Version: 55
OS: All

What steps will reproduce the problem?
(1) Have a Java Mojo service that takes a callback.
(2) Drop all references to the callback without calling it.
(3) Wait for a garbage collection.
(4) Try to send more messages to the service from the client.

What is the expected output?
DCHECK or some kind of indication that you made a mistake by deleting the callback without calling it.

What do you see instead?
The Mojo pipe closes silently (from the Java service perspective; a connection error is delivered to the client). You are puzzled for hours because you can't figure out why the pipe is mysteriously closing; see  Issue 640324 .