#include <BusMaster.hxx>

Inheritance diagram for Bus< MessageType >::Master:

Public Member Functions
	Master (Service s, PacketSink sink, Activity *idle, unsigned num_enqueued)
	Constructor.

void	set_policy (unsigned num_prio, const Fixed16 *strides)
	Sets the scheduling policy.

void	schedule_activity (Activity *a, unsigned prio)
	Adds an activity to the bus master's scheduler.

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 Member Functions
Action	get_buffer ()
	Start of scheduling flow.

Action	fill_pkt ()
	Executes the scheduling decision, fills in the packet by the selected activity and sends it to the bus sink.

Private Attributes
uninitialized< ScheduledQueue >	queue_
	Handles the policy of polling.

Activity *	idle_
	If we have no activity to do, this activity gets invoked.

PacketSink *	sink_
	Where to send the generated packets.

LimitedPool	pool_
	Source of the buffers that we fill and hand out.

uint16_t	numPacketsInPool_
	Total number of packets that the pool can generate.

uint16_t	needShutdown_: 1
	True if shutdown was requested.

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

template<class MessageType>
class Bus< MessageType >::Master

The Bus Master class.

This keeps the scheduler of activities and owns a variety of auxiliary objects and memory management.

Definition at line 74 of file BusMaster.hxx.

Constructor & Destructor Documentation

◆ Master()

template<class MessageType >

Bus< MessageType >::Master::Master	(	Service *	s,
		PacketSink *	sink,
		Activity *	idle,
		unsigned	num_enqueued
	)

inline

Constructor.

Parameters

s	the executor to run the service on.
sink	this is where the generated packets will be sent out.
idle	when no activity is scheduled, this activity will be invoked with the packet. This activity must be ready to render a packet at all times.
num_enqueued	this is how many packets we fill in and enqueue for the sink. It is a tradeoff between the sink being out of work vs the what is the lowest latency between enqueueing a high priority activity and that getting the next packet. Recommended values are 2 or 3.

Definition at line 88 of file BusMaster.hxx.

Member Function Documentation

◆ fill_pkt()

template<class MessageType >

Action Bus< MessageType >::Master::fill_pkt ( )

inlineprivate

Executes the scheduling decision, fills in the packet by the selected activity and sends it to the bus sink.

Definition at line 143 of file BusMaster.hxx.

◆ get_buffer()

template<class MessageType >

Action Bus< MessageType >::Master::get_buffer ( )

inlineprivate

Start of scheduling flow.

Definition at line 136 of file BusMaster.hxx.

◆ schedule_activity()

template<class MessageType >

void Bus< MessageType >::Master::schedule_activity	(	Activity *	a,
		unsigned	prio
	)

inline

Adds an activity to the bus master's scheduler.

The activity must be ready to fill in a packet right now.

Parameters

a	the activity to schedule. The caller retains ownership.
prio	the priority band to schedule in.

Definition at line 129 of file BusMaster.hxx.

◆ set_policy()

template<class MessageType >

void Bus< MessageType >::Master::set_policy	(	unsigned	num_prio,
		const Fixed16 *	strides
	)

inline

Sets the scheduling policy.

This must be called exactly once after construction before scheduling any bus activity.

Definition at line 119 of file BusMaster.hxx.

Member Data Documentation

◆ idle_

template<class MessageType >

Activity* Bus< MessageType >::Master::idle_

private

If we have no activity to do, this activity gets invoked.

It must always be able to fill in a packet.

Definition at line 165 of file BusMaster.hxx.

◆ needShutdown_

template<class MessageType >

uint16_t Bus< MessageType >::Master::needShutdown_

private

True if shutdown was requested.

Definition at line 173 of file BusMaster.hxx.

◆ numPacketsInPool_

template<class MessageType >

uint16_t Bus< MessageType >::Master::numPacketsInPool_

private

Total number of packets that the pool can generate.

Definition at line 171 of file BusMaster.hxx.

◆ pool_

template<class MessageType >

LimitedPool Bus< MessageType >::Master::pool_

private

Source of the buffers that we fill and hand out.

Definition at line 169 of file BusMaster.hxx.

◆ queue_

template<class MessageType >

uninitialized<ScheduledQueue> Bus< MessageType >::Master::queue_

private

Handles the policy of polling.

Definition at line 162 of file BusMaster.hxx.

◆ sink_

template<class MessageType >

PacketSink* Bus< MessageType >::Master::sink_

private

Where to send the generated packets.

Definition at line 167 of file BusMaster.hxx.

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

BusMaster.hxx

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Master()

Member Function Documentation

◆ fill_pkt()

◆ get_buffer()

◆ schedule_activity()

◆ set_policy()

Member Data Documentation

◆ idle_

◆ needShutdown_

◆ numPacketsInPool_

◆ pool_

◆ queue_

◆ sink_