ELECTION

Data Structures
struct	rte_election_candidate_t
	One candidate's info for one rte_election_execute() call. The caller builds this array fresh each call from whatever transport it uses to learn about the other replicas - this module does not retain it between calls except via the state recomputed into rte_election_t itself. More...
struct	rte_election_t
	One rte_election_t instance's state. Caller-owned storage; every field is private - reach it only through the functions below. More...
struct	rte_election_config_t
	Configuration for rte_election_init(). More...

Functions
rte_status_t	rte_election_init (rte_election_t *election, const rte_election_config_t *config)
	Initializes a rte_election_t. own_last_state starts at RTE_DUAL_STATE_IDLE (never yet evaluated).
rte_status_t	rte_election_execute (rte_election_t *election, const rte_election_candidate_t *candidates, uint32_t candidate_count)
	Evaluates one round of election against the caller-supplied candidate snapshot (REQ-ELECTION-002 through -005). Empty snapshot (candidate_count == 0, or this instance's own_id not present in it) yields RTE_DUAL_STATE_UNKNOWN - no quorum to decide anything from, same "report, do not react" posture as rte_dual_negotiator_execute() on a lost peer.
rte_dual_state_t	rte_election_get_own_state (const rte_election_t *election)
	Returns this instance's own current rte_dual_state_t, as of the last rte_election_execute() call.
rte_status_t	rte_election_get_winner_id (const rte_election_t *election, uint32_t *out_id)
	Returns the last-elected winner's id.

Detailed Description

Function Documentation

rte_election_init()

rte_status_t rte_election_init	(	rte_election_t *	election,
		const rte_election_config_t *	config )

Initializes a rte_election_t. own_last_state starts at RTE_DUAL_STATE_IDLE (never yet evaluated).

Parameters

election	Caller-owned storage to initialize. Must not be NULL.
config	Configuration. Must not be NULL.

Returns

RTE_STATUS_OK; RTE_STATUS_INVALID_PARAM otherwise.

Local variables declarations Global functions

Definition at line 21 of file rte_election.c.

rte_election_execute()

rte_status_t rte_election_execute	(	rte_election_t *	election,
		const rte_election_candidate_t *	candidates,
		uint32_t	candidate_count )

Evaluates one round of election against the caller-supplied candidate snapshot (REQ-ELECTION-002 through -005). Empty snapshot (candidate_count == 0, or this instance's own_id not present in it) yields RTE_DUAL_STATE_UNKNOWN - no quorum to decide anything from, same "report, do not react" posture as rte_dual_negotiator_execute() on a lost peer.

Parameters

election	Initialized election. Must not be NULL.
candidates	This round's snapshot. May be NULL only if candidate_count is 0.
candidate_count	Number of entries in candidates; must not exceed RTE_REDUNDANCY_CONFIG_MAX_REPLICAS (RTE_STATUS_INVALID_PARAM if it does - a caller-side bug, not a runtime condition to degrade gracefully from).

Returns

RTE_STATUS_OK; RTE_STATUS_INVALID_PARAM for a NULL election, an over-long candidate_count, or a NULL candidates with a nonzero candidate_count.

Definition at line 36 of file rte_election.c.

rte_election_get_own_state()

rte_dual_state_t rte_election_get_own_state

(

const rte_election_t *

election

)

Returns this instance's own current rte_dual_state_t, as of the last rte_election_execute() call.

Parameters

election

Election to query. May be NULL (returns RTE_DUAL_STATE_IDLE, defensive default).

Returns

The current own state.

Definition at line 83 of file rte_election.c.

rte_election_get_winner_id()

rte_status_t rte_election_get_winner_id	(	const rte_election_t *	election,
		uint32_t *	out_id )

Returns the last-elected winner's id.

Parameters

election	Election to query. May be NULL.
out_id	Receives the winner's id. Must not be NULL.

Returns

RTE_STATUS_OK; RTE_STATUS_NOT_INITIALIZED if no round has ever produced a winner yet (e.g. every rte_election_execute() call so far had an empty/self-absent snapshot); RTE_STATUS_INVALID_PARAM if election or out_id is NULL.

Definition at line 92 of file rte_election.c.