From cb71d66001170e8ab716bf41f874e715959d3dfe Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=B4me=20Benoit?= <jerome.benoit@piment-noir.org>
Date: Sat, 2 Dec 2023 21:49:12 +0100
Subject: [PATCH] perf: optimize tasks stealing in corner case
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Signed-off-by: Jérôme Benoit <jerome.benoit@piment-noir.org>
---
 CHANGELOG.md               | 4 ++++
 src/pools/abstract-pool.ts | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a17a4ed5..41e0f411 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Add a fastpath when tasks stealing or redistribution is impossible
+
 ## [3.0.9] - 2023-11-26
 
 ### Fixed
diff --git a/src/pools/abstract-pool.ts b/src/pools/abstract-pool.ts
index 3da4c70f..7ea93796 100644
--- a/src/pools/abstract-pool.ts
+++ b/src/pools/abstract-pool.ts
@@ -1445,6 +1445,9 @@ export abstract class AbstractPool<
   }
 
   private redistributeQueuedTasks (workerNodeKey: number): void {
+    if (this.workerNodes.length <= 1) {
+      return
+    }
     while (this.tasksQueueSize(workerNodeKey) > 0) {
       const destinationWorkerNodeKey = this.workerNodes.reduce(
         (minWorkerNodeKey, workerNode, workerNodeKey, workerNodes) => {
@@ -1538,6 +1541,9 @@ export abstract class AbstractPool<
     eventDetail: WorkerNodeEventDetail,
     previousStolenTask?: Task<Data>
   ): void => {
+    if (this.workerNodes.length <= 1) {
+      return
+    }
     const { workerNodeKey } = eventDetail
     if (workerNodeKey == null) {
       throw new Error(
@@ -1629,6 +1635,9 @@ export abstract class AbstractPool<
   private readonly handleBackPressureEvent = (
     eventDetail: WorkerNodeEventDetail
   ): void => {
+    if (this.workerNodes.length <= 1) {
+      return
+    }
     const { workerId } = eventDetail
     const sizeOffset = 1
     if ((this.opts.tasksQueueOptions?.size as number) <= sizeOffset) {
-- 
2.34.1