| Copyright | Copyright (c) 2009-2014, David Sorokin <david.sorokin@gmail.com> |
|---|---|
| License | BSD3 |
| Maintainer | David Sorokin <david.sorokin@gmail.com> |
| Stability | experimental |
| Safe Haskell | None |
| Language | Haskell2010 |
Simulation.Aivika.Trans.Task
Description
Tested with: GHC 7.8.3
The Task value represents a process that was already started in background.
We can check the completion of the task, receive notifications about changing
its state and even suspend an outer process awaiting the final result of the task.
It complements the Process monad as it allows immediately continuing the main
computation without suspension.
- data Task m a
- data TaskResult a
- taskId :: Task m a -> ProcessId m
- tryGetTaskResult :: MonadComp m => Task m a -> Event m (Maybe (TaskResult a))
- taskResult :: MonadComp m => Task m a -> Process m (TaskResult a)
- taskResultReceived :: Task m a -> Signal m (TaskResult a)
- taskProcess :: MonadComp m => Task m a -> Process m a
- cancelTask :: MonadComp m => Task m a -> Event m ()
- taskCancelled :: MonadComp m => Task m a -> Event m Bool
- runTask :: MonadComp m => Process m a -> Event m (Task m a)
- runTaskUsingId :: MonadComp m => ProcessId m -> Process m a -> Event m (Task m a)
- spawnTask :: MonadComp m => ContCancellation -> Process m a -> Process m (Task m a)
- spawnTaskUsingId :: MonadComp m => ContCancellation -> ProcessId m -> Process m a -> Process m (Task m a)
- enqueueTask :: MonadComp m => Double -> Process m a -> Event m (Task m a)
- enqueueTaskUsingId :: MonadComp m => Double -> ProcessId m -> Process m a -> Event m (Task m a)
Task
data TaskResult a Source
Represents the result of the task.
Constructors
| TaskCompleted a | the task was successfully completed and it returned the specified result |
| TaskError SomeException | the specified exception was raised when performing the task. |
| TaskCancelled | the task was cancelled |
taskId :: Task m a -> ProcessId m Source
Return an identifier for the process that was launched in background for this task.
tryGetTaskResult :: MonadComp m => Task m a -> Event m (Maybe (TaskResult a)) Source
Try to get the task result immediately without suspension.
taskResult :: MonadComp m => Task m a -> Process m (TaskResult a) Source
Return the task result suspending the outer process if required.
taskResultReceived :: Task m a -> Signal m (TaskResult a) Source
Return a signal that notifies about receiving the result of the task.
taskProcess :: MonadComp m => Task m a -> Process m a Source
Return an outer process that behaves like the task itself except for one thing: if the outer process is cancelled then it is not enough to cancel the task.
cancelTask :: MonadComp m => Task m a -> Event m () Source
Cancel the task.
Running Task
runTask :: MonadComp m => Process m a -> Event m (Task m a) Source
Run the process in background and return the corresponded task immediately.
runTaskUsingId :: MonadComp m => ProcessId m -> Process m a -> Event m (Task m a) Source
Run the process with the specified identifier in background and return the corresponded task immediately.
Spawning Tasks
spawnTask :: MonadComp m => ContCancellation -> Process m a -> Process m (Task m a) Source
Run a child process in background and return immediately the corresponded task.
spawnTaskUsingId :: MonadComp m => ContCancellation -> ProcessId m -> Process m a -> Process m (Task m a) Source
Run using the specified identifier a child process in background and return immediately the corresponded task.