Memory Leak when subscribing to messages containing UInt8Array

Description It seems memory is not getting released for subscribers subscribing to messages containing a UInt8Array. If a sufficiently large array is published, the memory of the Node.js process can grow very quickly.

• Library Version: ^0.21.0
• ROS Version: foxy
• Platform / OS: Ubuntu 20.04.3 LTS (64-bit)

Steps To Reproduce Attached is a small nodejs example of the issue I’m seeing. In the example, I have set up a publisher to publish a large image every 100ms. I’ve set up a subscriber to subscribe to that topic, and print process.memoryUsage().rss each time it receives a message.

The example can be run by running npx ts-node server.ts in a terminal window and npx ts-node client.ts in another window.

When both are running, you can see that the memory footprint of the node process running the client grows whenever a message is received.

Expected Behavior Memory should not grow with each message

Actual Behavior Memory grows with each message rosleak.zip

[minggangw]

Thanks for testing it! So I am pretty sure it is the change of ref-napi that leads to the memory leak, thanks for finding this critical issue! will fix it asap.

[xhy279]

Ty for the fix. Good job man.