[Vogtinator]

Linux can do that as well, see SIGEV_THREAD.

[quotemstr]

Only for AIO, which few use.

[andreyv]

You can spawn a thread manually and use the POSIX sigwait() function.

[quotemstr]

That won't stop the process-wide registered signal handler working and it won't do anything about being able to reliably handle synchronous signals.