I believe the URCU library is LGPLed and with IBM blessing: https://github.com/urcu/userspace-rcu/blob/master/lgpl-relicensing.txt https://github.com/urcu/users

I believe the URCU library is LGPLed and with IBM blessing: https://github.com/urcu/userspace-rcu/blob/master/lgpl-relicensing.txt https://github.com/urcu/userspace-rcu/blob/master/lgpl-relic... . So you're probably okay if you use that, or a derivative work of that (that you contribute back). There's other similar methods RCU like hazard pointers. There was a patent application filed, but it was abandoned before it was granted.