Implementation of Broadcast Time Protocol. More...

#include <BroadcastTime.hxx>

Inheritance diagram for openlcb::BroadcastTime:

Public Types
typedef size_t	UpdateSubscribeHandle
	An opaque data element that is returned from update subscriber registration, and allows unregistering a subscriber.

typedef std::function< void(time_t old, time_t current)>	TimeUpdateCallback
	Callback type used for time update subscribers.

Public Types inherited from openlcb::EventHandler
using	EventReport = openlcb::EventReport

using	EventRegistryEntry = openlcb::EventRegistryEntry

using	EventId = openlcb::EventId

Public Member Functions
virtual	~BroadcastTime ()
	Destructor.

void	set_time (int hours, int minutes)
	Set the time in seconds since the system Epoch.

void	set_date (int month, int day)
	Set the time in seconds since the system Epoch.

void	set_year (int year)
	Set the time in seconds since the system Epoch.

void	set_date_year_str (const char *date_year)
	Set the date and year from a C string.

void	set_rate_quarters (int16_t rate)
	Set Rate.

void	start ()
	Start clock.

void	stop ()
	Stop clock.

void	query ()
	Query the current time.

UpdateSubscribeHandle	update_subscribe_add (TimeUpdateCallback callback)
	Register a callback for when the time synchronization is updated.

void	update_subscribe_remove (UpdateSubscribeHandle handle)
	Unregister a callback for when the time synchronization is updated.

Node *	node ()
	Accessor method to get the Node reference.

NodeID	clock_id ()
	Accessor method to get the (48-bit) Clock ID.

EventId	event_base ()
	Access method to get the (64-bit) Event ID base.

const struct tm *	gmtime_recalculate ()
	Recalculate the struct tm representation of time.

const struct tm *	gmtime_get ()
	Get the last calculated reprentation of time.

virtual bool	is_server_detected ()=0
	Has a time server been detected?

virtual bool	is_server_self ()=0
	Test if this is a server.

Public Member Functions inherited from openlcb::SimpleEventHandler
	IGNOREFN (handle_event_report)

	IGNOREFN (handle_consumer_identified)

	IGNOREFN (handle_consumer_range_identified)

	IGNOREFN (handle_producer_identified)

	IGNOREFN (handle_producer_range_identified)

	IGNOREFN (handle_identify_consumer)

	IGNOREFN (handle_identify_producer)

Public Member Functions inherited from openlcb::EventHandler
virtual void	handle_event_report (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)=0
	Called on incoming EventReport messages.

virtual void	handle_consumer_identified (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)
	Called on another node sending ConsumerIdentified for this event.

virtual void	handle_consumer_range_identified (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)
	Called on another node sending ConsumerRangeIdentified.

virtual void	handle_producer_identified (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)
	Called on another node sending ProducerIdentified for this event.

virtual void	handle_producer_range_identified (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)
	Called on another node sending ProducerRangeIdentified for this event.

virtual void	handle_identify_global (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)=0
	Called on the need of sending out identification messages.

virtual void	handle_identify_consumer (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)=0
	Called on another node sending IdentifyConsumer.

virtual void	handle_identify_producer (const EventRegistryEntry &registry_entry, EventReport event, BarrierNotifiable done)=0
	Called on another node sending IdentifyProducer.

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.

Public Member Functions inherited from TimeBase
void	sync (const TimeBase &other)
	Synchronizes this time with a different clock.

std::pair< time_t, int16_t >	time_and_rate_quarters ()
	Get the time as a value of seconds relative to the system epoch.

time_t	compare_realtime (time_t t1, time_t t2)
	Get the difference in time scaled to real time.

time_t	time ()
	Get the time as a value of seconds relative to the system epoch.

struct tm *	gmtime_r (struct tm *result)
	Get the time as a standard struct tm.

int	date (int month, int day)
	Get the date (month/day).

int	day_of_week ()
	Get the day of the week.

int	day_of_year ()
	Get the day of the year.

int	year ()
	Get the year.

int16_t	get_rate_quarters ()
	Report the clock rate as a 12-bit fixed point number (-512.00 to 511.75).

bool	is_running ()
	Test of the clock is running.

bool	is_started ()
	Test of the clock is started (rate could still be 0).

bool	fast_sec_to_real_nsec_period (int16_t rate, time_t fast_sec, long long *real_nsec)
	Convert fast clock period to a period in real nsec.

bool	real_nsec_to_fast_sec_period (int16_t rate, long long real_nsec, time_t *fast_sec)
	Convert period in real nsec to a fast clock period.

bool	real_nsec_until_fast_time_abs (time_t fast_sec, long long *real_nsec)
	Convert a fast time to absolute nsec until it will occur.

bool	fast_sec_to_real_nsec_period_abs (time_t fast_sec, long long *real_nsec)
	Convert fast clock absolute (negative or positive) period to a positive (absolute) period in real nsec.

Protected Member Functions
	BroadcastTime (Node *node, NodeID clock_id)
	Constructor.

virtual void	set_shortcut (uint64_t event)
	Try the possible set event shortcut.

void	service_callbacks (time_t old, time_t current)
	Service all of the attached update subscribers.

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 Member Functions inherited from Atomic
void	lock ()

void	unlock ()

Protected Attributes
struct tm	tm_
	the time we are last set to as a struct tm

Node *	node_
	OpenLCB node to export the consumer on.

EventId	eventBase_
	48-bit unique identifier for the clock instance

WriteHelper	writer_
	helper for sending event messages

StateFlowTimer	timer_
	timer helper

std::vector< TimeUpdateCallback >	callbacks_
	update subscribers

int16_t	rateRequested_
	pending clock rate

Protected Attributes inherited from QMember
QMember *	next
	pointer to the next member in the queue

Protected Attributes inherited from TimeBase
long long	timestamp_ {OSTime::get_monotonic()}
	OS time at the last time update.

time_t	seconds_ {0}
	Clock time at the last time update.

int16_t	rate_ {0}
	effective clock rate

uint16_t	started_: 1
	true if clock is started

Private Member Functions
void	clear_timezone ()
	Reset our process local timezone environment to GMT0.

	DISALLOW_COPY_AND_ASSIGN (BroadcastTime)

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.

Detailed Description

Implementation of Broadcast Time Protocol.

Definition at line 48 of file BroadcastTime.hxx.

Member Typedef Documentation

◆ TimeUpdateCallback

typedef std::function<void(time_t old, time_t current)> openlcb::BroadcastTime::TimeUpdateCallback

Callback type used for time update subscribers.

Parameters

old	Fast clock's current time according to the pre-update state.
current	Fast clock's current time according to the post-update state.

Definition at line 62 of file BroadcastTime.hxx.

◆ UpdateSubscribeHandle

typedef size_t openlcb::BroadcastTime::UpdateSubscribeHandle

An opaque data element that is returned from update subscriber registration, and allows unregistering a subscriber.

Definition at line 55 of file BroadcastTime.hxx.

Constructor & Destructor Documentation

◆ ~BroadcastTime()

virtual openlcb::BroadcastTime::~BroadcastTime ( )

inlinevirtual

Destructor.

Definition at line 65 of file BroadcastTime.hxx.

◆ BroadcastTime()

openlcb::BroadcastTime::BroadcastTime	(	Node *	node,
		NodeID	clock_id
	)

inlineprotected

Constructor.

Parameters

node	the virtual node that will be listening for events and responding to Identify messages.
clock_id	48-bit unique identifier for the clock instance

Definition at line 211 of file BroadcastTime.hxx.

Member Function Documentation

◆ clear_timezone()

void openlcb::BroadcastTime::clear_timezone ( )

private

Reset our process local timezone environment to GMT0.

Definition at line 47 of file BroadcastTime.cxx.

◆ clock_id()

NodeID openlcb::BroadcastTime::clock_id ( )

inline

Accessor method to get the (48-bit) Clock ID.

Returns: clock ID

Definition at line 172 of file BroadcastTime.hxx.

◆ event_base()

EventId openlcb::BroadcastTime::event_base ( )

inline

Access method to get the (64-bit) Event ID base.

Definition at line 178 of file BroadcastTime.hxx.

◆ gmtime_get()

const struct tm * openlcb::BroadcastTime::gmtime_get ( )

inline

Get the last calculated reprentation of time.

Returns: last calculated time in the form of a struct tm

Definition at line 193 of file BroadcastTime.hxx.

◆ gmtime_recalculate()

const struct tm * openlcb::BroadcastTime::gmtime_recalculate ( )

inline

Recalculate the struct tm representation of time.

Returns: last calculated time in the form of a struct tm

Definition at line 185 of file BroadcastTime.hxx.

◆ is_server_detected()

virtual bool openlcb::BroadcastTime::is_server_detected ( )

pure virtual

Has a time server been detected?

Returns: true if a time server has been detected, else false

Implemented in openlcb::BroadcastTimeClient, and openlcb::BroadcastTimeServer.

◆ is_server_self()

virtual bool openlcb::BroadcastTime::is_server_self ( )

pure virtual

Test if this is a server.

Returns: true if a BroadcastTimeServer, else false

Implemented in openlcb::BroadcastTimeClient, and openlcb::BroadcastTimeServer.

◆ node()

Node * openlcb::BroadcastTime::node ( )

inline

Accessor method to get the Node reference.

Returns: Node reference

Definition at line 165 of file BroadcastTime.hxx.

◆ query()

void openlcb::BroadcastTime::query ( )

inline

Query the current time.

Definition at line 129 of file BroadcastTime.hxx.

◆ service_callbacks()

void openlcb::BroadcastTime::service_callbacks	(	time_t	old,
		time_t	current
	)

inlineprotected

Service all of the attached update subscribers.

These are called when there are jumps in time or if the clock is stopped or started.

Parameters

old	Fast clock's current time according to the pre-update state.
current	Fast clock's current time according to the post-update state.

Definition at line 240 of file BroadcastTime.hxx.

◆ set_date()

void openlcb::BroadcastTime::set_date	(	int	month,
		int	day
	)

inline

Set the time in seconds since the system Epoch.

The new date does not become valid until the update callbacks are called.

Parameters

month	month (1 to 12)
day	day of month (1 to 31)

Definition at line 84 of file BroadcastTime.hxx.

◆ set_date_year_str()

void openlcb::BroadcastTime::set_date_year_str ( const char * date_year )

Set the date and year from a C string.

Parameters

date_year date and year format in "Mmm dd, yyyy" format

Definition at line 58 of file BroadcastTime.cxx.

◆ set_rate_quarters()

void openlcb::BroadcastTime::set_rate_quarters ( int16_t rate )

inline

Set Rate.

The new rate does not become valid until the update callbacks are called.

Parameters

rate	clock rate ratio as 12 bit sign extended fixed point rrrrrrrrrr.rr

Definition at line 109 of file BroadcastTime.hxx.

◆ set_shortcut()

virtual void openlcb::BroadcastTime::set_shortcut ( uint64_t event )

inlineprotectedvirtual

Try the possible set event shortcut.

This is typically a bypass of the OpenLCB loopback.

Parameters

event event that we would be "setting"

Reimplemented in openlcb::BroadcastTimeServer.

Definition at line 231 of file BroadcastTime.hxx.

◆ set_time()

void openlcb::BroadcastTime::set_time	(	int	hours,
		int	minutes
	)

inline

Set the time in seconds since the system Epoch.

The new time does not become valid until the update callbacks are called.

Parameters

hour	hour (0 to 23)
minutes	minutes (0 to 59)

Definition at line 73 of file BroadcastTime.hxx.

◆ set_year()

void openlcb::BroadcastTime::set_year ( int year )

inline

Set the time in seconds since the system Epoch.

The new year does not become valid until the update callbacks are called.

Parameters

year	(0AD to 4095AD)

Definition at line 94 of file BroadcastTime.hxx.

◆ start()

void openlcb::BroadcastTime::start ( )

inline

Start clock.

Definition at line 117 of file BroadcastTime.hxx.

◆ stop()

void openlcb::BroadcastTime::stop ( )

inline

Stop clock.

Definition at line 123 of file BroadcastTime.hxx.

◆ update_subscribe_add()

UpdateSubscribeHandle openlcb::BroadcastTime::update_subscribe_add ( TimeUpdateCallback callback )

inline

Register a callback for when the time synchronization is updated.

The context of the caller will be from a state flow on the Node Interface executor.

Parameters

callback function callback to be called.

Returns: handle to entry that can be used in update_unsubscribe

Definition at line 139 of file BroadcastTime.hxx.

◆ update_subscribe_remove()

void openlcb::BroadcastTime::update_subscribe_remove ( UpdateSubscribeHandle handle )

inline

Unregister a callback for when the time synchronization is updated.

Parameters

handle returned from corresponding update_subscribe

Definition at line 157 of file BroadcastTime.hxx.

Member Data Documentation

◆ callbacks_

std::vector<TimeUpdateCallback> openlcb::BroadcastTime::callbacks_

protected

update subscribers

Definition at line 260 of file BroadcastTime.hxx.

◆ eventBase_

EventId openlcb::BroadcastTime::eventBase_

protected

48-bit unique identifier for the clock instance

Definition at line 255 of file BroadcastTime.hxx.

◆ node_

Node* openlcb::BroadcastTime::node_

protected

OpenLCB node to export the consumer on.

Definition at line 254 of file BroadcastTime.hxx.

◆ rateRequested_

int16_t openlcb::BroadcastTime::rateRequested_

protected

pending clock rate

Definition at line 262 of file BroadcastTime.hxx.

◆ timer_

StateFlowTimer openlcb::BroadcastTime::timer_

protected

timer helper

Definition at line 257 of file BroadcastTime.hxx.

◆ tm_

struct tm openlcb::BroadcastTime::tm_

protected

the time we are last set to as a struct tm

Definition at line 252 of file BroadcastTime.hxx.

◆ writer_

WriteHelper openlcb::BroadcastTime::writer_

protected

helper for sending event messages

Definition at line 256 of file BroadcastTime.hxx.

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ TimeUpdateCallback

◆ UpdateSubscribeHandle

Constructor & Destructor Documentation

◆ ~BroadcastTime()

◆ BroadcastTime()

Member Function Documentation

◆ clear_timezone()

◆ clock_id()

◆ event_base()

◆ gmtime_get()

◆ gmtime_recalculate()

◆ is_server_detected()

◆ is_server_self()

◆ node()

◆ query()

◆ service_callbacks()

◆ set_date()

◆ set_date_year_str()

◆ set_rate_quarters()

◆ set_shortcut()

◆ set_time()

◆ set_year()

◆ start()

◆ stop()

◆ update_subscribe_add()

◆ update_subscribe_remove()

Member Data Documentation

◆ callbacks_

◆ eventBase_

◆ node_

◆ rateRequested_

◆ timer_

◆ tm_

◆ writer_