On smalltalk systems like squeak or Pharo, the user interrupts the execution of a thread when it hangs with a keyboard shortcut. And people don't run untrusted

On smalltalk systems like squeak or Pharo, the user interrupts the execution of a thread when it hangs with a keyboard shortcut. And people don't run untrusted code in their "main" image, they would run it in a throw away VM. The same type of model could be used here using an hypervisor. This said, no one uses exclusively a Smalltalk system, it needs some infrastructure.