fix(presence-sync): tick mutex so setInterval overlap can't spawn parallel ticks

The presence-sync tick iterates accounts serially with await on each
agent-login + PUT round-trip — a single tick can easily run 20+s when
there are several accounts. setInterval(intervalMs) does NOT wait for
the previous tick to finish, so on a busy gateway the next tick fires
on top of a still-running one and two parallel iterations each PUT
the same agentId within ~10 ms. That tipped the guild backend's
first-time-insert race (separate fix in nav/Fabric.Backend.Guild) into
500s on prod (caught in t2 gateway 2026-05-25 23:23:35Z; 6 of 6 agents
showed paired log lines 4-10 ms apart for the same agent → idle).

Fix: a simple `inflight` boolean. tick() returns immediately if
already running; the next interval beat catches up. lastStatus !==
bridge.get gating already means status changes catch the next tick
anyway, so skipping a beat costs nothing the next beat won't fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
h z
2026-05-26 02:25:08 +01:00
parent 79b29db26c
commit 9419d270e5
2 changed files with 48 additions and 0 deletions

View File

@@ -8,6 +8,15 @@ export class PresenceSync {
lastStatus = new Map(); // by agentId
accounts = new Map();
tokenCache = new Map(); // by agentId
// Mutex flag: a tick iterates accounts serially with `await` on each
// agent-login + PUT round-trip, so a single tick can easily run 20+s
// when there are many accounts. setInterval(intervalMs) does NOT wait
// for the previous tick to finish — without this guard the next tick
// fires on top of a still-running one and two parallel iterations
// PUT the same agentId within milliseconds. That tipped the backend's
// first-time-insert race (separate fix in Fabric.Backend.Guild) into
// 500s on prod. Guarded ticks just skip a beat instead.
inflight = false;
constructor(logger, client) {
this.logger = logger;
this.client = client;
@@ -60,6 +69,21 @@ export class PresenceSync {
return entry.token;
}
async tick() {
// Mutex: see the `inflight` field declaration for the why. Drop
// overlapping ticks rather than letting them run concurrently —
// status is gated by `lastStatus !== bridge.get`, so skipping a
// beat costs nothing the next beat won't catch.
if (this.inflight)
return;
this.inflight = true;
try {
await this.tickInner();
}
finally {
this.inflight = false;
}
}
async tickInner() {
const bridge = globalThis['__hfAgentStatus'];
if (!bridge || typeof bridge.get !== 'function')
return; // HF plugin not loaded — skip