From a304206ae63dea1c2fb74814df372ad9f890cf68 Mon Sep 17 00:00:00 2001
From: Rich Trott <rtrott@gmail.com>
Date: Sun, 10 Dec 2017 18:47:48 -0800
Subject: [PATCH] test: fix flaky test-child-process-pass-fd

test-child-process-pass-fd needs to launch many processes
simultaneously. On Fedora 24, this can result in EAGAIN "Resource
temporarily unavailable" errors. When this occurs, simply try to launch
a worker again.

PR-URL: https://github.com/nodejs/node/pull/17598
Fixes: https://github.com/nodejs/node/issues/17589
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
---
 test/sequential/test-child-process-pass-fd.js | 48 ++++++++++++-------
 1 file changed, 32 insertions(+), 16 deletions(-)

diff --git a/test/sequential/test-child-process-pass-fd.js b/test/sequential/test-child-process-pass-fd.js
index 73e469cdede2be..98832c57a3df67 100644
--- a/test/sequential/test-child-process-pass-fd.js
+++ b/test/sequential/test-child-process-pass-fd.js
@@ -18,26 +18,42 @@ const { fork } = require('child_process');
 const net = require('net');
 
 const N = 80;
+let messageCallbackCount = 0;
 
-if (process.argv[2] !== 'child') {
-  for (let i = 0; i < N; ++i) {
-    const worker = fork(__filename, ['child']);
-    worker.once('message', common.mustCall((msg, handle) => {
-      assert.strictEqual(msg, 'handle');
-      assert.ok(handle);
-      worker.send('got');
-
-      let recvData = '';
-      handle.on('data', common.mustCall((data) => {
-        recvData += data;
-      }));
+function forkWorker() {
+  const messageCallback = (msg, handle) => {
+    messageCallbackCount++;
+    assert.strictEqual(msg, 'handle');
+    assert.ok(handle);
+    worker.send('got');
 
-      handle.on('end', () => {
-        assert.strictEqual(recvData, 'hello');
-        worker.kill();
-      });
+    let recvData = '';
+    handle.on('data', common.mustCall((data) => {
+      recvData += data;
     }));
+
+    handle.on('end', () => {
+      assert.strictEqual(recvData, 'hello');
+      worker.kill();
+    });
+  };
+
+  const worker = fork(__filename, ['child']);
+  worker.on('error', (err) => {
+    if (/\bEAGAIN\b/.test(err.message)) {
+      forkWorker();
+      return;
+    }
+    throw err;
+  });
+  worker.once('message', messageCallback);
+}
+
+if (process.argv[2] !== 'child') {
+  for (let i = 0; i < N; ++i) {
+    forkWorker();
   }
+  process.on('exit', () => { assert.strictEqual(messageCallbackCount, N); });
 } else {
   let socket;
   let cbcalls = 0;