1 files changed, 12 insertions, 0 deletions
diff --git a/Control/Concurrent/Sema.hs b/Control/Concurrent/Sema.hs
new file mode 100644
index 0000000..e804cc3
--- /dev/null
+++ b/Control/Concurrent/Sema.hs
@@ -0,0 +1,12 @@
+module Control.Concurrent.Sema
+    ( mapPool
+    )
+where
+
+import qualified Control.Concurrent.MSem as Sem
+
+-- | Simaphore-based throttled 'mapConcurrently'.
+mapPool :: Traversable t => Int -> (a -> IO b) -> t a -> IO (t b)
+mapPool n f xs = do
+    sima <- Sem.new n
+    mapConcurrently (Sem.with sima . f) xs