PolledQueue Class Reference

PolledQueue. More...

#include <PolledQueue.h>

Inheritance diagram for PolledQueue:

Public Member Functions
	PolledQueue (mbed::Callback< void()> cb=nullptr)
	Create a PolledQueue. More...
virtual void	post (TaskBase *event)
	Add this event to the queue for execution. More...
virtual void	cancel (TaskBase *event)
	Cancel an in-flight event. More...
void	dispatch ()
	Process all the events in this queue. More...
void	attach (mbed::Callback< void()> cb)
	Attach a callback indicating that this queue needs to be processed. More...

Static Protected Member Functions
static uint32_t	task_size (TaskBase *task)
	Get the size required to run this task. More...
static TaskBase::run_callback_t	task_start (TaskBase *task, uint8_t *dest, uint32_t size)
	Start processing this event by copying out its data. More...
static void	task_finish (TaskBase *task)
	Finish processing this event. More...

Detailed Description

PolledQueue.

This class is an implementation of TaskQueue which is processed synchronously by calls to dispatch.

Definition at line 37 of file PolledQueue.h.

Constructor & Destructor Documentation

PolledQueue()

PolledQueue

(

mbed::Callback< void()>

cb = nullptr

)

Create a PolledQueue.

Create an event queue.

Parameters

cb	Callback called when dispatch needs to be called

Member Function Documentation

post()

virtual void post ( TaskBase *  event )

virtual

Add this event to the queue for execution.

If the event is already in the queue then it is canceled and added to the end of the queue.

Parameters

event

Pointer to the event

Implements TaskQueue.

cancel()

virtual void cancel ( TaskBase *  event )

virtual

Cancel an in-flight event.

Cancels the given event so the event's memory can be reused.

The cancel function is IRQ safe.

If called while the event queue's dispatch loop is active, the cancel function does not guarantee that the event will not execute after it returns, as the event may have already begun executing. It does guarantee that the event queue is no longer using event data so the event can be freed or reused.

Parameters

event

Pointer to the event

Implements TaskQueue.

dispatch()

void dispatch

(

)

Process all the events in this queue.

attach()

void attach

(

mbed::Callback< void()>

cb

)

Attach a callback indicating that this queue needs to be processed.

Parameters

cb	Callback called when dispatch needs to be called

task_size()

static uint32_t task_size ( TaskBase *  task )

staticprotectedinherited

Get the size required to run this task.

Get the minimum size required for TaskQueue::task_start

Parameters

task	The task to check size on

Returns

required size

Note

This call must be made in a critical section

Definition at line 95 of file TaskQueue.h.

task_start()

static TaskBase::run_callback_t task_start ( TaskBase *  task, uint8_t *  dest, uint32_t  size  )

staticprotectedinherited

Start processing this event by copying out its data.

Inform this event both that callback execution has started and that the event is free to be posted again.

Parameters

task	The task to start processing
dest	The buffer to copy the callback arguments to
size	maximum size to copy

Returns

Pointer to function run

Note

event_start must not be called on a canceled event as the memory may have been freed already

Every call to event_start must be paired with event_finish

This call must be made in a critical section

Definition at line 117 of file TaskQueue.h.

task_finish()

static void task_finish ( TaskBase *  task )

staticprotectedinherited

Finish processing this event.

Inform this event that the callback has run to completion.

Parameters

task	The task to finish processing

Note

Every call to event_finish must be preceded by a call to event_start

This call must be made in a critical section

Definition at line 133 of file TaskQueue.h.