Changes between Version 8 and Version 9 of BlockObjects


Ignore:
Timestamp:
Aug 13, 2011 5:48:05 AM (4 years ago)
Author:
chak
Comment:

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  • BlockObjects

    v8 v9  
    4141== Example: returning a C block ==
    4242
    43 Conversely, a C block object can be used as a function in Haskell.  Assume the declaration
     43Conversely, a C block object can be used as a function in Haskell.  Given the following C prototype
     44{{{
     45typedef void (^callback_t)(handle);
     46
     47callback_t
     48get_callback (void);
     49}}}
     50assume the FFI declaration
    4451{{{
    4552foreign import ccall get_callback :: IO (Handle -> IO ())
     53  -- where 'Handle' is a new type of some C pointer type
    4654}}}
     55We might use the imported C function as follows:
     56{{{
     57do
     58  callback <- get_callback
     59  callback myHandle
     60}}}
     61'''TODO:''' Is there a better example? Something from an official API?
    4762
    48 {{{
    49 use it
    50 }}}
     63== Storage management ==
     64
     65'''TODO:''' How do we recover a Haskell function's storage once it has been turned into a block object and passed to a C function?  (NB: the environment of the function may hold on to large data structures, which will only be freed once the function is freed.)
     66
     67When we marshal a C block object into a Haskell function, we need to ensure that the Haskell storage manager releases the block object once the Haskell land function becomes unreachable in the Haskell heap.
    5168
    5269== The gory details ==
    5370
    54 The following subpages provide details on implementing this functionality.
     71The following subpages provide details on implementing this functionality.  '''(The following three subpages are forthcoming.)
    5572 * [wiki:BlockObjects/Specification] (pure versus impure; corner cases `void (^foo) (void)` in the pure cases)
    5673 * [wiki:BlockObjects/FakingIt]