Merge pull request #230 from nagisa/watch-threading

Use OS threads for watch in Windows

2 files changed, 15 insertions, 8 deletions

diff --git a/src/Hakyll/Commands.hs b/src/Hakyll/Commands.hs
index 7951f4e..6664181 100644
--- a/src/Hakyll/Commands.hs
+++ b/src/Hakyll/Commands.hs
@@ -9,13 +9,15 @@ module Hakyll.Commands
     , rebuild
     , server
     , deploy
-    , watch 
+    , watch
     ) where
 
 
 --------------------------------------------------------------------------------
 import           System.Exit                (exitWith, ExitCode)
+import           System.IO.Error            (catchIOError)
 import           Control.Applicative
+import           Control.Monad              (void)
 import           Control.Concurrent
 
 --------------------------------------------------------------------------------
@@ -83,17 +85,22 @@ preview _ _ _ _ = previewServerDisabled
 watch :: Configuration -> Verbosity -> Int -> Bool -> Rules a -> IO ()
 #ifdef WATCH_SERVER
 watch conf verbosity port runServer rules = do
-    watchUpdates conf update
-    _ <- forkIO (server')
-    loop
+#ifndef mingw32_HOST_OS
+    _ <- forkIO $ watchUpdates conf update
+#else
+    -- Force windows users to compile with -threaded flag, as otherwise
+    -- thread is blocked indefinitely.
+    catchIOError (void $ forkOS $ watchUpdates conf update) $ do
+        fail $ "Hakyll.Commands.watch: Could not start update watching " ++
+               "thread. Did you compile with -threaded flag?"
+#endif
+    server'
   where
     update = do
         (_, ruleSet) <- run conf verbosity rules
         return $ rulesPattern ruleSet
-
     loop = threadDelay 100000 >> loop
-
-    server' = if runServer then server conf port else return ()
+    server' = if runServer then server conf port else loop
 #else
 watch _ _ _ _ _ = watchServerDisabled
 #endif
diff --git a/web/tutorials/01-installation.markdown b/web/tutorials/01-installation.markdown
index c02a86e..5421c73 100644
--- a/web/tutorials/01-installation.markdown
+++ b/web/tutorials/01-installation.markdown
@@ -49,7 +49,7 @@ The file `site.hs` holds the configuration of your site, as an executable
 haskell program. We can compile and run it like this:
 
     $ cd my-site
-    $ ghc --make site.hs
+    $ ghc --make -threaded site.hs
     $ ./site build
 
 If you installed `hakyll` with a preview server (this is the default), you can