[project @ 2004-10-25 13:40:08 by simonmar]

Doc update: notes on finalization of Handles

diff --git a/GHC/IOBase.lhs b/GHC/IOBase.lhs
index 07273f9..8700128 100644 (file)
--- a/GHC/IOBase.lhs
+++ b/GHC/IOBase.lhs
@@ -266,6 +266,15 @@ instance Eq (MVar a) where
 -- enough information to identify the handle for debugging.  A handle is
 -- equal according to '==' only to itself; no attempt
 -- is made to compare the internal state of different handles for equality.
+--
+-- GHC note: a 'Handle' will be automatically closed when the garbage
+-- collector detects that it has become unreferenced by the program.
+-- However, relying on this behaviour is not generally recommended:
+-- the garbage collector is unpredictable.  If possible, use explicit
+-- an explicit 'hClose' to close 'Handle's when they are no longer
+-- required.  GHC does not currently attempt to free up file
+-- descriptors when they have run out, it is your responsibility to
+-- ensure that this doesn't happen.
 
 data Handle 
   = FileHandle                         -- A normal handle to a file