diff options
| -rw-r--r-- | libraries/base/GHC/Event/Control.hs | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/libraries/base/GHC/Event/Control.hs b/libraries/base/GHC/Event/Control.hs index 0b0f5587a7..83950c24a6 100644 --- a/libraries/base/GHC/Event/Control.hs +++ b/libraries/base/GHC/Event/Control.hs @@ -30,11 +30,12 @@ module GHC.Event.Control import Foreign.ForeignPtr (ForeignPtr) import GHC.Base +import GHC.IORef import GHC.Conc.Signal (Signal) import GHC.Real (fromIntegral) import GHC.Show (Show) import GHC.Word (Word8) -import Foreign.C.Error (throwErrnoIfMinus1_) +import Foreign.C.Error (throwErrnoIfMinus1_, throwErrno, getErrno, eBADF) import Foreign.C.Types (CInt(..), CSize(..)) import Foreign.ForeignPtr (mallocForeignPtrBytes, withForeignPtr) import Foreign.Marshal (alloca, allocaBytes) @@ -69,7 +70,9 @@ data Control = W { , wakeupWriteFd :: {-# UNPACK #-} !Fd #endif , didRegisterWakeupFd :: !Bool - } deriving (Show) + -- | Have this Control's fds been cleaned up? + , controlIsDead :: !(IORef Bool) + } #if defined(HAVE_EVENTFD) wakeupReadFd :: Control -> Fd @@ -101,6 +104,7 @@ newControl shouldRegister = allocaArray 2 $ \fds -> do (wake_rd, wake_wr) <- createPipe when shouldRegister $ c_setIOManagerWakeupFd wake_wr #endif + isDead <- newIORef False return W { controlReadFd = fromIntegral ctrl_rd , controlWriteFd = fromIntegral ctrl_wr #if defined(HAVE_EVENTFD) @@ -110,6 +114,7 @@ newControl shouldRegister = allocaArray 2 $ \fds -> do , wakeupWriteFd = fromIntegral wake_wr #endif , didRegisterWakeupFd = shouldRegister + , controlIsDead = isDead } -- | Close the control structure used by the IO manager thread. @@ -119,6 +124,7 @@ newControl shouldRegister = allocaArray 2 $ \fds -> do -- file after it has been closed. closeControl :: Control -> IO () closeControl w = do + atomicModifyIORef (controlIsDead w) (\_ -> (True, ())) _ <- c_close . fromIntegral . controlReadFd $ w _ <- c_close . fromIntegral . controlWriteFd $ w when (didRegisterWakeupFd w) $ c_setIOManagerWakeupFd (-1) @@ -172,9 +178,21 @@ readControlMessage ctrl fd sendWakeup :: Control -> IO () #if defined(HAVE_EVENTFD) -sendWakeup c = - throwErrnoIfMinus1_ "sendWakeup" $ - c_eventfd_write (fromIntegral (controlEventFd c)) 1 +sendWakeup c = do + n <- c_eventfd_write (fromIntegral (controlEventFd c)) 1 + case n of + 0 -> return () + _ -> do errno <- getErrno + -- Check that Control is still alive if we failed, since it's + -- possible that someone cleaned up the fds behind our backs and + -- consequently eventfd_write failed with EBADF. If it is dead + -- then just swallow the error since we are shutting down + -- anyways. Otherwise we will see failures during shutdown from + -- setnumcapabilities001 (#12038) + isDead <- readIORef (controlIsDead c) + if isDead && errno == eBADF + then return () + else throwErrno "sendWakeup" #else sendWakeup c = do n <- sendMessage (wakeupWriteFd c) CMsgWakeup |