Node.js freezes on stdin buffer larger than 163840 bytes

[zanona]

Hey guys, I have been experiencing a very odd issue where node is simply freezing whenever calling cmd.stdin.end() with data larger than 163840 bytes.
Perhaps this can be related to #1774, however I decided it's best to open a new issue, since it may as well be a different thing.

The code below works fine on OSX and Linux, but surprisingly fails on WSL runnnig Ubuntu.

const spawn = require('child_process').spawn;
const cmd = spawn('wc', ['-c']);
const stdin = Buffer.alloc(163841); // works when using 163840
cmd.stdout.pipe(process.stdout);
cmd.stdin.write(stdin);
cmd.stdin.end();

I also noticed that when piping a large stdin directly with process.stdin.pipe(cmd.stdin) the problem didn't occurr at all, however, whenever manipulating stdin like the above, will cause this unexpected behaviour.

specs

• Windows 10 - 1803 (build 17686.1003)
• Ubuntu 16.04 LTS (build 20180510.1)
• Same behaviour on Debian 9
• Node.js 10.4.1

[therealkenc]

You deleted the template. strace -f -o yourthing.strace node yourthing.js. Please link a gist.

[therealkenc]

nvm. Spins on epoll_wait(). This is a tight repro of #3191

[zanona]

Fixed on build 17704 as per #3191 (comment)

Thanks, so much!