Language.Embedded.Concurrent

Basic concurrency primitives.

Documentation

data ThreadId

Constructors

TIDEval ThreadId (Flag ())

TIDComp TID

Instances

Show ThreadId

type ChanBound = Word16

Maximum number of elements in some bounded channel.

data Chan t a

A bounded channel.

Constructors

ChanEval (BoundedChan a) (IORef Bool) (IORef Bool)

ChanComp CID

data ThreadCMD prog a

Instances

Interp ThreadCMD IO

HFunctor * * ThreadCMD

type IExp ((:+:) (* -> *) * ThreadCMD i) = IExp i

data ChanCMD exp prog a

Instances

HFunctor * * (ChanCMD exp)

EvalExp exp => Interp (ChanCMD exp) IO

type IExp (ChanCMD e) = e

type IExp ((:+:) (* -> *) * (ChanCMD e) i) = e

data Closeable

data Uncloseable

fork :: ThreadCMD :<: instr => ProgramT instr m () -> ProgramT instr m ThreadId

Fork off a computation as a new thread.

forkWithId :: ThreadCMD :<: instr => (ThreadId -> ProgramT instr m ()) -> ProgramT instr m ThreadId

Fork off a computation as a new thread, with access to its own thread ID.

asyncKillThread :: ThreadCMD :<: instr => ThreadId -> ProgramT instr m ()

Forcibly terminate a thread, then continue execution immediately.

killThread :: (ThreadCMD :<: instr, Monad m) => ThreadId -> ProgramT instr m ()

Forcibly terminate a thread. Blocks until the thread is actually dead.

waitThread :: ThreadCMD :<: instr => ThreadId -> ProgramT instr m ()

Wait for a thread to terminate.

newChan :: (VarPred (IExp instr) a, ChanCMD (IExp instr) :<: instr) => IExp instr ChanBound -> ProgramT instr m (Chan Uncloseable a)

Create a new channel. Writing a reference type to a channel will copy the reference into the queue, not its contents.

We'll likely want to change this, actually copying arrays and the like into the queue instead of sharing them across threads.

newCloseableChan :: (VarPred (IExp instr) a, ChanCMD (IExp instr) :<: instr) => IExp instr ChanBound -> ProgramT instr m (Chan Closeable a)

readChan :: (VarPred (IExp instr) a, ChanCMD (IExp instr) :<: instr) => Chan t a -> ProgramT instr m (IExp instr a)

Read an element from a channel. If channel is empty, blocks until there is an item available. If closeChan has been called on the channel *and* if the channel is empty, readChan returns an undefined value immediately.

writeChan :: (VarPred (IExp instr) a, VarPred (IExp instr) Bool, ChanCMD (IExp instr) :<: instr) => Chan t a -> IExp instr a -> ProgramT instr m (IExp instr Bool)

Write a data element to a channel. If closeChan has been called on the channel, all calls to writeChan become non-blocking no-ops and return False, otherwise returns True.

closeChan :: ChanCMD (IExp instr) :<: instr => Chan Closeable a -> ProgramT instr m ()

Close a channel. All subsequent write operations will be no-ops. After the channel is drained, all subsequent read operations will be no-ops as well.

lastChanReadOK :: (VarPred (IExp instr) Bool, ChanCMD (IExp instr) :<: instr) => Chan Closeable a -> ProgramT instr m (IExp instr Bool)

When readChan was last called on the given channel, did the read succeed? Always returns True unless closeChan has been called on the channel. Always returns True if the channel has never been read.