Limiting compute is trivial on any modern operating system. On Linux you can create a second supervisor thread, block on a mutex with a timeout, and then if you timed out before acquiring the mutex you can just tgkill the runner thread. On BSDs it's even easier since you can just hand the runner thread port to your supervisor thread and, after you timeout, you can just set RIP/PC to whatever location you want without having to screw around with signals.