From a40e7daf3ceca3cddc208c1c82222f52762f4650 Mon Sep 17 00:00:00 2001
From: Harshitha KP <harshi46@in.ibm.com>
Date: Wed, 11 Mar 2020 01:41:54 -0400
Subject: [PATCH] test: harden the tick sampling logic

Under peculiar system load conditions, the profiler thread
does not get enough CPU slices to perform the sampling.
Improve the interaction between worker and parent thread
by performing a large disc read, which is a better blend of
CPU and I/O bound work, than earlier versions.
This produces x10 more samples than the existing one,
in 10 iterations, as opposed to 1024.

Also capture worker error situations to improve debugging

Refs: https://github.com/nodejs/node/issues/26401#issuecomment-597438516

PR-URL: https://github.com/nodejs/node/pull/32190
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 test/sequential/test-worker-prof.js | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/test/sequential/test-worker-prof.js b/test/sequential/test-worker-prof.js
index 80596a76f94f66..f89ff962ff785d 100644
--- a/test/sequential/test-worker-prof.js
+++ b/test/sequential/test-worker-prof.js
@@ -11,6 +11,7 @@ const { spawnSync } = require('child_process');
 // Refs: https://github.com/nodejs/node/issues/24016
 
 if (process.argv[2] === 'child') {
+  const fs = require('fs');
   let files = fs.readdirSync(tmpdir.path);
   const plog = files.filter((name) => /\.log$/.test(name))[0];
   if (plog === undefined) {
@@ -19,20 +20,20 @@ if (process.argv[2] === 'child') {
   }
   const pingpong = `
   let counter = 0;
+  const fs = require('fs');
   const { Worker, parentPort  } = require('worker_threads');
   parentPort.on('message', (m) => {
-    if (counter++ === 1024)
+    if (counter++ === 10)
       process.exit(0);
      parentPort.postMessage(
-       m.toString().split('').reverse().toString().replace(/,/g, ''));
+       fs.readFileSync(m.toString()).slice(0, 1024 * 1024));
   });
   `;
 
   const { Worker } = require('worker_threads');
-  const data = 'x'.repeat(1024);
   const w = new Worker(pingpong, { eval: true });
   w.on('message', (m) => {
-    w.postMessage(m.toString().split('').reverse().toString().replace(/,/g, ''));
+    w.postMessage(process.execPath);
   });
 
   w.on('exit', common.mustCall(() => {
@@ -45,7 +46,7 @@ if (process.argv[2] === 'child') {
     }
     process.exit(0);
   }));
-  w.postMessage(data);
+  w.postMessage(process.execPath);
 } else {
   tmpdir.refresh();
   const spawnResult = spawnSync(