Websocket server hangs on Create token action

[containerman17]

When the createToken action is submitted, the WebSocket server hangs and stops responding. There are no errors in the logs, and the action itself is executed successfully. However, all WebSocket connections to the node freeze after this action.

Source Code:

• createToken action source: create_token.go
• Example block listener: Block Listener Example

Details:

• Transfer transactions work correctly through WebSocket without any issues.
• The issue happens consistently after every createToken action.
• The problem is not related to the client. The same behavior occurs when listening for new blocks in Go, suggesting that the WebSocket server itself hangs, though it's unclear if block production stops or if it's solely a WebSocket issue.
• User get's charged gas fees, so looks like Tx is being processed

Additional Information:

• Aaron's suggestion: This issue could be related to the pubsub package used by the WebSocket server. Possible problematic areas include message_buffer.go#L124 and message_buffer.go#L116, where a deadlock might occur.

[containerman17]

To reproduce, clone https://github.com/ava-labs/hypersdk-starter, check out the cfmm-demo branch, and then run docker compose up -d --build frontend faucet. Refer to https://github.com/ava-labs/hypersdk-starter/blob/main/README.md for instructions on how to get started. @aaronbuchwald

[containerman17]

Replaced by #1619