This class helps waiting for traction responses. More...

#include <TractionClient.hxx>

Inheritance diagram for openlcb::TractionResponseHandler:

Public Member Functions
	TractionResponseHandler (openlcb::If iface, openlcb::Node local_node)

void	wait_for_response (NodeHandle target_node, uint8_t expected_type, ::Timer *trigger)
	Starts waiting for a traction control reply from a given node with the first byte 'expected_type'.

Buffer< GenMessage > *	response ()
	Caller must unref this buffer when done with it.

void	wait_timeout ()
	Call this if the timeout has expired.

Public Member Functions inherited from openlcb::IncomingMessageStateFlow
	IncomingMessageStateFlow (If *iface)

If *	iface ()

GenMessage *	nmsg ()
	Returns the NMRAnet message we received.

Public Member Functions inherited from StateFlow< Buffer< GenMessage >, QList< 4 > >
	StateFlow (Service *service)
	Constructor.

Public Member Functions inherited from TypedStateFlow< MessageType, Base >
	TypedStateFlow (Service *service)
	Constructor.

virtual	~TypedStateFlow ()
	Destructor.

void	send (MessageType *msg, unsigned priority=UINT_MAX) OVERRIDE
	Sends a message to the state flow for processing.

Public Member Functions inherited from FlowInterface< MessageType >
virtual Pool *	pool ()

virtual MessageType *	type_helper ()
	This function is never user in the code, but GDB can use it to infer the correct message types.

MessageType *	alloc ()
	Synchronously allocates a message buffer from the pool of this flow.

void	alloc_async (Executable *target)
	Asynchronously allocates a message buffer from the pool of this flow.

Private Member Functions
void	start_listening ()

void	stop_listening ()

Action	entry () OVERRIDE
	Entry into the StateFlow activity.

Private Attributes
openlcb::NodeHandle	expectedSrc_

openlcb::Node *	expectedDst_

uint8_t	expectedType_

::Timer *	trigger_

Buffer< GenMessage > *	response_

Additional Inherited Members
Public Types inherited from TypedStateFlow< MessageType, Base >
typedef Base::Action	Action
	Allows using Action without having StateFlowBase:: prefix in front of it.

Public Types inherited from FlowInterface< MessageType >
typedef MessageType	message_type
	Stores the message template type for external reference.

Static Public Member Functions inherited from FlowInterface< MessageType >
static MessageType *	cast_alloc (QMember *entry)
	Down casts and initializes an asynchronous allocation result to the appropriate flow's buffer type.

Protected Member Functions inherited from TypedStateFlow< MessageType, Base >
void	release () OVERRIDE
	Unrefs the current buffer.

void	return_buffer ()
	For state flows that are operated using invoke_subflow_and_wait this is a way to hand back the buffer to the caller.

MessageType *	message ()

MessageType *	transfer_message ()
	Releases ownership of the current message.

Detailed Description

This class helps waiting for traction responses.

It listens for traction control response messages, matches them to an expected destination/responsetype pair, and triggers a timeout when the matching response arrives.

Synchronous usage: auto* b = ... // allocate and fill reuqest buffer. SyncTimeout t(g_executor.active_timers()); t.start(MSEC_TO_NSEC(300)); response_handler.wait_for_response(b->data()->dst, b->data()->payload[0], &t); iface->addressed_message_write_flow()->send(b); t.wait_for_notification(); response_handler.wait_timeout(); // Stops listening. if (response_handler.response()) { // we have a response – use it from response_handler->response() response_handler.response()->unref(); } else { // timeout }

Asynchronous usage:

FlowClass : public StateFlow... {

Action send_request() { auto* b = get_allocation_result(iface->addressed_message_write_flow()); // fill b responseHandler_.wait_for_response(b->data()->dst, b->data()->payload[0], &t_); iface->addressed_message_write_flow()->send(b); return sleep_and_call(&t_, MSEC_TO_NSEC(), STATE(parse_response)); }

Action parse_response() { responseHandler_.wait_timeout(); if (response_handler.response()) { // parse response ... do useful stuff. responseHandler_.response()->unref(); } else { return gone_to_error(); } }

TractionResponseHandler responseHandler_; StateFlowTimer t_; };

Definition at line 95 of file TractionClient.hxx.

Constructor & Destructor Documentation

◆ TractionResponseHandler()

openlcb::TractionResponseHandler::TractionResponseHandler	(	openlcb::If *	iface,
		openlcb::Node *	local_node
	)

inline

Definition at line 98 of file TractionClient.hxx.

Member Function Documentation

◆ entry()

Action openlcb::TractionResponseHandler::entry ( )

inlineprivatevirtual

Entry into the StateFlow activity.

Pure virtual which must be defined by derived class.

Returns: function pointer to next state

@TODO(balazs.racz) factor out this code into a helper function that allows matching an incoming response frame to an expected NodeHandle.

@TODO(balazs.racz) we should start an alias resolution process here.

Implements TypedStateFlow< MessageType, Base >.

Definition at line 154 of file TractionClient.hxx.

◆ response()

Buffer< GenMessage > * openlcb::TractionResponseHandler::response ( )

inline

Caller must unref this buffer when done with it.

Definition at line 121 of file TractionClient.hxx.

◆ start_listening()

void openlcb::TractionResponseHandler::start_listening ( )

inlineprivate

Definition at line 140 of file TractionClient.hxx.

◆ stop_listening()

void openlcb::TractionResponseHandler::stop_listening ( )

inlineprivate

Definition at line 147 of file TractionClient.hxx.

◆ wait_for_response()

void openlcb::TractionResponseHandler::wait_for_response	(	NodeHandle	target_node,
		uint8_t	expected_type,
		::Timer *	trigger
	)

inline

Starts waiting for a traction control reply from a given node with the first byte 'expected_type'.

Will wake up the given timer if a reply arrives.

Definition at line 110 of file TractionClient.hxx.

◆ wait_timeout()

void openlcb::TractionResponseHandler::wait_timeout ( )

inline

Call this if the timeout has expired.

Call only on the service executor. If the caller got notified due to a response, it is still okay to call this. @TODO(balazs.racz) rename to something like wait_done_or_timeout()

Definition at line 130 of file TractionClient.hxx.

Member Data Documentation

◆ expectedDst_

openlcb::Node* openlcb::TractionResponseHandler::expectedDst_

private

Definition at line 213 of file TractionClient.hxx.

◆ expectedSrc_

openlcb::NodeHandle openlcb::TractionResponseHandler::expectedSrc_

private

Definition at line 212 of file TractionClient.hxx.

◆ expectedType_

uint8_t openlcb::TractionResponseHandler::expectedType_

private

Definition at line 215 of file TractionClient.hxx.

◆ response_

Buffer<GenMessage>* openlcb::TractionResponseHandler::response_

private

Definition at line 217 of file TractionClient.hxx.

◆ trigger_

::Timer* openlcb::TractionResponseHandler::trigger_

private

Definition at line 216 of file TractionClient.hxx.

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

TractionClient.hxx

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TractionResponseHandler()

Member Function Documentation

◆ entry()

◆ response()

◆ start_listening()

◆ stop_listening()

◆ wait_for_response()

◆ wait_timeout()

Member Data Documentation

◆ expectedDst_

◆ expectedSrc_

◆ expectedType_

◆ response_

◆ trigger_