We propose a new type system for information flow analysis for the pi-calculus. As demonstrated by recent studies, information about whether each communication succeeds is important for precise information flow analysis for concurrent programs. By collecting such information using ideas of our previous type systems for deadlock/livelock-freedom, our type system can perform more precise analysis for certain communication/synchronization patterns (like synchronization using locks) than previous type systems. Our type system treats a wide range of communication/synchronization primitives in a uniform manner, which enabled development of a clear proof of type soundness and a sound and complete type inference algorithm.