ab_gp_sibling_state.h File Reference

The A/B sibling's last site-state frame (PEER_MSG_KIND_SITE_STATE), kept raw and handed to Platform_RTE's rte_site_role through its sibling source (REQ-SITEROLE-016, ADR-040 step 5b). Pure, no I/O (the ab_gp_standby_policy pattern): the peer-link readers store the frame, the service takes it. More...

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include "rte/redundancy/site_role/rte_site_role.h"
#include "../../common/common_config.h"

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Data Structures
struct	ab_gp_sibling_state_t

Functions
void	ab_gp_sibling_state_reset (ab_gp_sibling_state_t *st)
	Resets the state to "no frame seen" (all zero).
bool	ab_gp_sibling_state_store (ab_gp_sibling_state_t *st, const uint8_t *payload, size_t size)
	Stores a received site-state frame payload: the rule of on_peer_frame_received() (the payload must carry at least the whole frame). A later store before a take replaces the earlier bytes.
bool	ab_gp_sibling_state_take (ab_gp_sibling_state_t *st, rte_site_role_sibling_t *out)
	The rte_site_role_sibling_source_fn contract: hands out the frame stored since the previous take.

Detailed Description

The A/B sibling's last site-state frame (PEER_MSG_KIND_SITE_STATE), kept raw and handed to Platform_RTE's rte_site_role through its sibling source (REQ-SITEROLE-016, ADR-040 step 5b). Pure, no I/O (the ab_gp_standby_policy pattern): the peer-link readers store the frame, the service takes it.

GP no longer decodes the frame itself: rte_site_role polls ab_gp_sibling_state_take() once per rte_site_role_execute(), derives the sibling's online / ready / reachable facts and runs the A/B agreement check (REQ-SITEROLE-014); GP only reacts to the verdict (ab_gp_channel_crosscompare_check_site_state()). The frame is not stamped with a cycle here: the service stamps the cycle of the poll that delivered it, so a frame read on the checkpoint path (poll_for_checkpoint_frame()) counts for reachability like one read by the per-cycle peer pump.

Wire layout (RTE_EXAMPLE_AB_SITE_STATE_WIRE_SIZE bytes): is_online(1) | single_mode(1) | ready_for_online(1).

Definition in file ab_gp_sibling_state.h.

Function Documentation

ab_gp_sibling_state_reset()

void ab_gp_sibling_state_reset

(

ab_gp_sibling_state_t *

st

)

Resets the state to "no frame seen" (all zero).

Parameters

st	the state; NULL is ignored

Definition at line 7 of file ab_gp_sibling_state.c.

ab_gp_sibling_state_store()

bool ab_gp_sibling_state_store	(	ab_gp_sibling_state_t *	st,
		const uint8_t *	payload,
		size_t	size )

Stores a received site-state frame payload: the rule of on_peer_frame_received() (the payload must carry at least the whole frame). A later store before a take replaces the earlier bytes.

Parameters

st	the state
payload	the frame payload (the bytes after the message kind)
size	number of bytes available in payload

Returns

true when size is at least RTE_EXAMPLE_AB_SITE_STATE_WIRE_SIZE and the first RTE_EXAMPLE_AB_SITE_STATE_WIRE_SIZE bytes were copied (known and fresh set); false otherwise (NULL argument or a short payload: the state is left unchanged)

Definition at line 22 of file ab_gp_sibling_state.c.

ab_gp_sibling_state_take()

bool ab_gp_sibling_state_take	(	ab_gp_sibling_state_t *	st,
		rte_site_role_sibling_t *	out )

The rte_site_role_sibling_source_fn contract: hands out the frame stored since the previous take.

Parameters

st	the state
out	receives known = true, online = (byte 0 != 0), single_mode = (byte 1 == RTE_EXAMPLE_SINGLE_MODE_FLAG_SINGLE), ready = (byte 2 != 0) when the result is true; left untouched otherwise

Returns

true when a fresh frame was handed out (fresh is cleared, known stays); false when nothing fresh is held or an argument is NULL

Definition at line 41 of file ab_gp_sibling_state.c.