Structure of Message-Passing Programs

• Message-passing programs are often written using the asynchronous or loosely synchronous paradigms.
• In the asynchronous paradigm, all concurrent tasks execute asynchronously.
  • However, such programs can be harder and can have non-deterministic behavior due to race conditions.
• Loosely synchronous programs are a good compromise between two extremes.
  • In such programs, tasks or subsets of tasks synchronize to perform interactions.
  • However, between these interactions, tasks execute completely asynchronously.
• Most message-passing programs are written using the single program multiple data (SPMD).
• SPMD programs can be loosely synchronous or completely asynchronous.