le_eventLoop.h File Reference

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Macros
#define	LE_CI_LINKAGE
#define	COMPONENT_INIT   LE_CI_LINKAGE LE_SHARED void _le_event_InitializeComponent(void)
#define	LE_EVENT_INIT_HANDLER   COMPONENT_INIT
	Deprecated name for COMPONENT_INIT.

Typedefs
typedef struct le_event_Id *	le_event_Id_t
typedef void(*	le_event_HandlerFunc_t) (void *reportPtr)
typedef void(*	le_event_LayeredHandlerFunc_t) (void *reportPtr, void *secondLayerFunc)
typedef void(*	le_event_DeferredFunc_t) (void *param1Ptr, void *param2Ptr)
typedef struct le_event_Handler *	le_event_HandlerRef_t

Functions
le_event_Id_t	le_event_CreateId (const char *name, size_t payloadSize)
le_event_Id_t	le_event_CreateIdWithRefCounting (const char *name)
le_event_HandlerRef_t	le_event_AddHandler (const char *name, le_event_Id_t eventId, le_event_HandlerFunc_t handlerFunc)
le_event_HandlerRef_t	le_event_AddLayeredHandler (const char *name, le_event_Id_t eventId, le_event_LayeredHandlerFunc_t firstLayerFunc, void *secondLayerFunc)
void	le_event_RemoveHandler (le_event_HandlerRef_t handlerRef)
void	le_event_Report (le_event_Id_t eventId, void *payloadPtr, size_t payloadSize)
void	le_event_ReportWithRefCounting (le_event_Id_t eventId, void *objectPtr)
void	le_event_SetContextPtr (le_event_HandlerRef_t handlerRef, void *contextPtr)
void *	le_event_GetContextPtr (void)
void	le_event_QueueFunction (le_event_DeferredFunc_t func, void *param1Ptr, void *param2Ptr)
void	le_event_QueueFunctionToThread (le_thread_Ref_t thread, le_event_DeferredFunc_t func, void *param1Ptr, void *param2Ptr)
void	le_event_RunLoop (void)
int	le_event_GetFd (void)
le_result_t	le_event_ServiceLoop (void)

Detailed Description

Legato Event Loop API include file.

Copyright (C) Sierra Wireless Inc. Use of this work is subject to license.

Macro Definition Documentation

#define COMPONENT_INIT   LE_CI_LINKAGE LE_SHARED void _le_event_InitializeComponent(void)

Initialization event handler function.

#define LE_CI_LINKAGE

Initialization event handler function declaration macro.

Use this macro instead of a normal function prototype to create an Initialization Event Handler function. E.g.,

COMPONENT_INIT
{
    // Do my initialization here...
}

Returns

Nothing.

Typedef Documentation

typedef void(* le_event_DeferredFunc_t) (void *param1Ptr, void *param2Ptr)

Prototype for deferred functions look like this:

Parameters

param1Ptr	[in] Value passed in as param1Ptr to le_event_QueueFunction().
param2Ptr	[in] Value passed in as param2Ptr to le_event_QueueFunction().

See Deferred Function Calls for more information.

typedef void(* le_event_HandlerFunc_t) (void *reportPtr)

Prototype for publish-subscribe event handler functions look like this:

Parameters

reportPtr

[in] Pointer to the event report payload.

Warning

The reportPtr is only valid until the handler function returns.

typedef struct le_event_Handler* le_event_HandlerRef_t

Handler reference.

Used to refer to handlers that have been added for events. Only needed if you want to set the handler's context pointer or need to remove the handler later.

typedef struct le_event_Id* le_event_Id_t

Event ID.

An Event ID ties event reports to event handlers. See Publish-Subscribe Events for more details.

typedef void(* le_event_LayeredHandlerFunc_t) (void *reportPtr, void *secondLayerFunc)

Prototype for the first layer of a layered publish-subscribe event handler function look like this:

Parameters

reportPtr	[in] Pointer to the event report payload.
secondLayerFunc	[in] Address of the second layer handler function.

Warning

The reportPtr is only valid until the handler function returns.

Function Documentation

le_event_HandlerRef_t le_event_AddHandler	(	const char *	name,
		le_event_Id_t	eventId,
		le_event_HandlerFunc_t	handlerFunc
	)

Adds a handler function for a publish-subscribe event ID.

Tells the calling thread event loop to call a specified handler function when a defined event reaches the front of the event queue.

Returns

Handler reference, only needed to remove the handler (using le_event_RemoveHandler() ). Can be ignored if the handler will never be removed.

Note

Doesn't return on failure, there's no need to check the return value for errors.

Parameters

[in]	name	Handler name.
[in]	eventId	Event ID.
[in]	handlerFunc	Handler function.

le_event_HandlerRef_t le_event_AddLayeredHandler	(	const char *	name,
		le_event_Id_t	eventId,
		le_event_LayeredHandlerFunc_t	firstLayerFunc,
		void *	secondLayerFunc
	)

Adds a layered handler function for a publish-subscribe event ID.

Tells the calling thread event loop to call a specified handler function when a defined event reaches the front of the event queue. Passes the required handler functions when called.

This is intended for use in implementing Layered Publish-Subscribe Handlers.

Returns

Handler reference, only needed for later removal of the handler (using le_event_RemoveHandler() ). Can be ignored if the handler will never be removed.

Note

Doesn't return on failure, there's no need to check the return value for errors.

Parameters

[in]	name	Handler name.
[in]	eventId	Event ID.
[in]	firstLayerFunc	Pointer to first-layer handler func.
[in]	secondLayerFunc	Pointer to second-layer handler func.

le_event_Id_t le_event_CreateId	(	const char *	name,
		size_t	payloadSize
	)

Create a new event ID.

Returns

Event ID.

Note

Doesn't return on failure, there's no need to check the return value for errors.

Parameters

[in]	name	Name of the event ID. (Named for diagnostic purposes.)
[in]	payloadSize	Data payload size (in bytes) of the event reports (can be 0).

le_event_Id_t le_event_CreateIdWithRefCounting

(

const char *

name

)

Create a new event ID to report events where the payload is a pointer to a reference-counted memory pool object allocated using the Dynamic Memory Allocation API.

Returns

Event ID.

Note

Doesn't return on failure, there's no need to check the return value for errors.

Parameters

[in]

name

Name of the event ID. (Named for diagnostic purposes.)

void* le_event_GetContextPtr

(

void

)

Fetches the context pointer for the currently running event handler.

Can only be called from within an event handler function.

Returns

Context pointer that was set using le_event_SetContextPtr(), or NULL if le_event_SetContextPtr() was not called.

int le_event_GetFd

(

void

)

Fetches a file descriptor that will appear readable to poll(), select(), epoll_wait(), etc. when the calling thread's Event Loop needs servicing (via a call to le_event_ServiceLoop()).

Warning

Only intended for use when integrating with legacy POSIX-based software that cannot be easily refactored to use the Legato Event Loop. The preferred approach is to call le_event_RunLoop().

Returns

The file descriptor.

void le_event_QueueFunction	(	le_event_DeferredFunc_t	func,
		void *	param1Ptr,
		void *	param2Ptr
	)

Queue a function onto the calling thread's Event Queue. When it reaches the head of the Event Queue, it will be called by the calling thread's Event Loop.

Parameters

[in]	func	Function to be called later.
[in]	param1Ptr	Value to be passed to the function when called.
[in]	param2Ptr	Value to be passed to the function when called.

void le_event_QueueFunctionToThread	(	le_thread_Ref_t	thread,
		le_event_DeferredFunc_t	func,
		void *	param1Ptr,
		void *	param2Ptr
	)

Queue a function onto a specific thread's Event Queue. When it reaches the head of that Event Queue, it will be called by that thread's Event Loop.

Parameters

[in]	thread	Thread to queue the function to.
[in]	func	The function.
[in]	param1Ptr	Value to be passed to the function when called.
[in]	param2Ptr	Value to be passed to the function when called.

void le_event_RemoveHandler

(

le_event_HandlerRef_t

handlerRef

)

Remove Handler

Removes a previously added event handler function.

Parameters

[in]

handlerRef

Handler reference.

void le_event_Report	(	le_event_Id_t	eventId,
		void *	payloadPtr,
		size_t	payloadSize
	)

Report an Event

Queues an Event Report to any and all event loops that have handlers for that event.

Note

Copies the event report payload, so it is safe to release or reuse the buffer that payloadPtr points to as soon as le_event_Report() returns.

Parameters

[in]	eventId	Event ID created using le_event_CreateId().
[in]	payloadPtr	Pointer to the payload bytes to be copied into the report.
[in]	payloadSize	Number of bytes of payload to copy into the report.

void le_event_ReportWithRefCounting	(	le_event_Id_t	eventId,
		void *	objectPtr
	)

Sends an Event Report with a pointer to a reference-counted object as its payload. The pointer must have been obtained from a memory pool using the Dynamic Memory Allocation API.

Calling this function passes ownership of the reference to the Event Loop API. The Event Loop API will ensure that the reference is properly counted while it passes through the event report dispatching system. Each handler will receive one counted reference to the object, so the handler is responsible for releasing the object when it is finished with it.

Parameters

[in]	eventId	Event ID created using le_event_CreateIdWithRefCounting().
[in]	objectPtr	Pointer to an object allocated from a memory pool (using the Dynamic Memory Allocation API).

void le_event_RunLoop

(

void

)

Runs the event loop for the calling thread.

This starts processing events by the calling thread.

Can only be called once for each thread, and must never be called in the process's main thread.

Note

Function never returns.

le_result_t le_event_ServiceLoop

(

void

)

Services the calling thread's Event Loop.

Warning

Only intended for use when integrating with legacy POSIX-based software that can't be easily refactored to use the Legato Event Loop. The preferred approach is to call le_event_RunLoop().

See also: le_event_GetFd().

Returns

• LE_OK if there is more to be done. DO NOT GO BACK TO SLEEP without calling le_event_ServiceLoop() again.
• LE_WOULD_BLOCK if there is nothing left to do for now and it is safe to go back to sleep.

void le_event_SetContextPtr	(	le_event_HandlerRef_t	handlerRef,
		void *	contextPtr
	)

Sets the context pointer for a given event handler.

This can later be retrieved using le_event_GetContextPtr() from within the handler function when it is called.

Parameters

[in]	handlerRef	Handler where context pointer is to be set.
[in]	contextPtr	Context pointer value.