ab_gp_util_link_gate.h File Reference

Open gate of the UTIL relay link (ab-relay-util, ISS-020): bounds how often the A/B cycle thread may try the link's first open while the status service (rte_gateway_c_status) is unreachable. More...

#include <stdbool.h>
#include <stdint.h>
#include "rte/utils/status/rte_status.h"
#include "rte/utils/types/rte_types.h"

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Data Structures
struct	ab_gp_util_link_gate_t
	Gate state; all-zero (or ab_gp_util_link_gate_init()) allows the first attempt at once. More...

Functions
void	ab_gp_util_link_gate_init (ab_gp_util_link_gate_t *gate)
	Resets the gate: never opened, first attempt allowed at any time.
bool	ab_gp_util_link_gate_is_open (const ab_gp_util_link_gate_t *gate)
	Whether an open attempt has succeeded (the link is open for good).
bool	ab_gp_util_link_gate_may_attempt (const ab_gp_util_link_gate_t *gate, rte_timestamp_ms_t now_ms)
	Whether a send (and with it, before the first success, an open attempt) may run now.
void	ab_gp_util_link_gate_on_attempt (ab_gp_util_link_gate_t *gate, rte_timestamp_ms_t now_ms)
	Records that an open attempt starts now (call right before the send that triggers the open).
void	ab_gp_util_link_gate_on_result (ab_gp_util_link_gate_t *gate, rte_status_t status, rte_timestamp_ms_t now_ms)
	Feeds back the result of a send that ran under the gate.

Detailed Description

Open gate of the UTIL relay link (ab-relay-util, ISS-020): bounds how often the A/B cycle thread may try the link's first open while the status service (rte_gateway_c_status) is unreachable.

The UTIL link is opened lazily by Platform_RTE's flow channel service on the first send or read, and each attempt blocks the caller until the peer answers the handshake or the timeout runs out. Its traffic is non-safety (status publish, JRU/diagnostic log forwarding, ADR-001 section 4) and runs on the cycle thread, so an absent status service used to cost one blocking open per INFO log event and per cycle (freedom-from-interference defect ISS-020). This gate allows one attempt, then none until RTE_EXAMPLE_UTIL_REOPEN_BACKOFF_MS has passed since the last failure. Once an open succeeded the link stays open (the flow channel service never closes it again) and the gate always allows.

Pure: no I/O, time is passed in (rte_timer_now() at the call site). The caller owns the instance.

Definition in file ab_gp_util_link_gate.h.

Function Documentation

ab_gp_util_link_gate_init()

void ab_gp_util_link_gate_init

(

ab_gp_util_link_gate_t *

gate

)

Resets the gate: never opened, first attempt allowed at any time.

Parameters

gate	gate to reset; ignored when NULL

Definition at line 9 of file ab_gp_util_link_gate.c.

ab_gp_util_link_gate_is_open()

bool ab_gp_util_link_gate_is_open

(

const ab_gp_util_link_gate_t *

gate

)

Whether an open attempt has succeeded (the link is open for good).

Parameters

gate	gate to query

Returns

true once ab_gp_util_link_gate_on_result() saw RTE_STATUS_OK; false before that or when gate is NULL

Definition at line 18 of file ab_gp_util_link_gate.c.

ab_gp_util_link_gate_may_attempt()

bool ab_gp_util_link_gate_may_attempt	(	const ab_gp_util_link_gate_t *	gate,
		rte_timestamp_ms_t	now_ms )

Whether a send (and with it, before the first success, an open attempt) may run now.

Parameters

gate	gate to query
now_ms	current monotonic time

Returns

true when the link is open, or when now_ms has reached the next allowed attempt time; false otherwise and when gate is NULL

Definition at line 29 of file ab_gp_util_link_gate.c.

ab_gp_util_link_gate_on_attempt()

void ab_gp_util_link_gate_on_attempt	(	ab_gp_util_link_gate_t *	gate,
		rte_timestamp_ms_t	now_ms )

Records that an open attempt starts now (call right before the send that triggers the open).

Before the first success this reserves the back-off interval at once, so a nested call during the attempt (the open itself logs INFO lines, which the JRU forwarder republishes over this same link) is refused instead of starting a second attempt. No effect once the link is open.

Parameters

gate	gate to update; ignored when NULL
now_ms	current monotonic time

Definition at line 40 of file ab_gp_util_link_gate.c.

ab_gp_util_link_gate_on_result()

void ab_gp_util_link_gate_on_result	(	ab_gp_util_link_gate_t *	gate,
		rte_status_t	status,
		rte_timestamp_ms_t	now_ms )

Feeds back the result of a send that ran under the gate.

RTE_STATUS_OK marks the link open for good. Any other status before the first success refuses further attempts until now_ms + RTE_EXAMPLE_UTIL_REOPEN_BACKOFF_MS. A failure after the first success changes nothing (the link stays open in the channel service and a send on it does not block).

Parameters

gate	gate to update; ignored when NULL
status	result of the send
now_ms	current monotonic time (after the attempt)

Definition at line 48 of file ab_gp_util_link_gate.c.