Why aren’t channels synchronous?
There’s a lot of debate on this topic; it’s easy to find a proponent of default-sync or default-async communication, and there are good reasons for either. Our choice rests on the following arguments: • Part of the point of isolating tasks is to decouple tasks from one another, such that assumptions in one task do not cause undue constraints (or bugs, if violated!) in another. Temporal coupling is as real as any other kind; async-by-default relaxes the default case to only causal coupling. • Default-async supports buffering and batching communication, reducing the frequency and severity of task-switching and inter-task / inter-domain synchronization. • Default-async with transmittable channels is the lowest-level building block on which more-complex synchronization topologies and strategies can be built; it is not clear to us that the majority of cases fit the 2-party full-synchronization pattern rather than some more complex multi-party or multi-stage scenario. We did not want to forc
