Revert "rts/base: Fix #9423"

This should fix the Windows fallout, and hopefully this will be fixed
once that's sorted out.

This reverts commit f9f89b7884ccc8ee5047cf4fffdf2b36df6832df.

Signed-off-by: Austin Seipp <austin@well-typed.com>

9 files changed, 51 insertions, 92 deletions

diff --git a/includes/rts/IOManager.h b/includes/rts/IOManager.h
index 7bf2cdf43c..1c331b97af 100644
--- a/includes/rts/IOManager.h
+++ b/includes/rts/IOManager.h
@@ -26,8 +26,7 @@ void     sendIOManagerEvent (HsWord32 event);
 
 #else
 
-void     setIOManagerControlFd   (nat cap_no, int fd);
-void     setTimerManagerControlFd(int fd);
+void     setIOManagerControlFd   (int fd);
 void     setIOManagerWakeupFd   (int fd);
 
 #endif
diff --git a/libraries/base/GHC/Event/Control.hs b/libraries/base/GHC/Event/Control.hs
index 53a9bc86d8..2951a6a681 100644
--- a/libraries/base/GHC/Event/Control.hs
+++ b/libraries/base/GHC/Event/Control.hs
@@ -17,7 +17,6 @@ module GHC.Event.Control
     , readControlMessage
     -- *** File descriptors
     , controlReadFd
-    , controlWriteFd
     , wakeupReadFd
     -- ** Control message sending
     , sendWakeup
@@ -92,6 +91,7 @@ newControl shouldRegister = allocaArray 2 $ \fds -> do
         setCloseOnExec wr
         return (rd, wr)
   (ctrl_rd, ctrl_wr) <- createPipe
+  when shouldRegister $ c_setIOManagerControlFd ctrl_wr
 #if defined(HAVE_EVENTFD)
   ev <- throwErrnoIfMinus1 "eventfd" $ c_eventfd 0 0
   setNonBlockingFD ev True
@@ -200,5 +200,9 @@ foreign import ccall unsafe "sys/eventfd.h eventfd_write"
    c_eventfd_write :: CInt -> CULLong -> IO CInt
 #endif
 
-foreign import ccall unsafe "setIOManagerWakeupFd"
+-- Used to tell the RTS how it can send messages to the I/O manager.
+foreign import ccall "setIOManagerControlFd"
+   c_setIOManagerControlFd :: CInt -> IO ()
+
+foreign import ccall "setIOManagerWakeupFd"
    c_setIOManagerWakeupFd :: CInt -> IO ()
diff --git a/libraries/base/GHC/Event/Manager.hs b/libraries/base/GHC/Event/Manager.hs
index 80c05f7c0c..d55d5b1193 100644
--- a/libraries/base/GHC/Event/Manager.hs
+++ b/libraries/base/GHC/Event/Manager.hs
@@ -27,7 +27,6 @@ module GHC.Event.Manager
 
       -- * State
     , callbackTableVar
-    , emControl
 
       -- * Registering interest in I/O events
     , Event
diff --git a/libraries/base/GHC/Event/Thread.hs b/libraries/base/GHC/Event/Thread.hs
index 0a82a548da..dcfa32aa28 100644
--- a/libraries/base/GHC/Event/Thread.hs
+++ b/libraries/base/GHC/Event/Thread.hs
@@ -22,7 +22,6 @@ import Data.List (zipWith3)
 import Data.Maybe (Maybe(..))
 import Data.Tuple (snd)
 import Foreign.C.Error (eBADF, errnoToIOError)
-import Foreign.C.Types (CInt(..), CUInt(..))
 import Foreign.Ptr (Ptr)
 import GHC.Base
 import GHC.Conc.Sync (TVar, ThreadId, ThreadStatus(..), atomically, forkIO,
@@ -34,14 +33,12 @@ import GHC.IO.Exception (ioError)
 import GHC.IOArray (IOArray, newIOArray, readIOArray, writeIOArray,
                     boundsIOArray)
 import GHC.MVar (MVar, newEmptyMVar, newMVar, putMVar, takeMVar)
-import GHC.Event.Control (controlWriteFd)
 import GHC.Event.Internal (eventIs, evtClose)
 import GHC.Event.Manager (Event, EventManager, evtRead, evtWrite, loop,
                              new, registerFd, unregisterFd_)
 import qualified GHC.Event.Manager as M
 import qualified GHC.Event.TimerManager as TM
 import GHC.Num ((-), (+))
-import GHC.Real (fromIntegral)
 import GHC.Show (showSignedInt)
 import System.IO.Unsafe (unsafePerformIO)
 import System.Posix.Types (Fd)
@@ -264,11 +261,7 @@ startIOManagerThread :: IOArray Int (Maybe (ThreadId, EventManager))
 startIOManagerThread eventManagerArray i = do
   let create = do
         !mgr <- new True
-        !t <- forkOn i $ do
-                c_setIOManagerControlFd
-                  (fromIntegral i)
-                  (fromIntegral $ controlWriteFd $ M.emControl mgr)
-                loop mgr
+        !t <- forkOn i $ loop mgr
         labelThread t ("IOManager on cap " ++ show_int i)
         writeIOArray eventManagerArray i (Just (t,mgr))
   old <- readIOArray eventManagerArray i
@@ -284,7 +277,6 @@ startIOManagerThread eventManagerArray i = do
           -- the fork, for example. In this case we should clean up
           -- open pipes and everything else related to the event manager.
           -- See #4449
-          c_setIOManagerControlFd (fromIntegral i) (-1)
           M.cleanup em
           create
         _other         -> return ()
@@ -293,10 +285,8 @@ startTimerManagerThread :: IO ()
 startTimerManagerThread = modifyMVar_ timerManagerThreadVar $ \old -> do
   let create = do
         !mgr <- TM.new
-        c_setTimerManagerControlFd
-          (fromIntegral $ controlWriteFd $ TM.emControl mgr)
         writeIORef timerManager $ Just mgr
-        !t <- forkIO $ TM.loop mgr
+        !t <- forkIO $ TM.loop mgr `finally` shutdownManagers
         labelThread t "TimerManager"
         return $ Just t
   case old of
@@ -314,11 +304,21 @@ startTimerManagerThread = modifyMVar_ timerManagerThreadVar $ \old -> do
           mem <- readIORef timerManager
           _ <- case mem of
                  Nothing -> return ()
-                 Just em -> do c_setTimerManagerControlFd (-1)
-                               TM.cleanup em
+                 Just em -> TM.cleanup em
           create
         _other         -> return st
 
+shutdownManagers :: IO ()
+shutdownManagers =
+  withMVar ioManagerLock $ \_ -> do
+    eventManagerArray <- readIORef eventManager
+    let (_, high) = boundsIOArray eventManagerArray
+    forM_ [0..high] $ \i -> do
+      mmgr <- readIOArray eventManagerArray i
+      case mmgr of
+        Nothing -> return ()
+        Just (_,mgr) -> M.shutdown mgr
+
 foreign import ccall unsafe "rtsSupportsBoundThreads" threaded :: Bool
 
 ioManagerCapabilitiesChanged :: IO ()
@@ -352,10 +352,3 @@ ioManagerCapabilitiesChanged = do
               Just (_,mgr) <- readIOArray eventManagerArray i
               tid <- restartPollLoop mgr i
               writeIOArray eventManagerArray i (Just (tid,mgr))
-
--- Used to tell the RTS how it can send messages to the I/O manager.
-foreign import ccall unsafe "setIOManagerControlFd"
-   c_setIOManagerControlFd :: CUInt -> CInt -> IO ()
-
-foreign import ccall unsafe "setTimerManagerControlFd"
-   c_setTimerManagerControlFd :: CInt -> IO ()
diff --git a/libraries/base/GHC/Event/TimerManager.hs b/libraries/base/GHC/Event/TimerManager.hs
index 63a72ef80b..f581330e25 100644
--- a/libraries/base/GHC/Event/TimerManager.hs
+++ b/libraries/base/GHC/Event/TimerManager.hs
@@ -15,7 +15,6 @@ module GHC.Event.TimerManager
     , new
     , newWith
     , newDefaultBackend
-    , emControl
 
       -- * Running
     , finished
diff --git a/rts/Capability.c b/rts/Capability.c
index 04f3a61993..fda9f4f278 100644
--- a/rts/Capability.c
+++ b/rts/Capability.c
@@ -256,7 +256,6 @@ initCapability( Capability *cap, nat i )
     cap->spark_stats.converted  = 0;
     cap->spark_stats.gcd        = 0;
     cap->spark_stats.fizzled    = 0;
-    cap->io_manager_control_wr_fd = -1;
 #endif
     cap->total_allocated        = 0;
 
@@ -1078,16 +1077,6 @@ rtsBool checkSparkCountInvariant (void)
 }
 #endif
 
-void setIOManagerControlFd(nat cap_no USED_IF_THREADS, int fd USED_IF_THREADS) {
-#if defined(THREADED_RTS)
-    if (cap_no < n_capabilities) {
-        capabilities[cap_no]->io_manager_control_wr_fd = fd;
-    } else {
-        errorBelch("warning: setIOManagerControlFd called with illegal capability number.");
-    }
-#endif
-}
-
 // Local Variables:
 // mode: C
 // fill-column: 80
diff --git a/rts/Capability.h b/rts/Capability.h
index d5f36c54bc..c7dceefe9f 100644
--- a/rts/Capability.h
+++ b/rts/Capability.h
@@ -126,9 +126,6 @@ struct Capability_ {
 
     // Stats on spark creation/conversion
     SparkCounters spark_stats;
-
-    // IO manager for this cap
-    int io_manager_control_wr_fd;
 #endif
     // Total words allocated by this cap since rts start
     W_ total_allocated;
diff --git a/rts/Linker.c b/rts/Linker.c
index 76cfa8cea0..e97580d61a 100644
--- a/rts/Linker.c
+++ b/rts/Linker.c
@@ -860,7 +860,6 @@ typedef struct _RtsSymbolVal {
 #if !defined(mingw32_HOST_OS)
 #define RTS_USER_SIGNALS_SYMBOLS        \
    SymI_HasProto(setIOManagerControlFd) \
-   SymI_HasProto(setTimerManagerControlFd) \
    SymI_HasProto(setIOManagerWakeupFd)  \
    SymI_HasProto(ioManagerWakeup)       \
    SymI_HasProto(blockUserSignals)      \
diff --git a/rts/posix/Signals.c b/rts/posix/Signals.c
index ba4a8b75ea..d5129f0996 100644
--- a/rts/posix/Signals.c
+++ b/rts/posix/Signals.c
@@ -127,16 +127,12 @@ more_handlers(int sig)
 
 // Here's the pipe into which we will send our signals
 static int io_manager_wakeup_fd = -1;
-static int timer_manager_control_wr_fd = -1;
+static int io_manager_control_fd = -1;
 
 #define IO_MANAGER_WAKEUP 0xff
 #define IO_MANAGER_DIE    0xfe
 #define IO_MANAGER_SYNC   0xfd
 
-void setTimerManagerControlFd(int fd) {
-    timer_manager_control_wr_fd = fd;
-}
-
 void
 setIOManagerWakeupFd (int fd)
 {
@@ -145,9 +141,14 @@ setIOManagerWakeupFd (int fd)
     io_manager_wakeup_fd = fd;
 }
 
-/* -----------------------------------------------------------------------------
- * Wake up at least one IO or timer manager HS thread.
- * -------------------------------------------------------------------------- */
+void
+setIOManagerControlFd (int fd)
+{
+    // only called when THREADED_RTS, but unconditionally
+    // compiled here because GHC.Event.Control depends on it.
+    io_manager_control_fd = fd;
+}
+
 void
 ioManagerWakeup (void)
 {
@@ -169,24 +170,14 @@ ioManagerWakeup (void)
 void
 ioManagerDie (void)
 {
-    StgWord8 byte = (StgWord8)IO_MANAGER_DIE;
-    nat i;
-    int fd;
     int r;
-
-    if (0 <= timer_manager_control_wr_fd) {
-        r = write(timer_manager_control_wr_fd, &byte, 1);
+    // Ask the IO Manager thread to exit
+    if (io_manager_control_fd >= 0) {
+        StgWord8 byte = (StgWord8)IO_MANAGER_DIE;
+        r = write(io_manager_control_fd, &byte, 1);
         if (r == -1) { sysErrorBelch("ioManagerDie: write"); }
-        timer_manager_control_wr_fd = -1;
-    }
-
-    for (i=0; i < n_capabilities; i++) {
-        fd = capabilities[i]->io_manager_control_wr_fd;
-        if (0 <= fd) {
-            r = write(fd, &byte, 1);
-            if (r == -1) { sysErrorBelch("ioManagerDie: write"); }
-            capabilities[i]->io_manager_control_wr_fd = -1;
-        }
+        io_manager_control_fd = -1;
+        io_manager_wakeup_fd = -1;
     }
 }
 
@@ -201,7 +192,7 @@ ioManagerStart (void)
 {
     // Make sure the IO manager thread is running
     Capability *cap;
-    if (timer_manager_control_wr_fd < 0 || io_manager_wakeup_fd < 0) {
+    if (io_manager_control_fd < 0 || io_manager_wakeup_fd < 0) {
         cap = rts_lock();
         ioManagerStartCap(&cap);
         rts_unlock(cap);
@@ -232,37 +223,26 @@ generic_handler(int sig USED_IF_THREADS,
 {
 #if defined(THREADED_RTS)
 
-    StgWord8 buf[sizeof(siginfo_t) + 1];
-    int r;
+    if (io_manager_control_fd != -1)
+    {
+        StgWord8 buf[sizeof(siginfo_t) + 1];
+        int r;
 
-    buf[0] = sig;
-    if (info == NULL) {
-        // info may be NULL on Solaris (see #3790)
-        memset(buf+1, 0, sizeof(siginfo_t));
-    } else {
-        memcpy(buf+1, info, sizeof(siginfo_t));
-    }
+        buf[0] = sig;
 
-    if (0 <= timer_manager_control_wr_fd)
-    {
-        r = write(timer_manager_control_wr_fd, buf, sizeof(siginfo_t)+1);
-        if (r == -1 && errno == EAGAIN) {
-            errorBelch("lost signal due to full pipe: %d\n", sig);
+        if (info == NULL) {
+            // info may be NULL on Solaris (see #3790)
+            memset(buf+1, 0, sizeof(siginfo_t));
+        } else {
+            memcpy(buf+1, info, sizeof(siginfo_t));
         }
-    }
 
-    nat i;
-    int fd;
-    for (i=0; i < n_capabilities; i++) {
-        fd = capabilities[i]->io_manager_control_wr_fd;
-        if (0 <= fd) {
-            r = write(fd, buf, sizeof(siginfo_t)+1);
-            if (r == -1 && errno == EAGAIN) {
-                errorBelch("lost signal due to full pipe: %d\n", sig);
-            }
+        r = write(io_manager_control_fd, buf, sizeof(siginfo_t)+1);
+        if (r == -1 && errno == EAGAIN)
+        {
+            errorBelch("lost signal due to full pipe: %d\n", sig);
         }
     }
-
     // If the IO manager hasn't told us what the FD of the write end
     // of its pipe is, there's not much we can do here, so just ignore
     // the signal..