System.Mem.Manager

This module supplies a variant of the selfish form of "Poor Richard's Memory Manager" by Hertz, Kane, Keudel, Bai, Ding, Gu and Bard, adapted to run in Haskell in user-space.

Usage:

main = do
  _ <- selfishManager
  ...

Now, the background thread that was spawned by selfishManager 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.

Memory Manager

selfishManager :: IO ThreadId

Run a background thread that checks for signs of memory pressure from the Host OS and kickstarts a garbage collection as needed.

Statistics and Utilities

currentResidentSetSize :: IO CSize

Retrieve the current resident set size for the currently executing program.

peakResidentSetSize :: IO CSize

Retrieve the current peak resident set size for the currently executing program.

hardPageFaults :: IO CSize

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

checkMemoryPressure :: IO Bool

Determine if memory pressure warrants further action.

This will return True if we are getting signs from the operating system that we should reign in our memory usage.

cumulativeManagedCollections :: IO Int

Return the total number of managed collections that the GC manager has forced.