miso1289 / usb-asio Goto Github PK

Hi,
I am trying to pass std::bind as completion token to async bulk read.
My inspiration is this boost example.
As I am total asio noob, I am quite lost. Do you know what could be the issue?

class Pump : public boost::enable_shared_from_this<Pump> {
public:
	std::array<std::byte, 512> buffer {};

	void start() {
		boost::asio::async_read(
			source,
			boost::asio::buffer(buffer),
			boost::bind(
				&Pump::handle_read, shared_from_this(),
				boost::asio::placeholders::error,
				boost::asio::placeholders::bytes_transferred
			)
		);
	}

  private:
	Pump(std::deque<std::byte> &sink, usb_asio::usb_in_bulk_transfer &source, const unsigned int id) :
		sink(sink),
		source(source),
		id(id)
		{}

	void handle_read(boost::system::error_code error_code, std::size_t bytes_read) {
		assert(error_code);
		if (bytes_read) {
			sink.insert(sink.end(), buffer.begin(), buffer.begin()+bytes_read);
		}
		start();
	}

	std::deque<std::byte> &sink;
	usb_asio::usb_in_bulk_transfer &source;
	unsigned int id {};
};
[error.txt](https://github.com/MiSo1289/usb-asio/files/10483346/error.txt)

Hi,
first of all, thank you for all your work... díky :)

I am trying to use your asio wrapper of libusb and I am struggling a little bit. It's all blowing up in interface claiming. There is uninitialized data access resulting in null pointer de-reference.

My code is just slightly modified example from readme.

Constructing interface object calls claim.

claim itself calls unclaim at first.

unclaim calls ::libusb_release_interface which takes device handler as argument.

Device handle pointer is obtained by calling device_handle, which returns device_handle_, but this data member is not set yet. That happens at the end of claim fcn.

Unless I am using it wrong, there is several ways to fix this:

• device_handle_ has to be set before calling unclaim
• there has to be overload of interface unclaim which accepts device handle directly (available in claim fcn).
• avoid calling unclaim when device_handle_ is not valid