http: avoid retaining unneeded memory

Prevent the events listeners of the sockets obtained with the HTTP
upgrade mechanism from retaining unneeded memory.

Ref: https://github.com/nodejs/node/issues/11868
PR-URL: https://github.com/nodejs/node/pull/11926
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/internal/http.js b/lib/internal/http.js
index 1ba68a41a5..0b12bc7c8f 100644
--- a/lib/internal/http.js
+++ b/lib/internal/http.js
@@ -1,5 +1,10 @@
 'use strict';
 
+function ondrain() {
+  if (this._httpMessage) this._httpMessage.emit('drain');
+}
+
 module.exports = {
-  outHeadersKey: Symbol('outHeadersKey')
+  outHeadersKey: Symbol('outHeadersKey'),
+  ondrain,
 };