Timeout

Core Functionality

Defined in namespace hal

#include <libhal/timeout.hpp>

group TimeoutCore

Typedefs

using timeout_function = status(void)

Timeout is a callable object or function that signals to a procedure that the procedure has exceeded its time allotment and should return control to the calling function.

Throws hal::timeout:

- when the timeout condition has been met.

Return:

status - sets error flag set when timeout condition has been met, otherwise returns success.

using work_function = result<work_state>()

A non-blocking callable that performs work with each call.

Each call to a work_function will perform a set of work. The worker will return a work_state to indicate its current state. Once the worker reaches a terminal state, it MUST perform no additional work and return the terminal state. For example, if a work function failed, it must always return failure and not interact with hardware or other software from that point on. Same will occur for the “finished” state.

This function can be repeatedly tried until it has reached a terminal state with the try_until() function.

Return:

result<work_state> - sets error flag set when an error occurs, otherwise returns work_state enum.

Enums

enum class work_state

Represents the state of a coroutine or resumable callable.

Values:

enumerator in_progress

enumerator failed

enumerator finished

Functions

inline status delay(timeout auto p_timeout)

Delay the execution of the application or thread for a duration of time.

Template Parameters:

Timeout – - timeout type

Parameters:

p_timeout – - callable timeout object

Returns:

status - success or failure

inline auto never_timeout()

Create a timeout that will never time out.

Returns:

auto - callable that will never return timeout

Utilities

Defined in namespace hal

#include <libhal-util/timeout.hpp>

group TimeoutUtil

Functions

inline result<work_state> try_until(worker auto &p_worker, timeout auto p_timeout)

Repeatedly call a worker function until it has reached a terminal state or a timeout has been reached.

Parameters:

• p_worker – - worker function to repeatedly call

• p_timeout – - callable timeout object

Returns:

result<work_state> - state of the worker function

inline result<work_state> try_until(worker auto &&p_worker, timeout auto p_timeout)

Repeatedly call a worker function until it has reached a terminal state or a timeout has been reached.

Parameters:

• p_worker – - worker function to repeatedly call

• p_timeout – - callable timeout object

Returns:

result<work_state> - state of the worker function