Furi Event Loop. More...

#include "base.h"

Typedefs
typedef struct FuriEventLoop	FuriEventLoop
	Anonymous message queue type.

typedef void(*	FuriEventLoopTickCallback) (void *context)
	Tick callback type.

typedef void(*	FuriEventLoopPendingCallback) (void *context)
	Timer callback type for functions to be called in a deferred manner.

typedef void	FuriEventLoopObject

typedef bool(*	FuriEventLoopEventCallback) (FuriEventLoopObject object, void context)
	Callback type for event loop events.

typedef struct FuriMessageQueue	FuriMessageQueue
	Opaque message queue type.

typedef struct FuriStreamBuffer	FuriStreamBuffer
	Opaque stream buffer type.

typedef struct FuriSemaphore	FuriSemaphore
	Opaque semaphore type.

typedef struct FuriMutex	FuriMutex
	Opaque mutex type.

Enumerations
enum	FuriEventLoopEvent { FuriEventLoopEventIn = 0x00000001U , FuriEventLoopEventOut = 0x00000002U , FuriEventLoopEventMask = 0x00000003U , FuriEventLoopEventFlagEdge = 0x00000004U , FuriEventLoopEventFlagOnce = 0x00000008U , FuriEventLoopEventFlagMask = 0xFFFFFFFCU , FuriEventLoopEventReserved = UINT32_MAX }
	Enumeration of event types, flags and masks. More...

Functions
FuriEventLoop *	furi_event_loop_alloc (void)
	Allocate Event Loop instance.

void	furi_event_loop_free (FuriEventLoop *instance)
	Free Event Loop instance.

void	furi_event_loop_run (FuriEventLoop *instance)
	Continuously poll for events.

void	furi_event_loop_stop (FuriEventLoop *instance)
	Stop Event Loop instance.

void	furi_event_loop_tick_set (FuriEventLoop instance, uint32_t interval, FuriEventLoopTickCallback callback, void context)
	Set Event Loop tick callback.

void	furi_event_loop_pend_callback (FuriEventLoop instance, FuriEventLoopPendingCallback callback, void context)
	Call a function when all preceding timer commands are processed.

void	furi_event_loop_subscribe_message_queue (FuriEventLoop instance, FuriMessageQueue message_queue, FuriEventLoopEvent event, FuriEventLoopEventCallback callback, void *context)
	Subscribe to message queue events.

void	furi_event_loop_subscribe_stream_buffer (FuriEventLoop instance, FuriStreamBuffer stream_buffer, FuriEventLoopEvent event, FuriEventLoopEventCallback callback, void *context)
	Subscribe to stream buffer events.

void	furi_event_loop_subscribe_semaphore (FuriEventLoop instance, FuriSemaphore semaphore, FuriEventLoopEvent event, FuriEventLoopEventCallback callback, void *context)
	Subscribe to semaphore events.

void	furi_event_loop_subscribe_mutex (FuriEventLoop instance, FuriMutex mutex, FuriEventLoopEvent event, FuriEventLoopEventCallback callback, void *context)
	Subscribe to mutex events.

void	furi_event_loop_unsubscribe (FuriEventLoop instance, FuriEventLoopObject object)
	Unsubscribe from events (common)

Detailed Description

Furi Event Loop.

        This module is designed to handle application event loop in fully
        asynchronous, reactive nature. On the low level this modules is
        inspired by epoll/kqueue concept, on the high level by asyncio
        event loop.

        This module is trying to best fit into Furi OS, so we don't
        provide any compatibility with other event driven APIs. But
        programming concepts are the same, except some runtime
        limitations from our side.

Typedef Documentation

◆ FuriEventLoopEventCallback

typedef bool(* FuriEventLoopEventCallback) (FuriEventLoopObject *object, void *context)

Callback type for event loop events.

Parameters

object	The object that triggered the event
context	The context that was provided upon subscription

Returns: true if event was processed, false if we need to delay processing

◆ FuriEventLoopPendingCallback

typedef void(* FuriEventLoopPendingCallback) (void *context)

Timer callback type for functions to be called in a deferred manner.

Parameters

[in,out] context pointer to a user-specific object that was provided during furi_event_loop_pend_callback() call

◆ FuriEventLoopTickCallback

typedef void(* FuriEventLoopTickCallback) (void *context)

Tick callback type.

Parameters

context The context for callback

Enumeration Type Documentation

◆ FuriEventLoopEvent

enum FuriEventLoopEvent

Enumeration of event types, flags and masks.

Only one event direction (In or Out) can be used per subscription. An object can have no more than one subscription for each direction.

Additional flags that modify the behaviour can be set using the bitwise OR operation (see flag description).

Enumerator
FuriEventLoopEventIn	Subscribe to In events. In events occur on the following conditions: One or more items were inserted into a FuriMessageQueue, Enough data has been written to a FuriStreamBuffer, A FuriSemaphore has been released at least once, A FuriMutex has been released.
FuriEventLoopEventOut	Subscribe to Out events. Out events occur on the following conditions: One or more items were removed from a FuriMessageQueue, Any amount of data has been read out of a FuriStreamBuffer, A FuriSemaphore has been acquired at least once, A FuriMutex has been acquired.
FuriEventLoopEventMask	Special value containing the event direction bits, used internally.
FuriEventLoopEventFlagEdge	Use edge triggered events. By default, level triggered events are used. A level above zero is reported based on the following conditions: In events: a FuriMessageQueue contains one or more items, a FuriStreamBuffer contains one or more bytes, a FuriSemaphore can be acquired at least once, a FuriMutex can be acquired. Out events: a FuriMessageQueue has at least one item of free space, a FuriStreamBuffer has at least one byte of free space, a FuriSemaphore has been acquired at least once, a FuriMutex has been acquired. If this flag is NOT set, the event will be generated repeatedly until the level becomes zero (e.g. all items have been removed from a FuriMessageQueue in case of the "In" event, etc.) If this flag IS set, then the above check is skipped and the event is generated ONLY when a change occurs, with the event direction (In or Out) taken into account.
FuriEventLoopEventFlagOnce	Automatically unsubscribe from events after one time. By default, events will be generated each time the specified conditions have been met. If this flag IS set, the event subscription will be cancelled upon the first occurred event and no further events will be generated.
FuriEventLoopEventFlagMask	Special value containing the event flag bits, used internally.
FuriEventLoopEventReserved	Special value to force the enum to 32-bit values.

Function Documentation

◆ furi_event_loop_alloc()

FuriEventLoop * furi_event_loop_alloc ( void )

Allocate Event Loop instance.

Couple things to keep in mind:

You can have 1 event_loop per 1 thread
You can not use event_loop instance in the other thread
Do not use blocking API to query object delegated to Event Loop

Returns: The Event Loop instance

◆ furi_event_loop_free()

void furi_event_loop_free ( FuriEventLoop * instance )

Free Event Loop instance.

Parameters

instance The Event Loop instance

◆ furi_event_loop_pend_callback()

void furi_event_loop_pend_callback	(	FuriEventLoop *	instance,
		FuriEventLoopPendingCallback	callback,
		void *	context )

Call a function when all preceding timer commands are processed.

This function may be useful to call another function when the event loop has been started.

Parameters

[in,out]	instance	pointer to the current FuriEventLoop instance
[in]	callback	pointer to the callback to be executed when previous commands have been processed
[in,out]	context	pointer to a user-specific object (will be passed to the callback)

◆ furi_event_loop_run()

void furi_event_loop_run ( FuriEventLoop * instance )

Continuously poll for events.

Can be stopped with furi_event_loop_stop

Parameters

instance The Event Loop instance

◆ furi_event_loop_stop()

void furi_event_loop_stop ( FuriEventLoop * instance )

Stop Event Loop instance.

Parameters

instance The Event Loop instance

◆ furi_event_loop_subscribe_message_queue()

void furi_event_loop_subscribe_message_queue	(	FuriEventLoop *	instance,
		FuriMessageQueue *	message_queue,
		FuriEventLoopEvent	event,
		FuriEventLoopEventCallback	callback,
		void *	context )

Subscribe to message queue events.

Warning: you can only have one subscription for one event type.

Parameters

	instance	The Event Loop instance
	message_queue	The message queue to add
[in]	event	The Event Loop event to trigger on
[in]	callback	The callback to call on event
	context	The context for callback

Subscribe to message queue events.

◆ furi_event_loop_subscribe_mutex()

void furi_event_loop_subscribe_mutex	(	FuriEventLoop *	instance,
		FuriMutex *	mutex,
		FuriEventLoopEvent	event,
		FuriEventLoopEventCallback	callback,
		void *	context )

Subscribe to mutex events.

Warning: you can only have one subscription for one event type.

Parameters

	instance	The Event Loop instance
	mutex	The mutex to add
[in]	event	The Event Loop event to trigger on
[in]	callback	The callback to call on event
	context	The context for callback

◆ furi_event_loop_subscribe_semaphore()

void furi_event_loop_subscribe_semaphore	(	FuriEventLoop *	instance,
		FuriSemaphore *	semaphore,
		FuriEventLoopEvent	event,
		FuriEventLoopEventCallback	callback,
		void *	context )

Subscribe to semaphore events.

Warning: you can only have one subscription for one event type.

Parameters

	instance	The Event Loop instance
	semaphore	The semaphore to add
[in]	event	The Event Loop event to trigger on
[in]	callback	The callback to call on event
	context	The context for callback

◆ furi_event_loop_subscribe_stream_buffer()

void furi_event_loop_subscribe_stream_buffer	(	FuriEventLoop *	instance,
		FuriStreamBuffer *	stream_buffer,
		FuriEventLoopEvent	event,
		FuriEventLoopEventCallback	callback,
		void *	context )

Subscribe to stream buffer events.

Warning: you can only have one subscription for one event type.

Parameters

	instance	The Event Loop instance
	stream_buffer	The stream buffer to add
[in]	event	The Event Loop event to trigger on
[in]	callback	The callback to call on event
	context	The context for callback

◆ furi_event_loop_tick_set()

void furi_event_loop_tick_set	(	FuriEventLoop *	instance,
		uint32_t	interval,
		FuriEventLoopTickCallback	callback,
		void *	context )

Set Event Loop tick callback.

Tick callback is called periodically after specified inactivity time. It acts like a low-priority timer: it will only fire if there is time left after processing the synchronization primitives and the regular timers. Therefore, it is not monotonic: ticks will be skipped if the event loop is busy.

Parameters

	instance	The Event Loop instance
[in]	interval	The tick interval
[in]	callback	The callback to call
	context	The context for callback

◆ furi_event_loop_unsubscribe()

void furi_event_loop_unsubscribe	(	FuriEventLoop *	instance,
		FuriEventLoopObject *	object )

Unsubscribe from events (common)

Parameters

instance	The Event Loop instance
object	The object to unsubscribe from

Unsubscribe from events (common)

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

◆ FuriEventLoopEventCallback

◆ FuriEventLoopPendingCallback

◆ FuriEventLoopTickCallback

Enumeration Type Documentation

◆ FuriEventLoopEvent

Function Documentation

◆ furi_event_loop_alloc()

◆ furi_event_loop_free()

◆ furi_event_loop_pend_callback()

◆ furi_event_loop_run()

◆ furi_event_loop_stop()

◆ furi_event_loop_subscribe_message_queue()

◆ furi_event_loop_subscribe_mutex()

◆ furi_event_loop_subscribe_semaphore()

◆ furi_event_loop_subscribe_stream_buffer()

◆ furi_event_loop_tick_set()

◆ furi_event_loop_unsubscribe()