net: set default highwatermark at socket creation time

Author: lukiano

lib/net.js

@@ -156,7 +156,6 @@ const {
   startPerf,
   stopPerf,
 } = require('internal/perf/observe');
-const { getDefaultHighWaterMark } = require('internal/streams/state');
 
 function getFlags(ipv6Only) {
   return ipv6Only === true ? TCPConstants.UV_TCP_IPV6ONLY : 0;
@@ -1735,11 +1734,8 @@ function Server(options, connectionListener) {
   if (typeof options.highWaterMark !== 'undefined') {
     validateNumber(
       options.highWaterMark, 'options.highWaterMark',
+      0,
     );
-
-    if (options.highWaterMark < 0) {
-      options.highWaterMark = getDefaultHighWaterMark();
-    }
   }
 
   this._connections = 0;
@@ -1755,7 +1751,7 @@ function Server(options, connectionListener) {
   this.noDelay = Boolean(options.noDelay);
   this.keepAlive = Boolean(options.keepAlive);
   this.keepAliveInitialDelay = ~~(options.keepAliveInitialDelay / 1000);
-  this.highWaterMark = options.highWaterMark ?? getDefaultHighWaterMark();
+  this.highWaterMark = options.highWaterMark;
 }
 ObjectSetPrototypeOf(Server.prototype, EventEmitter.prototype);
 ObjectSetPrototypeOf(Server, EventEmitter);

test/parallel/test-http-server-options-highwatermark.js

@@ -5,7 +5,7 @@ const assert = require('assert');
 const http = require('http');
 const { kHighWaterMark } = require('_http_outgoing');
 
-const { getDefaultHighWaterMark } = require('internal/streams/state');
+const { getDefaultHighWaterMark, setDefaultHighWaterMark } = require('internal/streams/state');
 
 function listen(server) {
   server.listen(0, common.mustCall(() => {
@@ -45,3 +45,17 @@ function listen(server) {
 
   listen(server);
 }
+
+{
+  const server = http.createServer(
+    common.mustCall((req, res) => {
+      assert.strictEqual(req._readableState.highWaterMark, getDefaultHighWaterMark() * 2);
+      assert.strictEqual(res[kHighWaterMark], getDefaultHighWaterMark() * 2);
+      res.statusCode = 200;
+      res.end();
+    })
+  );
+
+  setDefaultHighWaterMark(false, getDefaultHighWaterMark() * 2);
+  listen(server);
+}