Filing at oleg_nenashev's request.
VirtualChannel.call has no timeout parameter, so it is assumed to block the calling thread until the call completes, fails, or the thread is interrupted externally. In practice the programmer often knows that it is unreasonable for a given call to take more than a certain amount of time, and would prefer to pass a timeout, akin to Future.get(long timeout, TimeUnit unit) throwing TimeoutException.
Similarly, various calls in Jenkins core which are implemented using Remoting ought to have overloads which take a timeout, or even (arguably) ought to default to using a fixed timeout. For example, FilePath.isDirectory has been observed to hang indefinitely when an agent connection is broken. It is almost never desirable to just wait until it completes; if the agent cannot respond in a reasonable amount of time (a few minutes at most), it would be better to just fail.