Awaitable for submitting transfers. More...

#include <transfer_awaitable.hpp>

Collaboration diagram for co_usb::transfer_awaitable:

Classes
struct	cb_data

Public Member Functions
	transfer_awaitable (libusb_transfer *tfer) noexcept

bool	await_ready () noexcept

std::coroutine_handle	await_suspend (std::coroutine_handle<> h, boost::capy::io_env const *env)
	suspends and submits the transfer

boost::capy::io_result< size_t >	await_resume ()
	returns the result of a tranfer as an std::error_code and size of transfer's buffer contents after the operation.

Public Attributes
libusb_transfer *	transfer = nullptr

struct co_usb::transfer_awaitable::cb_data	m_data

Detailed Description

Awaitable for submitting transfers.

Note: This class does NOT allocate at all

This is the lowest possible representation level of an asynchronous unit of libusb. It does not care for any of a transfer's properties and does not have direction- or transfer type-related bevahioral differences.

You should use this awaitable for porting an existing codebase to co_usb or when you need ultimate control.

Note: user_data and callback fields of a transfer object ARE OVERRIDDEN on await_suspend with internal coroutine machinery, to access data from a completed transfer consider inspecting the transfer object after the completion of the awaitable.

Constructor & Destructor Documentation

◆ transfer_awaitable()

co_usb::transfer_awaitable::transfer_awaitable ( libusb_transfer * tfer )

noexcept

Member Function Documentation

◆ await_ready()

bool co_usb::transfer_awaitable::await_ready ( )

noexcept

Returns: always false, a transfer cannot be completed without roundtrip.

◆ await_resume()

boost::capy::io_result< size_t > co_usb::transfer_awaitable::await_resume ( )

returns the result of a tranfer as an std::error_code and size of transfer's buffer contents after the operation.

◆ await_suspend()

std::coroutine_handle co_usb::transfer_awaitable::await_suspend	(	std::coroutine_handle<>	h,
		boost::capy::io_env const *	env
	)

suspends and submits the transfer

Parameters

h	std::coroutine_handle to the awaiting coroutine
env	boost::capy::io_env* as per boost::capy::IoAwaitable concept

Returns: std::noop_coroutine on success; h on submission error or on cancellation

Member Data Documentation

◆ m_data

struct co_usb::transfer_awaitable::cb_data co_usb::transfer_awaitable::m_data

◆ transfer

libusb_transfer* co_usb::transfer_awaitable::transfer = nullptr

The documentation for this struct was generated from the following files:

/home/runner/work/co_usb/co_usb/include/co_usb/transfer/transfer_awaitable.hpp
/home/runner/work/co_usb/co_usb/src/transfer/transfer_awaitable.cpp

Classes

Public Member Functions

Public Attributes