From 663cabfbdab44df2e0775cabbc1171efce8f2aab Mon Sep 17 00:00:00 2001
From: Simon Woolf <simon.woolf@ably.com>
Date: Mon, 6 Nov 2023 20:22:49 +0000
Subject: [PATCH 1/2] Connection: close stream if close() is called while we're
 blocked

if the connection is blocked, we will not receive a close-ok until the
connection becomes unblocked, which may be some time. So just terminate
the connection immediately.
---
 lib/connection.js | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/connection.js b/lib/connection.js
index d36ea6aa..76d5018e 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -50,6 +50,7 @@ class Connection extends EventEmitter {
     this.recvSinceLastCheck = false;
 
     this.expectSocketClose = false;
+    this.blocked = false;
     this.freeChannels = new BitSet();
     this.channels = [{
       channel: { accept: channel0(this) },
@@ -317,6 +318,18 @@ class Connection extends EventEmitter {
   // ignored. We also have to shut down all the channels.
   toClosing (capturedStack, k) {
     var send = this.sendMethod.bind(this);
+    invalidateSend(this, 'Connection closing', capturedStack);
+
+    if(this.blocked) {
+      // if the connection is blocked, we will not receive a close-ok until the connection
+      // becomes unblocked, which may be some time. So just terminate the connection
+      // immediately
+      if (k)
+        k();
+      var s = stackCapture('Forcibly closing as connection is blocked');
+      this.toClosed(s, undefined);
+      return;
+    }
 
     this.accept = function (f) {
       if (f.id === defs.ConnectionCloseOk) {
@@ -330,7 +343,6 @@ class Connection extends EventEmitter {
       }
       // else ignore frame
     };
-    invalidateSend(this, 'Connection closing', capturedStack);
   }
 
   _closeChannels (capturedStack) {
@@ -606,9 +618,11 @@ function channel0(connection) {
       connection.toClosed(s, e);
     }
     else if (f.id === defs.ConnectionBlocked) {
+      connection.blocked = true;
       connection.emit('blocked', f.fields.reason);
     }
     else if (f.id === defs.ConnectionUnblocked) {
+      connection.blocked = false;
       connection.emit('unblocked');
     }
     else {

From ee10d3181bdfea9343f31a3a01ec7a8fbf3c56ff Mon Sep 17 00:00:00 2001
From: Simon Woolf <simon.woolf@ably.com>
Date: Mon, 6 Nov 2023 20:23:31 +0000
Subject: [PATCH 2/2] Connection.toClosed: destroy stream after calling end

---
 lib/connection.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/connection.js b/lib/connection.js
index 76d5018e..b48e2257 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -370,6 +370,7 @@ class Connection extends EventEmitter {
     // This is certainly true now, if it wasn't before
     this.expectSocketClose = true;
     this.stream.end();
+    this.stream.destroy();
     this.emit('close', maybeErr);
   }