lib: changed functional logic in cluster schedulers

Free pool in round_robin scheduler is implemented as an array. There
were constant lookups being for distributing load on other workers in
free pool. Reimplementing in Map will create will be more performant as
compared to Array implementation. This was done for all in past but free
wasn't implemented at that time.

PR-URL: #32505
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

lib/internal/cluster/round_robin_handle.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const {
+  ArrayIsArray,
   Boolean,
   Map,
 } = primordials;
@@ -15,7 +16,7 @@ module.exports = RoundRobinHandle;
 function RoundRobinHandle(key, address, port, addressType, fd, flags) {
   this.key = key;
   this.all = new Map();
-  this.free = [];
+  this.free = new Map();
   this.handles = [];
   this.handle = null;
   this.server = net.createServer(assert.fail);
@@ -73,10 +74,7 @@ RoundRobinHandle.prototype.remove = function(worker) {
   if (!existed)
     return false;
 
-  const index = this.free.indexOf(worker);
-
-  if (index !== -1)
-    this.free.splice(index, 1);
+  this.free.delete(worker.id);
 
   if (this.all.size !== 0)
     return false;
@@ -93,21 +91,24 @@ RoundRobinHandle.prototype.remove = function(worker) {
 
 RoundRobinHandle.prototype.distribute = function(err, handle) {
   this.handles.push(handle);
-  const worker = this.free.shift();
+  const [ workerEntry ] = this.free;
 
-  if (worker)
+  if (ArrayIsArray(workerEntry)) {
+    const [ workerId, worker ] = workerEntry;
+    this.free.delete(workerId);
     this.handoff(worker);
+  }
 };
 
 RoundRobinHandle.prototype.handoff = function(worker) {
-  if (this.all.has(worker.id) === false) {
+  if (!this.all.has(worker.id)) {
     return;  // Worker is closing (or has closed) the server.
   }
 
   const handle = this.handles.shift();
 
   if (handle === undefined) {
-    this.free.push(worker);  // Add to ready queue again.
+    this.free.set(worker.id, worker);  // Add to ready queue again.
     return;
   }
 

lib/internal/cluster/shared_handle.js

@@ -1,4 +1,5 @@
 'use strict';
+const { Map } = primordials;
 const assert = require('internal/assert');
 const dgram = require('internal/dgram');
 const net = require('net');
@@ -7,7 +8,7 @@ module.exports = SharedHandle;
 
 function SharedHandle(key, address, port, addressType, fd, flags) {
   this.key = key;
-  this.workers = [];
+  this.workers = new Map();
   this.handle = null;
   this.errno = 0;
 
@@ -24,20 +25,18 @@ function SharedHandle(key, address, port, addressType, fd, flags) {
 }
 
 SharedHandle.prototype.add = function(worker, send) {
-  assert(!this.workers.includes(worker));
-  this.workers.push(worker);
+  assert(!this.workers.has(worker.id));
+  this.workers.set(worker.id, worker);
   send(this.errno, null, this.handle);
 };
 
 SharedHandle.prototype.remove = function(worker) {
-  const index = this.workers.indexOf(worker);
-
-  if (index === -1)
-    return false; // The worker wasn't sharing this handle.
+  if (!this.workers.has(worker.id))
+    return false;
 
-  this.workers.splice(index, 1);
+  this.workers.delete(worker.id);
 
-  if (this.workers.length !== 0)
+  if (this.workers.size !== 0)
     return false;
 
   this.handle.close();