use unsafeUnmask instead of an IORef containing restore

This is much closer to how the test originally worked, so it's more
likely that the test is still testing what it was testing before :-)

1 files changed, 3 insertions, 2 deletions

diff --git a/testsuite/tests/concurrent/should_run/T3279.hs b/testsuite/tests/concurrent/should_run/T3279.hs
index f479704310..a90d38aaa4 100644
--- a/testsuite/tests/concurrent/should_run/T3279.hs
+++ b/testsuite/tests/concurrent/should_run/T3279.hs
@@ -3,19 +3,20 @@
 import System.IO.Unsafe
 import GHC.Conc
 import Control.Exception
+import GHC.IO (unsafeUnmask)
 
 f :: Int
 f = (1 +) . unsafePerformIO $ do
         error "foo" `catch` \(SomeException e) -> do
             myThreadId >>= flip throwTo e
             -- point X
-            unblock $ return 1
+            unsafeUnmask $ return 1
 
 main :: IO ()
 main = do
     evaluate f `catch` \(SomeException e) -> return 0
     -- the evaluation of 'x' is now suspended at point X
-    tid <- block $ forkIO (evaluate f >> return ())
+    tid <- mask_ $ forkIO (evaluate f >> return ())
     killThread tid
     -- now execute the 'unblock' above with a pending exception
     yield