http2: fix tracking received data for maxSessionMemory

Track received data correctly. Specifically, for the buffer that
is used for receiving data, we previously would try to increment
the current memory usage by its length, and later decrement it
by that, but in the meantime the buffer had been turned over to V8
and its length reset to zero. This gave the impression that more and
more memory was consumed by the HTTP/2 session when it was in fact not.

Fixes: https://github.com/nodejs/node/issues/27416
Refs: https://github.com/nodejs/node/pull/26207

PR-URL: https://github.com/nodejs/node/pull/27914
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/test/parallel/test-http2-max-session-memory-leak.js b/test/parallel/test-http2-max-session-memory-leak.js
new file mode 100644
index 0000000000..b066ca80bc
--- /dev/null
+++ b/test/parallel/test-http2-max-session-memory-leak.js
@@ -0,0 +1,46 @@
+'use strict';
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const http2 = require('http2');
+
+// Regression test for https://github.com/nodejs/node/issues/27416.
+// Check that received data is accounted for correctly in the maxSessionMemory
+// mechanism.
+
+const bodyLength = 8192;
+const maxSessionMemory = 1;  // 1 MB
+const requestCount = 1000;
+
+const server = http2.createServer({ maxSessionMemory });
+server.on('stream', (stream) => {
+  stream.respond();
+  stream.end();
+});
+
+server.listen(common.mustCall(() => {
+  const client = http2.connect(`http://localhost:${server.address().port}`, {
+    maxSessionMemory
+  });
+
+  function request() {
+    return new Promise((resolve, reject) => {
+      const stream = client.request({
+        ':method': 'POST',
+        'content-length': bodyLength
+      });
+      stream.on('error', reject);
+      stream.on('response', resolve);
+      stream.end('a'.repeat(bodyLength));
+    });
+  }
+
+  (async () => {
+    for (let i = 0; i < requestCount; i++) {
+      await request();
+    }
+
+    client.close();
+    server.close();
+  })().then(common.mustCall());
+}));