Thread-safe event wrapper for button IRQ notifications. More...

Collaboration diagram for c7222::ButtonEvent:

Public Member Functions
void	SetEvents (std::uint32_t new_events)
	Set the event bitmask and notify waiters.

bool	GetEvents (std::uint32_t timeout_ms, std::uint32_t &events_out)
	Wait for events with a timeout.

Detailed Description

Thread-safe event wrapper for button IRQ notifications.

Synchronization model and purpose:

Uses a std::mutex to protect the shared event state (events_ and event_ready_) from concurrent access by the ISR-dispatcher path and the consumer task.
Uses a std::condition_variable to block the consumer task efficiently until new events arrive, with optional timeout.
The flag event_ready_ is the condition predicate that prevents missed wake-ups (the consumer re-checks the flag after waking).
RAII is used for lock management inside GetEvents() via std::unique_lock, ensuring the mutex is released on all exit paths.
RAII is not used to represent the event itself because event ownership spans multiple threads and timeouts. The event is produced asynchronously (ISR-dispatcher path) and consumed later by a waiting task. An RAII guard would tie event lifetime to a single scope and thread, which is not appropriate for a cross-thread notification.

Intended usage:

SetEvents() is called by the IRQ dispatcher task or timer callback when a GPIO interrupt occurs.
GetEvents() is called by a consumer task that wants to wait for the next event without polling.

Member Function Documentation

bool c7222::ButtonEvent::GetEvents	(	std::uint32_t	timeout_ms,
		std::uint32_t &	events_out
	)

Wait for events with a timeout.

Parameters

timeout_ms	Maximum time to wait in milliseconds.
events_out	Filled with event bitmask on success.

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void c7222::ButtonEvent::SetEvents ( std::uint32_t new_events )

Set the event bitmask and notify waiters.

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