{-# LANGUAGE Trustworthy #-} {-# LANGUAGE NoImplicitPrelude #-} ----------------------------------------------------------------------------- -- | -- Module : Foreign.Concurrent -- Copyright : (c) The University of Glasgow 2003 -- License : BSD-style (see the file libraries/base/LICENSE) -- -- Maintainer : ffi@haskell.org -- Stability : provisional -- Portability : non-portable (requires concurrency) -- -- FFI datatypes and operations that use or require concurrency (GHC only). -- ----------------------------------------------------------------------------- module Foreign.Concurrent ( -- * Concurrency-based 'ForeignPtr' operations -- | These functions generalize their namesakes in the portable -- "Foreign.ForeignPtr" module by allowing arbitrary 'IO' actions -- as finalizers. These finalizers necessarily run in a separate -- thread, cf. /Destructors, Finalizers and Synchronization/, -- by Hans Boehm, /POPL/, 2003. newForeignPtr, addForeignPtrFinalizer, ) where import GHC.IO ( IO ) import GHC.Ptr ( Ptr ) import GHC.ForeignPtr ( ForeignPtr ) import qualified GHC.ForeignPtr newForeignPtr :: Ptr a -> IO () -> IO (ForeignPtr a) -- ^Turns a plain memory reference into a foreign object by associating -- a finalizer - given by the monadic operation - with the reference. -- The finalizer will be executed after the last reference to the -- foreign object is dropped. There is no guarantee of promptness, and -- in fact there is no guarantee that the finalizer will eventually -- run at all. newForeignPtr = GHC.ForeignPtr.newConcForeignPtr addForeignPtrFinalizer :: ForeignPtr a -> IO () -> IO () -- ^This function adds a finalizer to the given 'ForeignPtr'. -- The finalizer will run after the last reference to the foreign object -- is dropped, but /before/ all previously registered finalizers for the -- same object. addForeignPtrFinalizer = GHC.ForeignPtr.addForeignPtrConcFinalizer