This state flow is responsible for reserving node ID aliases. More...

#include <AliasAllocator.hxx>

Inheritance diagram for openlcb::AliasAllocator:

Classes
class	ConflictHandler
	Listens to incoming CAN frames and handles alias conflicts. More...

Public Member Functions
	AliasAllocator (NodeID if_id, IfCan *if_can)
	Constructs a new AliasAllocator flow.

virtual	~AliasAllocator ()
	Destructor.

NodeID	if_node_id ()

void	reinit_seed ()
	Resets the alias allocator to the state it was at construction.

NodeAlias	get_new_seed ()
	Returns a new alias to check from the random sequence.

NodeAlias	get_allocated_alias (NodeID destination_id, Executable *done)
	Allocates an alias from the reserved but unused aliases list.

unsigned	num_reserved_aliases ()

void	clear_reserved_aliases ()
	Removes all aliases that are reserved but not yet used.

void	return_alias (NodeID id, NodeAlias alias)
	Releases a given alias.

void	add_allocated_alias (NodeAlias alias)
	Call from an alternate alias allocator.

Public Member Functions inherited from StateFlow< Buffer< AliasInfo >, QList< 1 > >
	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
AliasInfo *	pending_alias ()

Action	entry () override
	Entry into the StateFlow activity.

Action	handle_allocate_for_cid_frame ()

Action	send_cid_frame ()

Action	wait_done ()

Action	send_rid_frame ()

Action	handle_alias_conflict ()

void	next_seed ()
	Generates the next alias to check in the seed_ variable.

IfCan *	if_can ()
	Physical interface for sending packets and assigning handlers to received packets.

Private Attributes
openlcb::AliasAllocator::ConflictHandler	conflictHandler_

StateFlowTimer	timer_

Q	waitingClients_
	Set of client flows that are waiting for allocating an alias.

NodeID	if_id_
	48-bit nodeID that we will use for alias reservations.

unsigned	cid_frame_sequence_: 3
	Which CID frame are we trying to send out. Valid values: 7..4.

unsigned	conflict_detected_: 1
	Set to 1 if an incoming frame signals an alias conflict.

unsigned	seed_: 12
	Seed for generating random-looking alias numbers.

unsigned	reserveUnusedAliases_: 8
	How many unused aliases we should reserve.

BarrierNotifiable	n_
	Notifiable used for tracking outgoing frames.

Friends
class	ConflictHandler

class	AsyncAliasAllocatorTest

class	AsyncIfTest

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 state flow is responsible for reserving node ID aliases.

For every incoming Buffer<AliasInfo> it will run through the standard-compliant flow of reserving an alias, and then push the alias into the queue of reserved aliases.

Users who need an allocated alias should get it from the queue in reserved_aliases().

Definition at line 95 of file AliasAllocator.hxx.

Constructor & Destructor Documentation

◆ AliasAllocator()

openlcb::AliasAllocator::AliasAllocator	(	NodeID	if_id,
		IfCan *	if_can
	)

Constructs a new AliasAllocator flow.

Parameters

if_id	is a 48-bit NMRAnet NodeID. This node id will be used for reserving all aliases. This NodeID must be unique to the hardware on the bus; it will typically be the same as the NodeID of some virtual node that the current application will be creating.
if_can	is the interface to which this alias allocator should talk to.

Definition at line 44 of file AliasAllocator.cxx.

◆ ~AliasAllocator()

openlcb::AliasAllocator::~AliasAllocator ( )

virtual

Destructor.

Definition at line 202 of file AliasAllocator.cxx.

Member Function Documentation

◆ add_allocated_alias()

void openlcb::AliasAllocator::add_allocated_alias ( NodeAlias alias )

Call from an alternate alias allocator.

Marks that alias is reserved for the local interface (RID frame is just sent out). Adds the alias to the local alias cache and wakes up a flow that might be waiting for an alias.

Parameters

alias a reserved node alias.

Definition at line 141 of file AliasAllocator.cxx.

◆ clear_reserved_aliases()

void openlcb::AliasAllocator::clear_reserved_aliases ( )

Removes all aliases that are reserved but not yet used.

Definition at line 106 of file AliasAllocator.cxx.

◆ entry()

StateFlowBase::Action openlcb::AliasAllocator::entry ( )

overrideprivatevirtual

Entry into the StateFlow activity.

Pure virtual which must be defined by derived class.

Returns: function pointer to next state

Implements TypedStateFlow< MessageType, Base >.

Definition at line 206 of file AliasAllocator.cxx.

◆ get_allocated_alias()

NodeAlias openlcb::AliasAllocator::get_allocated_alias	(	NodeID	destination_id,
		Executable *	done
	)

Allocates an alias from the reserved but unused aliases list.

If there is a free alias there, that alias will be reassigned to destination_id in the local alias cache, and done will never be notified. If there is no free alias, then a new alias will be allocated, and done will be notified when the allocation is complete. Then the call has to be re-tried by the destination flow.

Parameters

destination_id	if there is a free alias right now, it will be assigned to this Node ID in the local alias cache.
done	if an async allocation is necessary, this will be notified after a new alias has been received.

Returns: the alias if the it was allocated inline, or 0 if there will be an asynchronous notification coming later.

Definition at line 159 of file AliasAllocator.cxx.

◆ get_new_seed()

NodeAlias openlcb::AliasAllocator::get_new_seed ( )

Returns a new alias to check from the random sequence.

Checks that it is not in the alias cache yet.

Definition at line 224 of file AliasAllocator.cxx.

◆ handle_alias_conflict()

StateFlowBase::Action openlcb::AliasAllocator::handle_alias_conflict ( )

private

Definition at line 301 of file AliasAllocator.cxx.

◆ handle_allocate_for_cid_frame()

StateFlowBase::Action openlcb::AliasAllocator::handle_allocate_for_cid_frame ( )

private

Definition at line 267 of file AliasAllocator.cxx.

◆ if_can()

IfCan * openlcb::AliasAllocator::if_can ( )

inlineprivate

Physical interface for sending packets and assigning handlers to received packets.

Definition at line 223 of file AliasAllocator.hxx.

◆ if_node_id()

NodeID openlcb::AliasAllocator::if_node_id ( )

inline

Returns: the Node ID for the interface.

Definition at line 115 of file AliasAllocator.hxx.

◆ next_seed()

void openlcb::AliasAllocator::next_seed ( )

private

Generates the next alias to check in the seed_ variable.

Definition at line 249 of file AliasAllocator.cxx.

◆ num_reserved_aliases()

unsigned openlcb::AliasAllocator::num_reserved_aliases ( )

Returns: the number of aliases that are reserved and available for new virtual nodes to use.

Definition at line 84 of file AliasAllocator.cxx.

◆ pending_alias()

AliasInfo * openlcb::AliasAllocator::pending_alias ( )

inlineprivate

Definition at line 194 of file AliasAllocator.hxx.

◆ reinit_seed()

void openlcb::AliasAllocator::reinit_seed ( )

Resets the alias allocator to the state it was at construction.

useful after connection restart in order to ensure it will try to allocate the same alias.

Definition at line 58 of file AliasAllocator.cxx.

◆ return_alias()

void openlcb::AliasAllocator::return_alias	(	NodeID	id,
		NodeAlias	alias
	)

Releases a given alias.

Sends out an AMR frame and puts the alias into the reserved aliases queue.

Definition at line 126 of file AliasAllocator.cxx.

◆ send_cid_frame()

StateFlowBase::Action openlcb::AliasAllocator::send_cid_frame ( )

private

Definition at line 281 of file AliasAllocator.cxx.

◆ send_rid_frame()

StateFlowBase::Action openlcb::AliasAllocator::send_rid_frame ( )

private

Definition at line 325 of file AliasAllocator.cxx.

◆ wait_done()

StateFlowBase::Action openlcb::AliasAllocator::wait_done ( )

private

Definition at line 314 of file AliasAllocator.cxx.

Friends And Related Symbol Documentation

◆ AsyncAliasAllocatorTest

friend class AsyncAliasAllocatorTest

friend

Definition at line 210 of file AliasAllocator.hxx.

◆ AsyncIfTest

friend class AsyncIfTest

friend

Definition at line 211 of file AliasAllocator.hxx.

◆ ConflictHandler

friend class ConflictHandler

friend

Definition at line 192 of file AliasAllocator.hxx.

Member Data Documentation

◆ cid_frame_sequence_

unsigned openlcb::AliasAllocator::cid_frame_sequence_

private

Which CID frame are we trying to send out. Valid values: 7..4.

Definition at line 229 of file AliasAllocator.hxx.

◆ conflict_detected_

unsigned openlcb::AliasAllocator::conflict_detected_

private

Set to 1 if an incoming frame signals an alias conflict.

Definition at line 231 of file AliasAllocator.hxx.

◆ if_id_

NodeID openlcb::AliasAllocator::if_id_

private

48-bit nodeID that we will use for alias reservations.

Definition at line 219 of file AliasAllocator.hxx.

◆ n_

BarrierNotifiable openlcb::AliasAllocator::n_

private

Notifiable used for tracking outgoing frames.

Definition at line 241 of file AliasAllocator.hxx.

◆ reserveUnusedAliases_

unsigned openlcb::AliasAllocator::reserveUnusedAliases_

private

How many unused aliases we should reserve.

Currently we only support 0 or 1 as value.

Definition at line 238 of file AliasAllocator.hxx.

◆ seed_

unsigned openlcb::AliasAllocator::seed_

private

Seed for generating random-looking alias numbers.

Definition at line 234 of file AliasAllocator.hxx.

◆ timer_

StateFlowTimer openlcb::AliasAllocator::timer_

private

Definition at line 213 of file AliasAllocator.hxx.

◆ waitingClients_

Q openlcb::AliasAllocator::waitingClients_

private

Set of client flows that are waiting for allocating an alias.

Definition at line 216 of file AliasAllocator.hxx.

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

Classes

Public Member Functions

Private Member Functions

Private Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ AliasAllocator()

◆ ~AliasAllocator()

Member Function Documentation

◆ add_allocated_alias()

◆ clear_reserved_aliases()

◆ entry()

◆ get_allocated_alias()

◆ get_new_seed()

◆ handle_alias_conflict()

◆ handle_allocate_for_cid_frame()

◆ if_can()

◆ if_node_id()

◆ next_seed()

◆ num_reserved_aliases()

◆ pending_alias()

◆ reinit_seed()

◆ return_alias()

◆ send_cid_frame()

◆ send_rid_frame()

◆ wait_done()

Friends And Related Symbol Documentation

◆ AsyncAliasAllocatorTest

◆ AsyncIfTest

◆ ConflictHandler

Member Data Documentation

◆ cid_frame_sequence_

◆ conflict_detected_

◆ if_id_

◆ n_

◆ reserveUnusedAliases_

◆ seed_

◆ timer_

◆ waitingClients_