CpuDisplay Class Reference

Displays the current CPU load on a bicolor LED (red + green) by showing green when CPU load is light, yellow when moderate, and red when heavy. More...

#include <CpuDisplay.hxx>

Inheritance diagram for CpuDisplay:

Public Member Functions
	CpuDisplay (Service *s, const Gpio *red, const Gpio *green)
	Constructor.
Action	delay ()
	Wait for updating the display.
Action	update_display ()
	Update the display.
Public Member Functions inherited from StateFlowBase
void	run () override
	Callback from the executor.
void	notify () override
	Wakeup call arrived.
Service *	service ()
	Return a pointer to the service I am bound to.
Public Member Functions inherited from Executable
void	test_deletion ()
Public Member Functions inherited from QMember
void	init ()
	Initiailize a QMember, in place of a public placement construction.

Private Attributes
StateFlowTimer	timer_
	Helper struct for timer state.
const Gpio *	red_
	Red LED for display.
const Gpio *	green_
	Green LED for display.

Additional Inherited Members
Static Public Member Functions inherited from StateFlowBase
template<class T , typename... Args>
static void	invoke_subflow_and_ignore_result (FlowInterface< Buffer< T > > *target_flow, Args &&... args)
	Calls a helper flow to perform some actions.
Protected Types inherited from StateFlowBase
typedef Action(StateFlowBase::*	Callback) ()
	State Flow callback prototype.
Protected Member Functions inherited from StateFlowBase
	StateFlowBase (Service *service)
	Constructor.
	~StateFlowBase ()
	Destructor.
void	reset_flow (Callback c)
	Resets the flow to the specified state.
bool	is_state (Callback c)
bool	is_terminated ()
void	start_flow (Callback c)
	Resets the flow to the specified state and starts it.
Action	again ()
	Call the current state again via call_immediately.
Action	exit ()
	Terminate current StateFlow activity.
Action	delete_this ()
	Terminates the flow and deletes *this.
Action	set_terminated ()
	Sets the flow to terminated state.
Action	call_immediately (Callback c)
	Imediately call the next state upon return.
Action	wait ()
	Wait for an asynchronous call.
Action	wait_and_call (Callback c)
	Wait for resource to become available before proceeding to next state.
template<class T >
Action	allocate_and_call (FlowInterface< Buffer< T > > *target_flow, Callback c, Pool *pool=nullptr)
	Allocates a buffer from a pool and proceed to the next state when allocation is successful.
Action	allocate_and_call (Callback c, QAsync *queue)
	Allocates an entry from an asynchronous queue, and transitions to a state once the allocation is complete.
template<class T >
Buffer< T > *	full_allocation_result (FlowInterface< Buffer< T > > *target_flow)
	Takes the result of the asynchronous allocation without resetting the object.
template<class T >
T *	full_allocation_result (TypedQAsync< T > *queue)
	Takes the result of the asynchronous allocation without resetting the object.
template<class T >
void	cast_allocation_result (T **member)
	Takes the result of the asynchronous allocation without resetting the object.
template<class T >
Buffer< T > *	get_allocation_result (FlowInterface< Buffer< T > > *target_flow)
	Takes the result of the asynchronous allocation.
Action	yield_and_call (Callback c)
	Place the current flow to the back of the executor, and transition to a new state after we get the CPU again.
Action	yield ()
	Place the current flow to the back of the executor, and re-try the current state after we get the CPU again.
Action	sleep_and_call (::Timer *timer, long long timeout_nsec, Callback c)
	Suspends execution of this control flow for a specified time.
template<class T , typename... Args>
Action	invoke_subflow_and_wait (FlowInterface< Buffer< T > > *target_flow, Callback c, Args &&... args)
	Calls a helper flow to perform some actions.
Action	read_repeated (StateFlowSelectHelper *helper, int fd, void *buf, size_t size, Callback c, unsigned priority=Selectable::MAX_PRIO)
	Blocks until size bytes are read and then invokes the next state.
Action	read_single (StateFlowSelectHelper *helper, int fd, void *buf, size_t size, Callback c, unsigned priority=Selectable::MAX_PRIO)
	Attempts to read at most size_t bytes, and blocks the caller until at least one byte is read.
Action	read_nonblocking (StateFlowSelectHelper *helper, int fd, void *buf, size_t size, Callback c, unsigned priority=Selectable::MAX_PRIO)
	Attempts to read at most size bytes, and then invokes the next state, even if only zero bytes are available right now.
Action	read_repeated_with_timeout (StateFlowTimedSelectHelper *helper, long long timeout_nsec, int fd, void *buf, size_t size, Callback c, unsigned priority=Selectable::MAX_PRIO)
	Blocks until size bytes are read, or a timeout expires.
Action	internal_try_read ()
	Implementation state that gets repeatedly called upon every wakeup and tries to make progress on reading.
Action	write_repeated (StateFlowSelectHelper *helper, int fd, const void *buf, size_t size, Callback c, unsigned priority=Selectable::MAX_PRIO)
	Writes some data into a file descriptor, repeating the operation as necessary until all bytes are written.
Action	internal_try_write ()
	Implementation state that gets repeatedly called upon every wakeup and tries to make progress on writing.
Protected Member Functions inherited from QMember
	QMember ()
	Constructor.
	~QMember ()
	Destructor.
Protected Attributes inherited from QMember
QMember *	next
	pointer to the next member in the queue

Detailed Description

Displays the current CPU load on a bicolor LED (red + green) by showing green when CPU load is light, yellow when moderate, and red when heavy.

Works great for example on the onboard RGB led of the Tiva tm4c123 development board.

Definition at line 45 of file CpuDisplay.hxx.

Constructor & Destructor Documentation

CpuDisplay()

CpuDisplay::CpuDisplay ( Service *  s, const Gpio *  red, const Gpio *  green  )

inline

Constructor.

Parameters

s	Service specifying which thread to run this stateflow on.
red	Gpio for the red output pin.
green	Gpio for the green output pin.

Definition at line 53 of file CpuDisplay.hxx.

Member Function Documentation

delay()

Action CpuDisplay::delay ( )

inline

Wait for updating the display.

Returns

action.

Definition at line 63 of file CpuDisplay.hxx.

update_display()

Action CpuDisplay::update_display ( )

inline

Update the display.

Returns

action.

Definition at line 69 of file CpuDisplay.hxx.

Member Data Documentation

green_

const Gpio* CpuDisplay::green_

private

Green LED for display.

Definition at line 96 of file CpuDisplay.hxx.

red_

const Gpio* CpuDisplay::red_

private

Red LED for display.

Definition at line 94 of file CpuDisplay.hxx.

timer_

StateFlowTimer CpuDisplay::timer_

private

Helper struct for timer state.

Definition at line 92 of file CpuDisplay.hxx.

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

• CpuDisplay.hxx