Exceptions in concurrent Eiffel

We describe the problem of asynchronous exceptions in Eiffel’s Simple Concurrent Object-Oriented Programming (SCOOP). We discuss a range of possible solutions to further enable dependable computing in concurrent Eiffel. We propose a mechanism to handle aynchronous exceptions via a limited developer choice, including the notion of a failed or dead object, and necessarily introduce a small number of new exceptions. We additionally describe a number of mechanisms that were discarded as unsuitable.