Global escape in multiparty sessions

摘要

This article proposes a global escape mechanism which can handle unexpected or unwantedrnconditions changing the default execution of distributed communicational flows, preservingrncompatibility of the multiparty conversations. Our escape is realized by a collection ofrnasynchronous local exceptions which can be thrown at any stage of the communication andrnto any subsets of participants in a multiparty session. This flexibility enables to modelrncomplex exceptions such as criss-crossing global interactions and error handling forrndistributed cooperating threads. Guided by multiparty session types, our semantics is provenrnto provide a termination algorithm for global escapes. Our type system guarantees furtherrnsafety and liveness properties, such as progress within the session and atomicity of escapesrnwith respect to the subset of involved participants.