Habanero

Async, Finish

Async and finish make up the fundamental building blocks of task-level parallelism in Habanero.

async(body) creates a new child task that can run before, after, or in parallel with all remaining statements of the parent task.

finish(body) executes body and waits for all child tasks to complete.

These concepts are first covered in RiceX Topic 1.1.

Future

A future is a tasks that return a value.

future(body) returns an instance of HjFuture. Invoking the get() method on that instance waits for the task to complete.

Futures are covered in RiceX Topic 2.1.

FinishAccumulator

Finish Accumulators provide a convenient way to keep track of a count (for example: the number of solutions in the n-queens problem) or perform a reduction as in the MapReduce_Assignment.

There are several ways to create the different forms of accumulators, but the two that come up in CSE231s are:

newIntegerFinishAccumulator( NumberReductionOperator.SUM )

finish(register(accumulators), body)

FinishAccumulators are covered in RiceX Topic 2.3.