Threads And Data-Flow Synchronization

To create a thread:

      thread ... end

Primitive operations block until their arguments are sufficiently instantiated for the operation to be performed. For example:

      declare X = Y + 12

blocks until Y becomes instantiated. We say that it suspends on variable Y. This is known as data-flow synchronization.

The entire thread on which the operation executes suspends on variable Y:

      declare X = thread Y + 12 end