Anti-Starvation Promotion

Last updated 2026-10-02

This page explains how go-queue lifts long-waiting Low and Normal tasks so a steady stream of urgent work cannot starve them.

Promotion Rules

Each time a worker calls Pop, promoteLocked scans the whole heap and lifts long-waiting tasks one level (core/pending.go:111).

From	To	Wait Threshold
`PriorityLow`	`PriorityNormal`	`clamp(Config.Timeout, 30s, 120s)`
`PriorityNormal`	`PriorityHigh`	`clamp(Config.Timeout × 2, 30s, 120s)`

With the default Config.Timeout = 30s, a Low task becomes Normal after 30s, and a Normal task becomes High after 60s.

Wait time counts from startAt, which resets on retry
Immediate, High, and Retry never promote
Thresholds read only Config.Timeout, never a preset's Timeout
Promotion only runs on Pop, so no promotion checks happen while every worker is busy
Promotion changes the order only; the timeout fixed at Enqueue stays the same
Each promotion emits a Debug-level task.promoted event, see Log Events