Bug fix for space leak on too frequent calls to performGC

hasktorch/hasktorch.cabal

@@ -138,6 +138,7 @@ library
                     , megaparsec
                     , half
                     , constraints
+                    , auto-update
 
  default-extensions:  Strict
                     , StrictData

hasktorch/src/Torch/Optim.hs

@@ -8,6 +8,8 @@ import Torch.Autograd
 import Torch.Functional
 import Torch.Internal.GC (mallocTrim)
 import Torch.NN
+import System.IO.Unsafe          (unsafePerformIO)
+import Control.Debounce
 import Torch.Tensor
 import Torch.TensorFactories
 import Prelude hiding (sqrt)
@@ -23,6 +25,15 @@ newtype OptimizerState option = OptimizerState option
 grad' :: Loss -> [Parameter] -> Gradients
 grad' t p = Gradients (grad t p)
 
+-- | Action that performs garbage collection with a minimum waiting time between calls to `performGC`. This prevents a space leak, that occurs when calling `performGC` too frequently.
+performGC' :: IO ()
+performGC' = unsafePerformIO $ do
+  mkDebounce defaultDebounceSettings
+    { debounceAction = performGC
+    , debounceEdge = leadingEdge
+    , debounceFreq = 1000000
+    }
+
 class Optimizer optimizer where
   step :: LearningRate -> Gradients -> [Tensor] -> optimizer -> ([Tensor], optimizer)
 
@@ -33,7 +44,7 @@ class Optimizer optimizer where
   -- | run a single iteration of an optimizer, returning new parameters and updated optimizer state
   runStep' :: (Parameterized model) => model -> optimizer -> Gradients -> LearningRate -> IO (model, optimizer)
   runStep' paramState optState gradients lr = do
-    performGC
+    performGC'
     mallocTrim 0
     let (flatParameters', optState') = step lr gradients depParameters optState
     newFlatParam <- mapM makeIndependent flatParameters'