  Ensuring the correctness of software for communication centric programs is
important but challenging. Previous approaches, based on session types, have
been intensively investigated over the past decade. They provide a concise way
to express protocol specifications and a lightweight approach for checking
their implementation. Current solutions are based on only implicit
synchronization, and are based on the less precise types rather than logical
formulae. In this paper, we propose a more expressive session logic to capture
multiparty protocols. By using two kinds of ordering constraints, namely
"happens-before" <HB and "communicates-before" <CB, we show how to ensure from
first principle race-freedom over common channels. Our approach refines each
specification with both assumptions and proof obligations to ensure compliance
to some global protocol. Each specification is then projected for each party
and then each channel, to allow cooperative proving through localized automated
verification. Our primary goal in automated verification is to ensure
race-freedom and communication-safety, but the approach is extensible for
deadlock-freedom as well. We shall also describe how modular protocols can be
captured and handled by our approach.
