http2: strictly limit number on concurrent streams

Strictly limit the number of concurrent streams based on the
current setting of the MAX_CONCURRENT_STREAMS setting

PR-URL: https://github.com/nodejs/node/pull/16766
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Sebastiaan Deckers <sebdeckers83@gmail.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/test/parallel/test-http2-too-many-streams.js b/test/parallel/test-http2-too-many-streams.js
new file mode 100644
index 0000000000..a4a67befa0
--- /dev/null
+++ b/test/parallel/test-http2-too-many-streams.js
@@ -0,0 +1,60 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const Countdown = require('../common/countdown');
+const http2 = require('http2');
+const assert = require('assert');
+
+// Test that the maxConcurrentStreams setting is strictly enforced
+
+const server = http2.createServer({ settings: { maxConcurrentStreams: 1 } });
+
+let c = 0;
+
+server.on('stream', common.mustCall((stream) => {
+  // Because we only allow one open stream at a time,
+  // c should never be greater than 1.
+  assert.strictEqual(++c, 1);
+  stream.respond();
+  // Force some asynchronos stuff.
+  setImmediate(() => {
+    stream.end('ok');
+    assert.strictEqual(--c, 0);
+  });
+}, 3));
+
+server.listen(0, common.mustCall(() => {
+  const client = http2.connect(`http://localhost:${server.address().port}`);
+
+  const countdown = new Countdown(3, common.mustCall(() => {
+    server.close();
+    client.destroy();
+  }));
+
+  client.on('remoteSettings', common.mustCall(() => {
+    assert.strictEqual(client.remoteSettings.maxConcurrentStreams, 1);
+
+    {
+      const req = client.request();
+      req.resume();
+      req.on('close', () => {
+        countdown.dec();
+
+        setImmediate(() => {
+          const req = client.request();
+          req.resume();
+          req.on('close', () => countdown.dec());
+        });
+      });
+    }
+
+    {
+      const req = client.request();
+      req.resume();
+      req.on('close', () => countdown.dec());
+    }
+  }));
+}));