在函数中分配内存以返回给用户

Allocating Memory In A Function To Return to User

本文关键字：返回 给用户 内存 分配 函数      更新时间：2023-10-16

我有一个函数，它通过串行发送命令，然后接收未知大小的响应。 用

(ioctl(fd_, FIONREAD, &bytes_in_buffer);

我确定需要为读取分配多少内存。

//This code calls the function below
unsigned char CheckRefresh[] = {254, 124, 0};
unsigned char * response;
unsigned int size;
relay_board->SendCustomCommand(CheckRefresh, 3, &response, size);
ErrorCode SendCustomCommand(unsigned char * command, unsigned int command_size, unsigned char **response, unsigned int &response_size)
{
  //Send the command
  write(fd_, command, command_size);
  // ... Omitting Polling Code to Get correct number of bytes ...
  (ioctl(fd_, FIONREAD, &bytes_in_buffer);
  //Now getting the response
  response_size = (unsigned int)bytes_in_buffer;
  (*response) = new unsigned char(response_size);
  if(read(fd_, *response, response_size) < 0)
  {
    std::cout << "[ProXRSerial] SendCustomCommand: Read failed... -- Errno: " << errno << std::endl;
    return Failed;
  };
  return Success;
}

我相信这会损坏我的堆栈，因为我的下一个函数调用在

unsigned char * command = new unsigned char(3);

与以下内容：

sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) -
__builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || ((unsigned long) 
(old_size) >= (unsigned long)((((__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 
* (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && 
((unsigned long)old_end & pagemask) == 0)' failed.

谁能提供一些建议？ 我不知所措，我认为像这样传递双指针可以让我为用户分配内存......

提前谢谢你。

行

(*response) = new unsigned char(response_size);

应改为

(*response) = new unsigned char[response_size];

您的版本分配一个无符号字符，并使用值 response_size 对其进行初始化。

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