http2: improve session close/destroy procedures

Don't destroy the socket when closing the session but let it end
gracefully.
Also, when destroying the session, on Windows, we would get ECONNRESET
errors, make sure we take those into account in our tests.

PR-URL: #45115
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Rafael Gonzaga <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>

lib/internal/http2/core.js

@@ -1109,19 +1109,25 @@ function finishSessionClose(session, error) {
   cleanupSession(session);
 
   if (socket && !socket.destroyed) {
+    socket.on('close', () => {
+      emitClose(session, error);
+    });
+    if (session.closed) {
+      // If we're gracefully closing the socket, call resume() so we can detect
+      // the peer closing in case binding.Http2Session is already gone.
+      socket.resume();
+    }
+
     // Always wait for writable side to finish.
     socket.end((err) => {
       debugSessionObj(session, 'finishSessionClose socket end', err, error);
-      // Due to the way the underlying stream is handled in Http2Session we
-      // won't get graceful Readable end from the other side even if it was sent
-      // as the stream is already considered closed and will neither be read
-      // from nor keep the event loop alive.
-      // Therefore destroy the socket immediately.
-      // Fixing this would require some heavy juggling of ReadStart/ReadStop
-      // mostly on Windows as on Unix it will be fine with just ReadStart
-      // after this 'ondone' callback.
-      socket.destroy(error);
-      emitClose(session, error);
+      // If session.destroy() was called, destroy the underlying socket. Delay
+      // it a bit to try to avoid ECONNRESET on Windows.
+      if (!session.closed) {
+        setImmediate(() => {
+          socket.destroy(error);
+        });
+      }
     });
   } else {
     process.nextTick(emitClose, session, error);

src/node_http2.cc

@@ -703,6 +703,11 @@ void Http2Session::Close(uint32_t code, bool socket_closed) {
     Debug(this, "make done session callback");
     HandleScope scope(env()->isolate());
     MakeCallback(env()->ondone_string(), 0, nullptr);
+    if (stream_ != nullptr) {
+      // Start reading again to detect the other end finishing.
+      set_reading_stopped(false);
+      stream_->ReadStart();
+    }
   }
 
   // If there are outstanding pings, those will need to be canceled, do
@@ -1592,6 +1597,11 @@ void Http2Session::OnStreamAfterWrite(WriteWrap* w, int status) {
   if (is_destroyed()) {
     HandleScope scope(env()->isolate());
     MakeCallback(env()->ondone_string(), 0, nullptr);
+    if (stream_ != nullptr) {
+      // Start reading again to detect the other end finishing.
+      set_reading_stopped(false);
+      stream_->ReadStart();
+    }
     return;
   }
 
@@ -1640,7 +1650,9 @@ void Http2Session::MaybeScheduleWrite() {
 }
 
 void Http2Session::MaybeStopReading() {
-  if (is_reading_stopped()) return;
+  // If the session is already closing we don't want to stop reading as we want
+  // to detect when the other peer is actually closed.
+  if (is_reading_stopped() || is_closing()) return;
   int want_read = nghttp2_session_want_read(session_.get());
   Debug(this, "wants read? %d", want_read);
   if (want_read == 0 || is_write_in_progress()) {

test/parallel/test-http2-server-close-callback.js

@@ -13,7 +13,7 @@ let session;
 
 const countdown = new Countdown(2, () => {
   server.close(common.mustSucceed());
-  session.destroy();
+  session.close();
 });
 
 server.listen(0, common.mustCall(() => {

test/parallel/test-http2-server-sessionerror.js

@@ -44,17 +44,21 @@ server.on('sessionError', common.mustCall((err, session) => {
 server.listen(0, common.mustCall(() => {
   const url = `http://localhost:${server.address().port}`;
   http2.connect(url)
-    .on('error', common.expectsError({
-      code: 'ERR_HTTP2_SESSION_ERROR',
-      message: 'Session closed with error code 2',
+    .on('error', common.mustCall((err) => {
+      if (err.code !== 'ECONNRESET') {
+        assert.strictEqual(err.code, 'ERR_HTTP2_SESSION_ERROR');
+        assert.strictEqual(err.message, 'Session closed with error code 2');
+      }
     }))
     .on('close', () => {
       server.removeAllListeners('error');
       http2.connect(url)
-        .on('error', common.expectsError({
-          code: 'ERR_HTTP2_SESSION_ERROR',
-          message: 'Session closed with error code 2',
-        }))
+      .on('error', common.mustCall((err) => {
+        if (err.code !== 'ECONNRESET') {
+          assert.strictEqual(err.code, 'ERR_HTTP2_SESSION_ERROR');
+          assert.strictEqual(err.message, 'Session closed with error code 2');
+        }
+      }))
         .on('close', () => server.close());
     });
 }));

test/parallel/test-http2-too-many-settings.js

@@ -29,9 +29,11 @@ function doTest(session) {
 
   server.listen(0, common.mustCall(() => {
     const client = h2.connect(`http://localhost:${server.address().port}`);
-    client.on('error', common.expectsError({
-      code: 'ERR_HTTP2_SESSION_ERROR',
-      message: 'Session closed with error code 2',
+    client.on('error', common.mustCall((err) => {
+      if (err.code !== 'ECONNRESET') {
+        assert.strictEqual(err.code, 'ERR_HTTP2_SESSION_ERROR');
+        assert.strictEqual(err.message, 'Session closed with error code 2');
+      }
     }));
     client.on('close', common.mustCall(() => server.close()));
   }));