taskpool is a lightweight framework for managing a resource-constrained, potentially inter-dependent collection of concurrent tasks.
There are three basic elements in taskpool: Tasks, Handles that refer to registered tasks, a Pool to holds the tasks, and a Manager to execute the tasks.
Tasks form a partially ordered set, which ordered establishes serial execution, and lack of ordering allows for concurrent execution.
Results of a task are reported through its Handle, which may be waited on, polled, or canceled. Exceptions during task execution are reported back to the caller in the same way as the Async type. In fact, a Handle simply contains a TMVar that references an Async value.
The basic operations of taskpool are:
createPool :: Int -> IO Pool suspendPool :: Pool -> IO () resumePool :: Pool -> IO () cancelAll :: Pool -> IO ()
submitTask :: Pool -> Task -> IO Handle submitDependentTask :: Pool -> Handle -> Task -> IO Handle cancelTask :: Handle -> IO () waitOnTask :: Handle -> IO a waitOnTaskEither :: Exception e => Handle -> IO (Either e a) pollTask :: Handle -> IO (Maybe a) pollTaskEither :: Exception e => Handle -> IO (Maybe (Either e a))