http: reset parser.incoming when server request is finished

This resolves a memory leak for keep-alive connections and does not
regress in the way that 779a05d5d1bfe2eeb05386f did by waiting for
the incoming request to be finished before releasing the
`parser.incoming` object.

Refs: https://github.com/nodejs/node/pull/28646
Refs: https://github.com/nodejs/node/pull/29263
Fixes: https://github.com/nodejs/node/issues/9668

PR-URL: https://github.com/nodejs/node/pull/29297
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/test/parallel/test-http-server-keepalive-req-gc.js b/test/parallel/test-http-server-keepalive-req-gc.js
new file mode 100644
index 0000000000..aa4bf1a3de
--- /dev/null
+++ b/test/parallel/test-http-server-keepalive-req-gc.js
@@ -0,0 +1,47 @@
+// Flags: --expose-gc
+'use strict';
+const common = require('../common');
+const onGC = require('../common/ongc');
+const { createServer } = require('http');
+const { connect } = require('net');
+
+if (common.isWindows) {
+  // TODO(addaleax): Investigate why and remove the skip.
+  common.skip('This test is flaky on Windows.');
+}
+
+// Make sure that for HTTP keepalive requests, the req object can be
+// garbage collected once the request is finished.
+// Refs: https://github.com/nodejs/node/issues/9668
+
+let client;
+const server = createServer(common.mustCall((req, res) => {
+  onGC(req, { ongc: common.mustCall() });
+  req.resume();
+  req.on('end', common.mustCall(() => {
+    setImmediate(() => {
+      client.end();
+      global.gc();
+    });
+  }));
+  res.end('hello world');
+}));
+
+server.unref();
+
+server.listen(0, common.mustCall(() => {
+  client = connect(server.address().port);
+
+  const req = [
+    'POST / HTTP/1.1',
+    `Host: localhost:${server.address().port}`,
+    'Connection: keep-alive',
+    'Content-Length: 11',
+    '',
+    'hello world',
+    ''
+  ].join('\r\n');
+
+  client.write(req);
+  client.unref();
+}));