[gpderetta]

> In principle, I think many of these ideas could be applied to threaded IO.

That's how POSIX deferred [1] cancellation works. An uncatchable exception is thrown from blocking calls if a thread is requested to terminate. As POSIX is C centered, you can imagine that handling exceptions was never popular, but it should work fine in C++. For some reasons it wasn't added to std::thread though.

[1] there is also async cancellation, but friends do not let friends use PTHREAD_CANCEL_ASYNCHRONOUS.