberOfLoc) {

    if(*count == *numberOfLoc) { // Checks if the array is already full
        printf("count is %d and numberOfLoc is %d\n", *count, *numberOfLoc);
        resizeArray(myArray, numberOfLoc); //Resizes the array if it's full
    }
    .......
    (*count)++;
}

void resizeArray(LocationArray** myArray, int* numberOfLoc) {
    *numberOfLoc = *numberOfLoc * 2; //Double the size

    LocationArray* temp;
    temp = (LocationArray*)realloc(myArray, *numberOfLoc * sizeof(LocationArray)); //Reallocates more memory

    //Checks if the memory heap is exhausted
    if(temp == NULL) {
        printf("The memory heap is exhausted!\n");
    }
    else {
        *myArray = temp; //Copy from the temp struct variable to myArray
    }
}

Answer 1

我直接看到一个问题：

*myArray = temp; //Copy from the temp struct variable to myArray
free(*myArray);

我不认为你应该这样做，因为temp是新分配的内存，然后你放入*myArray然后立即释放它。

此外，由于resizeArray和addInfo都采用LocationArray **类型的变量，因此您可能希望按原样传递它。换句话说，addInfo的最后一行应该是：

resizeArray (myArray, numberOfLoc);

盲目地忽略使用它们表示失败的函数的返回码也不是一个好主意。

Answer 2

resizeArray（）接受private void sendHttpPost(String input, ChannelHandlerContext ctx) { try { String url = "http://localhost"; URI uri = new URI(url); Bootstrap b = new Bootstrap(); b.group(new NioEventLoopGroup()) .channel(NioServerSocketChannel.class) .handler(new PostRequestHandler()) .option(ChannelOption.AUTO_READ, false); Channel f = b.connect("REMOTE_HOST", 8888).sync().channel(); HttpRequest postReq = new DefaultHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.POST, uri.getRawPath()); postReq.headers().set(HttpHeaders.Names.HOST, "localhost"); postReq.headers().set(HttpHeaders.Names.CONNECTION, HttpHeaders.Values.CLOSE); postReq.headers().set(HttpHeaders.Names.CONTENT_TYPE,"application/x-www-form-urlencoded"); f.writeAndFlush(postReq); // Wait for the server to close the connection. f.closeFuture().sync(); } catch (Exception e) { e.printStackTrace(); } }，但addInfo（）将LocationArray **传递给它，所以你最终将垃圾传递给realloc（）。

realloc（）不会重新分配更多内存

2 个答案: