[commit: base] master: Add timer initialization for darwin. (a865c6c)

[Paolo Capriotti]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/a865c6cfc12afd59760a1993eff51f801e27eea1

>---------------------------------------------------------------

commit a865c6cfc12afd59760a1993eff51f801e27eea1
Author: Paolo Capriotti <p.capriotti at gmail.com>
Date:   Mon Apr 16 14:47:36 2012 +0100

    Add timer initialization for darwin.

>---------------------------------------------------------------

 GHC/Event/Clock.hsc |   11 ++++++++++-
 GHC/Event/Thread.hs |    8 +++++++-
 cbits/DarwinUtils.c |   20 ++++++++++----------
 3 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/GHC/Event/Clock.hsc b/GHC/Event/Clock.hsc
index 4dd6d1a..e3c1218 100644
--- a/GHC/Event/Clock.hsc
+++ b/GHC/Event/Clock.hsc
@@ -1,7 +1,7 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE NoImplicitPrelude, BangPatterns, ForeignFunctionInterface, CApiFFI #-}
 
-module GHC.Event.Clock (getMonotonicTime) where
+module GHC.Event.Clock (getMonotonicTime, initializeTimer) where
 
 #include "HsBase.h"
 
@@ -18,6 +18,8 @@ import GHC.Num
 
 -- TODO: Implement this for Windows.
 
+initializeTimer :: IO ()
+
 -- | Return monotonic time in seconds, since some unspecified starting point
 getMonotonicTime :: IO Double
 
@@ -26,6 +28,8 @@ getMonotonicTime :: IO Double
 
 #if HAVE_CLOCK_GETTIME
 
+initializeTimer = return ()
+
 getMonotonicTime = do
     tv <- with (CTimespec 0 0) $ \tvptr -> do
         throwErrnoIfMinus1_ "clock_gettime" (clock_gettime (#const CLOCK_ID) tvptr)
@@ -66,8 +70,13 @@ getMonotonicTime = do
 foreign import capi unsafe "HsBase.h absolute_time" absolute_time ::
     Ptr CDouble -> IO ()
 
+foreign import capi unsafe "HsBase.h initialize_timer"
+  initializeTimer :: IO ()
+
 #else
 
+initializeTimer = return ()
+
 getMonotonicTime = do
     tv <- with (CTimeval 0 0) $ \tvptr -> do
         throwErrnoIfMinus1_ "gettimeofday" (gettimeofday tvptr nullPtr)
diff --git a/GHC/Event/Thread.hs b/GHC/Event/Thread.hs
index 2643950..237cb45 100644
--- a/GHC/Event/Thread.hs
+++ b/GHC/Event/Thread.hs
@@ -25,6 +25,7 @@ import GHC.MVar (MVar, newEmptyMVar, newMVar, putMVar, takeMVar)
 import GHC.Event.Internal (eventIs, evtClose)
 import GHC.Event.Manager (Event, EventManager, evtRead, evtWrite, loop,
                              new, registerFd, unregisterFd_, registerTimeout)
+import GHC.Event.Clock (initializeTimer)
 import qualified GHC.Event.Manager as M
 import System.IO.Unsafe (unsafePerformIO)
 import System.Posix.Types (Fd)
@@ -122,7 +123,12 @@ ioManager = unsafePerformIO $ do
 ensureIOManagerIsRunning :: IO ()
 ensureIOManagerIsRunning
   | not threaded = return ()
-  | otherwise = modifyMVar_ ioManager $ \old -> do
+  | otherwise = do
+      initializeTimer
+      startIOManagerThread
+
+startIOManagerThread :: IO ()
+startIOManagerThread = modifyMVar_ ioManager $ \old -> do
   let create = do
         !mgr <- new
         writeIORef eventManager $ Just mgr
diff --git a/cbits/DarwinUtils.c b/cbits/DarwinUtils.c
index 851cd04..de1f352 100644
--- a/cbits/DarwinUtils.c
+++ b/cbits/DarwinUtils.c
@@ -2,19 +2,19 @@
 
 #ifdef darwin_HOST_OS
 
+static double scaling_factor = 0.0;
+
+void initialize_timer()
+{
+    mach_timebase_info_data_t info;
+    (void) mach_timebase_info(&info);
+    scaling_factor = (double)info.numer / (double)info.denom;
+    scaling_factor *= 1e-9;
+}
+
 void absolute_time(double *result)
 {
     uint64_t time = mach_absolute_time();
-    static double scaling_factor = 0.0;
-
-    if (scaling_factor == 0.0)
-    {
-        mach_timebase_info_data_t info;
-        (void) mach_timebase_info(&info);
-        scaling_factor = (double)info.numer / (double)info.denom;
-        scaling_factor *= 1e-9;
-    }
-
     *result = (double)time * scaling_factor;
 }