-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Poor Richard's Memory Manager
--   
--   This package implements a form of <a>Poor Richard's Memory Manager</a>
--   by Hertz, Kane, Keudel, Bai, Ding, Gu and Bard in user-space in GHC.
--   
--   Usage:
--   
--   <pre>
--   import System.Mem.Manager
--   main = do
--     _ &lt;- selfishManager
--     ...
--   </pre>
--   
--   Now, the background thread that was spawned by <tt>selfishManager</tt>
--   will watch for signs that the host operating system is starting to
--   cause the current process to page out to disk and respond with more
--   aggressive garbage collection.
--   
--   This empowers your code to try to avoid the inevitable death spiral
--   that follows when GC has to happen with paged out data.
@package gc
@version 0.1


-- | This module supplies a variant of the selfish form of <a>"Poor
--   Richard's Memory Manager"</a> by Hertz, Kane, Keudel, Bai, Ding, Gu
--   and Bard, adapted to run in Haskell in user-space.
--   
--   Due to the fact that Haskell returns memory to the operating system
--   and doesn't really tell me about it, this follows their
--   'GenMS+Selfish' (without RSS) scheme.
--   
--   Usage:
--   
--   <pre>
--   main = do
--     _ &lt;- <a>selfishManager</a>
--     ...
--   </pre>
--   
--   Now, the background thread that was spawned by <a>selfishManager</a>
--   will watch for signs that the host operating system is starting to
--   cause the current process to page out to disk and respond with more
--   aggressive garbage collection.
--   
--   This empowers your code to try to avoid the inevitable death spiral
--   that follows when GC has to happen with paged out data.
module System.Mem.Manager

-- | Run a background thread that checks for signs of memory pressure from
--   the Host OS and kickstarts a garbage collection as needed. Returns the
--   thread for the selfish gc manager and an IO action that can be run to
--   count the cumulative number of managed collections
selfishManager :: IO (ThreadId, IO Int)

-- | Return the total number of "hard page-faults" since the program
--   started. These are page-faults which required us to go out to disk.
hardPageFaults :: IO CSize