process: use more direct sync I/O for stdio

This avoids routing writes through the full LibuvStreamWrap
write machinery. In particular, it enables the next commit,
because otherwise the callback passed to `_write()`
would not be called synchronously for pipes on Windows
(because the latter does not support `uv_try_write()`,
even for blocking I/O).

PR-URL: https://github.com/nodejs/node/pull/18019
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/tty.js b/lib/tty.js
index 2a62fcb859..28f2a41184 100644
--- a/lib/tty.js
+++ b/lib/tty.js
@@ -24,6 +24,7 @@
 const util = require('util');
 const net = require('net');
 const { TTY, isTTY } = process.binding('tty_wrap');
+const { makeSyncWrite } = require('internal/net');
 const { inherits } = util;
 const errnoException = util._errnoException;
 const errors = require('internal/errors');
@@ -91,6 +92,8 @@ function WriteStream(fd) {
   // even though it was originally intended to change in v1.0.2 (Libuv 1.2.1).
   // Ref: https://github.com/nodejs/node/pull/1771#issuecomment-119351671
   this._handle.setBlocking(true);
+  this._writev = null;
+  this._write = makeSyncWrite(fd);
 
   var winSize = new Array(2);
   var err = this._handle.getWindowSize(winSize);